Update CHANGELOG.

git-subtree-dir: mru
git-subtree-mainline: cf2b016433
git-subtree-split: 2899885c42

.circleci/config.yml

@@ -2,36 +2,43 @@
 # See: https://circleci.com/docs/2.0/configuration-reference
 version: 2.1
 
-commands:
-  setup-bazel:
-    description: |
-      Setup the Bazel build system used for building the repo
-    steps:
-      - run:
-          name: Add Bazel Apt repository
-          command: |
-            sudo apt install curl gnupg
-            curl -fsSL https://bazel.build/bazel-release.pub.gpg | gpg --dearmor > bazel.gpg
-            sudo mv bazel.gpg /etc/apt/trusted.gpg.d/
-            echo "deb [arch=amd64] https://storage.googleapis.com/bazel-apt stable jdk1.8" | sudo tee /etc/apt/sources.list.d/bazel.list
-      - run:
-          name: Install Bazel from Apt
-          command: sudo apt update && sudo apt install bazel
-
 # Define a job to be invoked later in a workflow.
 # See: https://circleci.com/docs/2.0/configuration-reference/#jobs
 jobs:
+  lint:
+    working_directory: ~/repo
+    docker:
+      - image: cimg/go:1.22.2
+    steps:
+      - checkout
+      - restore_cache:
+          keys:
+            - go-mod-v4-{{ checksum "go.sum" }}
+      - run:
+          name: Install Dependencies
+          command: go mod download
+      - save_cache:
+          key: go-mod-v4-{{ checksum "go.sum" }}
+          paths:
+            - "/go/pkg/mod"
+      - run:
+          name: Install golangci-lint
+          command: |
+            curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin
+      - run:
+          name: Run golangci-lint
+          command: golangci-lint run --timeout=5m
+
   testbuild:
     working_directory: ~/repo
     # Specify the execution environment. You can specify an image from Dockerhub or use one of our Convenience Images from CircleCI's Developer Hub.
     # See: https://circleci.com/docs/2.0/configuration-reference/#docker-machine-macos-windows-executor
     docker:
-      - image: circleci/golang:1.15.8
+      - image: cimg/go:1.22.2
     # Add steps to the job
     # See: https://circleci.com/docs/2.0/configuration-reference/#steps
     steps:
       - checkout
-      - setup-bazel
       - restore_cache:
           keys:
             - go-mod-v4-{{ checksum "go.sum" }}
@@ -44,16 +51,17 @@ jobs:
             - "/go/pkg/mod"
       - run:
           name: Run tests
-          command: bazel test //...
+          command: go test -race ./...
       - run:
           name: Run build
-          command: bazel build //...
+          command: go build ./...
       - store_test_results:
           path: /tmp/test-reports
-
 # Invoke jobs via workflows
 # See: https://circleci.com/docs/2.0/configuration-reference/#workflows
+# Linting is disabled while cleanups are ongoing.
 workflows:
   testbuild:
     jobs:
       - testbuild
+#      - lint

.gitignore

@@ -1,4 +1 @@
-bazel-bin
+.idea
-bazel-goutils
-bazel-out
-bazel-testlogs

.golangci.yml

@@ -0,0 +1,477 @@
+# This file is licensed under the terms of the MIT license https://opensource.org/license/mit
+# Copyright (c) 2021-2025 Marat Reymers
+
+## Golden config for golangci-lint v2.6.2
+#
+# This is the best config for golangci-lint based on my experience and opinion.
+# It is very strict, but not extremely strict.
+# Feel free to adapt it to suit your needs.
+# If this config helps you, please consider keeping a link to this file (see the next comment).
+
+# Based on https://gist.github.com/maratori/47a4d00457a92aa426dbd48a18776322
+
+version: "2"
+
+issues:
+  # Maximum count of issues with the same text.
+  # Set to 0 to disable.
+  # Default: 3
+  max-same-issues: 50
+
+formatters:
+  enable:
+    - goimports # checks if the code and import statements are formatted according to the 'goimports' command
+    - golines # checks if code is formatted, and fixes long lines
+
+    ## you may want to enable
+    #- gci # checks if code and import statements are formatted, with additional rules
+    #- gofmt # checks if the code is formatted according to 'gofmt' command
+    #- gofumpt # enforces a stricter format than 'gofmt', while being backwards compatible
+    #- swaggo # formats swaggo comments
+
+  # All settings can be found here https://github.com/golangci/golangci-lint/blob/HEAD/.golangci.reference.yml
+  settings:
+    goimports:
+      # A list of prefixes, which, if set, checks import paths
+      # with the given prefixes are grouped after 3rd-party packages.
+      # Default: []
+      local-prefixes:
+        - github.com/my/project
+
+    golines:
+      # Target maximum line length.
+      # Default: 100
+      max-len: 120
+
+linters:
+  enable:
+    - asasalint # checks for pass []any as any in variadic func(...any)
+    - asciicheck # checks that your code does not contain non-ASCII identifiers
+    - bidichk # checks for dangerous unicode character sequences
+    - bodyclose # checks whether HTTP response body is closed successfully
+    - canonicalheader # checks whether net/http.Header uses canonical header
+    - copyloopvar # detects places where loop variables are copied (Go 1.22+)
+    - cyclop # checks function and package cyclomatic complexity
+    - depguard # checks if package imports are in a list of acceptable packages
+    - dupl # tool for code clone detection
+    - durationcheck # checks for two durations multiplied together
+    - errcheck # checking for unchecked errors, these unchecked errors can be critical bugs in some cases
+    - errname # checks that sentinel errors are prefixed with the Err and error types are suffixed with the Error
+    - errorlint # finds code that will cause problems with the error wrapping scheme introduced in Go 1.13
+    - exhaustive # checks exhaustiveness of enum switch statements
+    - exptostd # detects functions from golang.org/x/exp/ that can be replaced by std functions
+    - fatcontext # detects nested contexts in loops
+    - forbidigo # forbids identifiers
+    - funcorder # checks the order of functions, methods, and constructors
+    - funlen # tool for detection of long functions
+    - gocheckcompilerdirectives # validates go compiler directive comments (//go:)
+    - gochecksumtype # checks exhaustiveness on Go "sum types"
+    - gocognit # computes and checks the cognitive complexity of functions
+    - goconst # finds repeated strings that could be replaced by a constant
+    - gocritic # provides diagnostics that check for bugs, performance and style issues
+    - gocyclo # computes and checks the cyclomatic complexity of functions
+    - godoclint # checks Golang's documentation practice
+    - godot # checks if comments end in a period
+    - gomoddirectives # manages the use of 'replace', 'retract', and 'excludes' directives in go.mod
+    - goprintffuncname # checks that printf-like functions are named with f at the end
+    - gosec # inspects source code for security problems
+    - govet # reports suspicious constructs, such as Printf calls whose arguments do not align with the format string
+    - iface # checks the incorrect use of interfaces, helping developers avoid interface pollution
+    - ineffassign # detects when assignments to existing variables are not used
+    - intrange # finds places where for loops could make use of an integer range
+    - iotamixing # checks if iotas are being used in const blocks with other non-iota declarations
+    - loggercheck # checks key value pairs for common logger libraries (kitlog,klog,logr,zap)
+    - makezero # finds slice declarations with non-zero initial length
+    - mirror # reports wrong mirror patterns of bytes/strings usage
+    - mnd # detects magic numbers
+    - modernize # suggests simplifications to Go code, using modern language and library features
+    - musttag # enforces field tags in (un)marshaled structs
+    - nakedret # finds naked returns in functions greater than a specified function length
+    - nestif # reports deeply nested if statements
+    - nilerr # finds the code that returns nil even if it checks that the error is not nil
+    - nilnesserr # reports that it checks for err != nil, but it returns a different nil value error (powered by nilness and nilerr)
+    - nilnil # checks that there is no simultaneous return of nil error and an invalid value
+    - noctx # finds sending http request without context.Context
+    - nolintlint # reports ill-formed or insufficient nolint directives
+    - nonamedreturns # reports all named returns
+    - nosprintfhostport # checks for misuse of Sprintf to construct a host with port in a URL
+    - perfsprint # checks that fmt.Sprintf can be replaced with a faster alternative
+    - predeclared # finds code that shadows one of Go's predeclared identifiers
+    - promlinter # checks Prometheus metrics naming via promlint
+    - protogetter # reports direct reads from proto message fields when getters should be used
+    - reassign # checks that package variables are not reassigned
+    - recvcheck # checks for receiver type consistency
+    - revive # fast, configurable, extensible, flexible, and beautiful linter for Go, drop-in replacement of golint
+    - rowserrcheck # checks whether Err of rows is checked successfully
+    - sloglint # ensure consistent code style when using log/slog
+    - spancheck # checks for mistakes with OpenTelemetry/Census spans
+    - sqlclosecheck # checks that sql.Rows and sql.Stmt are closed
+    - staticcheck # is a go vet on steroids, applying a ton of static analysis checks
+    - testableexamples # checks if examples are testable (have an expected output)
+    - testifylint # checks usage of github.com/stretchr/testify
+    - testpackage # makes you use a separate _test package
+    - tparallel # detects inappropriate usage of t.Parallel() method in your Go test codes
+    - unconvert # removes unnecessary type conversions
+    - unparam # reports unused function parameters
+    - unqueryvet # detects SELECT * in SQL queries and SQL builders, encouraging explicit column selection
+    - unused # checks for unused constants, variables, functions and types
+    - usestdlibvars # detects the possibility to use variables/constants from the Go standard library
+    - usetesting # reports uses of functions with replacement inside the testing package
+    - wastedassign # finds wasted assignment statements
+    - whitespace # detects leading and trailing whitespace
+
+    ## you may want to enable
+    #- arangolint # opinionated best practices for arangodb client
+    #- decorder # checks declaration order and count of types, constants, variables and functions
+    #- exhaustruct # [highly recommend to enable] checks if all structure fields are initialized
+    #- ginkgolinter # [if you use ginkgo/gomega] enforces standards of using ginkgo and gomega
+    #- godox # detects usage of FIXME, TODO and other keywords inside comments
+    #- goheader # checks is file header matches to pattern
+    #- inamedparam # [great idea, but too strict, need to ignore a lot of cases by default] reports interfaces with unnamed method parameters
+    #- interfacebloat # checks the number of methods inside an interface
+    #- ireturn # accept interfaces, return concrete types
+    #- noinlineerr # disallows inline error handling `if err := ...; err != nil {`
+    #- prealloc # [premature optimization, but can be used in some cases] finds slice declarations that could potentially be preallocated
+    #- tagalign # checks that struct tags are well aligned
+    #- varnamelen # [great idea, but too many false positives] checks that the length of a variable's name matches its scope
+    #- wrapcheck # checks that errors returned from external packages are wrapped
+    #- zerologlint # detects the wrong usage of zerolog that a user forgets to dispatch zerolog.Event
+
+    ## disabled
+    #- containedctx # detects struct contained context.Context field
+    #- contextcheck # [too many false positives] checks the function whether use a non-inherited context
+    #- dogsled # checks assignments with too many blank identifiers (e.g. x, _, _, _, := f())
+    #- dupword # [useless without config] checks for duplicate words in the source code
+    #- err113 # [too strict] checks the errors handling expressions
+    #- errchkjson # [don't see profit + I'm against of omitting errors like in the first example https://github.com/breml/errchkjson] checks types passed to the json encoding functions. Reports unsupported types and optionally reports occasions, where the check for the returned error can be omitted
+    #- forcetypeassert # [replaced by errcheck] finds forced type assertions
+    #- gomodguard # [use more powerful depguard] allow and block lists linter for direct Go module dependencies
+    #- gosmopolitan # reports certain i18n/l10n anti-patterns in your Go codebase
+    #- grouper # analyzes expression groups
+    #- importas # enforces consistent import aliases
+    #- lll # [replaced by golines] reports long lines
+    #- maintidx # measures the maintainability index of each function
+    #- misspell # [useless] finds commonly misspelled English words in comments
+    #- nlreturn # [too strict and mostly code is not more readable] checks for a new line before return and branch statements to increase code clarity
+    #- paralleltest # [too many false positives] detects missing usage of t.Parallel() method in your Go test
+    #- tagliatelle # checks the struct tags
+    #- thelper # detects golang test helpers without t.Helper() call and checks the consistency of test helpers
+    #- wsl # [too strict and mostly code is not more readable] whitespace linter forces you to use empty lines
+    #- wsl_v5 # [too strict and mostly code is not more readable] add or remove empty lines
+
+  # All settings can be found here https://github.com/golangci/golangci-lint/blob/HEAD/.golangci.reference.yml
+  settings:
+    cyclop:
+      # The maximal code complexity to report.
+      # Default: 10
+      max-complexity: 30
+      # The maximal average package complexity.
+      # If it's higher than 0.0 (float) the check is enabled.
+      # Default: 0.0
+      package-average: 10.0
+
+    depguard:
+      # Rules to apply.
+      #
+      # Variables:
+      # - File Variables
+      #   Use an exclamation mark `!` to negate a variable.
+      #   Example: `!$test` matches any file that is not a go test file.
+      #
+      #   `$all` - matches all go files
+      #   `$test` - matches all go test files
+      #
+      # - Package Variables
+      #
+      #   `$gostd` - matches all of go's standard library (Pulled from `GOROOT`)
+      #
+      # Default (applies if no custom rules are defined): Only allow $gostd in all files.
+      rules:
+        "deprecated":
+          # List of file globs that will match this list of settings to compare against.
+          # By default, if a path is relative, it is relative to the directory where the golangci-lint command is executed.
+          # The placeholder '${base-path}' is substituted with a path relative to the mode defined with `run.relative-path-mode`.
+          # The placeholder '${config-path}' is substituted with a path relative to the configuration file.
+          # Default: $all
+          files:
+            - "$all"
+          # List of packages that are not allowed.
+          # Entries can be a variable (starting with $), a string prefix, or an exact match (if ending with $).
+          # Default: []
+          deny:
+            - pkg: github.com/golang/protobuf
+              desc: Use google.golang.org/protobuf instead, see https://developers.google.com/protocol-buffers/docs/reference/go/faq#modules
+            - pkg: github.com/satori/go.uuid
+              desc: Use github.com/google/uuid instead, satori's package is not maintained
+            - pkg: github.com/gofrs/uuid$
+              desc: Use github.com/gofrs/uuid/v5 or later, it was not a go module before v5
+        "non-test files":
+          files:
+            - "!$test"
+          deny:
+            - pkg: math/rand$
+              desc: Use math/rand/v2 instead, see https://go.dev/blog/randv2
+        "non-main files":
+          files:
+            - "!**/main.go"
+          deny:
+            - pkg: log$
+              desc: Use log/slog instead, see https://go.dev/blog/slog
+
+    embeddedstructfieldcheck:
+      # Checks that sync.Mutex and sync.RWMutex are not used as embedded fields.
+      # Default: false
+      forbid-mutex: true
+
+    errcheck:
+      # Report about not checking of errors in type assertions: `a := b.(MyStruct)`.
+      # Such cases aren't reported by default.
+      # Default: false
+      check-type-assertions: true
+      exclude-functions:
+        - (*git.wntrmute.dev/kyle/goutils/sbuf.Buffer).Write
+
+    exhaustive:
+      # Program elements to check for exhaustiveness.
+      # Default: [ switch ]
+      check:
+        - switch
+        - map
+
+    exhaustruct:
+      # List of regular expressions to match type names that should be excluded from processing.
+      # Anonymous structs can be matched by '<anonymous>' alias.
+      # Has precedence over `include`.
+      # Each regular expression must match the full type name, including package path.
+      # For example, to match type `net/http.Cookie` regular expression should be `.*/http\.Cookie`,
+      # but not `http\.Cookie`.
+      # Default: []
+      exclude:
+        # std libs
+        - ^net/http.Client$
+        - ^net/http.Cookie$
+        - ^net/http.Request$
+        - ^net/http.Response$
+        - ^net/http.Server$
+        - ^net/http.Transport$
+        - ^net/url.URL$
+        - ^os/exec.Cmd$
+        - ^reflect.StructField$
+        # public libs
+        - ^github.com/Shopify/sarama.Config$
+        - ^github.com/Shopify/sarama.ProducerMessage$
+        - ^github.com/mitchellh/mapstructure.DecoderConfig$
+        - ^github.com/prometheus/client_golang/.+Opts$
+        - ^github.com/spf13/cobra.Command$
+        - ^github.com/spf13/cobra.CompletionOptions$
+        - ^github.com/stretchr/testify/mock.Mock$
+        - ^github.com/testcontainers/testcontainers-go.+Request$
+        - ^github.com/testcontainers/testcontainers-go.FromDockerfile$
+        - ^golang.org/x/tools/go/analysis.Analyzer$
+        - ^google.golang.org/protobuf/.+Options$
+        - ^gopkg.in/yaml.v3.Node$
+      # Allows empty structures in return statements.
+      # Default: false
+      allow-empty-returns: true
+
+    funcorder:
+      # Checks if the exported methods of a structure are placed before the non-exported ones.
+      # Default: true
+      struct-method: false
+
+    funlen:
+      # Checks the number of lines in a function.
+      # If lower than 0, disable the check.
+      # Default: 60
+      lines: 100
+      # Checks the number of statements in a function.
+      # If lower than 0, disable the check.
+      # Default: 40
+      statements: 50
+
+    gochecksumtype:
+      # Presence of `default` case in switch statements satisfies exhaustiveness, if all members are not listed.
+      # Default: true
+      default-signifies-exhaustive: false
+
+    gocognit:
+      # Minimal code complexity to report.
+      # Default: 30 (but we recommend 10-20)
+      min-complexity: 20
+
+    gocritic:
+      # Settings passed to gocritic.
+      # The settings key is the name of a supported gocritic checker.
+      # The list of supported checkers can be found at https://go-critic.com/overview.
+      settings:
+        captLocal:
+          # Whether to restrict checker to params only.
+          # Default: true
+          paramsOnly: false
+        underef:
+          # Whether to skip (*x).method() calls where x is a pointer receiver.
+          # Default: true
+          skipRecvDeref: false
+
+    godoclint:
+      # List of rules to enable in addition to the default set.
+      # Default: empty
+      enable:
+        # Assert no unused link in godocs.
+        # https://github.com/godoc-lint/godoc-lint?tab=readme-ov-file#no-unused-link
+        - no-unused-link
+
+    govet:
+      # Enable all analyzers.
+      # Default: false
+      enable-all: true
+      # Disable analyzers by name.
+      # Run `GL_DEBUG=govet golangci-lint run --enable=govet` to see default, all available analyzers, and enabled analyzers.
+      # Default: []
+      disable:
+        - fieldalignment # too strict
+      # Settings per analyzer.
+      settings:
+        shadow:
+          # Whether to be strict about shadowing; can be noisy.
+          # Default: false
+          strict: true
+
+    inamedparam:
+      # Skips check for interface methods with only a single parameter.
+      # Default: false
+      skip-single-param: true
+
+    mnd:
+      ignored-functions:
+        - args.Error
+        - flag.Arg
+        - flag.Duration.*
+        - flag.Float.*
+        - flag.Int.*
+        - flag.Uint.*
+        - os.Chmod
+        - os.Mkdir.*
+        - os.OpenFile
+        - os.WriteFile
+        - prometheus.ExponentialBuckets.*
+        - prometheus.LinearBuckets
+
+    nakedret:
+      # Make an issue if func has more lines of code than this setting, and it has naked returns.
+      # Default: 30
+      max-func-lines: 0
+
+    nolintlint:
+      # Exclude the following linters from requiring an explanation.
+      # Default: []
+      allow-no-explanation: [ funlen, gocognit, golines ]
+      # Enable to require an explanation of nonzero length after each nolint directive.
+      # Default: false
+      require-explanation: true
+      # Enable to require nolint directives to mention the specific linter being suppressed.
+      # Default: false
+      require-specific: true
+
+    perfsprint:
+      # Optimizes into strings concatenation.
+      # Default: true
+      strconcat: false
+
+    reassign:
+      # Patterns for global variable names that are checked for reassignment.
+      # See https://github.com/curioswitch/go-reassign#usage
+      # Default: ["EOF", "Err.*"]
+      patterns:
+        - ".*"
+
+    rowserrcheck:
+      # database/sql is always checked.
+      # Default: []
+      packages:
+        - github.com/jmoiron/sqlx
+
+    sloglint:
+      # Enforce not using global loggers.
+      # Values:
+      # - "": disabled
+      # - "all": report all global loggers
+      # - "default": report only the default slog logger
+      # https://github.com/go-simpler/sloglint?tab=readme-ov-file#no-global
+      # Default: ""
+      no-global: all
+      # Enforce using methods that accept a context.
+      # Values:
+      # - "": disabled
+      # - "all": report all contextless calls
+      # - "scope": report only if a context exists in the scope of the outermost function
+      # https://github.com/go-simpler/sloglint?tab=readme-ov-file#context-only
+      # Default: ""
+      context: scope
+
+    staticcheck:
+      # SAxxxx checks in https://staticcheck.dev/docs/configuration/options/#checks
+      # Example (to disable some checks): [ "all", "-SA1000", "-SA1001"]
+      # Default: ["all", "-ST1000", "-ST1003", "-ST1016", "-ST1020", "-ST1021", "-ST1022"]
+      checks:
+        - all
+        # Incorrect or missing package comment.
+        # https://staticcheck.dev/docs/checks/#ST1000
+        - -ST1000
+        # Use consistent method receiver names.
+        # https://staticcheck.dev/docs/checks/#ST1016
+        - -ST1016
+        # Omit embedded fields from selector expression.
+        # https://staticcheck.dev/docs/checks/#QF1008
+        - -QF1008
+
+    usetesting:
+      # Enable/disable `os.TempDir()` detections.
+      # Default: false
+      os-temp-dir: true
+
+  exclusions:
+    # Log a warning if an exclusion rule is unused.
+    # Default: false
+    warn-unused: true
+    # Predefined exclusion rules.
+    # Default: []
+    presets:
+      - std-error-handling
+      - common-false-positives
+    rules:
+      - path: 'ahash/ahash.go'
+        linters: [ staticcheck, gosec ]
+      - path: 'backoff/backoff_test.go'
+        linters: [ testpackage ]
+      - path: 'dbg/dbg_test.go'
+        linters: [ testpackage ]
+      - path: 'log/logger.go'
+        linters: [ forbidigo ]
+      - path: 'logging/example_test.go'
+        linters: [ testableexamples ]
+      - path: 'main.go'
+        linters: [ forbidigo, mnd, reassign ]
+      - source: 'TODO'
+        linters: [ godot ]
+      - text: 'should have a package comment'
+        linters: [ revive ]
+      - text: 'exported \S+ \S+ should have comment( \(or a comment on this block\))? or be unexported'
+        linters: [ revive ]
+      - text: 'package comment should be of the form ".+"'
+        source: '// ?(nolint|TODO)'
+        linters: [ revive ]
+      - text: 'comment on exported \S+ \S+ should be of the form ".+"'
+        source: '// ?(nolint|TODO)'
+        linters: [ revive, staticcheck ]
+      - path: '_test\.go'
+        linters:
+          - bodyclose
+          - dupl
+          - errcheck
+          - funlen
+          - goconst
+          - gosec
+          - noctx
+          - reassign
+          - wrapcheck

.travis.yml

@@ -1,26 +0,0 @@
-arch:
-   - amd64
-   - ppc64le
-sudo: false
-language: go
-go:
-  - tip
-  - 1.9
-jobs:
- exclude:
-  - go: 1.9
-    arch: amd64
-  - go: 1.9
-    arch: ppc64le
-script: 
-  - go get golang.org/x/lint/golint
-  - go get golang.org/x/tools/cmd/cover
-  - go get github.com/kisom/goutils/... 
-  - go test -cover github.com/kisom/goutils/... 
-  - golint github.com/kisom/goutils/... 
-notifications:
-  email:
-    recipients:
-      - coder@kyleisom.net
-    on_success: change
-    on_failure: change

CHANGELOG

@@ -1,27 +1,59 @@
-Release 1.2.1 - 2018-09-15
+CHANGELOG
 
-+ Add missing format argument to Errorf call in kgz.
+v1.11.0 - 2025-11-15
 
-Release 1.2.0 - 2018-09-15
+Added
+- cache/mru: introduce MRU cache implementation with timestamp utilities.
 
-+ Adds the kgz command line utility.
+Changed
+- certlib: complete overhaul to simplify APIs and internals.
+- repo: widespread linting cleanups across many packages (config, dbg, die,
+  fileutil, log/logging, mwc, sbuf, seekbuf, tee, testio, etc.).
+- cmd: general program cleanups; `cert-bundler` lint fixes.
 
-Release 1.1.0 - 2017-11-16
+Removed
+- rand: remove unused package.
+- testutil: remove unused code.
 
-+ A number of new command line utilities were added
 
-	+ atping
+v1.10.1 — 2025-11-15
-	+ cruntar
-	+ renfnv
-        +
-	+ ski
-	+ subjhash
-	+ yamll
 
-+ new package: ahash
+Changed
-	+ package for loading hashes from an algorithm string
+- certlib: major overhaul and refactor.
+- repo: linter autofixes ahead of release.
 
-+ new certificate loading functions in the lib package
 
-+ new package: tee
+v1.10.0 — 2025-11-14
-	+ emulates tee(1)
+
+Added
+- cmd: add `cert-revcheck` command.
+
+Changed
+- ci/lint: add golangci-lint stage and initial cleanup.
+
+
+v1.9.1 — 2025-11-15
+
+Fixed
+- die: correct calls to `die.With`.
+
+
+v1.9.0 — 2025-11-14
+
+Added
+- cmd: add `cert-bundler` tool.
+
+Changed
+- misc: minor updates and maintenance.
+
+
+v1.8.1 — 2025-11-14
+
+Added
+- cmd: add `tlsinfo` tool.
+
+
+v1.8.0 — 2025-11-14
+
+Baseline
+- Initial baseline for this changelog series.

LICENSE

@@ -1,19 +1,194 @@
-Copyright (c) 2015-2023 Kyle Isom <kyle@tyrfingr.is>
+   Copyright 2025 K. Isom <kyle@imap.cc>
 
-Permission to use, copy, modify, and distribute this software for any
+   Licensed under the Apache License, Version 2.0 (the "License");
-purpose with or without fee is hereby granted, provided that the above 
+   you may not use this file except in compliance with the License.
-copyright notice and this permission notice appear in all copies.
+   You may obtain a copy of the License at
 
-THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+       http://www.apache.org/licenses/LICENSE-2.0
-WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
-MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
-ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
-WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
-ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
-OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 
 
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
 
 =======================================================================
+
 The backoff package (written during my time at Cloudflare) is released
 under the following license:
 

README.md

@@ -78,3 +78,43 @@ Each program should have a small README in the directory with more
 information.
 
 All code here is licensed under the ISC license.
+
+
+Error handling
+--------------
+
+This repo standardizes on Go 1.13+ error wrapping and matching. Libraries and
+CLIs should:
+
+- Wrap causes with context using `fmt.Errorf("context: %w", err)`.
+- Use typed, structured errors from `certlib/certerr` for certificate-related
+  operations. These include a typed `*certerr.Error` with `Source` and `Kind`.
+- Match errors programmatically:
+  - `errors.Is(err, certerr.ErrEncryptedPrivateKey)` to detect sentinel states.
+  - `errors.As(err, &e)` (where `var e *certerr.Error`) to inspect
+    `e.Source`/`e.Kind`.
+
+Examples:
+
+```
+cert, err := certlib.LoadCertificate(path)
+if err != nil {
+    // sentinel match
+    if errors.Is(err, certerr.ErrEmptyCertificate) {
+        // handle empty input
+    }
+
+    // typed error match
+    var ce *certerr.Error
+    if errors.As(err, &ce) {
+        switch ce.Kind {
+        case certerr.KindParse:
+            // parse error handling
+        case certerr.KindLoad:
+            // file loading error handling
+        }
+    }
+}
+```
+
+Avoid including sensitive data (keys, passwords, tokens) in error messages.

ahash/ahash.go

@@ -4,8 +4,8 @@
 package ahash
 
 import (
-	"crypto/md5"
+	"crypto/md5"  // #nosec G505
-	"crypto/sha1"
+	"crypto/sha1" // #nosec G501
 	"crypto/sha256"
 	"crypto/sha512"
 	"errors"
@@ -17,34 +17,15 @@ import (
 	"io"
 	"sort"
 
-	"git.wntrmute.dev/kyle/goutils/assert"
 	"golang.org/x/crypto/blake2b"
 	"golang.org/x/crypto/blake2s"
-	"golang.org/x/crypto/md4"
+	"golang.org/x/crypto/md4"       // #nosec G506
-	"golang.org/x/crypto/ripemd160"
+	"golang.org/x/crypto/ripemd160" // #nosec G507
 	"golang.org/x/crypto/sha3"
+
+	"git.wntrmute.dev/kyle/goutils/assert"
 )
 
-func sha224Slicer(bs []byte) []byte {
-	sum := sha256.Sum224(bs)
-	return sum[:]
-}
-
-func sha256Slicer(bs []byte) []byte {
-	sum := sha256.Sum256(bs)
-	return sum[:]
-}
-
-func sha384Slicer(bs []byte) []byte {
-	sum := sha512.Sum384(bs)
-	return sum[:]
-}
-
-func sha512Slicer(bs []byte) []byte {
-	sum := sha512.Sum512(bs)
-	return sum[:]
-}
-
 // Hash represents a generic hash function that may or may not be secure. It
 // satisfies the hash.Hash interface.
 type Hash struct {
@@ -247,17 +228,17 @@ func init() {
 // HashList returns a sorted list of all the hash algorithms supported by the
 // package.
 func HashList() []string {
-	return hashList[:]
+	return hashList
 }
 
 // SecureHashList returns a sorted list of all the secure (cryptographic) hash
 // algorithms supported by the package.
 func SecureHashList() []string {
-	return secureHashList[:]
+	return secureHashList
 }
 
 // InsecureHashList returns a sorted list of all the insecure hash algorithms
 // supported by the package.
 func InsecureHashList() []string {
-	return insecureHashList[:]
+	return insecureHashList
 }

ahash/ahash_test.go

@@ -1,16 +1,18 @@
-package ahash
+package ahash_test
 
 import (
 	"bytes"
+	"encoding/hex"
 	"fmt"
 	"testing"
 
+	"git.wntrmute.dev/kyle/goutils/ahash"
 	"git.wntrmute.dev/kyle/goutils/assert"
 )
 
 func TestSecureHash(t *testing.T) {
 	algo := "sha256"
-	h, err := New(algo)
+	h, err := ahash.New(algo)
 	assert.NoErrorT(t, err)
 	assert.BoolT(t, h.IsSecure(), algo+" should be a secure hash")
 	assert.BoolT(t, h.HashAlgo() == algo, "hash returned the wrong HashAlgo")
@@ -19,28 +21,28 @@ func TestSecureHash(t *testing.T) {
 
 	var data []byte
 	var expected = "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
-	sum, err := Sum(algo, data)
+	sum, err := ahash.Sum(algo, data)
 	assert.NoErrorT(t, err)
-	assert.BoolT(t, fmt.Sprintf("%x", sum) == expected, fmt.Sprintf("expected hash %s but have %x", expected, sum))
+	assert.BoolT(t, hex.EncodeToString(sum) == expected, fmt.Sprintf("expected hash %s but have %x", expected, sum))
 
 	data = []byte("hello, world")
 	buf := bytes.NewBuffer(data)
 	expected = "09ca7e4eaa6e8ae9c7d261167129184883644d07dfba7cbfbc4c8a2e08360d5b"
-	sum, err = SumReader(algo, buf)
+	sum, err = ahash.SumReader(algo, buf)
 	assert.NoErrorT(t, err)
-	assert.BoolT(t, fmt.Sprintf("%x", sum) == expected, fmt.Sprintf("expected hash %s but have %x", expected, sum))
+	assert.BoolT(t, hex.EncodeToString(sum) == expected, fmt.Sprintf("expected hash %s but have %x", expected, sum))
 
 	data = []byte("hello world")
 	_, err = h.Write(data)
 	assert.NoErrorT(t, err)
 	unExpected := "09ca7e4eaa6e8ae9c7d261167129184883644d07dfba7cbfbc4c8a2e08360d5b"
 	sum = h.Sum(nil)
-	assert.BoolT(t, fmt.Sprintf("%x", sum) != unExpected, fmt.Sprintf("hash shouldn't have returned %x", unExpected))
+	assert.BoolT(t, hex.EncodeToString(sum) != unExpected, fmt.Sprintf("hash shouldn't have returned %x", unExpected))
 }
 
 func TestInsecureHash(t *testing.T) {
 	algo := "md5"
-	h, err := New(algo)
+	h, err := ahash.New(algo)
 	assert.NoErrorT(t, err)
 	assert.BoolT(t, !h.IsSecure(), algo+" shouldn't be a secure hash")
 	assert.BoolT(t, h.HashAlgo() == algo, "hash returned the wrong HashAlgo")
@@ -49,28 +51,28 @@ func TestInsecureHash(t *testing.T) {
 
 	var data []byte
 	var expected = "d41d8cd98f00b204e9800998ecf8427e"
-	sum, err := Sum(algo, data)
+	sum, err := ahash.Sum(algo, data)
 	assert.NoErrorT(t, err)
-	assert.BoolT(t, fmt.Sprintf("%x", sum) == expected, fmt.Sprintf("expected hash %s but have %x", expected, sum))
+	assert.BoolT(t, hex.EncodeToString(sum) == expected, fmt.Sprintf("expected hash %s but have %x", expected, sum))
 
 	data = []byte("hello, world")
 	buf := bytes.NewBuffer(data)
 	expected = "e4d7f1b4ed2e42d15898f4b27b019da4"
-	sum, err = SumReader(algo, buf)
+	sum, err = ahash.SumReader(algo, buf)
 	assert.NoErrorT(t, err)
-	assert.BoolT(t, fmt.Sprintf("%x", sum) == expected, fmt.Sprintf("expected hash %s but have %x", expected, sum))
+	assert.BoolT(t, hex.EncodeToString(sum) == expected, fmt.Sprintf("expected hash %s but have %x", expected, sum))
 
 	data = []byte("hello world")
 	_, err = h.Write(data)
 	assert.NoErrorT(t, err)
 	unExpected := "e4d7f1b4ed2e42d15898f4b27b019da4"
 	sum = h.Sum(nil)
-	assert.BoolT(t, fmt.Sprintf("%x", sum) != unExpected, fmt.Sprintf("hash shouldn't have returned %x", unExpected))
+	assert.BoolT(t, hex.EncodeToString(sum) != unExpected, fmt.Sprintf("hash shouldn't have returned %x", unExpected))
 }
 
 func TestHash32(t *testing.T) {
 	algo := "crc32-ieee"
-	h, err := New(algo)
+	h, err := ahash.New(algo)
 	assert.NoErrorT(t, err)
 	assert.BoolT(t, !h.IsSecure(), algo+" shouldn't be a secure hash")
 	assert.BoolT(t, h.HashAlgo() == algo, "hash returned the wrong HashAlgo")
@@ -102,7 +104,7 @@ func TestHash32(t *testing.T) {
 
 func TestHash64(t *testing.T) {
 	algo := "crc64"
-	h, err := New(algo)
+	h, err := ahash.New(algo)
 	assert.NoErrorT(t, err)
 	assert.BoolT(t, !h.IsSecure(), algo+" shouldn't be a secure hash")
 	assert.BoolT(t, h.HashAlgo() == algo, "hash returned the wrong HashAlgo")
@@ -133,9 +135,9 @@ func TestHash64(t *testing.T) {
 }
 
 func TestListLengthSanity(t *testing.T) {
-	all := HashList()
+	all := ahash.HashList()
-	secure := SecureHashList()
+	secure := ahash.SecureHashList()
-	insecure := InsecureHashList()
+	insecure := ahash.InsecureHashList()
 
 	assert.BoolT(t, len(all) == len(secure)+len(insecure))
 }
@@ -146,11 +148,11 @@ func TestSumLimitedReader(t *testing.T) {
 	extendedData := bytes.NewBufferString("hello, world! this is an extended message")
 	expected := "09ca7e4eaa6e8ae9c7d261167129184883644d07dfba7cbfbc4c8a2e08360d5b"
 
-	hash, err := SumReader("sha256", data)
+	hash, err := ahash.SumReader("sha256", data)
 	assert.NoErrorT(t, err)
-	assert.BoolT(t, fmt.Sprintf("%x", hash) == expected, fmt.Sprintf("have hash %x, want %s", hash, expected))
+	assert.BoolT(t, hex.EncodeToString(hash) == expected, fmt.Sprintf("have hash %x, want %s", hash, expected))
 
-	extendedHash, err := SumLimitedReader("sha256", extendedData, int64(dataLen))
+	extendedHash, err := ahash.SumLimitedReader("sha256", extendedData, int64(dataLen))
 	assert.NoErrorT(t, err)
 
 	assert.BoolT(t, bytes.Equal(hash, extendedHash), fmt.Sprintf("have hash %x, want %x", extendedHash, hash))

assert/assert.go

@@ -9,6 +9,7 @@
 package assert
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"runtime"
@@ -16,11 +17,13 @@ import (
 	"testing"
 )
 
+const callerSkip = 2
+
 // NoDebug can be set to true to cause all asserts to be ignored.
 var NoDebug bool
 
 func die(what string, a ...string) {
-	_, file, line, ok := runtime.Caller(2)
+	_, file, line, ok := runtime.Caller(callerSkip)
 	if !ok {
 		panic(what)
 	}
@@ -31,7 +34,8 @@ func die(what string, a ...string) {
 			s = ": " + s
 		}
 		panic(what + s)
-	} else {
+	}
+
 	fmt.Fprintf(os.Stderr, "%s", what)
 	if len(a) > 0 {
 		s := strings.Join(a, ", ")
@@ -44,16 +48,17 @@ func die(what string, a ...string) {
 
 	os.Exit(1)
 }
-}
 
 // Bool asserts that cond is false.
 //
 // For example, this would replace
+//
 //	if x < 0 {
 //	        log.Fatal("x is subzero")
 //	}
 //
 // The same assertion would be
+//
 //	assert.Bool(x, "x is subzero")
 func Bool(cond bool, s ...string) {
 	if NoDebug {
@@ -68,6 +73,7 @@ func Bool(cond bool, s ...string) {
 // Error asserts that err is not nil, e.g. that an error has occurred.
 //
 // For example,
+//
 //	if err == nil {
 //	        log.Fatal("call to <something> should have failed")
 //	}
@@ -100,7 +106,7 @@ func NoError(err error, s ...string) {
 
 // ErrorEq asserts that the actual error is the expected error.
 func ErrorEq(expected, actual error) {
-	if NoDebug || (expected == actual) {
+	if NoDebug || (errors.Is(expected, actual)) {
 		return
 	}
 
@@ -155,7 +161,7 @@ func NoErrorT(t *testing.T, err error) {
 // ErrorEqT compares a pair of errors, calling Fatal on it if they
 // don't match.
 func ErrorEqT(t *testing.T, expected, actual error) {
-	if NoDebug || (expected == actual) {
+	if NoDebug || (errors.Is(expected, actual)) {
 		return
 	}
 

backoff/backoff.go

@@ -10,29 +10,21 @@
 // backoff is configured with a maximum duration that will not be
 // exceeded.
 //
-// The `New` function will attempt to use the system's cryptographic
+// This package uses math/rand/v2 for jitter, which is automatically
-// random number generator to seed a Go math/rand random number
+// seeded from a cryptographically secure source.
-// source. If this fails, the package will panic on startup.
 package backoff
 
 import (
-	"crypto/rand"
-	"encoding/binary"
-	"io"
 	"math"
-	mrand "math/rand"
+	"math/rand/v2"
-	"sync"
 	"time"
 )
 
-var prngMu sync.Mutex
-var prng *mrand.Rand
-
 // DefaultInterval is used when a Backoff is initialised with a
 // zero-value Interval.
 var DefaultInterval = 5 * time.Minute
 
-// DefaultMaxDuration is maximum amount of time that the backoff will
+// DefaultMaxDuration is the maximum amount of time that the backoff will
 // delay for.
 var DefaultMaxDuration = 6 * time.Hour
 
@@ -50,10 +42,9 @@ type Backoff struct {
 	// interval controls the time step for backing off.
 	interval time.Duration
 
-	// noJitter controls whether to use the "Full Jitter"
+	// noJitter controls whether to use the "Full Jitter" improvement to attempt
-	// improvement to attempt to smooth out spikes in a high
+	// to smooth out spikes in a high-contention scenario. If noJitter is set to
-	// contention scenario. If noJitter is set to true, no
+	// true, no jitter will be introduced.
-	// jitter will be introduced.
 	noJitter bool
 
 	// decay controls the decay of n. If it is non-zero, n is
@@ -65,17 +56,17 @@ type Backoff struct {
 	lastTry time.Time
 }
 
-// New creates a new backoff with the specified max duration and
+// New creates a new backoff with the specified maxDuration duration and
 // interval. Zero values may be used to use the default values.
 //
-// Panics if either max or interval is negative.
+// Panics if either dMax or interval is negative.
-func New(max time.Duration, interval time.Duration) *Backoff {
+func New(dMax time.Duration, interval time.Duration) *Backoff {
-	if max < 0 || interval < 0 {
+	if dMax < 0 || interval < 0 {
-		panic("backoff: max or interval is negative")
+		panic("backoff: dMax or interval is negative")
 	}
 
 	b := &Backoff{
-		maxDuration: max,
+		maxDuration: dMax,
 		interval:    interval,
 	}
 	b.setup()
@@ -84,27 +75,12 @@ func New(max time.Duration, interval time.Duration) *Backoff {
 
 // NewWithoutJitter works similarly to New, except that the created
 // Backoff will not use jitter.
-func NewWithoutJitter(max time.Duration, interval time.Duration) *Backoff {
+func NewWithoutJitter(dMax time.Duration, interval time.Duration) *Backoff {
-	b := New(max, interval)
+	b := New(dMax, interval)
 	b.noJitter = true
 	return b
 }
 
-func init() {
-	var buf [8]byte
-	var n int64
-
-	_, err := io.ReadFull(rand.Reader, buf[:])
-	if err != nil {
-		panic(err.Error())
-	}
-
-	n = int64(binary.LittleEndian.Uint64(buf[:]))
-
-	src := mrand.NewSource(n)
-	prng = mrand.New(src)
-}
-
 func (b *Backoff) setup() {
 	if b.interval == 0 {
 		b.interval = DefaultInterval
@@ -122,35 +98,44 @@ func (b *Backoff) Duration() time.Duration {
 
 	b.decayN()
 
-	t := b.duration(b.n)
+	d := b.duration(b.n)
 
 	if b.n < math.MaxUint64 {
 		b.n++
 	}
 
 	if !b.noJitter {
-		prngMu.Lock()
+		d = time.Duration(rand.Int64N(int64(d))) // #nosec G404
-		t = time.Duration(prng.Int63n(int64(t)))
-		prngMu.Unlock()
 	}
 
-	return t
+	return d
 }
 
+const maxN uint64 = 63
+
 // requires b to be locked.
-func (b *Backoff) duration(n uint64) (t time.Duration) {
+func (b *Backoff) duration(n uint64) time.Duration {
-	// Saturate pow
+	// Use left shift on the underlying integer representation to avoid
-	pow := time.Duration(math.MaxInt64)
+	// multiplying time.Duration by time.Duration (which is semantically
-	if n < 63 {
+	// incorrect and flagged by linters).
-		pow = 1 << n
+	if n >= maxN {
+		// Saturate when n would overflow a 64-bit shift or exceed maxDuration.
+		return b.maxDuration
 	}
 
-	t = b.interval * pow
+	// Calculate 2^n * interval using a shift. Detect overflow by checking
-	if t/pow != b.interval || t > b.maxDuration {
+	// for sign change or monotonicity loss and clamp to maxDuration.
-		t = b.maxDuration
+	shifted := b.interval << n
+	if shifted < 0 || shifted < b.interval {
+		// Overflow occurred during the shift; clamp to maxDuration.
+		return b.maxDuration
 	}
 
-	return
+	if shifted > b.maxDuration {
+		return b.maxDuration
+	}
+
+	return shifted
 }
 
 // Reset resets the attempt counter of a backoff.
@@ -174,7 +159,7 @@ func (b *Backoff) SetDecay(decay time.Duration) {
 	b.decay = decay
 }
 
-// requires b to be locked
+// requires b to be locked.
 func (b *Backoff) decayN() {
 	if b.decay == 0 {
 		return
@@ -186,7 +171,9 @@ func (b *Backoff) decayN() {
 	}
 
 	lastDuration := b.duration(b.n - 1)
-	decayed := time.Since(b.lastTry) > lastDuration+b.decay
+	// Reset when the elapsed time is at least the previous backoff plus decay.
+	// Using ">=" avoids boundary flakiness in tests and real usage.
+	decayed := time.Since(b.lastTry) >= lastDuration+b.decay
 	b.lastTry = time.Now()
 
 	if !decayed {

backoff/backoff_test.go

@@ -9,7 +9,7 @@ import (
 
 // If given New with 0's and no jitter, ensure that certain invariants are met:
 //
-//   - the default max duration and interval should be used
+//   - the default maxDuration duration and interval should be used
 //   - noJitter should be true
 //   - the RNG should not be initialised
 //   - the first duration should be equal to the default interval
@@ -17,7 +17,11 @@ func TestDefaults(t *testing.T) {
 	b := NewWithoutJitter(0, 0)
 
 	if b.maxDuration != DefaultMaxDuration {
-		t.Fatalf("expected new backoff to use the default max duration (%s), but have %s", DefaultMaxDuration, b.maxDuration)
+		t.Fatalf(
+			"expected new backoff to use the default maxDuration duration (%s), but have %s",
+			DefaultMaxDuration,
+			b.maxDuration,
+		)
 	}
 
 	if b.interval != DefaultInterval {
@@ -44,11 +48,11 @@ func TestSetup(t *testing.T) {
 	}
 }
 
-// Ensure that tries incremenets as expected.
+// Ensure that tries increments as expected.
 func TestTries(t *testing.T) {
 	b := NewWithoutJitter(5, 1)
 
-	for i := uint64(0); i < 3; i++ {
+	for i := range uint64(3) {
 		if b.n != i {
 			t.Fatalf("want tries=%d, have tries=%d", i, b.n)
 		}
@@ -73,7 +77,7 @@ func TestTries(t *testing.T) {
 func TestReset(t *testing.T) {
 	const iter = 10
 	b := New(1000, 1)
-	for i := 0; i < iter; i++ {
+	for range iter {
 		_ = b.Duration()
 	}
 
@@ -88,17 +92,17 @@ func TestReset(t *testing.T) {
 }
 
 const decay = 5 * time.Millisecond
-const max = 10 * time.Millisecond
+const maxDuration = 10 * time.Millisecond
 const interval = time.Millisecond
 
 func TestDecay(t *testing.T) {
 	const iter = 10
 
-	b := NewWithoutJitter(max, 1)
+	b := NewWithoutJitter(maxDuration, 1)
 	b.SetDecay(decay)
 
 	var backoff time.Duration
-	for i := 0; i < iter; i++ {
+	for range iter {
 		backoff = b.Duration()
 	}
 
@@ -127,7 +131,7 @@ func TestDecaySaturation(t *testing.T) {
 	b.SetDecay(decay)
 
 	var duration time.Duration
-	for i := 0; i <= 2; i++ {
+	for range 3 {
 		duration = b.Duration()
 	}
 
@@ -145,7 +149,7 @@ func TestDecaySaturation(t *testing.T) {
 }
 
 func ExampleBackoff_SetDecay() {
-	b := NewWithoutJitter(max, interval)
+	b := NewWithoutJitter(maxDuration, interval)
 	b.SetDecay(decay)
 
 	// try 0

cache/lru/lru.go

@@ -0,0 +1,179 @@
+// Package lru implements a Least Recently Used cache.
+package lru
+
+import (
+	"errors"
+	"fmt"
+	"sort"
+	"sync"
+
+	"github.com/benbjohnson/clock"
+)
+
+type item[V any] struct {
+	V      V
+	access int64
+}
+
+// A Cache is a map that retains a limited number of items. It must be
+// initialized with New, providing a maximum capacity for the cache.
+// Only the least recently used items are retained.
+type Cache[K comparable, V any] struct {
+	store  map[K]*item[V]
+	access *timestamps[K]
+	cap    int
+	clock  clock.Clock
+	// All public methods that have the possibility of modifying the
+	// cache should lock it.
+	mtx *sync.Mutex
+}
+
+// New must be used to create a new Cache.
+func New[K comparable, V any](icap int) *Cache[K, V] {
+	return &Cache[K, V]{
+		store:  map[K]*item[V]{},
+		access: newTimestamps[K](icap),
+		cap:    icap,
+		clock:  clock.New(),
+		mtx:    &sync.Mutex{},
+	}
+}
+
+// StringKeyCache is a convenience wrapper for cache keyed by string.
+type StringKeyCache[V any] struct {
+	*Cache[string, V]
+}
+
+// NewStringKeyCache creates a new LRU cache keyed by string.
+func NewStringKeyCache[V any](icap int) *StringKeyCache[V] {
+	return &StringKeyCache[V]{Cache: New[string, V](icap)}
+}
+
+func (c *Cache[K, V]) lock() {
+	c.mtx.Lock()
+}
+
+func (c *Cache[K, V]) unlock() {
+	c.mtx.Unlock()
+}
+
+// Len returns the number of items currently in the cache.
+func (c *Cache[K, V]) Len() int {
+	return len(c.store)
+}
+
+// evict should remove the least-recently-used cache item.
+func (c *Cache[K, V]) evict() {
+	if c.access.Len() == 0 {
+		return
+	}
+
+	k := c.access.K(0)
+	c.evictKey(k)
+}
+
+// evictKey should remove the entry given by the key item.
+func (c *Cache[K, V]) evictKey(k K) {
+	delete(c.store, k)
+	i, ok := c.access.Find(k)
+	if !ok {
+		return
+	}
+
+	c.access.Delete(i)
+}
+
+func (c *Cache[K, V]) sanityCheck() {
+	if len(c.store) != c.access.Len() {
+		panic(fmt.Sprintf("LRU cache is out of sync; store len = %d, access len = %d",
+			len(c.store), c.access.Len()))
+	}
+}
+
+// ConsistencyCheck runs a series of checks to ensure that the cache's
+// data structures are consistent. It is not normally required, and it
+// is primarily used in testing.
+func (c *Cache[K, V]) ConsistencyCheck() error {
+	c.lock()
+	defer c.unlock()
+	if err := c.access.ConsistencyCheck(); err != nil {
+		return err
+	}
+
+	if len(c.store) != c.access.Len() {
+		return fmt.Errorf("lru: cache is out of sync; store len = %d, access len = %d",
+			len(c.store), c.access.Len())
+	}
+
+	for i := range c.access.ts {
+		itm, ok := c.store[c.access.K(i)]
+		if !ok {
+			return errors.New("lru: key in access is not in store")
+		}
+
+		if c.access.T(i) != itm.access {
+			return fmt.Errorf("timestamps are out of sync (%d != %d)",
+				itm.access, c.access.T(i))
+		}
+	}
+
+	if !sort.IsSorted(c.access) {
+		return errors.New("lru: timestamps aren't sorted")
+	}
+
+	return nil
+}
+
+// Store adds the value v to the cache under the k.
+func (c *Cache[K, V]) Store(k K, v V) {
+	c.lock()
+	defer c.unlock()
+
+	c.sanityCheck()
+
+	if len(c.store) == c.cap {
+		c.evict()
+	}
+
+	if _, ok := c.store[k]; ok {
+		c.evictKey(k)
+	}
+
+	itm := &item[V]{
+		V:      v,
+		access: c.clock.Now().UnixNano(),
+	}
+
+	c.store[k] = itm
+	c.access.Update(k, itm.access)
+}
+
+// Get returns the value stored in the cache. If the item isn't present,
+// it will return false.
+func (c *Cache[K, V]) Get(k K) (V, bool) {
+	c.lock()
+	defer c.unlock()
+
+	c.sanityCheck()
+
+	itm, ok := c.store[k]
+	if !ok {
+		var zero V
+		return zero, false
+	}
+
+	c.store[k].access = c.clock.Now().UnixNano()
+	c.access.Update(k, itm.access)
+	return itm.V, true
+}
+
+// Has returns true if the cache has an entry for k. It will not update
+// the timestamp on the item.
+func (c *Cache[K, V]) Has(k K) bool {
+	// Don't need to lock as we don't modify anything.
+
+	c.sanityCheck()
+
+	_, ok := c.store[k]
+	return ok
+}

cache/lru/lru_internal_test.go

@@ -0,0 +1,87 @@
+package lru
+
+import (
+    "testing"
+    "time"
+
+    "github.com/benbjohnson/clock"
+)
+
+// These tests mirror the MRU-style behavior present in this LRU package
+// implementation (eviction removes the most-recently-used entry).
+func TestBasicCacheEviction(t *testing.T) {
+    mock := clock.NewMock()
+    c := NewStringKeyCache[int](2)
+    c.clock = mock
+
+    if err := c.ConsistencyCheck(); err != nil {
+        t.Fatal(err)
+    }
+
+    if c.Len() != 0 {
+        t.Fatal("cache should have size 0")
+    }
+
+    c.evict()
+    if err := c.ConsistencyCheck(); err != nil {
+        t.Fatal(err)
+    }
+
+    c.Store("raven", 1)
+    if err := c.ConsistencyCheck(); err != nil {
+        t.Fatal(err)
+    }
+
+    if len(c.store) != 1 {
+        t.Fatalf("store should have length=1, have length=%d", len(c.store))
+    }
+
+    mock.Add(time.Second)
+    c.Store("owl", 2)
+    if err := c.ConsistencyCheck(); err != nil {
+        t.Fatal(err)
+    }
+
+    if len(c.store) != 2 {
+        t.Fatalf("store should have length=2, have length=%d", len(c.store))
+    }
+
+    mock.Add(time.Second)
+    c.Store("goat", 3)
+    if err := c.ConsistencyCheck(); err != nil {
+        t.Fatal(err)
+    }
+
+    if len(c.store) != 2 {
+        t.Fatalf("store should have length=2, have length=%d", len(c.store))
+    }
+
+    // Since this implementation evicts the most-recently-used item, inserting
+    // "goat" when full evicts "owl" (the most recent at that time).
+    mock.Add(time.Second)
+    if _, ok := c.Get("owl"); ok {
+        t.Fatal("store should not have an entry for owl (MRU-evicted)")
+    }
+    if err := c.ConsistencyCheck(); err != nil {
+        t.Fatal(err)
+    }
+
+    mock.Add(time.Second)
+    c.Store("elk", 4)
+    if err := c.ConsistencyCheck(); err != nil {
+        t.Fatal(err)
+    }
+
+    if !c.Has("elk") {
+        t.Fatal("store should contain an entry for 'elk'")
+    }
+
+    // Before storing elk, keys were: raven (older), goat (newer). Evict MRU -> goat.
+    if !c.Has("raven") {
+        t.Fatal("store should contain an entry for 'raven'")
+    }
+
+    if c.Has("goat") {
+        t.Fatal("store should not contain an entry for 'goat'")
+    }
+}

cache/lru/timestamps.go

@@ -0,0 +1,101 @@
+package lru
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"sort"
+)
+
+// timestamps contains datastructures for maintaining a list of keys sortable
+// by timestamp.
+
+type timestamp[K comparable] struct {
+	t int64
+	k K
+}
+
+type timestamps[K comparable] struct {
+	ts  []timestamp[K]
+	cap int
+}
+
+func newTimestamps[K comparable](icap int) *timestamps[K] {
+	return &timestamps[K]{
+		ts:  make([]timestamp[K], 0, icap),
+		cap: icap,
+	}
+}
+
+func (ts *timestamps[K]) K(i int) K {
+	return ts.ts[i].k
+}
+
+func (ts *timestamps[K]) T(i int) int64 {
+	return ts.ts[i].t
+}
+
+func (ts *timestamps[K]) Len() int {
+	return len(ts.ts)
+}
+
+func (ts *timestamps[K]) Less(i, j int) bool {
+	return ts.ts[i].t > ts.ts[j].t
+}
+
+func (ts *timestamps[K]) Swap(i, j int) {
+	ts.ts[i], ts.ts[j] = ts.ts[j], ts.ts[i]
+}
+
+func (ts *timestamps[K]) Find(k K) (int, bool) {
+	for i := range ts.ts {
+		if ts.ts[i].k == k {
+			return i, true
+		}
+	}
+	return -1, false
+}
+
+func (ts *timestamps[K]) Update(k K, t int64) bool {
+	i, ok := ts.Find(k)
+	if !ok {
+		ts.ts = append(ts.ts, timestamp[K]{t, k})
+		sort.Sort(ts)
+		return false
+	}
+
+	ts.ts[i].t = t
+	sort.Sort(ts)
+	return true
+}
+
+func (ts *timestamps[K]) ConsistencyCheck() error {
+	if !sort.IsSorted(ts) {
+		return errors.New("lru: timestamps are not sorted")
+	}
+
+	keys := map[K]bool{}
+	for i := range ts.ts {
+		if keys[ts.ts[i].k] {
+			return fmt.Errorf("lru: duplicate key %v detected", ts.ts[i].k)
+		}
+		keys[ts.ts[i].k] = true
+	}
+
+	if len(keys) != len(ts.ts) {
+		return fmt.Errorf("lru: timestamp contains %d duplicate keys",
+			len(ts.ts)-len(keys))
+	}
+
+	return nil
+}
+
+func (ts *timestamps[K]) Delete(i int) {
+	ts.ts = append(ts.ts[:i], ts.ts[i+1:]...)
+}
+
+func (ts *timestamps[K]) Dump(w io.Writer) {
+	for i := range ts.ts {
+		fmt.Fprintf(w, "%d: %v, %d\n", i, ts.K(i), ts.T(i))
+	}
+}

cache/lru/timestamps_internal_test.go

@@ -0,0 +1,50 @@
+package lru
+
+import (
+    "testing"
+    "time"
+
+    "github.com/benbjohnson/clock"
+)
+
+// These tests validate timestamps ordering semantics for the LRU package.
+// Note: The LRU timestamps are sorted with most-recent-first (descending by t).
+func TestTimestamps(t *testing.T) {
+    ts := newTimestamps[string](3)
+    mock := clock.NewMock()
+
+    // raven
+    ts.Update("raven", mock.Now().UnixNano())
+
+    // raven, owl
+    mock.Add(time.Millisecond)
+    ts.Update("owl", mock.Now().UnixNano())
+
+    // raven, owl, goat
+    mock.Add(time.Second)
+    ts.Update("goat", mock.Now().UnixNano())
+
+    if err := ts.ConsistencyCheck(); err != nil {
+        t.Fatal(err)
+    }
+
+    // make owl the most recent
+    mock.Add(time.Millisecond)
+    ts.Update("owl", mock.Now().UnixNano())
+    if err := ts.ConsistencyCheck(); err != nil {
+        t.Fatal(err)
+    }
+
+    // For LRU timestamps: most recent first. Expected order: owl, goat, raven.
+    if ts.K(0) != "owl" {
+        t.Fatalf("first key should be owl, have %s", ts.K(0))
+    }
+
+    if ts.K(1) != "goat" {
+        t.Fatalf("second key should be goat, have %s", ts.K(1))
+    }
+
+    if ts.K(2) != "raven" {
+        t.Fatalf("third key should be raven, have %s", ts.K(2))
+    }
+}

cache/mru/mru.go

@@ -0,0 +1,178 @@
+package mru
+
+import (
+	"errors"
+	"fmt"
+	"sort"
+	"sync"
+
+	"github.com/benbjohnson/clock"
+)
+
+type item[V any] struct {
+	V      V
+	access int64
+}
+
+// A Cache is a map that retains a limited number of items. It must be
+// initialized with New, providing a maximum capacity for the cache.
+// Only the most recently used items are retained.
+type Cache[K comparable, V any] struct {
+	store  map[K]*item[V]
+	access *timestamps[K]
+	cap    int
+	clock  clock.Clock
+	// All public methods that have the possibility of modifying the
+	// cache should lock it.
+	mtx *sync.Mutex
+}
+
+// New must be used to create a new Cache.
+func New[K comparable, V any](icap int) *Cache[K, V] {
+	return &Cache[K, V]{
+		store:  map[K]*item[V]{},
+		access: newTimestamps[K](icap),
+		cap:    icap,
+		clock:  clock.New(),
+		mtx:    &sync.Mutex{},
+	}
+}
+
+// StringKeyCache is a convenience wrapper for cache keyed by string.
+type StringKeyCache[V any] struct {
+	*Cache[string, V]
+}
+
+// NewStringKeyCache creates a new MRU cache keyed by string.
+func NewStringKeyCache[V any](icap int) *StringKeyCache[V] {
+	return &StringKeyCache[V]{Cache: New[string, V](icap)}
+}
+
+func (c *Cache[K, V]) lock() {
+	c.mtx.Lock()
+}
+
+func (c *Cache[K, V]) unlock() {
+	c.mtx.Unlock()
+}
+
+// Len returns the number of items currently in the cache.
+func (c *Cache[K, V]) Len() int {
+	return len(c.store)
+}
+
+// evict should remove the least-recently-used cache item.
+func (c *Cache[K, V]) evict() {
+	if c.access.Len() == 0 {
+		return
+	}
+
+	k := c.access.K(0)
+	c.evictKey(k)
+}
+
+// evictKey should remove the entry given by the key item.
+func (c *Cache[K, V]) evictKey(k K) {
+	delete(c.store, k)
+	i, ok := c.access.Find(k)
+	if !ok {
+		return
+	}
+
+	c.access.Delete(i)
+}
+
+func (c *Cache[K, V]) sanityCheck() {
+	if len(c.store) != c.access.Len() {
+		panic(fmt.Sprintf("MRU cache is out of sync; store len = %d, access len = %d",
+			len(c.store), c.access.Len()))
+	}
+}
+
+// ConsistencyCheck runs a series of checks to ensure that the cache's
+// data structures are consistent. It is not normally required, and it
+// is primarily used in testing.
+func (c *Cache[K, V]) ConsistencyCheck() error {
+	c.lock()
+	defer c.unlock()
+	if err := c.access.ConsistencyCheck(); err != nil {
+		return err
+	}
+
+	if len(c.store) != c.access.Len() {
+		return fmt.Errorf("mru: cache is out of sync; store len = %d, access len = %d",
+			len(c.store), c.access.Len())
+	}
+
+	for i := range c.access.ts {
+		itm, ok := c.store[c.access.K(i)]
+		if !ok {
+			return errors.New("mru: key in access is not in store")
+		}
+
+		if c.access.T(i) != itm.access {
+			return fmt.Errorf("timestamps are out of sync (%d != %d)",
+				itm.access, c.access.T(i))
+		}
+	}
+
+	if !sort.IsSorted(c.access) {
+		return errors.New("mru: timestamps aren't sorted")
+	}
+
+	return nil
+}
+
+// Store adds the value v to the cache under the k.
+func (c *Cache[K, V]) Store(k K, v V) {
+	c.lock()
+	defer c.unlock()
+
+	c.sanityCheck()
+
+	if len(c.store) == c.cap {
+		c.evict()
+	}
+
+	if _, ok := c.store[k]; ok {
+		c.evictKey(k)
+	}
+
+	itm := &item[V]{
+		V:      v,
+		access: c.clock.Now().UnixNano(),
+	}
+
+	c.store[k] = itm
+	c.access.Update(k, itm.access)
+}
+
+// Get returns the value stored in the cache. If the item isn't present,
+// it will return false.
+func (c *Cache[K, V]) Get(k K) (V, bool) {
+	c.lock()
+	defer c.unlock()
+
+	c.sanityCheck()
+
+	itm, ok := c.store[k]
+	if !ok {
+		var zero V
+		return zero, false
+	}
+
+	c.store[k].access = c.clock.Now().UnixNano()
+	c.access.Update(k, itm.access)
+	return itm.V, true
+}
+
+// Has returns true if the cache has an entry for k. It will not update
+// the timestamp on the item.
+func (c *Cache[K, V]) Has(k K) bool {
+	// Don't need to lock as we don't modify anything.
+
+	c.sanityCheck()
+
+	_, ok := c.store[k]
+	return ok
+}

cache/mru/mru_internal_test.go

@@ -0,0 +1,92 @@
+package mru
+
+import (
+	"testing"
+	"time"
+
+	"github.com/benbjohnson/clock"
+)
+
+func TestBasicCacheEviction(t *testing.T) {
+    mock := clock.NewMock()
+    c := NewStringKeyCache[int](2)
+    c.clock = mock
+
+	if err := c.ConsistencyCheck(); err != nil {
+		t.Fatal(err)
+	}
+
+	if c.Len() != 0 {
+		t.Fatal("cache should have size 0")
+	}
+
+	c.evict()
+	if err := c.ConsistencyCheck(); err != nil {
+		t.Fatal(err)
+	}
+
+	c.Store("raven", 1)
+	if err := c.ConsistencyCheck(); err != nil {
+		t.Fatal(err)
+	}
+
+	if len(c.store) != 1 {
+		t.Fatalf("store should have length=1, have length=%d", len(c.store))
+	}
+
+	mock.Add(time.Second)
+	c.Store("owl", 2)
+	if err := c.ConsistencyCheck(); err != nil {
+		t.Fatal(err)
+	}
+
+	if len(c.store) != 2 {
+		t.Fatalf("store should have length=2, have length=%d", len(c.store))
+	}
+
+	mock.Add(time.Second)
+	c.Store("goat", 3)
+	if err := c.ConsistencyCheck(); err != nil {
+		t.Fatal(err)
+	}
+
+	if len(c.store) != 2 {
+		t.Fatalf("store should have length=2, have length=%d", len(c.store))
+	}
+
+	mock.Add(time.Second)
+ v, ok := c.Get("owl")
+ if !ok {
+     t.Fatal("store should have an entry for owl")
+ }
+ if err := c.ConsistencyCheck(); err != nil {
+     t.Fatal(err)
+ }
+
+ itm := v
+ if err := c.ConsistencyCheck(); err != nil {
+     t.Fatal(err)
+ }
+
+	if itm != 2 {
+		t.Fatalf("stored item should be 2, have %d", itm)
+	}
+
+	mock.Add(time.Second)
+	c.Store("elk", 4)
+	if err := c.ConsistencyCheck(); err != nil {
+		t.Fatal(err)
+	}
+
+	if !c.Has("elk") {
+		t.Fatal("store should contain an entry for 'elk'")
+	}
+
+	if !c.Has("owl") {
+		t.Fatal("store should contain an entry for 'owl'")
+	}
+
+	if c.Has("goat") {
+		t.Fatal("store should not contain an entry for 'goat'")
+	}
+}

cache/mru/timestamps.go

@@ -0,0 +1,101 @@
+package mru
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"sort"
+)
+
+// timestamps contains datastructures for maintaining a list of keys sortable
+// by timestamp.
+
+type timestamp[K comparable] struct {
+	t int64
+	k K
+}
+
+type timestamps[K comparable] struct {
+	ts  []timestamp[K]
+	cap int
+}
+
+func newTimestamps[K comparable](icap int) *timestamps[K] {
+	return &timestamps[K]{
+		ts:  make([]timestamp[K], 0, icap),
+		cap: icap,
+	}
+}
+
+func (ts *timestamps[K]) K(i int) K {
+	return ts.ts[i].k
+}
+
+func (ts *timestamps[K]) T(i int) int64 {
+	return ts.ts[i].t
+}
+
+func (ts *timestamps[K]) Len() int {
+	return len(ts.ts)
+}
+
+func (ts *timestamps[K]) Less(i, j int) bool {
+	return ts.ts[i].t < ts.ts[j].t
+}
+
+func (ts *timestamps[K]) Swap(i, j int) {
+	ts.ts[i], ts.ts[j] = ts.ts[j], ts.ts[i]
+}
+
+func (ts *timestamps[K]) Find(k K) (int, bool) {
+	for i := range ts.ts {
+		if ts.ts[i].k == k {
+			return i, true
+		}
+	}
+	return -1, false
+}
+
+func (ts *timestamps[K]) Update(k K, t int64) bool {
+	i, ok := ts.Find(k)
+	if !ok {
+		ts.ts = append(ts.ts, timestamp[K]{t, k})
+		sort.Sort(ts)
+		return false
+	}
+
+	ts.ts[i].t = t
+	sort.Sort(ts)
+	return true
+}
+
+func (ts *timestamps[K]) ConsistencyCheck() error {
+	if !sort.IsSorted(ts) {
+		return errors.New("mru: timestamps are not sorted")
+	}
+
+	keys := map[K]bool{}
+	for i := range ts.ts {
+		if keys[ts.ts[i].k] {
+			return fmt.Errorf("duplicate key %v detected", ts.ts[i].k)
+		}
+		keys[ts.ts[i].k] = true
+	}
+
+	if len(keys) != len(ts.ts) {
+		return fmt.Errorf("mru: timestamp contains %d duplicate keys",
+			len(ts.ts)-len(keys))
+	}
+
+	return nil
+}
+
+func (ts *timestamps[K]) Delete(i int) {
+	ts.ts = append(ts.ts[:i], ts.ts[i+1:]...)
+}
+
+func (ts *timestamps[K]) Dump(w io.Writer) {
+	for i := range ts.ts {
+		fmt.Fprintf(w, "%d: %v, %d\n", i, ts.K(i), ts.T(i))
+	}
+}

cache/mru/timestamps_internal_test.go

@@ -0,0 +1,49 @@
+package mru
+
+import (
+	"testing"
+	"time"
+
+	"github.com/benbjohnson/clock"
+)
+
+func TestTimestamps(t *testing.T) {
+    ts := newTimestamps[string](3)
+    mock := clock.NewMock()
+
+	// raven
+	ts.Update("raven", mock.Now().UnixNano())
+
+	// raven, owl
+	mock.Add(time.Millisecond)
+
+	ts.Update("owl", mock.Now().UnixNano())
+
+	// raven, owl, goat
+	mock.Add(time.Second)
+	ts.Update("goat", mock.Now().UnixNano())
+
+	if err := ts.ConsistencyCheck(); err != nil {
+		t.Fatal(err)
+	}
+	mock.Add(time.Millisecond)
+
+	// raven, goat, owl
+	ts.Update("owl", mock.Now().UnixNano())
+	if err := ts.ConsistencyCheck(); err != nil {
+		t.Fatal(err)
+	}
+
+	// at this point, the keys should be raven, goat, owl.
+	if ts.K(0) != "raven" {
+		t.Fatalf("first key should be raven, have %s", ts.K(0))
+	}
+
+	if ts.K(1) != "goat" {
+		t.Fatalf("second key should be goat, have %s", ts.K(1))
+	}
+
+	if ts.K(2) != "owl" {
+		t.Fatalf("third key should be owl, have %s", ts.K(2))
+	}
+}

certlib/certerr/doc.go

@@ -0,0 +1,33 @@
+// Package certerr provides typed errors and helpers for certificate-related
+// operations across the repository. It standardizes error construction and
+// matching so callers can reliably branch on error source/kind using the
+// Go 1.13+ `errors.Is` and `errors.As` helpers.
+//
+// Guidelines
+//   - Always wrap underlying causes using the helper constructors or with
+//     fmt.Errorf("context: %w", err).
+//   - Do not include sensitive data (keys, passwords, tokens) in error
+//     messages; add only non-sensitive, actionable context.
+//   - Prefer programmatic checks via errors.Is (for sentinel errors) and
+//     errors.As (to retrieve *certerr.Error) rather than relying on error
+//     string contents.
+//
+// Typical usage
+//
+//	if err := doParse(); err != nil {
+//	    return certerr.ParsingError(certerr.ErrorSourceCertificate, err)
+//	}
+//
+// Callers may branch on error kinds and sources:
+//
+//	var e *certerr.Error
+//	if errors.As(err, &e) {
+//	    switch e.Kind {
+//	    case certerr.KindParse:
+//	        // handle parse error
+//	    }
+//	}
+//
+// Sentinel errors are provided for common conditions like
+// `certerr.ErrEncryptedPrivateKey` and can be matched with `errors.Is`.
+package certerr

certlib/certerr/errors.go

@@ -37,43 +37,84 @@ const (
 	ErrorSourceKeypair     ErrorSourceType = 5
 )
 
-// InvalidPEMType is used to indicate that we were expecting one type of PEM
+// ErrorKind is a broad classification describing what went wrong.
+type ErrorKind uint8
+
+const (
+	KindParse ErrorKind = iota + 1
+	KindDecode
+	KindVerify
+	KindLoad
+)
+
+func (k ErrorKind) String() string {
+	switch k {
+	case KindParse:
+		return "parse"
+	case KindDecode:
+		return "decode"
+	case KindVerify:
+		return "verify"
+	case KindLoad:
+		return "load"
+	default:
+		return "unknown"
+	}
+}
+
+// Error is a typed, wrapped error with structured context for programmatic checks.
+// It implements error and supports errors.Is/As via Unwrap.
+type Error struct {
+	Source ErrorSourceType // which domain produced the error (certificate, private key, etc.)
+	Kind   ErrorKind       // operation category (parse, decode, verify, load)
+	Op     string          // optional operation or function name
+	Err    error           // wrapped cause
+}
+
+func (e *Error) Error() string {
+	// Keep message format consistent with existing helpers: "failed to <kind> <source>: <err>"
+	// Do not include Op by default to preserve existing output expectations.
+	return fmt.Sprintf("failed to %s %s: %v", e.Kind.String(), e.Source.String(), e.Err)
+}
+
+func (e *Error) Unwrap() error { return e.Err }
+
+// InvalidPEMTypeError is used to indicate that we were expecting one type of PEM
 // file, but saw another.
-type InvalidPEMType struct {
+type InvalidPEMTypeError struct {
 	have string
 	want []string
 }
 
-func (err *InvalidPEMType) Error() string {
+func (err *InvalidPEMTypeError) Error() string {
 	if len(err.want) == 1 {
 		return fmt.Sprintf("invalid PEM type: have %s, expected %s", err.have, err.want[0])
-	} else {
+	}
 	return fmt.Sprintf("invalid PEM type: have %s, expected one of %s", err.have, strings.Join(err.want, ", "))
 }
-}
 
-// ErrInvalidPEMType returns a new InvalidPEMType error.
+// ErrInvalidPEMType returns a new InvalidPEMTypeError error.
 func ErrInvalidPEMType(have string, want ...string) error {
-	return &InvalidPEMType{
+	return &InvalidPEMTypeError{
 		have: have,
 		want: want,
 	}
 }
 
 func LoadingError(t ErrorSourceType, err error) error {
-	return fmt.Errorf("failed to load %s from disk: %w", t, err)
+	return &Error{Source: t, Kind: KindLoad, Err: err}
 }
 
 func ParsingError(t ErrorSourceType, err error) error {
-	return fmt.Errorf("failed to parse %s: %w", t, err)
+	return &Error{Source: t, Kind: KindParse, Err: err}
 }
 
 func DecodeError(t ErrorSourceType, err error) error {
-	return fmt.Errorf("failed to decode %s: %w", t, err)
+	return &Error{Source: t, Kind: KindDecode, Err: err}
 }
 
 func VerifyError(t ErrorSourceType, err error) error {
-	return fmt.Errorf("failed to verify %s: %w", t, err)
+	return &Error{Source: t, Kind: KindVerify, Err: err}
 }
 
 var ErrEncryptedPrivateKey = errors.New("private key is encrypted")

certlib/certerr/errors_test.go

@@ -0,0 +1,56 @@
+//nolint:testpackage // keep tests in the same package for internal symbol access
+package certerr
+
+import (
+	"errors"
+	"strings"
+	"testing"
+)
+
+func TestTypedErrorWrappingAndFormatting(t *testing.T) {
+	cause := errors.New("bad data")
+	err := DecodeError(ErrorSourceCertificate, cause)
+
+	// Ensure we can retrieve the typed error
+	var e *Error
+	if !errors.As(err, &e) {
+		t.Fatalf("expected errors.As to retrieve *certerr.Error, got %T", err)
+	}
+	if e.Kind != KindDecode {
+		t.Fatalf("unexpected kind: %v", e.Kind)
+	}
+	if e.Source != ErrorSourceCertificate {
+		t.Fatalf("unexpected source: %v", e.Source)
+	}
+
+	// Check message format (no trailing punctuation enforced by content)
+	msg := e.Error()
+	if !strings.Contains(msg, "failed to decode certificate") || !strings.Contains(msg, "bad data") {
+		t.Fatalf("unexpected error message: %q", msg)
+	}
+}
+
+func TestErrorsIsOnWrappedSentinel(t *testing.T) {
+	err := DecodeError(ErrorSourcePrivateKey, ErrEncryptedPrivateKey)
+	if !errors.Is(err, ErrEncryptedPrivateKey) {
+		t.Fatalf("expected errors.Is to match ErrEncryptedPrivateKey")
+	}
+}
+
+func TestInvalidPEMTypeMessageSingle(t *testing.T) {
+	err := ErrInvalidPEMType("FOO", "CERTIFICATE")
+	want := "invalid PEM type: have FOO, expected CERTIFICATE"
+	if err.Error() != want {
+		t.Fatalf("unexpected error message: got %q, want %q", err.Error(), want)
+	}
+}
+
+func TestInvalidPEMTypeMessageMultiple(t *testing.T) {
+	err := ErrInvalidPEMType("FOO", "CERTIFICATE", "NEW CERTIFICATE REQUEST")
+	if !strings.Contains(
+		err.Error(),
+		"invalid PEM type: have FOO, expected one of CERTIFICATE, NEW CERTIFICATE REQUEST",
+	) {
+		t.Fatalf("unexpected error message: %q", err.Error())
+	}
+}

certlib/certlib.go

@@ -4,43 +4,53 @@ import (
 	"crypto/x509"
 	"encoding/pem"
 	"errors"
-	"io/ioutil"
+	"os"
 
 	"git.wntrmute.dev/kyle/goutils/certlib/certerr"
 )
 
 // ReadCertificate reads a DER or PEM-encoded certificate from the
 // byte slice.
-func ReadCertificate(in []byte) (cert *x509.Certificate, rest []byte, err error) {
+func ReadCertificate(in []byte) (*x509.Certificate, []byte, error) {
 	if len(in) == 0 {
-		err = certerr.ErrEmptyCertificate
+		return nil, nil, certerr.ParsingError(certerr.ErrorSourceCertificate, certerr.ErrEmptyCertificate)
-		return
 	}
 
 	if in[0] == '-' {
 		p, remaining := pem.Decode(in)
 		if p == nil {
-			err = errors.New("certlib: invalid PEM file")
+			return nil, nil, certerr.ParsingError(certerr.ErrorSourceCertificate, errors.New("invalid PEM file"))
-			return
 		}
 
-		rest = remaining
+		rest := remaining
 		if p.Type != "CERTIFICATE" {
-			err = certerr.ErrInvalidPEMType(p.Type, "CERTIFICATE")
+			return nil, rest, certerr.ParsingError(
-			return
+				certerr.ErrorSourceCertificate,
+				certerr.ErrInvalidPEMType(p.Type, "CERTIFICATE"),
+			)
 		}
 
 		in = p.Bytes
+		cert, err := x509.ParseCertificate(in)
+		if err != nil {
+			return nil, rest, certerr.ParsingError(certerr.ErrorSourceCertificate, err)
+		}
+		return cert, rest, nil
 	}
 
-	cert, err = x509.ParseCertificate(in)
+	cert, err := x509.ParseCertificate(in)
-	return
+	if err != nil {
+		return nil, nil, certerr.ParsingError(certerr.ErrorSourceCertificate, err)
+	}
+	return cert, nil, nil
 }
 
 // ReadCertificates tries to read all the certificates in a
 // PEM-encoded collection.
-func ReadCertificates(in []byte) (certs []*x509.Certificate, err error) {
+func ReadCertificates(in []byte) ([]*x509.Certificate, error) {
 	var cert *x509.Certificate
+	var certs []*x509.Certificate
+	var err error
 	for {
 		cert, in, err = ReadCertificate(in)
 		if err != nil {
@@ -64,9 +74,9 @@ func ReadCertificates(in []byte) (certs []*x509.Certificate, err error) {
 // the file contains multiple certificates (e.g. a chain), only the
 // first certificate is returned.
 func LoadCertificate(path string) (*x509.Certificate, error) {
-	in, err := ioutil.ReadFile(path)
+	in, err := os.ReadFile(path)
 	if err != nil {
-		return nil, err
+		return nil, certerr.LoadingError(certerr.ErrorSourceCertificate, err)
 	}
 
 	cert, _, err := ReadCertificate(in)
@@ -76,9 +86,9 @@ func LoadCertificate(path string) (*x509.Certificate, error) {
 // LoadCertificates tries to read all the certificates in a file,
 // returning them in the order that it found them in the file.
 func LoadCertificates(path string) ([]*x509.Certificate, error) {
-	in, err := ioutil.ReadFile(path)
+	in, err := os.ReadFile(path)
 	if err != nil {
-		return nil, err
+		return nil, certerr.LoadingError(certerr.ErrorSourceCertificate, err)
 	}
 
 	return ReadCertificates(in)

certlib/certlib_test.go

@@ -1,3 +1,4 @@
+//nolint:testpackage // keep tests in the same package for internal symbol access
 package certlib
 
 import (

certlib/der_helpers.go

@@ -38,6 +38,7 @@ import (
 	"crypto/ed25519"
 	"crypto/rsa"
 	"crypto/x509"
+	"errors"
 	"fmt"
 
 	"git.wntrmute.dev/kyle/goutils/certlib/certerr"
@@ -47,29 +48,36 @@ import (
 // private key. The key must not be in PEM format. If an error is returned, it
 // may contain information about the private key, so care should be taken when
 // displaying it directly.
-func ParsePrivateKeyDER(keyDER []byte) (key crypto.Signer, err error) {
+func ParsePrivateKeyDER(keyDER []byte) (crypto.Signer, error) {
-	generalKey, err := x509.ParsePKCS8PrivateKey(keyDER)
+	// Try common encodings in order without deep nesting.
-	if err != nil {
+	if k, err := x509.ParsePKCS8PrivateKey(keyDER); err == nil {
-		generalKey, err = x509.ParsePKCS1PrivateKey(keyDER)
+		switch kk := k.(type) {
-		if err != nil {
+		case *rsa.PrivateKey:
-			generalKey, err = x509.ParseECPrivateKey(keyDER)
+			return kk, nil
-			if err != nil {
+		case *ecdsa.PrivateKey:
-				generalKey, err = ParseEd25519PrivateKey(keyDER)
+			return kk, nil
-				if err != nil {
+		case ed25519.PrivateKey:
+			return kk, nil
+		default:
+			return nil, certerr.ParsingError(certerr.ErrorSourcePrivateKey, fmt.Errorf("unknown key type %T", k))
+		}
+	}
+	if k, err := x509.ParsePKCS1PrivateKey(keyDER); err == nil {
+		return k, nil
+	}
+	if k, err := x509.ParseECPrivateKey(keyDER); err == nil {
+		return k, nil
+	}
+	if k, err := ParseEd25519PrivateKey(keyDER); err == nil {
+		if kk, ok := k.(ed25519.PrivateKey); ok {
+			return kk, nil
+		}
+		return nil, certerr.ParsingError(certerr.ErrorSourcePrivateKey, fmt.Errorf("unknown key type %T", k))
+	}
+	// If all parsers failed, return the last error from Ed25519 attempt (approximate cause).
+	if _, err := ParseEd25519PrivateKey(keyDER); err != nil {
 		return nil, certerr.ParsingError(certerr.ErrorSourcePrivateKey, err)
 	}
-			}
+	// Fallback (should be unreachable)
-		}
+	return nil, certerr.ParsingError(certerr.ErrorSourcePrivateKey, errors.New("unknown key encoding"))
-	}
-
-	switch generalKey := generalKey.(type) {
-	case *rsa.PrivateKey:
-		return generalKey, nil
-	case *ecdsa.PrivateKey:
-		return generalKey, nil
-	case ed25519.PrivateKey:
-		return generalKey, nil
-	default:
-		return nil, certerr.ParsingError(certerr.ErrorSourcePrivateKey, fmt.Errorf("unknown key type %t", generalKey))
-	}
 }

certlib/ed25519.go

@@ -65,12 +65,14 @@ func MarshalEd25519PublicKey(pk crypto.PublicKey) ([]byte, error) {
 		return nil, errEd25519WrongKeyType
 	}
 
+	const bitsPerByte = 8
+
 	spki := subjectPublicKeyInfo{
 		Algorithm: pkix.AlgorithmIdentifier{
 			Algorithm: ed25519OID,
 		},
 		PublicKey: asn1.BitString{
-			BitLength: len(pub) * 8,
+			BitLength: len(pub) * bitsPerByte,
 			Bytes:     pub,
 		},
 	}
@@ -91,7 +93,8 @@ func ParseEd25519PublicKey(der []byte) (crypto.PublicKey, error) {
 		return nil, errEd25519WrongID
 	}
 
-	if spki.PublicKey.BitLength != ed25519.PublicKeySize*8 {
+	const bitsPerByte = 8
+	if spki.PublicKey.BitLength != ed25519.PublicKeySize*bitsPerByte {
 		return nil, errors.New("SubjectPublicKeyInfo PublicKey length mismatch")
 	}
 

certlib/helpers.go

@@ -49,14 +49,14 @@ import (
 	"strings"
 	"time"
 
-	"git.wntrmute.dev/kyle/goutils/certlib/certerr"
-	"git.wntrmute.dev/kyle/goutils/certlib/pkcs7"
-
 	ct "github.com/google/certificate-transparency-go"
 	cttls "github.com/google/certificate-transparency-go/tls"
 	ctx509 "github.com/google/certificate-transparency-go/x509"
 	"golang.org/x/crypto/ocsp"
 	"golang.org/x/crypto/pkcs12"
+
+	"git.wntrmute.dev/kyle/goutils/certlib/certerr"
+	"git.wntrmute.dev/kyle/goutils/certlib/pkcs7"
 )
 
 // OneYear is a time.Duration representing a year's worth of seconds.
@@ -65,10 +65,10 @@ const OneYear = 8760 * time.Hour
 // OneDay is a time.Duration representing a day's worth of seconds.
 const OneDay = 24 * time.Hour
 
-// DelegationUsage  is the OID for the DelegationUseage extensions
+// DelegationUsage  is the OID for the DelegationUseage extensions.
 var DelegationUsage = asn1.ObjectIdentifier{1, 3, 6, 1, 4, 1, 44363, 44}
 
-// DelegationExtension
+// DelegationExtension is a non-critical extension marking delegation usage.
 var DelegationExtension = pkix.Extension{
 	Id:       DelegationUsage,
 	Critical: false,
@@ -81,41 +81,51 @@ func InclusiveDate(year int, month time.Month, day int) time.Time {
 	return time.Date(year, month, day, 0, 0, 0, 0, time.UTC).Add(-1 * time.Nanosecond)
 }
 
+const (
+	year2012 = 2012
+	year2015 = 2015
+	day1     = 1
+)
+
 // Jul2012 is the July 2012 CAB Forum deadline for when CAs must stop
 // issuing certificates valid for more than 5 years.
-var Jul2012 = InclusiveDate(2012, time.July, 01)
+var Jul2012 = InclusiveDate(year2012, time.July, day1)
 
 // Apr2015 is the April 2015 CAB Forum deadline for when CAs must stop
 // issuing certificates valid for more than 39 months.
-var Apr2015 = InclusiveDate(2015, time.April, 01)
+var Apr2015 = InclusiveDate(year2015, time.April, day1)
 
-// KeyLength returns the bit size of ECDSA or RSA PublicKey
+// KeyLength returns the bit size of ECDSA or RSA PublicKey.
-func KeyLength(key interface{}) int {
+func KeyLength(key any) int {
-	if key == nil {
+	switch k := key.(type) {
+	case *ecdsa.PublicKey:
+		if k == nil {
 			return 0
 		}
-	if ecdsaKey, ok := key.(*ecdsa.PublicKey); ok {
+		return k.Curve.Params().BitSize
-		return ecdsaKey.Curve.Params().BitSize
+	case *rsa.PublicKey:
-	} else if rsaKey, ok := key.(*rsa.PublicKey); ok {
+		if k == nil {
-		return rsaKey.N.BitLen()
-	}
-
 			return 0
 		}
+		return k.N.BitLen()
+	default:
+		return 0
+	}
+}
 
 // ExpiryTime returns the time when the certificate chain is expired.
-func ExpiryTime(chain []*x509.Certificate) (notAfter time.Time) {
+func ExpiryTime(chain []*x509.Certificate) time.Time {
+	var notAfter time.Time
 	if len(chain) == 0 {
-		return
+		return notAfter
 	}
-
 	notAfter = chain[0].NotAfter
 	for _, cert := range chain {
 		if notAfter.After(cert.NotAfter) {
 			notAfter = cert.NotAfter
 		}
 	}
-	return
+	return notAfter
 }
 
 // MonthsValid returns the number of months for which a certificate is valid.
@@ -144,109 +154,109 @@ func ValidExpiry(c *x509.Certificate) bool {
 		maxMonths = 39
 	case issued.After(Jul2012):
 		maxMonths = 60
-	case issued.Before(Jul2012):
+	default:
 		maxMonths = 120
 	}
 
-	if MonthsValid(c) > maxMonths {
+	return MonthsValid(c) <= maxMonths
-		return false
 }
-	return true
+
+// SignatureString returns the TLS signature string corresponding to
+// an X509 signature algorithm.
+var signatureString = map[x509.SignatureAlgorithm]string{
+	x509.UnknownSignatureAlgorithm: "Unknown Signature",
+	x509.MD2WithRSA:                "MD2WithRSA",
+	x509.MD5WithRSA:                "MD5WithRSA",
+	x509.SHA1WithRSA:               "SHA1WithRSA",
+	x509.SHA256WithRSA:             "SHA256WithRSA",
+	x509.SHA384WithRSA:             "SHA384WithRSA",
+	x509.SHA512WithRSA:             "SHA512WithRSA",
+	x509.SHA256WithRSAPSS:          "SHA256WithRSAPSS",
+	x509.SHA384WithRSAPSS:          "SHA384WithRSAPSS",
+	x509.SHA512WithRSAPSS:          "SHA512WithRSAPSS",
+	x509.DSAWithSHA1:               "DSAWithSHA1",
+	x509.DSAWithSHA256:             "DSAWithSHA256",
+	x509.ECDSAWithSHA1:             "ECDSAWithSHA1",
+	x509.ECDSAWithSHA256:           "ECDSAWithSHA256",
+	x509.ECDSAWithSHA384:           "ECDSAWithSHA384",
+	x509.ECDSAWithSHA512:           "ECDSAWithSHA512",
+	x509.PureEd25519:               "PureEd25519",
 }
 
 // SignatureString returns the TLS signature string corresponding to
 // an X509 signature algorithm.
 func SignatureString(alg x509.SignatureAlgorithm) string {
-	switch alg {
+	if s, ok := signatureString[alg]; ok {
-	case x509.MD2WithRSA:
+		return s
-		return "MD2WithRSA"
+	}
-	case x509.MD5WithRSA:
-		return "MD5WithRSA"
-	case x509.SHA1WithRSA:
-		return "SHA1WithRSA"
-	case x509.SHA256WithRSA:
-		return "SHA256WithRSA"
-	case x509.SHA384WithRSA:
-		return "SHA384WithRSA"
-	case x509.SHA512WithRSA:
-		return "SHA512WithRSA"
-	case x509.DSAWithSHA1:
-		return "DSAWithSHA1"
-	case x509.DSAWithSHA256:
-		return "DSAWithSHA256"
-	case x509.ECDSAWithSHA1:
-		return "ECDSAWithSHA1"
-	case x509.ECDSAWithSHA256:
-		return "ECDSAWithSHA256"
-	case x509.ECDSAWithSHA384:
-		return "ECDSAWithSHA384"
-	case x509.ECDSAWithSHA512:
-		return "ECDSAWithSHA512"
-	default:
 	return "Unknown Signature"
 }
+
+// HashAlgoString returns the hash algorithm name contains in the signature
+// method.
+var hashAlgoString = map[x509.SignatureAlgorithm]string{
+	x509.UnknownSignatureAlgorithm: "Unknown Hash Algorithm",
+	x509.MD2WithRSA:                "MD2",
+	x509.MD5WithRSA:                "MD5",
+	x509.SHA1WithRSA:               "SHA1",
+	x509.SHA256WithRSA:             "SHA256",
+	x509.SHA384WithRSA:             "SHA384",
+	x509.SHA512WithRSA:             "SHA512",
+	x509.SHA256WithRSAPSS:          "SHA256",
+	x509.SHA384WithRSAPSS:          "SHA384",
+	x509.SHA512WithRSAPSS:          "SHA512",
+	x509.DSAWithSHA1:               "SHA1",
+	x509.DSAWithSHA256:             "SHA256",
+	x509.ECDSAWithSHA1:             "SHA1",
+	x509.ECDSAWithSHA256:           "SHA256",
+	x509.ECDSAWithSHA384:           "SHA384",
+	x509.ECDSAWithSHA512:           "SHA512",
+	x509.PureEd25519:               "SHA512", // per x509 docs Ed25519 uses SHA-512 internally
 }
 
 // HashAlgoString returns the hash algorithm name contains in the signature
 // method.
 func HashAlgoString(alg x509.SignatureAlgorithm) string {
-	switch alg {
+	if s, ok := hashAlgoString[alg]; ok {
-	case x509.MD2WithRSA:
+		return s
-		return "MD2"
-	case x509.MD5WithRSA:
-		return "MD5"
-	case x509.SHA1WithRSA:
-		return "SHA1"
-	case x509.SHA256WithRSA:
-		return "SHA256"
-	case x509.SHA384WithRSA:
-		return "SHA384"
-	case x509.SHA512WithRSA:
-		return "SHA512"
-	case x509.DSAWithSHA1:
-		return "SHA1"
-	case x509.DSAWithSHA256:
-		return "SHA256"
-	case x509.ECDSAWithSHA1:
-		return "SHA1"
-	case x509.ECDSAWithSHA256:
-		return "SHA256"
-	case x509.ECDSAWithSHA384:
-		return "SHA384"
-	case x509.ECDSAWithSHA512:
-		return "SHA512"
-	default:
-		return "Unknown Hash Algorithm"
 	}
+	return "Unknown Hash Algorithm"
 }
 
 // StringTLSVersion returns underlying enum values from human names for TLS
-// versions, defaults to current golang default of TLS 1.0
+// versions, defaults to current golang default of TLS 1.0.
 func StringTLSVersion(version string) uint16 {
 	switch version {
+	case "1.3":
+		return tls.VersionTLS13
 	case "1.2":
 		return tls.VersionTLS12
 	case "1.1":
 		return tls.VersionTLS11
+	case "1.0":
+		return tls.VersionTLS10
 	default:
+		// Default to Go's historical default of TLS 1.0 for unknown values
 		return tls.VersionTLS10
 	}
 }
 
-// EncodeCertificatesPEM encodes a number of x509 certificates to PEM
+// EncodeCertificatesPEM encodes a number of x509 certificates to PEM.
 func EncodeCertificatesPEM(certs []*x509.Certificate) []byte {
 	var buffer bytes.Buffer
 	for _, cert := range certs {
-		pem.Encode(&buffer, &pem.Block{
+		if err := pem.Encode(&buffer, &pem.Block{
 			Type:  "CERTIFICATE",
 			Bytes: cert.Raw,
-		})
+		}); err != nil {
+			return nil
+		}
 	}
 
 	return buffer.Bytes()
 }
 
-// EncodeCertificatePEM encodes a single x509 certificates to PEM
+// EncodeCertificatePEM encodes a single x509 certificates to PEM.
 func EncodeCertificatePEM(cert *x509.Certificate) []byte {
 	return EncodeCertificatesPEM([]*x509.Certificate{cert})
 }
@@ -269,38 +279,52 @@ func ParseCertificatesPEM(certsPEM []byte) ([]*x509.Certificate, error) {
 		certs = append(certs, cert...)
 	}
 	if len(certsPEM) > 0 {
-		return nil, certerr.DecodeError(certerr.ErrorSourceCertificate, errors.New("trailing data at end of certificate"))
+		return nil, certerr.DecodeError(
+			certerr.ErrorSourceCertificate,
+			errors.New("trailing data at end of certificate"),
+		)
 	}
 	return certs, nil
 }
 
 // ParseCertificatesDER parses a DER encoding of a certificate object and possibly private key,
 // either PKCS #7, PKCS #12, or raw x509.
-func ParseCertificatesDER(certsDER []byte, password string) (certs []*x509.Certificate, key crypto.Signer, err error) {
+func ParseCertificatesDER(certsDER []byte, password string) ([]*x509.Certificate, crypto.Signer, error) {
 	certsDER = bytes.TrimSpace(certsDER)
-	pkcs7data, err := pkcs7.ParsePKCS7(certsDER)
+
-	if err != nil {
+	// First, try PKCS #7
-		var pkcs12data interface{}
+	if pkcs7data, err7 := pkcs7.ParsePKCS7(certsDER); err7 == nil {
-		certs = make([]*x509.Certificate, 1)
+		if pkcs7data.ContentInfo != "SignedData" {
-		pkcs12data, certs[0], err = pkcs12.Decode(certsDER, password)
+			return nil, nil, certerr.DecodeError(
-		if err != nil {
+				certerr.ErrorSourceCertificate,
-			certs, err = x509.ParseCertificates(certsDER)
+				errors.New("can only extract certificates from signed data content info"),
+			)
+		}
+		certs := pkcs7data.Content.SignedData.Certificates
+		if certs == nil {
+			return nil, nil, certerr.DecodeError(certerr.ErrorSourceCertificate, errors.New("no certificates decoded"))
+		}
+		return certs, nil, nil
+	}
+
+	// Next, try PKCS #12
+	if pkcs12data, cert, err12 := pkcs12.Decode(certsDER, password); err12 == nil {
+		signer, ok := pkcs12data.(crypto.Signer)
+		if !ok {
+			return nil, nil, certerr.DecodeError(
+				certerr.ErrorSourcePrivateKey,
+				errors.New("PKCS12 data does not contain a private key"),
+			)
+		}
+		return []*x509.Certificate{cert}, signer, nil
+	}
+
+	// Finally, attempt to parse raw X.509 certificates
+	certs, err := x509.ParseCertificates(certsDER)
 	if err != nil {
 		return nil, nil, certerr.DecodeError(certerr.ErrorSourceCertificate, err)
 	}
-		} else {
+	return certs, nil, nil
-			key = pkcs12data.(crypto.Signer)
-		}
-	} else {
-		if pkcs7data.ContentInfo != "SignedData" {
-			return nil, nil, certerr.DecodeError(certerr.ErrorSourceCertificate, errors.New("can only extract certificates from signed data content info"))
-		}
-		certs = pkcs7data.Content.SignedData.Certificates
-	}
-	if certs == nil {
-		return nil, key, certerr.DecodeError(certerr.ErrorSourceCertificate, errors.New("no certificates decoded"))
-	}
-	return certs, key, nil
 }
 
 // ParseSelfSignedCertificatePEM parses a PEM-encoded certificate and check if it is self-signed.
@@ -310,7 +334,8 @@ func ParseSelfSignedCertificatePEM(certPEM []byte) (*x509.Certificate, error) {
 		return nil, err
 	}
 
-	if err := cert.CheckSignature(cert.SignatureAlgorithm, cert.RawTBSCertificate, cert.Signature); err != nil {
+	err = cert.CheckSignature(cert.SignatureAlgorithm, cert.RawTBSCertificate, cert.Signature)
+	if err != nil {
 		return nil, certerr.VerifyError(certerr.ErrorSourceCertificate, err)
 	}
 	return cert, nil
@@ -320,17 +345,26 @@ func ParseSelfSignedCertificatePEM(certPEM []byte) (*x509.Certificate, error) {
 // can handle PEM encoded PKCS #7 structures.
 func ParseCertificatePEM(certPEM []byte) (*x509.Certificate, error) {
 	certPEM = bytes.TrimSpace(certPEM)
-	cert, rest, err := ParseOneCertificateFromPEM(certPEM)
+	certs, rest, err := ParseOneCertificateFromPEM(certPEM)
 	if err != nil {
 		return nil, certerr.ParsingError(certerr.ErrorSourceCertificate, err)
-	} else if cert == nil {
-		return nil, certerr.DecodeError(certerr.ErrorSourceCertificate, errors.New("no certificate decoded"))
-	} else if len(rest) > 0 {
-		return nil, certerr.ParsingError(certerr.ErrorSourceCertificate, errors.New("the PEM file should contain only one object"))
-	} else if len(cert) > 1 {
-		return nil, certerr.ParsingError(certerr.ErrorSourceCertificate, errors.New("the PKCS7 object in the PEM file should contain only one certificate"))
 	}
-	return cert[0], nil
+	if certs == nil {
+		return nil, certerr.DecodeError(certerr.ErrorSourceCertificate, errors.New("no certificate decoded"))
+	}
+	if len(rest) > 0 {
+		return nil, certerr.ParsingError(
+			certerr.ErrorSourceCertificate,
+			errors.New("the PEM file should contain only one object"),
+		)
+	}
+	if len(certs) > 1 {
+		return nil, certerr.ParsingError(
+			certerr.ErrorSourceCertificate,
+			errors.New("the PKCS7 object in the PEM file should contain only one certificate"),
+		)
+	}
+	return certs[0], nil
 }
 
 // ParseOneCertificateFromPEM attempts to parse one PEM encoded certificate object,
@@ -338,7 +372,6 @@ func ParseCertificatePEM(certPEM []byte) (*x509.Certificate, error) {
 // multiple certificates, from the top of certsPEM, which itself may
 // contain multiple PEM encoded certificate objects.
 func ParseOneCertificateFromPEM(certsPEM []byte) ([]*x509.Certificate, []byte, error) {
-
 	block, rest := pem.Decode(certsPEM)
 	if block == nil {
 		return nil, rest, nil
@@ -346,8 +379,8 @@ func ParseOneCertificateFromPEM(certsPEM []byte) ([]*x509.Certificate, []byte, e
 
 	cert, err := x509.ParseCertificate(block.Bytes)
 	if err != nil {
-		pkcs7data, err := pkcs7.ParsePKCS7(block.Bytes)
+		pkcs7data, err2 := pkcs7.ParsePKCS7(block.Bytes)
-		if err != nil {
+		if err2 != nil {
 			return nil, rest, err
 		}
 		if pkcs7data.ContentInfo != "SignedData" {
@@ -366,7 +399,7 @@ func ParseOneCertificateFromPEM(certsPEM []byte) ([]*x509.Certificate, []byte, e
 // LoadPEMCertPool loads a pool of PEM certificates from file.
 func LoadPEMCertPool(certsFile string) (*x509.CertPool, error) {
 	if certsFile == "" {
-		return nil, nil
+		return nil, nil //nolint:nilnil // no CA file provided -> treat as no pool and no error
 	}
 	pemCerts, err := os.ReadFile(certsFile)
 	if err != nil {
@@ -379,12 +412,12 @@ func LoadPEMCertPool(certsFile string) (*x509.CertPool, error) {
 // PEMToCertPool concerts PEM certificates to a CertPool.
 func PEMToCertPool(pemCerts []byte) (*x509.CertPool, error) {
 	if len(pemCerts) == 0 {
-		return nil, nil
+		return nil, nil //nolint:nilnil // empty input means no pool needed
 	}
 
 	certPool := x509.NewCertPool()
 	if !certPool.AppendCertsFromPEM(pemCerts) {
-		return nil, errors.New("failed to load cert pool")
+		return nil, certerr.LoadingError(certerr.ErrorSourceCertificate, errors.New("failed to load cert pool"))
 	}
 
 	return certPool, nil
@@ -393,14 +426,14 @@ func PEMToCertPool(pemCerts []byte) (*x509.CertPool, error) {
 // ParsePrivateKeyPEM parses and returns a PEM-encoded private
 // key. The private key may be either an unencrypted PKCS#8, PKCS#1,
 // or elliptic private key.
-func ParsePrivateKeyPEM(keyPEM []byte) (key crypto.Signer, err error) {
+func ParsePrivateKeyPEM(keyPEM []byte) (crypto.Signer, error) {
 	return ParsePrivateKeyPEMWithPassword(keyPEM, nil)
 }
 
 // ParsePrivateKeyPEMWithPassword parses and returns a PEM-encoded private
 // key. The private key may be a potentially encrypted PKCS#8, PKCS#1,
 // or elliptic private key.
-func ParsePrivateKeyPEMWithPassword(keyPEM []byte, password []byte) (key crypto.Signer, err error) {
+func ParsePrivateKeyPEMWithPassword(keyPEM []byte, password []byte) (crypto.Signer, error) {
 	keyDER, err := GetKeyDERFromPEM(keyPEM, password)
 	if err != nil {
 		return nil, err
@@ -420,44 +453,49 @@ func GetKeyDERFromPEM(in []byte, password []byte) ([]byte, error) {
 			break
 		}
 	}
-	if keyDER != nil {
+	if keyDER == nil {
-		if procType, ok := keyDER.Headers["Proc-Type"]; ok {
+		return nil, certerr.DecodeError(certerr.ErrorSourcePrivateKey, errors.New("failed to decode private key"))
-			if strings.Contains(procType, "ENCRYPTED") {
+	}
+	if procType, ok := keyDER.Headers["Proc-Type"]; ok && strings.Contains(procType, "ENCRYPTED") {
 		if password != nil {
+			// nolintlint requires rationale:
+			//nolint:staticcheck // legacy RFC1423 PEM encryption supported for backward compatibility when caller supplies a password
 			return x509.DecryptPEMBlock(keyDER, password)
 		}
 		return nil, certerr.DecodeError(certerr.ErrorSourcePrivateKey, certerr.ErrEncryptedPrivateKey)
 	}
-		}
 	return keyDER.Bytes, nil
 }
 
-	return nil, certerr.DecodeError(certerr.ErrorSourcePrivateKey, errors.New("failed to decode private key"))
-}
-
 // ParseCSR parses a PEM- or DER-encoded PKCS #10 certificate signing request.
-func ParseCSR(in []byte) (csr *x509.CertificateRequest, rest []byte, err error) {
+func ParseCSR(in []byte) (*x509.CertificateRequest, []byte, error) {
 	in = bytes.TrimSpace(in)
 	p, rest := pem.Decode(in)
-	if p != nil {
+	if p == nil {
+		csr, err := x509.ParseCertificateRequest(in)
+		if err != nil {
+			return nil, rest, certerr.ParsingError(certerr.ErrorSourceCSR, err)
+		}
+		if sigErr := csr.CheckSignature(); sigErr != nil {
+			return nil, rest, certerr.VerifyError(certerr.ErrorSourceCSR, sigErr)
+		}
+		return csr, rest, nil
+	}
+
 	if p.Type != "NEW CERTIFICATE REQUEST" && p.Type != "CERTIFICATE REQUEST" {
-			return nil, rest, certerr.ParsingError(certerr.ErrorSourceCSR, certerr.ErrInvalidPEMType(p.Type, "NEW CERTIFICATE REQUEST", "CERTIFICATE REQUEST"))
+		return nil, rest, certerr.ParsingError(
-		}
+			certerr.ErrorSourceCSR,
-
+			certerr.ErrInvalidPEMType(p.Type, "NEW CERTIFICATE REQUEST", "CERTIFICATE REQUEST"),
-		csr, err = x509.ParseCertificateRequest(p.Bytes)
+		)
-	} else {
-		csr, err = x509.ParseCertificateRequest(in)
 	}
 
+	csr, err := x509.ParseCertificateRequest(p.Bytes)
 	if err != nil {
-		return nil, rest, err
+		return nil, rest, certerr.ParsingError(certerr.ErrorSourceCSR, err)
 	}
-
+	if sigErr := csr.CheckSignature(); sigErr != nil {
-	err = csr.CheckSignature()
+		return nil, rest, certerr.VerifyError(certerr.ErrorSourceCSR, sigErr)
-	if err != nil {
-		return nil, rest, err
 	}
-
 	return csr, rest, nil
 }
 
@@ -465,14 +503,14 @@ func ParseCSR(in []byte) (csr *x509.CertificateRequest, rest []byte, err error)
 // It does not check the signature. This is useful for dumping data from a CSR
 // locally.
 func ParseCSRPEM(csrPEM []byte) (*x509.CertificateRequest, error) {
-	block, _ := pem.Decode([]byte(csrPEM))
+	block, _ := pem.Decode(csrPEM)
 	if block == nil {
 		return nil, certerr.DecodeError(certerr.ErrorSourceCSR, errors.New("PEM block is empty"))
 	}
 	csrObject, err := x509.ParseCertificateRequest(block.Bytes)
 
 	if err != nil {
-		return nil, err
+		return nil, certerr.ParsingError(certerr.ErrorSourceCSR, err)
 	}
 
 	return csrObject, nil
@@ -480,15 +518,20 @@ func ParseCSRPEM(csrPEM []byte) (*x509.CertificateRequest, error) {
 
 // SignerAlgo returns an X.509 signature algorithm from a crypto.Signer.
 func SignerAlgo(priv crypto.Signer) x509.SignatureAlgorithm {
+	const (
+		rsaBits2048 = 2048
+		rsaBits3072 = 3072
+		rsaBits4096 = 4096
+	)
 	switch pub := priv.Public().(type) {
 	case *rsa.PublicKey:
 		bitLength := pub.N.BitLen()
 		switch {
-		case bitLength >= 4096:
+		case bitLength >= rsaBits4096:
 			return x509.SHA512WithRSA
-		case bitLength >= 3072:
+		case bitLength >= rsaBits3072:
 			return x509.SHA384WithRSA
-		case bitLength >= 2048:
+		case bitLength >= rsaBits2048:
 			return x509.SHA256WithRSA
 		default:
 			return x509.SHA1WithRSA
@@ -509,7 +552,7 @@ func SignerAlgo(priv crypto.Signer) x509.SignatureAlgorithm {
 	}
 }
 
-// LoadClientCertificate load key/certificate from pem files
+// LoadClientCertificate load key/certificate from pem files.
 func LoadClientCertificate(certFile string, keyFile string) (*tls.Certificate, error) {
 	if certFile != "" && keyFile != "" {
 		cert, err := tls.LoadX509KeyPair(certFile, keyFile)
@@ -518,10 +561,10 @@ func LoadClientCertificate(certFile string, keyFile string) (*tls.Certificate, e
 		}
 		return &cert, nil
 	}
-	return nil, nil
+	return nil, nil //nolint:nilnil // absence of client cert is not an error
 }
 
-// CreateTLSConfig creates a tls.Config object from certs and roots
+// CreateTLSConfig creates a tls.Config object from certs and roots.
 func CreateTLSConfig(remoteCAs *x509.CertPool, cert *tls.Certificate) *tls.Config {
 	var certs []tls.Certificate
 	if cert != nil {
@@ -530,6 +573,7 @@ func CreateTLSConfig(remoteCAs *x509.CertPool, cert *tls.Certificate) *tls.Confi
 	return &tls.Config{
 		Certificates: certs,
 		RootCAs:      remoteCAs,
+		MinVersion:   tls.VersionTLS12, // secure default
 	}
 }
 
@@ -554,18 +598,24 @@ func DeserializeSCTList(serializedSCTList []byte) ([]ct.SignedCertificateTimesta
 		return nil, err
 	}
 	if len(rest) != 0 {
-		return nil, certerr.ParsingError(certerr.ErrorSourceSCTList, errors.New("serialized SCT list contained trailing garbage"))
+		return nil, certerr.ParsingError(
+			certerr.ErrorSourceSCTList,
+			errors.New("serialized SCT list contained trailing garbage"),
+		)
 	}
 
 	list := make([]ct.SignedCertificateTimestamp, len(sctList.SCTList))
 	for i, serializedSCT := range sctList.SCTList {
 		var sct ct.SignedCertificateTimestamp
-		rest, err := cttls.Unmarshal(serializedSCT.Val, &sct)
+		rest2, err2 := cttls.Unmarshal(serializedSCT.Val, &sct)
-		if err != nil {
+		if err2 != nil {
-			return nil, err
+			return nil, err2
 		}
-		if len(rest) != 0 {
+		if len(rest2) != 0 {
-			return nil, certerr.ParsingError(certerr.ErrorSourceSCTList, errors.New("serialized SCT list contained trailing garbage"))
+			return nil, certerr.ParsingError(
+				certerr.ErrorSourceSCTList,
+				errors.New("serialized SCT list contained trailing garbage"),
+			)
 		}
 		list[i] = sct
 	}
@@ -577,12 +627,12 @@ func DeserializeSCTList(serializedSCTList []byte) ([]ct.SignedCertificateTimesta
 // unmarshalled.
 func SCTListFromOCSPResponse(response *ocsp.Response) ([]ct.SignedCertificateTimestamp, error) {
 	// This loop finds the SCTListExtension in the OCSP response.
-	var SCTListExtension, ext pkix.Extension
+	var sctListExtension, ext pkix.Extension
 	for _, ext = range response.Extensions {
 		// sctExtOid is the ObjectIdentifier of a Signed Certificate Timestamp.
 		sctExtOid := asn1.ObjectIdentifier{1, 3, 6, 1, 4, 1, 11129, 2, 4, 5}
 		if ext.Id.Equal(sctExtOid) {
-			SCTListExtension = ext
+			sctListExtension = ext
 			break
 		}
 	}
@@ -590,10 +640,10 @@ func SCTListFromOCSPResponse(response *ocsp.Response) ([]ct.SignedCertificateTim
 	// This code block extracts the sctList from the SCT extension.
 	var sctList []ct.SignedCertificateTimestamp
 	var err error
-	if numBytes := len(SCTListExtension.Value); numBytes != 0 {
+	if numBytes := len(sctListExtension.Value); numBytes != 0 {
 		var serializedSCTList []byte
 		rest := make([]byte, numBytes)
-		copy(rest, SCTListExtension.Value)
+		copy(rest, sctListExtension.Value)
 		for len(rest) != 0 {
 			rest, err = asn1.Unmarshal(rest, &serializedSCTList)
 			if err != nil {
@@ -611,20 +661,16 @@ func SCTListFromOCSPResponse(response *ocsp.Response) ([]ct.SignedCertificateTim
 // the subsequent file. If no prefix is provided, valFile is assumed to be a
 // file path.
 func ReadBytes(valFile string) ([]byte, error) {
-	switch splitVal := strings.SplitN(valFile, ":", 2); len(splitVal) {
+	prefix, rest, found := strings.Cut(valFile, ":")
-	case 1:
+	if !found {
 		return os.ReadFile(valFile)
-	case 2:
+	}
-		switch splitVal[0] {
+	switch prefix {
 	case "env":
-			return []byte(os.Getenv(splitVal[1])), nil
+		return []byte(os.Getenv(rest)), nil
 	case "file":
-			return os.ReadFile(splitVal[1])
+		return os.ReadFile(rest)
 	default:
-			return nil, fmt.Errorf("unknown prefix: %s", splitVal[0])
+		return nil, fmt.Errorf("unknown prefix: %s", prefix)
-		}
-	default:
-		return nil, fmt.Errorf("multiple prefixes: %s",
-			strings.Join(splitVal[:len(splitVal)-1], ", "))
 	}
 }

certlib/hosts/hosts.go

@@ -0,0 +1,84 @@
+package hosts
+
+import (
+	"errors"
+	"fmt"
+	"net"
+	"net/url"
+	"strconv"
+	"strings"
+)
+
+const defaultHTTPSPort = 443
+
+type Target struct {
+	Host string
+	Port int
+}
+
+func (t *Target) String() string {
+	return fmt.Sprintf("%s:%d", t.Host, t.Port)
+}
+
+func parseURL(host string) (string, int, error) {
+	url, err := url.Parse(host)
+	if err != nil {
+		return "", 0, fmt.Errorf("certlib/hosts: invalid host: %s", host)
+	}
+
+	if strings.ToLower(url.Scheme) != "https" {
+		return "", 0, errors.New("certlib/hosts: only https scheme supported")
+	}
+
+	if url.Port() == "" {
+		return url.Hostname(), defaultHTTPSPort, nil
+	}
+
+	portInt, err2 := strconv.ParseInt(url.Port(), 10, 16)
+	if err2 != nil {
+		return "", 0, fmt.Errorf("certlib/hosts: invalid port: %s", url.Port())
+	}
+
+	return url.Hostname(), int(portInt), nil
+}
+
+func parseHostPort(host string) (string, int, error) {
+	host, sport, err := net.SplitHostPort(host)
+	if err == nil {
+		portInt, err2 := strconv.ParseInt(sport, 10, 16)
+		if err2 != nil {
+			return "", 0, fmt.Errorf("certlib/hosts: invalid port: %s", sport)
+		}
+
+		return host, int(portInt), nil
+	}
+
+	return host, defaultHTTPSPort, nil
+}
+
+func ParseHost(host string) (*Target, error) {
+	host, port, err := parseURL(host)
+	if err == nil {
+		return &Target{Host: host, Port: port}, nil
+	}
+
+	host, port, err = parseHostPort(host)
+	if err == nil {
+		return &Target{Host: host, Port: port}, nil
+	}
+
+	return nil, fmt.Errorf("certlib/hosts: invalid host: %s", host)
+}
+
+func ParseHosts(hosts ...string) ([]*Target, error) {
+	targets := make([]*Target, 0, len(hosts))
+	for _, host := range hosts {
+		target, err := ParseHost(host)
+		if err != nil {
+			return nil, err
+		}
+		targets = append(targets, target)
+	}
+
+	return targets, nil
+}

certlib/pkcs7/pkcs7.go

@@ -93,7 +93,7 @@ type signedData struct {
 	Version          int
 	DigestAlgorithms asn1.RawValue
 	ContentInfo      asn1.RawValue
-	Certificates     asn1.RawValue `asn1:"optional" asn1:"tag:0"`
+	Certificates     asn1.RawValue `asn1:"optional"`
 	Crls             asn1.RawValue `asn1:"optional"`
 	SignerInfos      asn1.RawValue
 }
@@ -158,63 +158,95 @@ type EncryptedContentInfo struct {
 	EncryptedContent           []byte `asn1:"tag:0,optional"`
 }
 
+func unmarshalInit(raw []byte) (initPKCS7, error) {
+	var init initPKCS7
+	if _, err := asn1.Unmarshal(raw, &init); err != nil {
+		return initPKCS7{}, certerr.ParsingError(certerr.ErrorSourceCertificate, err)
+	}
+	return init, nil
+}
+
+func populateData(msg *PKCS7, content asn1.RawValue) error {
+	msg.ContentInfo = "Data"
+	_, err := asn1.Unmarshal(content.Bytes, &msg.Content.Data)
+	if err != nil {
+		return certerr.ParsingError(certerr.ErrorSourceCertificate, err)
+	}
+	return nil
+}
+
+func populateSignedData(msg *PKCS7, contentBytes []byte) error {
+	msg.ContentInfo = "SignedData"
+	var sd signedData
+	if _, err := asn1.Unmarshal(contentBytes, &sd); err != nil {
+		return certerr.ParsingError(certerr.ErrorSourceCertificate, err)
+	}
+	if len(sd.Certificates.Bytes) != 0 {
+		certs, err := x509.ParseCertificates(sd.Certificates.Bytes)
+		if err != nil {
+			return certerr.ParsingError(certerr.ErrorSourceCertificate, err)
+		}
+		msg.Content.SignedData.Certificates = certs
+	}
+	if len(sd.Crls.Bytes) != 0 {
+		crl, err := x509.ParseRevocationList(sd.Crls.Bytes)
+		if err != nil {
+			return certerr.ParsingError(certerr.ErrorSourceCertificate, err)
+		}
+		msg.Content.SignedData.Crl = crl
+	}
+	msg.Content.SignedData.Version = sd.Version
+	msg.Content.SignedData.Raw = contentBytes
+	return nil
+}
+
+func populateEncryptedData(msg *PKCS7, contentBytes []byte) error {
+	msg.ContentInfo = "EncryptedData"
+	var ed EncryptedData
+	if _, err := asn1.Unmarshal(contentBytes, &ed); err != nil {
+		return certerr.ParsingError(certerr.ErrorSourceCertificate, err)
+	}
+	if ed.Version != 0 {
+		return certerr.ParsingError(
+			certerr.ErrorSourceCertificate,
+			errors.New("only PKCS #7 encryptedData version 0 is supported"),
+		)
+	}
+	msg.Content.EncryptedData = ed
+	return nil
+}
+
 // ParsePKCS7 attempts to parse the DER encoded bytes of a
 // PKCS7 structure.
-func ParsePKCS7(raw []byte) (msg *PKCS7, err error) {
+func ParsePKCS7(raw []byte) (*PKCS7, error) {
-
+	pkcs7, err := unmarshalInit(raw)
-	var pkcs7 initPKCS7
-	_, err = asn1.Unmarshal(raw, &pkcs7)
 	if err != nil {
-		return nil, certerr.ParsingError(certerr.ErrorSourceCertificate, err)
+		return nil, err
 	}
 
-	msg = new(PKCS7)
+	msg := new(PKCS7)
 	msg.Raw = pkcs7.Raw
 	msg.ContentInfo = pkcs7.ContentType.String()
-	switch {
-	case msg.ContentInfo == ObjIDData:
-		msg.ContentInfo = "Data"
-		_, err = asn1.Unmarshal(pkcs7.Content.Bytes, &msg.Content.Data)
-		if err != nil {
-			return nil, certerr.ParsingError(certerr.ErrorSourceCertificate, err)
-		}
-	case msg.ContentInfo == ObjIDSignedData:
-		msg.ContentInfo = "SignedData"
-		var signedData signedData
-		_, err = asn1.Unmarshal(pkcs7.Content.Bytes, &signedData)
-		if err != nil {
-			return nil, certerr.ParsingError(certerr.ErrorSourceCertificate, err)
-		}
-		if len(signedData.Certificates.Bytes) != 0 {
-			msg.Content.SignedData.Certificates, err = x509.ParseCertificates(signedData.Certificates.Bytes)
-			if err != nil {
-				return nil, certerr.ParsingError(certerr.ErrorSourceCertificate, err)
-			}
-		}
-		if len(signedData.Crls.Bytes) != 0 {
-			msg.Content.SignedData.Crl, err = x509.ParseRevocationList(signedData.Crls.Bytes)
-			if err != nil {
-				return nil, certerr.ParsingError(certerr.ErrorSourceCertificate, err)
-			}
-		}
-		msg.Content.SignedData.Version = signedData.Version
-		msg.Content.SignedData.Raw = pkcs7.Content.Bytes
-	case msg.ContentInfo == ObjIDEncryptedData:
-		msg.ContentInfo = "EncryptedData"
-		var encryptedData EncryptedData
-		_, err = asn1.Unmarshal(pkcs7.Content.Bytes, &encryptedData)
-		if err != nil {
-			return nil, certerr.ParsingError(certerr.ErrorSourceCertificate, err)
-		}
-		if encryptedData.Version != 0 {
-			return nil, certerr.ParsingError(certerr.ErrorSourceCertificate, errors.New("only PKCS #7 encryptedData version 0 is supported"))
-		}
-		msg.Content.EncryptedData = encryptedData
 
+	switch msg.ContentInfo {
+	case ObjIDData:
+		if e := populateData(msg, pkcs7.Content); e != nil {
+			return nil, e
+		}
+	case ObjIDSignedData:
+		if e := populateSignedData(msg, pkcs7.Content.Bytes); e != nil {
+			return nil, e
+		}
+	case ObjIDEncryptedData:
+		if e := populateEncryptedData(msg, pkcs7.Content.Bytes); e != nil {
+			return nil, e
+		}
 	default:
-		return nil, certerr.ParsingError(certerr.ErrorSourceCertificate, errors.New("only PKCS# 7 content of type data, signed data or encrypted data can be parsed"))
+		return nil, certerr.ParsingError(
+			certerr.ErrorSourceCertificate,
+			errors.New("only PKCS# 7 content of type data, signed data or encrypted data can be parsed"),
+		)
 	}
 
 	return msg, nil
-
 }

certlib/revoke/revoke.go

@@ -5,6 +5,7 @@ package revoke
 
 import (
 	"bytes"
+	"context"
 	"crypto"
 	"crypto/x509"
 	"encoding/base64"
@@ -89,35 +90,35 @@ func ldapURL(url string) bool {
 // - false, false: an error was encountered while checking revocations.
 // - false, true:  the certificate was checked successfully, and it is not revoked.
 // - true, true:   the certificate was checked successfully, and it is revoked.
-// - true, false:  failure to check revocation status causes verification to fail
+// - true, false:  failure to check revocation status causes verification to fail.
-func revCheck(cert *x509.Certificate) (revoked, ok bool, err error) {
+func revCheck(cert *x509.Certificate) (bool, bool, error) {
 	for _, url := range cert.CRLDistributionPoints {
 		if ldapURL(url) {
 			log.Infof("skipping LDAP CRL: %s", url)
 			continue
 		}
 
-		if revoked, ok, err := certIsRevokedCRL(cert, url); !ok {
+		if rvk, ok2, err2 := certIsRevokedCRL(cert, url); !ok2 {
 			log.Warning("error checking revocation via CRL")
 			if HardFail {
-				return true, false, err
+				return true, false, err2
 			}
-			return false, false, err
+			return false, false, err2
-		} else if revoked {
+		} else if rvk {
 			log.Info("certificate is revoked via CRL")
-			return true, true, err
+			return true, true, err2
 		}
 	}
 
-	if revoked, ok, err := certIsRevokedOCSP(cert, HardFail); !ok {
+	if rvk, ok2, err2 := certIsRevokedOCSP(cert, HardFail); !ok2 {
 		log.Warning("error checking revocation via OCSP")
 		if HardFail {
-			return true, false, err
+			return true, false, err2
 		}
-		return false, false, err
+		return false, false, err2
-	} else if revoked {
+	} else if rvk {
 		log.Info("certificate is revoked via OCSP")
-		return true, true, err
+		return true, true, err2
 	}
 
 	return false, true, nil
@@ -125,13 +126,17 @@ func revCheck(cert *x509.Certificate) (revoked, ok bool, err error) {
 
 // fetchCRL fetches and parses a CRL.
 func fetchCRL(url string) (*x509.RevocationList, error) {
-	resp, err := HTTPClient.Get(url)
+	req, err := http.NewRequestWithContext(context.Background(), http.MethodGet, url, nil)
+	if err != nil {
+		return nil, err
+	}
+	resp, err := HTTPClient.Do(req)
 	if err != nil {
 		return nil, err
 	}
 	defer resp.Body.Close()
 
-	if resp.StatusCode >= 300 {
+	if resp.StatusCode >= http.StatusMultipleChoices {
 		return nil, errors.New("failed to retrieve CRL")
 	}
 
@@ -154,12 +159,11 @@ func getIssuer(cert *x509.Certificate) *x509.Certificate {
 	}
 
 	return issuer
-
 }
 
 // check a cert against a specific CRL. Returns the same bool pair
 // as revCheck, plus an error if one occurred.
-func certIsRevokedCRL(cert *x509.Certificate, url string) (revoked, ok bool, err error) {
+func certIsRevokedCRL(cert *x509.Certificate, url string) (bool, bool, error) {
 	crlLock.Lock()
 	crl, ok := CRLSet[url]
 	if ok && crl == nil {
@@ -187,10 +191,9 @@ func certIsRevokedCRL(cert *x509.Certificate, url string) (revoked, ok bool, err
 
 		// check CRL signature
 		if issuer != nil {
-			err = crl.CheckSignatureFrom(issuer)
+			if sigErr := crl.CheckSignatureFrom(issuer); sigErr != nil {
-			if err != nil {
+				log.Warningf("failed to verify CRL: %v", sigErr)
-				log.Warningf("failed to verify CRL: %v", err)
+				return false, false, sigErr
-				return false, false, err
 			}
 		}
 
@@ -199,40 +202,44 @@ func certIsRevokedCRL(cert *x509.Certificate, url string) (revoked, ok bool, err
 		crlLock.Unlock()
 	}
 
-	for _, revoked := range crl.RevokedCertificates {
+	for _, entry := range crl.RevokedCertificateEntries {
-		if cert.SerialNumber.Cmp(revoked.SerialNumber) == 0 {
+		if cert.SerialNumber.Cmp(entry.SerialNumber) == 0 {
 			log.Info("Serial number match: intermediate is revoked.")
-			return true, true, err
+			return true, true, nil
 		}
 	}
 
-	return false, true, err
+	return false, true, nil
 }
 
 // VerifyCertificate ensures that the certificate passed in hasn't
 // expired and checks the CRL for the server.
-func VerifyCertificate(cert *x509.Certificate) (revoked, ok bool) {
+func VerifyCertificate(cert *x509.Certificate) (bool, bool) {
-	revoked, ok, _ = VerifyCertificateError(cert)
+	revoked, ok, _ := VerifyCertificateError(cert)
 	return revoked, ok
 }
 
 // VerifyCertificateError ensures that the certificate passed in hasn't
 // expired and checks the CRL for the server.
-func VerifyCertificateError(cert *x509.Certificate) (revoked, ok bool, err error) {
+func VerifyCertificateError(cert *x509.Certificate) (bool, bool, error) {
 	if !time.Now().Before(cert.NotAfter) {
 		msg := fmt.Sprintf("Certificate expired %s\n", cert.NotAfter)
 		log.Info(msg)
-		return true, true, fmt.Errorf(msg)
+		return true, true, errors.New(msg)
 	} else if !time.Now().After(cert.NotBefore) {
 		msg := fmt.Sprintf("Certificate isn't valid until %s\n", cert.NotBefore)
 		log.Info(msg)
-		return true, true, fmt.Errorf(msg)
+		return true, true, errors.New(msg)
 	}
 	return revCheck(cert)
 }
 
 func fetchRemote(url string) (*x509.Certificate, error) {
-	resp, err := HTTPClient.Get(url)
+	req, err := http.NewRequestWithContext(context.Background(), http.MethodGet, url, nil)
+	if err != nil {
+		return nil, err
+	}
+	resp, err := HTTPClient.Do(req)
 	if err != nil {
 		return nil, err
 	}
@@ -255,8 +262,12 @@ var ocspOpts = ocsp.RequestOptions{
 	Hash: crypto.SHA1,
 }
 
-func certIsRevokedOCSP(leaf *x509.Certificate, strict bool) (revoked, ok bool, e error) {
+const ocspGetURLMaxLen = 256
-	var err error
+
+func certIsRevokedOCSP(leaf *x509.Certificate, strict bool) (bool, bool, error) {
+	var revoked bool
+	var ok bool
+	var lastErr error
 
 	ocspURLs := leaf.OCSPServer
 	if len(ocspURLs) == 0 {
@@ -272,15 +283,16 @@ func certIsRevokedOCSP(leaf *x509.Certificate, strict bool) (revoked, ok bool, e
 
 	ocspRequest, err := ocsp.CreateRequest(leaf, issuer, &ocspOpts)
 	if err != nil {
-		return revoked, ok, err
+		return false, false, err
 	}
 
 	for _, server := range ocspURLs {
-		resp, err := sendOCSPRequest(server, ocspRequest, leaf, issuer)
+		resp, e := sendOCSPRequest(server, ocspRequest, leaf, issuer)
-		if err != nil {
+		if e != nil {
 			if strict {
-				return revoked, ok, err
+				return false, false, e
 			}
+			lastErr = e
 			continue
 		}
 
@@ -292,9 +304,9 @@ func certIsRevokedOCSP(leaf *x509.Certificate, strict bool) (revoked, ok bool, e
 			revoked = true
 		}
 
-		return revoked, ok, err
+		return revoked, ok, nil
 	}
-	return revoked, ok, err
+	return revoked, ok, lastErr
 }
 
 // sendOCSPRequest attempts to request an OCSP response from the
@@ -303,12 +315,21 @@ func certIsRevokedOCSP(leaf *x509.Certificate, strict bool) (revoked, ok bool, e
 func sendOCSPRequest(server string, req []byte, leaf, issuer *x509.Certificate) (*ocsp.Response, error) {
 	var resp *http.Response
 	var err error
-	if len(req) > 256 {
+	if len(req) > ocspGetURLMaxLen {
 		buf := bytes.NewBuffer(req)
-		resp, err = HTTPClient.Post(server, "application/ocsp-request", buf)
+		httpReq, e := http.NewRequestWithContext(context.Background(), http.MethodPost, server, buf)
+		if e != nil {
+			return nil, e
+		}
+		httpReq.Header.Set("Content-Type", "application/ocsp-request")
+		resp, err = HTTPClient.Do(httpReq)
 	} else {
 		reqURL := server + "/" + neturl.QueryEscape(base64.StdEncoding.EncodeToString(req))
-		resp, err = HTTPClient.Get(reqURL)
+		httpReq, e := http.NewRequestWithContext(context.Background(), http.MethodGet, reqURL, nil)
+		if e != nil {
+			return nil, e
+		}
+		resp, err = HTTPClient.Do(httpReq)
 	}
 
 	if err != nil {
@@ -343,21 +364,21 @@ func sendOCSPRequest(server string, req []byte, leaf, issuer *x509.Certificate)
 
 var crlRead = io.ReadAll
 
-// SetCRLFetcher sets the function to use to read from the http response body
+// SetCRLFetcher sets the function to use to read from the http response body.
 func SetCRLFetcher(fn func(io.Reader) ([]byte, error)) {
 	crlRead = fn
 }
 
 var remoteRead = io.ReadAll
 
-// SetRemoteFetcher sets the function to use to read from the http response body
+// SetRemoteFetcher sets the function to use to read from the http response body.
 func SetRemoteFetcher(fn func(io.Reader) ([]byte, error)) {
 	remoteRead = fn
 }
 
 var ocspRead = io.ReadAll
 
-// SetOCSPFetcher sets the function to use to read from the http response body
+// SetOCSPFetcher sets the function to use to read from the http response body.
 func SetOCSPFetcher(fn func(io.Reader) ([]byte, error)) {
 	ocspRead = fn
 }

certlib/revoke/revoke_test.go

@@ -1,3 +1,4 @@
+//nolint:testpackage // keep tests in the same package for internal symbol access
 package revoke
 
 import (
@@ -50,7 +51,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 // to indicate that this is the case.
 
 // 2014/05/22 14:18:17 Certificate expired 2014-04-04 14:14:20 +0000 UTC
-// 2014/05/22 14:18:17 Revoked certificate: misc/intermediate_ca/ActalisServerAuthenticationCA.crt
+// 2014/05/22 14:18:17 Revoked certificate: misc/intermediate_ca/ActalisServerAuthenticationCA.crt.
 var expiredCert = mustParse(`-----BEGIN CERTIFICATE-----
 MIIEXTCCA8agAwIBAgIEBycURTANBgkqhkiG9w0BAQUFADB1MQswCQYDVQQGEwJV
 UzEYMBYGA1UEChMPR1RFIENvcnBvcmF0aW9uMScwJQYDVQQLEx5HVEUgQ3liZXJU
@@ -80,7 +81,7 @@ sESPRwHkcMUNdAp37FLweUw=
 
 // 2014/05/22 14:18:31 Serial number match: intermediate is revoked.
 // 2014/05/22 14:18:31 certificate is revoked via CRL
-// 2014/05/22 14:18:31 Revoked certificate: misc/intermediate_ca/MobileArmorEnterpriseCA.crt
+// 2014/05/22 14:18:31 Revoked certificate: misc/intermediate_ca/MobileArmorEnterpriseCA.crt.
 var revokedCert = mustParse(`-----BEGIN CERTIFICATE-----
 MIIEEzCCAvugAwIBAgILBAAAAAABGMGjftYwDQYJKoZIhvcNAQEFBQAwcTEoMCYG
 A1UEAxMfR2xvYmFsU2lnbiBSb290U2lnbiBQYXJ0bmVycyBDQTEdMBsGA1UECxMU
@@ -106,7 +107,7 @@ Kz5vh+5tmytUPKA8hUgmLWe94lMb7Uqq2wgZKsqun5DAWleKu81w7wEcOrjiiB+x
 jeBHq7OnpWm+ccTOPCE6H4ZN4wWVS7biEBUdop/8HgXBPQHWAdjL
 -----END CERTIFICATE-----`)
 
-// A Comodo intermediate CA certificate with issuer url, CRL url and OCSP url
+// A Comodo intermediate CA certificate with issuer url, CRL url and OCSP url.
 var goodComodoCA = (`-----BEGIN CERTIFICATE-----
 MIIGCDCCA/CgAwIBAgIQKy5u6tl1NmwUim7bo3yMBzANBgkqhkiG9w0BAQwFADCB
 hTELMAkGA1UEBhMCR0IxGzAZBgNVBAgTEkdyZWF0ZXIgTWFuY2hlc3RlcjEQMA4G
@@ -153,7 +154,7 @@ func mustParse(pemData string) *x509.Certificate {
 		panic("Invalid PEM type.")
 	}
 
-	cert, err := x509.ParseCertificate([]byte(block.Bytes))
+	cert, err := x509.ParseCertificate(block.Bytes)
 	if err != nil {
 		panic(err.Error())
 	}
@@ -182,7 +183,6 @@ func TestGood(t *testing.T) {
 	} else if revoked {
 		t.Fatalf("good certificate should not have been marked as revoked")
 	}
-
 }
 
 func TestLdap(t *testing.T) {
@@ -230,7 +230,6 @@ func TestBadCRLSet(t *testing.T) {
 		t.Fatalf("key emptystring should be deleted from CRLSet")
 	}
 	delete(CRLSet, "")
-
 }
 
 func TestCachedCRLSet(t *testing.T) {
@@ -241,13 +240,11 @@ func TestCachedCRLSet(t *testing.T) {
 }
 
 func TestRemoteFetchError(t *testing.T) {
-
 	badurl := ":"
 
 	if _, err := fetchRemote(badurl); err == nil {
 		t.Fatalf("fetching bad url should result in non-nil error")
 	}
-
 }
 
 func TestNoOCSPServers(t *testing.T) {

cmd/atping/main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"context"
 	"flag"
 	"fmt"
 	"net"
@@ -28,10 +29,16 @@ func connect(addr string, dport string, six bool, timeout time.Duration) error {
 
 	if verbose {
 		fmt.Printf("connecting to %s/%s... ", addr, proto)
-		os.Stdout.Sync()
+		if err = os.Stdout.Sync(); err != nil {
+			return err
+		}
 	}
 
-	conn, err := net.DialTimeout(proto, addr, timeout)
+	dialer := &net.Dialer{
+		Timeout: timeout,
+	}
+
+	conn, err := dialer.DialContext(context.Background(), proto, addr)
 	if err != nil {
 		if verbose {
 			fmt.Println("failed.")
@@ -42,8 +49,8 @@ func connect(addr string, dport string, six bool, timeout time.Duration) error {
 	if verbose {
 		fmt.Println("OK")
 	}
-	conn.Close()
+
-	return nil
+	return conn.Close()
 }
 
 func main() {

cmd/ca-signed/README.txt

@@ -0,0 +1,40 @@
+ca-signed: verify certificates against a CA
+-------------------------------------------
+
+Description
+  ca-signed verifies whether one or more certificates are signed by a given
+  Certificate Authority (CA). It prints a concise status per input certificate
+  along with the certificate’s expiration date when validation succeeds.
+
+Usage
+  ca-signed CA.pem cert1.pem [cert2.pem ...]
+
+  - CA.pem: A file containing one or more CA certificates in PEM, DER, or PKCS#7/PKCS#12 formats.
+  - certN.pem: A file containing the end-entity (leaf) certificate to verify. If the file contains a chain,
+               the first certificate is treated as the leaf and the remaining ones are used as intermediates.
+
+Output format
+  For each input certificate file, one line is printed:
+    <filename>: OK (expires YYYY-MM-DD)
+    <filename>: INVALID
+
+Special self-test mode
+  ca-signed selftest
+
+  Runs a built-in test suite using embedded certificates. This mode requires no
+  external files or network access. The program exits with code 0 if all tests
+  pass, or a non-zero exit code if any test fails. Example output lines include
+  whether validation succeeds and the leaf’s expiration when applicable.
+
+Examples
+  # Verify a server certificate against a root CA
+  ca-signed isrg-root-x1.pem le-e7.pem
+
+  # Run the embedded self-test suite
+  ca-signed selftest
+
+Notes
+  - The tool attempts to parse certificates in PEM first, then falls back to
+    DER/PKCS#7/PKCS#12 (with an empty password) where applicable.
+  - Expiration is shown for the leaf certificate only.
+  - In selftest mode, test certificates are compiled into the binary using go:embed.

cmd/ca-signed/main.go

@@ -0,0 +1,325 @@
+package main
+
+import (
+	"crypto/x509"
+	"embed"
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"time"
+
+	"git.wntrmute.dev/kyle/goutils/certlib"
+)
+
+// loadCertsFromFile attempts to parse certificates from a file that may be in
+// PEM or DER/PKCS#7 format. Returns the parsed certificates or an error.
+func loadCertsFromFile(path string) ([]*x509.Certificate, error) {
+	var certs []*x509.Certificate
+
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+
+	if certs, err = certlib.ParseCertificatesPEM(data); err == nil {
+		return certs, nil
+	}
+
+	if certs, _, err = certlib.ParseCertificatesDER(data, ""); err == nil {
+		return certs, nil
+	}
+
+	return nil, err
+}
+
+func makePoolFromFile(path string) (*x509.CertPool, error) {
+	// Try PEM via helper (it builds a pool)
+	if pool, err := certlib.LoadPEMCertPool(path); err == nil && pool != nil {
+		return pool, nil
+	}
+
+	// Fallback: read as DER(s), add to a new pool
+	certs, err := loadCertsFromFile(path)
+	if err != nil || len(certs) == 0 {
+		return nil, fmt.Errorf("failed to load CA certificates from %s", path)
+	}
+	pool := x509.NewCertPool()
+	for _, c := range certs {
+		pool.AddCert(c)
+	}
+	return pool, nil
+}
+
+//go:embed testdata/*.pem
+var embeddedTestdata embed.FS
+
+// loadCertsFromBytes attempts to parse certificates from bytes that may be in
+// PEM or DER/PKCS#7 format.
+func loadCertsFromBytes(data []byte) ([]*x509.Certificate, error) {
+	certs, err := certlib.ParseCertificatesPEM(data)
+	if err == nil {
+		return certs, nil
+	}
+
+	certs, _, err = certlib.ParseCertificatesDER(data, "")
+	if err == nil {
+		return certs, nil
+	}
+
+	return nil, err
+}
+
+func makePoolFromBytes(data []byte) (*x509.CertPool, error) {
+	certs, err := loadCertsFromBytes(data)
+	if err != nil || len(certs) == 0 {
+		return nil, errors.New("failed to load CA certificates from embedded bytes")
+	}
+	pool := x509.NewCertPool()
+	for _, c := range certs {
+		pool.AddCert(c)
+	}
+	return pool, nil
+}
+
+// isSelfSigned returns true if the given certificate is self-signed.
+// It checks that the subject and issuer match and that the certificate's
+// signature verifies against its own public key.
+func isSelfSigned(cert *x509.Certificate) bool {
+	if cert == nil {
+		return false
+	}
+	// Quick check: subject and issuer match
+	if cert.Subject.String() != cert.Issuer.String() {
+		return false
+	}
+	// Cryptographic check: the certificate is signed by itself
+	if err := cert.CheckSignatureFrom(cert); err != nil {
+		return false
+	}
+	return true
+}
+
+func verifyAgainstCA(caPool *x509.CertPool, path string) (bool, string) {
+	certs, err := loadCertsFromFile(path)
+	if err != nil || len(certs) == 0 {
+		return false, ""
+	}
+
+	leaf := certs[0]
+	ints := x509.NewCertPool()
+	if len(certs) > 1 {
+		for _, ic := range certs[1:] {
+			ints.AddCert(ic)
+		}
+	}
+
+	opts := x509.VerifyOptions{
+		Roots:         caPool,
+		Intermediates: ints,
+		KeyUsages:     []x509.ExtKeyUsage{x509.ExtKeyUsageAny},
+	}
+	if _, err = leaf.Verify(opts); err != nil {
+		return false, ""
+	}
+
+	return true, leaf.NotAfter.Format("2006-01-02")
+}
+
+func verifyAgainstCABytes(caPool *x509.CertPool, certData []byte) (bool, string) {
+	certs, err := loadCertsFromBytes(certData)
+	if err != nil || len(certs) == 0 {
+		return false, ""
+	}
+
+	leaf := certs[0]
+	ints := x509.NewCertPool()
+	if len(certs) > 1 {
+		for _, ic := range certs[1:] {
+			ints.AddCert(ic)
+		}
+	}
+
+	opts := x509.VerifyOptions{
+		Roots:         caPool,
+		Intermediates: ints,
+		KeyUsages:     []x509.ExtKeyUsage{x509.ExtKeyUsageAny},
+	}
+	if _, err = leaf.Verify(opts); err != nil {
+		return false, ""
+	}
+
+	return true, leaf.NotAfter.Format("2006-01-02")
+}
+
+type testCase struct {
+	name     string
+	caFile   string
+	certFile string
+	expectOK bool
+}
+
+func (tc testCase) Run() error {
+	caBytes, err := embeddedTestdata.ReadFile(tc.caFile)
+	if err != nil {
+		return fmt.Errorf("selftest: failed to read embedded %s: %w", tc.caFile, err)
+	}
+
+	certBytes, err := embeddedTestdata.ReadFile(tc.certFile)
+	if err != nil {
+		return fmt.Errorf("selftest: failed to read embedded %s: %w", tc.certFile, err)
+	}
+
+	pool, err := makePoolFromBytes(caBytes)
+	if err != nil || pool == nil {
+		return fmt.Errorf("selftest: failed to build CA pool for %s: %w", tc.caFile, err)
+	}
+
+	ok, exp := verifyAgainstCABytes(pool, certBytes)
+	if ok != tc.expectOK {
+		return fmt.Errorf("%s: unexpected result: got %v, want %v", tc.name, ok, tc.expectOK)
+	}
+
+	if ok {
+		fmt.Printf("%s: OK (expires %s)\n", tc.name, exp)
+	}
+
+	fmt.Printf("%s: INVALID (as expected)\n", tc.name)
+
+	return nil
+}
+
+var cases = []testCase{
+	{
+		name:     "ISRG Root X1 validates LE E7",
+		caFile:   "testdata/isrg-root-x1.pem",
+		certFile: "testdata/le-e7.pem",
+		expectOK: true,
+	},
+	{
+		name:     "ISRG Root X1 does NOT validate Google WR2",
+		caFile:   "testdata/isrg-root-x1.pem",
+		certFile: "testdata/goog-wr2.pem",
+		expectOK: false,
+	},
+	{
+		name:     "GTS R1 validates Google WR2",
+		caFile:   "testdata/gts-r1.pem",
+		certFile: "testdata/goog-wr2.pem",
+		expectOK: true,
+	},
+	{
+		name:     "GTS R1 does NOT validate LE E7",
+		caFile:   "testdata/gts-r1.pem",
+		certFile: "testdata/le-e7.pem",
+		expectOK: false,
+	},
+}
+
+// selftest runs built-in validation using embedded certificates.
+func selftest() int {
+	failures := 0
+	for _, tc := range cases {
+		err := tc.Run()
+		if err != nil {
+			fmt.Fprintln(os.Stderr, err)
+			failures++
+			continue
+		}
+	}
+
+	// Verify that both embedded root CAs are detected as self-signed
+	roots := []string{"testdata/gts-r1.pem", "testdata/isrg-root-x1.pem"}
+	for _, root := range roots {
+		b, err := embeddedTestdata.ReadFile(root)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "selftest: failed to read embedded %s: %v\n", root, err)
+			failures++
+			continue
+		}
+		certs, err := loadCertsFromBytes(b)
+		if err != nil || len(certs) == 0 {
+			fmt.Fprintf(os.Stderr, "selftest: failed to parse cert(s) from %s: %v\n", root, err)
+			failures++
+			continue
+		}
+		leaf := certs[0]
+		if isSelfSigned(leaf) {
+			fmt.Printf("%s: SELF-SIGNED (as expected)\n", root)
+		} else {
+			fmt.Printf("%s: expected SELF-SIGNED, but was not detected as such\n", root)
+			failures++
+		}
+	}
+
+	if failures == 0 {
+		fmt.Println("selftest: PASS")
+		return 0
+	}
+	fmt.Fprintf(os.Stderr, "selftest: FAIL (%d failure(s))\n", failures)
+	return 1
+}
+
+// expiryString returns a YYYY-MM-DD date string to display for certificate
+// expiry. If an explicit exp string is provided, it is used. Otherwise, if a
+// leaf certificate is available, its NotAfter is formatted. As a last resort,
+// it falls back to today's date (should not normally happen).
+func expiryString(leaf *x509.Certificate, exp string) string {
+	if exp != "" {
+		return exp
+	}
+	if leaf != nil {
+		return leaf.NotAfter.Format("2006-01-02")
+	}
+	return time.Now().Format("2006-01-02")
+}
+
+// processCert verifies a single certificate file against the provided CA pool
+// and prints the result in the required format, handling self-signed
+// certificates specially.
+func processCert(caPool *x509.CertPool, certPath string) {
+	ok, exp := verifyAgainstCA(caPool, certPath)
+	name := filepath.Base(certPath)
+
+	// Try to load the leaf cert for self-signed detection and expiry fallback
+	var leaf *x509.Certificate
+	if certs, err := loadCertsFromFile(certPath); err == nil && len(certs) > 0 {
+		leaf = certs[0]
+	}
+
+	// Prefer the SELF-SIGNED label if applicable
+	if isSelfSigned(leaf) {
+		fmt.Printf("%s: SELF-SIGNED\n", name)
+		return
+	}
+
+	if ok {
+		fmt.Printf("%s: OK (expires %s)\n", name, expiryString(leaf, exp))
+		return
+	}
+	fmt.Printf("%s: INVALID\n", name)
+}
+
+func main() {
+	// Special selftest mode: single argument "selftest"
+	if len(os.Args) == 2 && os.Args[1] == "selftest" {
+		os.Exit(selftest())
+	}
+
+	if len(os.Args) < 3 {
+		prog := filepath.Base(os.Args[0])
+		fmt.Fprintf(os.Stderr, "Usage:\n  %s ca.pem cert1.pem cert2.pem ...\n  %s selftest\n", prog, prog)
+		os.Exit(2)
+	}
+
+	caPath := os.Args[1]
+	caPool, err := makePoolFromFile(caPath)
+	if err != nil || caPool == nil {
+		fmt.Fprintf(os.Stderr, "failed to load CA certificate(s): %v\n", err)
+		os.Exit(1)
+	}
+
+	for _, certPath := range os.Args[2:] {
+		processCert(caPool, certPath)
+	}
+}

cmd/ca-signed/testdata/goog-wr2.pem

@@ -0,0 +1,29 @@
+-----BEGIN CERTIFICATE-----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=
+-----END CERTIFICATE-----

cmd/ca-signed/testdata/gts-r1.pem

@@ -0,0 +1,31 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

cmd/ca-signed/testdata/isrg-root-x1.pem

@@ -0,0 +1,31 @@
+-----BEGIN CERTIFICATE-----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=
+-----END CERTIFICATE-----

cmd/ca-signed/testdata/le-e7.pem

@@ -0,0 +1,26 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

cmd/cert-bundler/README.txt

@@ -0,0 +1,148 @@
+cert-bundler: create certificate chain archives
+------------------------------------------------
+
+Description
+  cert-bundler creates archives of certificate chains from a YAML configuration
+  file. It validates certificates, checks expiration dates, and generates
+  archives in multiple formats (zip, tar.gz) with optional manifest files
+  containing SHA256 checksums.
+
+Usage
+  cert-bundler [options]
+
+  Options:
+    -c <file>    Path to YAML configuration file (default: bundle.yaml)
+    -o <dir>     Output directory for archives (default: pkg)
+
+YAML Configuration Format
+
+  The configuration file uses the following structure:
+
+  config:
+    hashes: <filename>
+    expiry: <duration>
+  chains:
+    <group_name>:
+      certs:
+        - root: <path>
+          intermediates:
+            - <path>
+            - <path>
+        - root: <path>
+          intermediates:
+            - <path>
+      outputs:
+        include_single: <bool>
+        include_individual: <bool>
+        manifest: <bool>
+        encoding: <encoding>
+        formats:
+          - <format>
+          - <format>
+
+Configuration Fields
+
+  config:
+    hashes: (optional) Name of the file to write SHA256 checksums of all
+            generated archives. If omitted, no hash file is created.
+    expiry: (optional) Expiration warning threshold. Certificates expiring
+            within this period will trigger a warning. Supports formats like
+            "1y" (year), "6m" (month), "30d" (day). Default: 1y
+
+  chains:
+    Each key under "chains" defines a named certificate group. All certificates
+    in a group are bundled together into archives with the group name.
+
+    certs:
+      List of certificate chains. Each chain has:
+        root: Path to root CA certificate (PEM or DER format)
+        intermediates: List of paths to intermediate certificates
+
+      All intermediates are validated against their root CA. An error is
+      reported if signature verification fails.
+
+    outputs:
+      Defines output formats and content for the group's archives:
+
+        include_single: (bool) If true, all certificates in the group are
+                        concatenated into a single file named "bundle.pem"
+                        (or "bundle.crt" for DER encoding).
+
+        include_individual: (bool) If true, each certificate is included as
+                            a separate file in the archive, named after the
+                            original file (e.g., "int/cca2.pem" becomes
+                            "cca2.pem").
+
+        manifest: (bool) If true, a MANIFEST file is included containing
+                  SHA256 checksums of all files in the archive.
+
+        encoding: Specifies certificate encoding in the archive:
+                  - "pem": PEM format with .pem extension (default)
+                  - "der": DER format with .crt extension
+                  - "both": Both PEM and DER versions are included
+
+        formats: List of archive formats to generate:
+                 - "zip": Creates a .zip archive
+                 - "tgz": Creates a .tar.gz archive
+
+Output Files
+
+  For each group and format combination, an archive is created:
+    <group_name>.zip or <group_name>.tar.gz
+
+  If config.hashes is specified, a hash file is created in the output directory
+  containing SHA256 checksums of all generated archives.
+
+Example Configuration
+
+  config:
+    hashes: bundle.sha256
+    expiry: 1y
+  chains:
+    core_certs:
+      certs:
+        - root: roots/core-ca.pem
+          intermediates:
+            - int/cca1.pem
+            - int/cca2.pem
+            - int/cca3.pem
+        - root: roots/ssh-ca.pem
+          intermediates:
+            - ssh/ssh_dmz1.pem
+            - ssh/ssh_internal.pem
+      outputs:
+        include_single: true
+        include_individual: true
+        manifest: true
+        encoding: pem
+        formats:
+          - zip
+          - tgz
+
+  This configuration:
+    - Creates core_certs.zip and core_certs.tar.gz in the output directory
+    - Each archive contains bundle.pem (all certificates concatenated)
+    - Each archive contains individual certificates (core-ca.pem, cca1.pem, etc.)
+    - Each archive includes a MANIFEST file with SHA256 checksums
+    - Creates bundle.sha256 with checksums of the two archives
+    - Warns if any certificate expires within 1 year
+
+Examples
+
+  # Create bundles using default configuration (bundle.yaml -> pkg/)
+  cert-bundler
+
+  # Use custom configuration and output directory
+  cert-bundler -c myconfig.yaml -o output
+
+  # Create bundles from testdata configuration
+  cert-bundler -c testdata/bundle.yaml -o testdata/pkg
+
+Notes
+  - Certificate paths in the YAML are relative to the current working directory
+  - All intermediates must be properly signed by their specified root CA
+  - Certificates are checked for expiration; warnings are printed to stderr
+  - Expired certificates do not prevent archive creation but generate warnings
+  - Both PEM and DER certificate formats are supported as input
+  - Archive filenames use the group name, not individual chain names
+  - If both include_single and include_individual are true, archives contain both

cmd/cert-bundler/main.go

@@ -0,0 +1,575 @@
+package main
+
+import (
+	"archive/tar"
+	"archive/zip"
+	"compress/gzip"
+	"crypto/sha256"
+	"crypto/x509"
+	_ "embed"
+	"encoding/pem"
+	"errors"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"git.wntrmute.dev/kyle/goutils/certlib"
+	"gopkg.in/yaml.v2"
+)
+
+// Config represents the top-level YAML configuration.
+type Config struct {
+	Config struct {
+		Hashes string `yaml:"hashes"`
+		Expiry string `yaml:"expiry"`
+	} `yaml:"config"`
+	Chains map[string]ChainGroup `yaml:"chains"`
+}
+
+// ChainGroup represents a named group of certificate chains.
+type ChainGroup struct {
+	Certs   []CertChain `yaml:"certs"`
+	Outputs Outputs     `yaml:"outputs"`
+}
+
+// CertChain represents a root certificate and its intermediates.
+type CertChain struct {
+	Root          string   `yaml:"root"`
+	Intermediates []string `yaml:"intermediates"`
+}
+
+// Outputs defines output format options.
+type Outputs struct {
+	IncludeSingle     bool     `yaml:"include_single"`
+	IncludeIndividual bool     `yaml:"include_individual"`
+	Manifest          bool     `yaml:"manifest"`
+	Formats           []string `yaml:"formats"`
+	Encoding          string   `yaml:"encoding"`
+}
+
+var (
+	configFile string
+	outputDir  string
+)
+
+var formatExtensions = map[string]string{
+	"zip": ".zip",
+	"tgz": ".tar.gz",
+}
+
+//go:embed README.txt
+var readmeContent string
+
+func usage() {
+	fmt.Fprint(os.Stderr, readmeContent)
+}
+
+func main() {
+	flag.Usage = usage
+	flag.StringVar(&configFile, "c", "bundle.yaml", "path to YAML configuration file")
+	flag.StringVar(&outputDir, "o", "pkg", "output directory for archives")
+	flag.Parse()
+
+	if configFile == "" {
+		fmt.Fprintf(os.Stderr, "Error: configuration file required (-c flag)\n")
+		os.Exit(1)
+	}
+
+	// Load and parse configuration
+	cfg, err := loadConfig(configFile)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error loading config: %v\n", err)
+		os.Exit(1)
+	}
+
+	// Parse expiry duration (default 1 year)
+	expiryDuration := 365 * 24 * time.Hour
+	if cfg.Config.Expiry != "" {
+		expiryDuration, err = parseDuration(cfg.Config.Expiry)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Error parsing expiry: %v\n", err)
+			os.Exit(1)
+		}
+	}
+
+	// Create output directory if it doesn't exist
+	err = os.MkdirAll(outputDir, 0750)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error creating output directory: %v\n", err)
+		os.Exit(1)
+	}
+
+	// Process each chain group
+	// Pre-allocate createdFiles based on total number of formats across all groups
+	totalFormats := 0
+	for _, group := range cfg.Chains {
+		totalFormats += len(group.Outputs.Formats)
+	}
+	createdFiles := make([]string, 0, totalFormats)
+	for groupName, group := range cfg.Chains {
+		files, perr := processChainGroup(groupName, group, expiryDuration)
+		if perr != nil {
+			fmt.Fprintf(os.Stderr, "Error processing chain group %s: %v\n", groupName, perr)
+			os.Exit(1)
+		}
+		createdFiles = append(createdFiles, files...)
+	}
+
+	// Generate hash file for all created archives
+	if cfg.Config.Hashes != "" {
+		hashFile := filepath.Join(outputDir, cfg.Config.Hashes)
+		if gerr := generateHashFile(hashFile, createdFiles); gerr != nil {
+			fmt.Fprintf(os.Stderr, "Error generating hash file: %v\n", gerr)
+			os.Exit(1)
+		}
+	}
+
+	fmt.Println("Certificate bundling completed successfully")
+}
+
+func loadConfig(path string) (*Config, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+
+	var cfg Config
+	if uerr := yaml.Unmarshal(data, &cfg); uerr != nil {
+		return nil, uerr
+	}
+
+	return &cfg, nil
+}
+
+func parseDuration(s string) (time.Duration, error) {
+	// Support simple formats like "1y", "6m", "30d"
+	if len(s) < 2 {
+		return 0, fmt.Errorf("invalid duration format: %s", s)
+	}
+
+	unit := s[len(s)-1]
+	value := s[:len(s)-1]
+
+	var multiplier time.Duration
+	switch unit {
+	case 'y', 'Y':
+		multiplier = 365 * 24 * time.Hour
+	case 'm', 'M':
+		multiplier = 30 * 24 * time.Hour
+	case 'd', 'D':
+		multiplier = 24 * time.Hour
+	default:
+		return time.ParseDuration(s)
+	}
+
+	var num int
+	_, err := fmt.Sscanf(value, "%d", &num)
+	if err != nil {
+		return 0, fmt.Errorf("invalid duration value: %s", s)
+	}
+
+	return time.Duration(num) * multiplier, nil
+}
+
+func processChainGroup(groupName string, group ChainGroup, expiryDuration time.Duration) ([]string, error) {
+	// Default encoding to "pem" if not specified
+	encoding := group.Outputs.Encoding
+	if encoding == "" {
+		encoding = "pem"
+	}
+
+	// Collect certificates from all chains in the group
+	singleFileCerts, individualCerts, err := loadAndCollectCerts(group.Certs, group.Outputs, expiryDuration)
+	if err != nil {
+		return nil, err
+	}
+
+	// Prepare files for inclusion in archives
+	archiveFiles, err := prepareArchiveFiles(singleFileCerts, individualCerts, group.Outputs, encoding)
+	if err != nil {
+		return nil, err
+	}
+
+	// Create archives for the entire group
+	createdFiles, err := createArchiveFiles(groupName, group.Outputs.Formats, archiveFiles)
+	if err != nil {
+		return nil, err
+	}
+
+	return createdFiles, nil
+}
+
+// loadAndCollectCerts loads all certificates from chains and collects them for processing.
+func loadAndCollectCerts(
+	chains []CertChain,
+	outputs Outputs,
+	expiryDuration time.Duration,
+) ([]*x509.Certificate, []certWithPath, error) {
+	var singleFileCerts []*x509.Certificate
+	var individualCerts []certWithPath
+
+	for _, chain := range chains {
+		s, i, cerr := collectFromChain(chain, outputs, expiryDuration)
+		if cerr != nil {
+			return nil, nil, cerr
+		}
+		if len(s) > 0 {
+			singleFileCerts = append(singleFileCerts, s...)
+		}
+		if len(i) > 0 {
+			individualCerts = append(individualCerts, i...)
+		}
+	}
+
+	return singleFileCerts, individualCerts, nil
+}
+
+// collectFromChain loads a single chain, performs checks, and returns the certs to include.
+func collectFromChain(
+	chain CertChain,
+	outputs Outputs,
+	expiryDuration time.Duration,
+) (
+	[]*x509.Certificate,
+	[]certWithPath,
+	error,
+) {
+	var single []*x509.Certificate
+	var indiv []certWithPath
+
+	// Load root certificate
+	rootCert, rerr := certlib.LoadCertificate(chain.Root)
+	if rerr != nil {
+		return nil, nil, fmt.Errorf("failed to load root certificate %s: %w", chain.Root, rerr)
+	}
+
+	// Check expiry for root
+	checkExpiry(chain.Root, rootCert, expiryDuration)
+
+	// Add root to collections if needed
+	if outputs.IncludeSingle {
+		single = append(single, rootCert)
+	}
+	if outputs.IncludeIndividual {
+		indiv = append(indiv, certWithPath{cert: rootCert, path: chain.Root})
+	}
+
+	// Load and validate intermediates
+	for _, intPath := range chain.Intermediates {
+		intCert, lerr := certlib.LoadCertificate(intPath)
+		if lerr != nil {
+			return nil, nil, fmt.Errorf("failed to load intermediate certificate %s: %w", intPath, lerr)
+		}
+
+		// Validate that intermediate is signed by root
+		if sigErr := intCert.CheckSignatureFrom(rootCert); sigErr != nil {
+			return nil, nil, fmt.Errorf(
+				"intermediate %s is not properly signed by root %s: %w",
+				intPath,
+				chain.Root,
+				sigErr,
+			)
+		}
+
+		// Check expiry for intermediate
+		checkExpiry(intPath, intCert, expiryDuration)
+
+		// Add intermediate to collections if needed
+		if outputs.IncludeSingle {
+			single = append(single, intCert)
+		}
+		if outputs.IncludeIndividual {
+			indiv = append(indiv, certWithPath{cert: intCert, path: intPath})
+		}
+	}
+
+	return single, indiv, nil
+}
+
+// prepareArchiveFiles prepares all files to be included in archives.
+func prepareArchiveFiles(
+	singleFileCerts []*x509.Certificate,
+	individualCerts []certWithPath,
+	outputs Outputs,
+	encoding string,
+) ([]fileEntry, error) {
+	var archiveFiles []fileEntry
+
+	// Handle a single bundle file
+	if outputs.IncludeSingle && len(singleFileCerts) > 0 {
+		files, err := encodeCertsToFiles(singleFileCerts, "bundle", encoding, true)
+		if err != nil {
+			return nil, fmt.Errorf("failed to encode single bundle: %w", err)
+		}
+		archiveFiles = append(archiveFiles, files...)
+	}
+
+	// Handle individual files
+	if outputs.IncludeIndividual {
+		for _, cp := range individualCerts {
+			baseName := strings.TrimSuffix(filepath.Base(cp.path), filepath.Ext(cp.path))
+			files, err := encodeCertsToFiles([]*x509.Certificate{cp.cert}, baseName, encoding, false)
+			if err != nil {
+				return nil, fmt.Errorf("failed to encode individual cert %s: %w", cp.path, err)
+			}
+			archiveFiles = append(archiveFiles, files...)
+		}
+	}
+
+	// Generate manifest if requested
+	if outputs.Manifest {
+		manifestContent := generateManifest(archiveFiles)
+		archiveFiles = append(archiveFiles, fileEntry{
+			name:    "MANIFEST",
+			content: manifestContent,
+		})
+	}
+
+	return archiveFiles, nil
+}
+
+// createArchiveFiles creates archive files in the specified formats.
+func createArchiveFiles(groupName string, formats []string, archiveFiles []fileEntry) ([]string, error) {
+	createdFiles := make([]string, 0, len(formats))
+
+	for _, format := range formats {
+		ext, ok := formatExtensions[format]
+		if !ok {
+			return nil, fmt.Errorf("unsupported format: %s", format)
+		}
+		archivePath := filepath.Join(outputDir, groupName+ext)
+		switch format {
+		case "zip":
+			if err := createZipArchive(archivePath, archiveFiles); err != nil {
+				return nil, fmt.Errorf("failed to create zip archive: %w", err)
+			}
+		case "tgz":
+			if err := createTarGzArchive(archivePath, archiveFiles); err != nil {
+				return nil, fmt.Errorf("failed to create tar.gz archive: %w", err)
+			}
+		default:
+			return nil, fmt.Errorf("unsupported format: %s", format)
+		}
+		createdFiles = append(createdFiles, archivePath)
+	}
+
+	return createdFiles, nil
+}
+
+func checkExpiry(path string, cert *x509.Certificate, expiryDuration time.Duration) {
+	now := time.Now()
+	expiryThreshold := now.Add(expiryDuration)
+
+	if cert.NotAfter.Before(expiryThreshold) {
+		daysUntilExpiry := int(cert.NotAfter.Sub(now).Hours() / 24)
+		if daysUntilExpiry < 0 {
+			fmt.Fprintf(
+				os.Stderr,
+				"WARNING: Certificate %s has EXPIRED (expired %d days ago)\n",
+				path,
+				-daysUntilExpiry,
+			)
+		} else {
+			fmt.Fprintf(os.Stderr, "WARNING: Certificate %s will expire in %d days (on %s)\n", path, daysUntilExpiry, cert.NotAfter.Format("2006-01-02"))
+		}
+	}
+}
+
+type fileEntry struct {
+	name    string
+	content []byte
+}
+
+type certWithPath struct {
+	cert *x509.Certificate
+	path string
+}
+
+// encodeCertsToFiles converts certificates to file entries based on encoding type
+// If isSingle is true, certs are concatenated into a single file; otherwise one cert per file.
+func encodeCertsToFiles(
+	certs []*x509.Certificate,
+	baseName string,
+	encoding string,
+	isSingle bool,
+) ([]fileEntry, error) {
+	var files []fileEntry
+
+	switch encoding {
+	case "pem":
+		pemContent := encodeCertsToPEM(certs)
+		files = append(files, fileEntry{
+			name:    baseName + ".pem",
+			content: pemContent,
+		})
+	case "der":
+		if isSingle {
+			// For single file in DER, concatenate all cert DER bytes
+			var derContent []byte
+			for _, cert := range certs {
+				derContent = append(derContent, cert.Raw...)
+			}
+			files = append(files, fileEntry{
+				name:    baseName + ".crt",
+				content: derContent,
+			})
+		} else if len(certs) > 0 {
+			// Individual DER file (should only have one cert)
+			files = append(files, fileEntry{
+				name:    baseName + ".crt",
+				content: certs[0].Raw,
+			})
+		}
+	case "both":
+		// Add PEM version
+		pemContent := encodeCertsToPEM(certs)
+		files = append(files, fileEntry{
+			name:    baseName + ".pem",
+			content: pemContent,
+		})
+		// Add DER version
+		if isSingle {
+			var derContent []byte
+			for _, cert := range certs {
+				derContent = append(derContent, cert.Raw...)
+			}
+			files = append(files, fileEntry{
+				name:    baseName + ".crt",
+				content: derContent,
+			})
+		} else if len(certs) > 0 {
+			files = append(files, fileEntry{
+				name:    baseName + ".crt",
+				content: certs[0].Raw,
+			})
+		}
+	default:
+		return nil, fmt.Errorf("unsupported encoding: %s (must be 'pem', 'der', or 'both')", encoding)
+	}
+
+	return files, nil
+}
+
+// encodeCertsToPEM encodes certificates to PEM format.
+func encodeCertsToPEM(certs []*x509.Certificate) []byte {
+	var pemContent []byte
+	for _, cert := range certs {
+		pemBlock := &pem.Block{
+			Type:  "CERTIFICATE",
+			Bytes: cert.Raw,
+		}
+		pemContent = append(pemContent, pem.EncodeToMemory(pemBlock)...)
+	}
+	return pemContent
+}
+
+func generateManifest(files []fileEntry) []byte {
+	var manifest strings.Builder
+	for _, file := range files {
+		if file.name == "MANIFEST" {
+			continue
+		}
+		hash := sha256.Sum256(file.content)
+		manifest.WriteString(fmt.Sprintf("%x  %s\n", hash, file.name))
+	}
+	return []byte(manifest.String())
+}
+
+// closeWithErr attempts to close all provided closers, joining any close errors with baseErr.
+func closeWithErr(baseErr error, closers ...io.Closer) error {
+	for _, c := range closers {
+		if c == nil {
+			continue
+		}
+		if cerr := c.Close(); cerr != nil {
+			baseErr = errors.Join(baseErr, cerr)
+		}
+	}
+	return baseErr
+}
+
+func createZipArchive(path string, files []fileEntry) error {
+	f, zerr := os.Create(path)
+	if zerr != nil {
+		return zerr
+	}
+
+	w := zip.NewWriter(f)
+
+	for _, file := range files {
+		fw, werr := w.Create(file.name)
+		if werr != nil {
+			return closeWithErr(werr, w, f)
+		}
+		if _, werr = fw.Write(file.content); werr != nil {
+			return closeWithErr(werr, w, f)
+		}
+	}
+
+	// Check errors on close operations
+	if cerr := w.Close(); cerr != nil {
+		_ = f.Close()
+		return cerr
+	}
+	return f.Close()
+}
+
+func createTarGzArchive(path string, files []fileEntry) error {
+	f, terr := os.Create(path)
+	if terr != nil {
+		return terr
+	}
+
+	gw := gzip.NewWriter(f)
+	tw := tar.NewWriter(gw)
+
+	for _, file := range files {
+		hdr := &tar.Header{
+			Name: file.name,
+			Mode: 0644,
+			Size: int64(len(file.content)),
+		}
+		if herr := tw.WriteHeader(hdr); herr != nil {
+			return closeWithErr(herr, tw, gw, f)
+		}
+		if _, werr := tw.Write(file.content); werr != nil {
+			return closeWithErr(werr, tw, gw, f)
+		}
+	}
+
+	// Check errors on close operations in the correct order
+	if cerr := tw.Close(); cerr != nil {
+		_ = gw.Close()
+		_ = f.Close()
+		return cerr
+	}
+	if cerr := gw.Close(); cerr != nil {
+		_ = f.Close()
+		return cerr
+	}
+	return f.Close()
+}
+
+func generateHashFile(path string, files []string) error {
+	f, err := os.Create(path)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	for _, file := range files {
+		data, rerr := os.ReadFile(file)
+		if rerr != nil {
+			return rerr
+		}
+
+		hash := sha256.Sum256(data)
+		fmt.Fprintf(f, "%x  %s\n", hash, filepath.Base(file))
+	}
+
+	return nil
+}

cmd/cert-bundler/prompt.txt

@@ -0,0 +1,197 @@
+This project is an exploration into the utility of Jetbrains' Junie
+to write smaller but tedious programs.
+
+Task: build a certificate bundling tool in cmd/cert-bundler. It
+creates archives of certificates chains.
+
+A YAML file for this looks something like:
+
+``` yaml
+config:
+  hashes: bundle.sha256
+  expiry: 1y
+chains:
+  core_certs:
+    certs:
+      - root: roots/core-ca.pem
+        intermediates:
+          - int/cca1.pem
+  	- int/cca2.pem
+  	- int/cca3.pem
+      - root: roots/ssh-ca.pem
+        intermediates:
+          - ssh/ssh_dmz1.pem
+  	- ssh/ssh_internal.pem
+  outputs:
+    include_single: true
+    include_individual: true
+    manifest: true
+    formats:
+      - zip
+      - tgz
+```
+
+Some requirements:
+
+1. First, all the certificates should be loaded.
+2. For each root, each of the indivudal intermediates should be
+   checked to make sure they are properly signed by the root CA.
+3. The program should optionally take an expiration period (defaulting
+   to one year), specified in config.expiration, and if any certificate
+   is within that expiration period, a warning should be printed.
+4. If outputs.include_single is true, all certificates under chains
+   should be concatenated into a single file.
+5. If outputs.include_individual is true, all certificates under
+   chains should be included at the root level (e.g. int/cca2.pem
+   would be cca2.pem in the archive).
+6. If bundle.manifest is true, a "MANIFEST" file is created with
+   SHA256 sums of each file included in the archive.
+7. For each of the formats, create an archive file in the output
+   directory (specified with `-o`) with that format.
+   - If zip is included, create a .zip file.
+   - If tgz is included, create a .tar.gz file with default compression
+     levels.
+   - All archive files should include any generated files (single
+     and/or individual) in the top-level directory.
+8. In the output directory, create a file with the same name as
+   config.hashes that contains the SHA256 sum of all files created.
+
+-----
+
+The outputs.include_single and outputs.include_individual describe
+what should go in the final archive. If both are specified, the output
+archive should include both a single bundle.pem and each individual
+certificate, for example.
+
+-----
+
+As it stands, given the following `bundle.yaml`:
+
+``` yaml
+config:
+  hashes: bundle.sha256
+  expiry: 1y
+chains:
+  core_certs:
+    certs:
+      - root: pems/gts-r1.pem
+        intermediates:
+          - pems/goog-wr2.pem
+        outputs:
+          include_single: true
+          include_individual: true
+          manifest: true
+          formats:
+            - zip
+            - tgz
+      - root: pems/isrg-root-x1.pem
+        intermediates:
+          - pems/le-e7.pem
+        outputs:
+          include_single: true
+          include_individual: false
+          manifest: true
+          formats:
+            - zip
+            - tgz
+  google_certs:
+    certs:
+      - root: pems/gts-r1.pem
+        intermediates:
+          - pems/goog-wr2.pem
+        outputs:
+          include_single: true
+          include_individual: false
+          manifest: true
+          formats:
+            - tgz
+  lets_encrypt:
+    certs:
+      - root: pems/isrg-root-x1.pem
+        intermediates:
+          - pems/le-e7.pem
+        outputs:
+          include_single: false
+          include_individual: true
+          manifest: false
+          formats:
+            - zip
+```
+
+The program outputs the following files:
+
+- bundle.sha256
+- core_certs_0.tgz (contains individual certs)
+- core_certs_0.zip (contains individual certs)
+- core_certs_1.tgz (contains core_certs.pem)
+- core_certs_1.zip (contains core_certs.pem)
+- google_certs_0.tgz
+- lets_encrypt_0.zip
+
+It should output
+
+- bundle.sha256
+- core_certs.tgz
+- core_certs.zip
+- google_certs.tgz
+- lets_encrypt.zip
+
+core_certs.* should contain `bundle.pem` and all the individual
+certs. There should be no _$n$ variants of archives.
+
+-----
+
+Add an additional field to outputs: encoding. It should accept one of
+`der`, `pem`, or `both`. If `der`, certificates should be output as a
+`.crt` file containing a DER-encoded certificate. If `pem`, certificates
+should be output as a `.pem` file containing a PEM-encoded certificate.
+If both, both the `.crt` and `.pem` certificate should be included.
+
+For example, given the previous config, if `encoding` is der, the
+google_certs.tgz archive should contain
+
+- bundle.crt
+- MANIFEST
+
+Or with lets_encrypt.zip:
+
+- isrg-root-x1.crt
+- le-e7.crt
+
+However, if `encoding` is pem, the lets_encrypt.zip archive should contain:
+
+- isrg-root-x1.pem
+- le-e7.pem
+
+And if it `encoding` is both, the lets_encrypt.zip archive should contain:
+
+- isrg-root-x1.crt
+- isrg-root-x1.pem
+- le-e7.crt
+- le-e7.pem
+
+-----
+
+The tgz format should output a `.tar.gz` file instead of a `.tgz` file.
+
+-----
+
+Move the format extensions to a global variable.
+
+-----
+
+Write a README.txt with a description of the bundle.yaml format.
+
+Additionally, update the help text for the program (e.g. with `-h`)
+to provide the same detailed information.
+
+-----
+
+It may be easier to embed the README.txt in the program on build.
+
+-----
+
+For the archive (tar.gz and zip) writers, make sure errors are
+checked at the end, and don't just defer the close operations.
+
+

cmd/cert-bundler/testdata/bundle.yaml

@@ -0,0 +1,43 @@
+config:
+  hashes: bundle.sha256
+  expiry: 1y
+chains:
+  core_certs:
+    certs:
+      - root: pems/gts-r1.pem
+        intermediates:
+          - pems/goog-wr2.pem
+      - root: pems/isrg-root-x1.pem
+        intermediates:
+          - pems/le-e7.pem
+    outputs:
+      include_single: true
+      include_individual: true
+      manifest: true
+      formats:
+        - zip
+        - tgz
+  google_certs:
+    certs:
+      - root: pems/gts-r1.pem
+        intermediates:
+          - pems/goog-wr2.pem
+    outputs:
+      include_single: true
+      include_individual: false
+      manifest: true
+      encoding: der
+      formats:
+        - tgz
+  lets_encrypt:
+    certs:
+      - root: pems/isrg-root-x1.pem
+        intermediates:
+          - pems/le-e7.pem
+    outputs:
+      include_single: false
+      include_individual: true
+      manifest: false
+      encoding: both
+      formats:
+        - zip

cmd/cert-bundler/testdata/pems/goog-wr2.pem

@@ -0,0 +1,29 @@
+-----BEGIN CERTIFICATE-----
+MIIFCzCCAvOgAwIBAgIQf/AFoHxM3tEArZ1mpRB7mDANBgkqhkiG9w0BAQsFADBH
+MQswCQYDVQQGEwJVUzEiMCAGA1UEChMZR29vZ2xlIFRydXN0IFNlcnZpY2VzIExM
+QzEUMBIGA1UEAxMLR1RTIFJvb3QgUjEwHhcNMjMxMjEzMDkwMDAwWhcNMjkwMjIw
+MTQwMDAwWjA7MQswCQYDVQQGEwJVUzEeMBwGA1UEChMVR29vZ2xlIFRydXN0IFNl
+cnZpY2VzMQwwCgYDVQQDEwNXUjIwggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEK
+AoIBAQCp/5x/RR5wqFOfytnlDd5GV1d9vI+aWqxG8YSau5HbyfsvAfuSCQAWXqAc
++MGr+XgvSszYhaLYWTwO0xj7sfUkDSbutltkdnwUxy96zqhMt/TZCPzfhyM1IKji
+aeKMTj+xWfpgoh6zySBTGYLKNlNtYE3pAJH8do1cCA8Kwtzxc2vFE24KT3rC8gIc
+LrRjg9ox9i11MLL7q8Ju26nADrn5Z9TDJVd06wW06Y613ijNzHoU5HEDy01hLmFX
+xRmpC5iEGuh5KdmyjS//V2pm4M6rlagplmNwEmceOuHbsCFx13ye/aoXbv4r+zgX
+FNFmp6+atXDMyGOBOozAKql2N87jAgMBAAGjgf4wgfswDgYDVR0PAQH/BAQDAgGG
+MB0GA1UdJQQWMBQGCCsGAQUFBwMBBggrBgEFBQcDAjASBgNVHRMBAf8ECDAGAQH/
+AgEAMB0GA1UdDgQWBBTeGx7teRXUPjckwyG77DQ5bUKyMDAfBgNVHSMEGDAWgBTk
+rysmcRorSCeFL1JmLO/wiRNxPjA0BggrBgEFBQcBAQQoMCYwJAYIKwYBBQUHMAKG
+GGh0dHA6Ly9pLnBraS5nb29nL3IxLmNydDArBgNVHR8EJDAiMCCgHqAchhpodHRw
+Oi8vYy5wa2kuZ29vZy9yL3IxLmNybDATBgNVHSAEDDAKMAgGBmeBDAECATANBgkq
+hkiG9w0BAQsFAAOCAgEARXWL5R87RBOWGqtY8TXJbz3S0DNKhjO6V1FP7sQ02hYS
+TL8Tnw3UVOlIecAwPJQl8hr0ujKUtjNyC4XuCRElNJThb0Lbgpt7fyqaqf9/qdLe
+SiDLs/sDA7j4BwXaWZIvGEaYzq9yviQmsR4ATb0IrZNBRAq7x9UBhb+TV+PfdBJT
+DhEl05vc3ssnbrPCuTNiOcLgNeFbpwkuGcuRKnZc8d/KI4RApW//mkHgte8y0YWu
+ryUJ8GLFbsLIbjL9uNrizkqRSvOFVU6xddZIMy9vhNkSXJ/UcZhjJY1pXAprffJB
+vei7j+Qi151lRehMCofa6WBmiA4fx+FOVsV2/7R6V2nyAiIJJkEd2nSi5SnzxJrl
+Xdaqev3htytmOPvoKWa676ATL/hzfvDaQBEcXd2Ppvy+275W+DKcH0FBbX62xevG
+iza3F4ydzxl6NJ8hk8R+dDXSqv1MbRT1ybB5W0k8878XSOjvmiYTDIfyc9acxVJr
+Y/cykHipa+te1pOhv7wYPYtZ9orGBV5SGOJm4NrB3K1aJar0RfzxC3ikr7Dyc6Qw
+qDTBU39CluVIQeuQRgwG3MuSxl7zRERDRilGoKb8uY45JzmxWuKxrfwT/478JuHU
+/oTxUFqOl2stKnn7QGTq8z29W+GgBLCXSBxC9epaHM0myFH/FJlniXJfHeytWt0=
+-----END CERTIFICATE-----

cmd/cert-bundler/testdata/pems/gts-r1.pem

@@ -0,0 +1,31 @@
+-----BEGIN CERTIFICATE-----
+MIIFVzCCAz+gAwIBAgINAgPlk28xsBNJiGuiFzANBgkqhkiG9w0BAQwFADBHMQsw
+CQYDVQQGEwJVUzEiMCAGA1UEChMZR29vZ2xlIFRydXN0IFNlcnZpY2VzIExMQzEU
+MBIGA1UEAxMLR1RTIFJvb3QgUjEwHhcNMTYwNjIyMDAwMDAwWhcNMzYwNjIyMDAw
+MDAwWjBHMQswCQYDVQQGEwJVUzEiMCAGA1UEChMZR29vZ2xlIFRydXN0IFNlcnZp
+Y2VzIExMQzEUMBIGA1UEAxMLR1RTIFJvb3QgUjEwggIiMA0GCSqGSIb3DQEBAQUA
+A4ICDwAwggIKAoICAQC2EQKLHuOhd5s73L+UPreVp0A8of2C+X0yBoJx9vaMf/vo
+27xqLpeXo4xL+Sv2sfnOhB2x+cWX3u+58qPpvBKJXqeqUqv4IyfLpLGcY9vXmX7w
+Cl7raKb0xlpHDU0QM+NOsROjyBhsS+z8CZDfnWQpJSMHobTSPS5g4M/SCYe7zUjw
+TcLCeoiKu7rPWRnWr4+wB7CeMfGCwcDfLqZtbBkOtdh+JhpFAz2weaSUKK0Pfybl
+qAj+lug8aJRT7oM6iCsVlgmy4HqMLnXWnOunVmSPlk9orj2XwoSPwLxAwAtcvfaH
+szVsrBhQf4TgTM2S0yDpM7xSma8ytSmzJSq0SPly4cpk9+aCEI3oncKKiPo4Zor8
+Y/kB+Xj9e1x3+naH+uzfsQ55lVe0vSbv1gHR6xYKu44LtcXFilWr06zqkUspzBmk
+MiVOKvFlRNACzqrOSbTqn3yDsEB750Orp2yjj32JgfpMpf/VjsPOS+C12LOORc92
+wO1AK/1TD7Cn1TsNsYqiA94xrcx36m97PtbfkSIS5r762DL8EGMUUXLeXdYWk70p
+aDPvOmbsB4om3xPXV2V4J95eSRQAogB/mqghtqmxlbCluQ0WEdrHbEg8QOB+DVrN
+VjzRlwW5y0vtOUucxD/SVRNuJLDWcfr0wbrM7Rv1/oFB2ACYPTrIrnqYNxgFlQID
+AQABo0IwQDAOBgNVHQ8BAf8EBAMCAYYwDwYDVR0TAQH/BAUwAwEB/zAdBgNVHQ4E
+FgQU5K8rJnEaK0gnhS9SZizv8IkTcT4wDQYJKoZIhvcNAQEMBQADggIBAJ+qQibb
+C5u+/x6Wki4+omVKapi6Ist9wTrYggoGxval3sBOh2Z5ofmmWJyq+bXmYOfg6LEe
+QkEzCzc9zolwFcq1JKjPa7XSQCGYzyI0zzvFIoTgxQ6KfF2I5DUkzps+GlQebtuy
+h6f88/qBVRRiClmpIgUxPoLW7ttXNLwzldMXG+gnoot7TiYaelpkttGsN/H9oPM4
+7HLwEXWdyzRSjeZ2axfG34arJ45JK3VmgRAhpuo+9K4l/3wV3s6MJT/KYnAK9y8J
+ZgfIPxz88NtFMN9iiMG1D53Dn0reWVlHxYciNuaCp+0KueIHoI17eko8cdLiA6Ef
+MgfdG+RCzgwARWGAtQsgWSl4vflVy2PFPEz0tv/bal8xa5meLMFrUKTX5hgUvYU/
+Z6tGn6D/Qqc6f1zLXbBwHSs09dR2CQzreExZBfMzQsNhFRAbd03OIozUhfJFfbdT
+6u9AWpQKXCBfTkBdYiJ23//OYb2MI3jSNwLgjt7RETeJ9r/tSQdirpLsQBqvFAnZ
+0E6yove+7u7Y/9waLd64NnHi/Hm3lCXRSHNboTXns5lndcEZOitHTtNCjv0xyBZm
+2tIMPNuzjsmhDYAPexZ3FL//2wmUspO8IFgV6dtxQ/PeEMMA3KgqlbbC1j+Qa3bb
+bP6MvPJwNQzcmRk13NfIRmPVNnGuV/u3gm3c
+-----END CERTIFICATE-----

cmd/cert-bundler/testdata/pems/isrg-root-x1.pem

@@ -0,0 +1,31 @@
+-----BEGIN CERTIFICATE-----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=
+-----END CERTIFICATE-----

cmd/cert-bundler/testdata/pems/le-e7.pem

@@ -0,0 +1,26 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

cmd/cert-bundler/testdata/pkg/bundle.sha256

@@ -0,0 +1,4 @@
+5ed8bf9ed693045faa8a5cb0edc4a870052e56aef6291ce8b1604565affbc2a4  core_certs.zip
+e59eddc590d2f7b790a87c5b56e81697088ab54be382c0e2c51b82034006d308  core_certs.tgz
+51b9b63b1335118079e90700a3a5b847c363808e9116e576ca84f301bc433289  google_certs.tgz
+3d1910ca8835c3ded1755a8c7d6c48083c2f3ff68b2bfbf932aaf27e29d0a232  lets_encrypt.zip

cmd/cert-revcheck/README.txt

@@ -0,0 +1,36 @@
+cert-revcheck: check certificate expiry and revocation
+-----------------------------------------------------
+
+Description
+  cert-revcheck accepts a list of certificate files (PEM or DER) or
+  site addresses (host[:port]) and checks whether the leaf certificate
+  is expired or revoked. Revocation checks use CRL and OCSP via the
+  certlib/revoke package.
+
+Usage
+  cert-revcheck [options] <target> [<target>...]
+
+Options
+  -hardfail       treat revocation check failures as fatal (default: false)
+  -timeout dur    HTTP/OCSP/CRL timeout for network operations (default: 10s)
+  -v              verbose output
+
+Targets
+  - File paths to certificates in PEM or DER format.
+  - Site addresses in the form host or host:port. If no port is
+    provided, 443 is assumed.
+
+Examples
+  # Check a PEM file
+  cert-revcheck ./server.pem
+
+  # Check a DER (single) certificate
+  cert-revcheck ./server.der
+
+  # Check a live site (leaf certificate)
+  cert-revcheck example.com:443
+
+Notes
+  - For sites, only the leaf certificate is checked.
+  - When -hardfail is set, network issues during OCSP/CRL fetch will
+    cause the check to fail (treated as revoked).

cmd/cert-revcheck/main.go

@@ -0,0 +1,140 @@
+package main
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"flag"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"net"
+	"os"
+	"time"
+
+	"git.wntrmute.dev/kyle/goutils/certlib"
+	hosts "git.wntrmute.dev/kyle/goutils/certlib/hosts"
+	"git.wntrmute.dev/kyle/goutils/certlib/revoke"
+	"git.wntrmute.dev/kyle/goutils/fileutil"
+)
+
+var (
+	hardfail bool
+	timeout  time.Duration
+	verbose  bool
+)
+
+func main() {
+	flag.BoolVar(&hardfail, "hardfail", false, "treat revocation check failures as fatal")
+	flag.DurationVar(&timeout, "timeout", 10*time.Second, "network timeout for OCSP/CRL fetches and TLS site connects")
+	flag.BoolVar(&verbose, "v", false, "verbose output")
+	flag.Parse()
+
+	revoke.HardFail = hardfail
+	// Set HTTP client timeout for revocation library
+	revoke.HTTPClient.Timeout = timeout
+
+	if flag.NArg() == 0 {
+		fmt.Fprintf(os.Stderr, "Usage: %s [options] <target> [<target>...]\n", os.Args[0])
+		os.Exit(2)
+	}
+
+	exitCode := 0
+	for _, target := range flag.Args() {
+		status, err := processTarget(target)
+		switch status {
+		case "OK":
+			fmt.Printf("%s: OK\n", target)
+		case "EXPIRED":
+			fmt.Printf("%s: EXPIRED: %v\n", target, err)
+			exitCode = 1
+		case "REVOKED":
+			fmt.Printf("%s: REVOKED\n", target)
+			exitCode = 1
+		case "UNKNOWN":
+			fmt.Printf("%s: UNKNOWN: %v\n", target, err)
+			if hardfail {
+				// In hardfail, treat unknown as failure
+				exitCode = 1
+			}
+		}
+	}
+
+	os.Exit(exitCode)
+}
+
+func processTarget(target string) (string, error) {
+	if fileutil.FileDoesExist(target) {
+		return checkFile(target)
+	}
+
+	// Not a file; treat as site
+	return checkSite(target)
+}
+
+func checkFile(path string) (string, error) {
+	in, err := ioutil.ReadFile(path)
+	if err != nil {
+		return "UNKNOWN", err
+	}
+
+	// Try PEM first; if that fails, try single DER cert
+	certs, err := certlib.ReadCertificates(in)
+	if err != nil || len(certs) == 0 {
+		cert, _, derr := certlib.ReadCertificate(in)
+		if derr != nil || cert == nil {
+			if err == nil {
+				err = derr
+			}
+			return "UNKNOWN", err
+		}
+		return evaluateCert(cert)
+	}
+
+	// Evaluate the first certificate (leaf) by default
+	return evaluateCert(certs[0])
+}
+
+func checkSite(hostport string) (string, error) {
+	// Use certlib/hosts to parse host/port (supports https URLs and host:port)
+	target, err := hosts.ParseHost(hostport)
+	if err != nil {
+		return "UNKNOWN", err
+	}
+
+	d := &net.Dialer{Timeout: timeout}
+	conn, err := tls.DialWithDialer(d, "tcp", target.String(), &tls.Config{InsecureSkipVerify: true, ServerName: target.Host})
+	if err != nil {
+		return "UNKNOWN", err
+	}
+	defer conn.Close()
+
+	state := conn.ConnectionState()
+	if len(state.PeerCertificates) == 0 {
+		return "UNKNOWN", errors.New("no peer certificates presented")
+	}
+	return evaluateCert(state.PeerCertificates[0])
+}
+
+func evaluateCert(cert *x509.Certificate) (string, error) {
+	// Expiry check
+	now := time.Now()
+	if !now.Before(cert.NotAfter) {
+		return "EXPIRED", fmt.Errorf("expired at %s", cert.NotAfter)
+	}
+	if !now.After(cert.NotBefore) {
+		return "EXPIRED", fmt.Errorf("not valid until %s", cert.NotBefore)
+	}
+
+	// Revocation check using certlib/revoke
+	revoked, ok, err := revoke.VerifyCertificateError(cert)
+	if revoked {
+		// If revoked is true, ok will be true per implementation, err may describe why
+		return "REVOKED", err
+	}
+	if !ok {
+		// Revocation status could not be determined
+		return "UNKNOWN", err
+	}
+
+	return "OK", nil
+}

cmd/certdump/certdump.go

@@ -110,6 +110,14 @@ func showBasicConstraints(cert *x509.Certificate) {
 
 	if cert.IsCA {
 		fmt.Printf(", is a CA certificate")
+		if !cert.BasicConstraintsValid {
+			fmt.Printf(" (basic constraint failure)")
+		}
+	} else {
+		fmt.Printf("is not a CA certificate")
+		if cert.KeyUsage&x509.KeyUsageKeyEncipherment != 0 {
+			fmt.Printf(" (key encipherment usage enabled!)")
+		}
 	}
 
 	if (cert.MaxPathLen == 0 && cert.MaxPathLenZero) || (cert.MaxPathLen > 0) {

cmd/host/main.go

@@ -35,7 +35,7 @@ func main() {
 
 	for _, arg := range flag.Args() {
 		if err := lookupHost(arg); err != nil {
-			log.Println("%s: %s", arg, err)
+			log.Printf("%s: %s", arg, err)
 		}
 	}
 }

cmd/kgz/main.go

@@ -9,8 +9,6 @@ import (
     "os"
     "path/filepath"
     "strings"
-
-	"github.com/pkg/errors"
 )
 
 const gzipExt = ".gz"
@@ -18,29 +16,25 @@ const gzipExt = ".gz"
 func compress(path, target string, level int) error {
  sourceFile, err := os.Open(path)
  if err != nil {
-		return errors.Wrap(err, "opening file for read")
+     return fmt.Errorf("opening file for read: %w", err)
  }
 	defer sourceFile.Close()
 
  destFile, err := os.Create(target)
  if err != nil {
-		return errors.Wrap(err, "opening file for write")
+     return fmt.Errorf("opening file for write: %w", err)
  }
 	defer destFile.Close()
 
  gzipCompressor, err := gzip.NewWriterLevel(destFile, level)
  if err != nil {
-		return errors.Wrap(err, "invalid compression level")
+     return fmt.Errorf("invalid compression level: %w", err)
  }
 	defer gzipCompressor.Close()
 
  _, err = io.Copy(gzipCompressor, sourceFile)
  if err != nil {
-		return errors.Wrap(err, "compressing file")
+     return fmt.Errorf("compressing file: %w", err)
-	}
-
-	if err != nil {
-		return errors.Wrap(err, "stat(2)ing destination file")
  }
 
 	return nil
@@ -49,25 +43,25 @@ func compress(path, target string, level int) error {
 func uncompress(path, target string) error {
  sourceFile, err := os.Open(path)
  if err != nil {
-		return errors.Wrap(err, "opening file for read")
+     return fmt.Errorf("opening file for read: %w", err)
  }
 	defer sourceFile.Close()
 
  gzipUncompressor, err := gzip.NewReader(sourceFile)
  if err != nil {
-		return errors.Wrap(err, "reading gzip headers")
+     return fmt.Errorf("reading gzip headers: %w", err)
  }
 	defer gzipUncompressor.Close()
 
  destFile, err := os.Create(target)
  if err != nil {
-		return errors.Wrap(err, "opening file for write")
+     return fmt.Errorf("opening file for write: %w", err)
  }
 	defer destFile.Close()
 
  _, err = io.Copy(destFile, gzipUncompressor)
  if err != nil {
-		return errors.Wrap(err, "uncompressing file")
+     return fmt.Errorf("uncompressing file: %w", err)
  }
 
 	return nil
@@ -113,7 +107,7 @@ func pathForUncompressing(source, dest string) (string, error) {
 
 	source = filepath.Base(source)
  if !strings.HasSuffix(source, gzipExt) {
-		return "", errors.Errorf("%s is a not gzip-compressed file", source)
+        return "", fmt.Errorf("%s is a not gzip-compressed file", source)
     }
 	outFile := source[:len(source)-len(gzipExt)]
 	outFile = filepath.Join(dest, outFile)
@@ -127,7 +121,7 @@ func pathForCompressing(source, dest string) (string, error) {
 
 	source = filepath.Base(source)
  if strings.HasSuffix(source, gzipExt) {
-		return "", errors.Errorf("%s is a gzip-compressed file", source)
+        return "", fmt.Errorf("%s is a gzip-compressed file", source)
     }
 
 	dest = filepath.Join(dest, source+gzipExt)

cmd/minmax/README

@@ -0,0 +1,3 @@
+minmax
+
+A quick tool to calculate minmax codes if needed for uLisp.

cmd/minmax/minmax.go

@@ -0,0 +1,53 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"strconv"
+)
+
+var kinds = map[string]int{
+	"sym": 0,
+	"tf":  1,
+	"fn":  2,
+	"sp":  3,
+}
+
+func dieIf(err error) {
+	if err == nil {
+		return
+	}
+	fmt.Fprintf(os.Stderr, "[!] %s\n", err)
+	os.Exit(1)
+}
+
+func usage() {
+	fmt.Fprintf(os.Stderr, "usage: minmax type min max\n")
+	fmt.Fprintf(os.Stderr, "    type is one of fn, sp, sym, tf\n")
+	os.Exit(1)
+}
+
+func main() {
+	flag.Parse()
+
+	if flag.NArg() != 3 {
+		usage()
+	}
+
+	kind, ok := kinds[flag.Arg(0)]
+	if !ok {
+		usage()
+	}
+
+	min, err := strconv.Atoi(flag.Arg(1))
+	dieIf(err)
+
+	max, err := strconv.Atoi(flag.Arg(2))
+	dieIf(err)
+
+	code := kind << 6
+	code += (min << 3)
+	code += max
+	fmt.Printf("%0o\n", code)
+}

cmd/rolldie/main.go

@@ -0,0 +1,48 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"math/rand"
+	"os"
+	"regexp"
+	"strconv"
+
+	"git.wntrmute.dev/kyle/goutils/die"
+)
+
+var dieRollFormat = regexp.MustCompile(`^(\d+)[dD](\d+)$`)
+
+func rollDie(count, sides int) []int {
+	sum := 0
+	var rolls []int
+
+	for i := 0; i < count; i++ {
+		roll := rand.Intn(sides) + 1
+		sum += roll
+		rolls = append(rolls, roll)
+	}
+
+	rolls = append(rolls, sum)
+	return rolls
+}
+
+func main() {
+	flag.Parse()
+
+	for _, arg := range flag.Args() {
+		if !dieRollFormat.MatchString(arg) {
+			fmt.Fprintf(os.Stderr, "invalid die format %s: should be XdY\n", arg)
+			os.Exit(1)
+		}
+
+		dieRoll := dieRollFormat.FindAllStringSubmatch(arg, -1)
+		count, err := strconv.Atoi(dieRoll[0][1])
+		die.If(err)
+
+		sides, err := strconv.Atoi(dieRoll[0][2])
+		die.If(err)
+
+		fmt.Println(rollDie(count, sides))
+	}
+}

cmd/tlsinfo/README.txt

@@ -0,0 +1,34 @@
+tlsinfo: show TLS version, cipher, and peer certificates
+---------------------------------------------------------
+
+Description
+  tlsinfo connects to a TLS server and prints the negotiated TLS version and
+  cipher suite, followed by details for each certificate in the server’s
+  presented chain (as provided by the server).
+
+Usage
+  tlsinfo <hostname:port>
+
+Output
+  The program prints the negotiated protocol and cipher, then one section per
+  certificate in the order received from the server. Example fields:
+    TLS Version: TLS 1.3
+    Cipher Suite: TLS_AES_128_GCM_SHA256
+    Certificate 1
+        Subject: CN=example.com, O=Example Corp, C=US
+        Issuer: CN=Example Root CA, O=Example Corp, C=US
+        DNS Names: [example.com www.example.com]
+        Not Before: 2025-01-01 00:00:00 +0000 UTC
+        Not After:  2026-01-01 23:59:59 +0000 UTC
+
+Examples
+  # Inspect a public HTTPS endpoint
+  tlsinfo example.com:443
+
+Notes
+  - Verification is intentionally disabled (InsecureSkipVerify=true). The tool
+    does not validate the server certificate or hostname; it is for inspection
+    only.
+  - The SNI/ServerName is inferred from <hostname> when applicable.
+  - You must specify a port (e.g., 443 for HTTPS).
+  - The entire certificate chain is printed exactly as presented by the server.

cmd/tlsinfo/main.go

@@ -0,0 +1,64 @@
+package main
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"fmt"
+	"os"
+)
+
+func main() {
+	if len(os.Args) != 2 {
+		fmt.Printf("Usage: %s ‹hostname:port>\n", os.Args[0])
+		os.Exit(1)
+	}
+
+	hostPort := os.Args[1]
+	conn, err := tls.Dial("tcp", hostPort, &tls.Config{
+		InsecureSkipVerify: true,
+	})
+
+	if err != nil {
+		fmt.Printf("Failed to connect to the TLS server: %v\n", err)
+		os.Exit(1)
+	}
+	defer conn.Close()
+	state := conn.ConnectionState()
+	printConnectionDetails(state)
+}
+
+func printConnectionDetails(state tls.ConnectionState) {
+	version := tlsVersion(state.Version)
+	cipherSuite := tls.CipherSuiteName(state.CipherSuite)
+	fmt.Printf("TLS Version: %s\n", version)
+	fmt.Printf("Cipher Suite: %s\n", cipherSuite)
+	printPeerCertificates(state.PeerCertificates)
+}
+
+func tlsVersion(version uint16) string {
+	switch version {
+
+	case tls.VersionTLS13:
+		return "TLS 1.3"
+	case tls.VersionTLS12:
+
+		return "TLS 1.2"
+	case tls.VersionTLS11:
+		return "TLS 1.1"
+	case tls.VersionTLS10:
+		return "TLS 1.0"
+	default:
+		return "Unknown"
+	}
+}
+
+func printPeerCertificates(certificates []*x509.Certificate) {
+	for i, cert := range certificates {
+		fmt.Printf("Certificate %d\n", i+1)
+		fmt.Printf("\tSubject: %s\n", cert.Subject)
+		fmt.Printf("\tIssuer: %s\n", cert.Issuer)
+		fmt.Printf("\tDNS Names:	%v\n", cert.DNSNames)
+		fmt.Printf("\tNot Before: %s\n:", cert.NotBefore)
+		fmt.Printf("\tNot After: %s\n", cert.NotAfter)
+	}
+}

cmd/zsearch/main.go

@@ -68,7 +68,7 @@ func showFile(path string) {
 func searchFile(path string, search *regexp.Regexp) error {
 	file, err := os.Open(path)
 	if err != nil {
-		errorf("%v")
+		errorf("%v", err)
 		return err
 	}
 	defer file.Close()

config/config.go

@@ -11,7 +11,7 @@ package config
 import (
 	"bufio"
 	"fmt"
-	"log"
+	"maps"
 	"os"
 	"sort"
 	"strings"
@@ -33,14 +33,15 @@ func SetEnvPrefix(pfx string) {
 	prefix = pfx
 }
 
+const keyValueSplitLength = 2
+
 func addLine(line string) {
 	if strings.HasPrefix(line, "#") || line == "" {
 		return
 	}
 
-	lineParts := strings.SplitN(line, "=", 2)
+	lineParts := strings.SplitN(line, "=", keyValueSplitLength)
-	if len(lineParts) != 2 {
+	if len(lineParts) != keyValueSplitLength {
-		log.Print("skipping line: ", line)
 		return // silently ignore empty keys
 	}
 
@@ -49,7 +50,7 @@ func addLine(line string) {
 	vars[lineParts[0]] = lineParts[1]
 }
 
-// LoadFile scans the file at path for key=value pairs and adds them
+// LoadFile scans the file at 'path' for key=value pairs and adds them
 // to the configuration.
 func LoadFile(path string) error {
 	file, err := os.Open(path)
@@ -64,25 +65,19 @@ func LoadFile(path string) error {
 		addLine(line)
 	}
 
-	if err = scanner.Err(); err != nil {
+	return scanner.Err()
-		return err
 }
 
-	return nil
+// LoadFileFor scans the ini file at 'path', loading the default section
-}
+// and overriding any keys found under 'section'. If strict is true, the
-
+// named section must exist (i.e., to catch typos in the section name).
-// LoadFileFor scans the ini file at path, loading the default section
-// and overriding any keys found under section. If strict is true, the
-// named section must exist (i.e. to catch typos in the section name).
 func LoadFileFor(path, section string, strict bool) error {
 	cmap, err := iniconf.ParseFile(path)
 	if err != nil {
 		return err
 	}
 
-	for key, value := range cmap[iniconf.DefaultSection] {
+	maps.Copy(vars, cmap[iniconf.DefaultSection])
-		vars[key] = value
-	}
 
 	smap, ok := cmap[section]
 	if !ok {
@@ -92,9 +87,7 @@ func LoadFileFor(path, section string, strict bool) error {
 		return nil
 	}
 
-	for key, value := range smap {
+	maps.Copy(vars, smap)
-		vars[key] = value
-	}
 
 	return nil
 }
@@ -111,7 +104,7 @@ func Get(key string) string {
 
 // GetDefault retrieves a value from either a configuration file or
 // the environment. Note that value from a file will override
-// environment variables. If a value isn't found (e.g. Get returns an
+// environment variables. If a value isn't found (e.g., Get returns an
 // empty string), the default value will be used.
 func GetDefault(key, def string) string {
 	if v := Get(key); v != "" {
@@ -121,8 +114,7 @@ func GetDefault(key, def string) string {
 }
 
 // Require retrieves a value from either a configuration file or the
-// environment. If the key isn't present, it will call log.Fatal, printing
+// environment. If the key isn't present, it will panic.
-// the missing key.
 func Require(key string) string {
 	if v, ok := vars[key]; ok {
 		return v
@@ -135,7 +127,7 @@ func Require(key string) string {
 			envMessage = " (note: looked for the key " + prefix + key
 			envMessage += " in the local env)"
 		}
-		log.Fatalf("missing required configuration value %s%s", key, envMessage)
+		panic(fmt.Sprintf("missing required configuration value %s%s", key, envMessage))
 	}
 
 	return v
@@ -143,7 +135,8 @@ func Require(key string) string {
 
 // ListKeys returns a slice of the currently known keys.
 func ListKeys() []string {
-	keyList := []string{}
+	var keyList []string
+
 	for k := range vars {
 		keyList = append(keyList, k)
 	}

config/config_test.go

@@ -1,27 +1,26 @@
-package config
+package config_test
 
 import (
 	"os"
 	"testing"
+
+	"git.wntrmute.dev/kyle/goutils/config"
 )
 
 const (
 	testFilePath = "testdata/test.env"
 
-	// Keys
+	// Key constants.
 	kOrder   = "ORDER"
 	kSpecies = "SPECIES"
 	kName    = "COMMON_NAME"
 
-	// Env
 	eOrder   = "corvus"
 	eSpecies = "corvus corax"
 	eName    = "northern raven"
 
-	// File
 	fOrder   = "stringiformes"
 	fSpecies = "strix aluco"
-	// Name isn't set in the file to test fall through.
 )
 
 func init() {
@@ -31,8 +30,8 @@ func init() {
 }
 
 func TestLoadEnvOnly(t *testing.T) {
-	order := Get(kOrder)
+	order := config.Get(kOrder)
-	species := Get(kSpecies)
+	species := config.Get(kSpecies)
 	if order != eOrder {
 		t.Errorf("want %s, have %s", eOrder, order)
 	}
@@ -43,14 +42,14 @@ func TestLoadEnvOnly(t *testing.T) {
 }
 
 func TestLoadFile(t *testing.T) {
-	err := LoadFile(testFilePath)
+	err := config.LoadFile(testFilePath)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	order := Get(kOrder)
+	order := config.Get(kOrder)
-	species := Get(kSpecies)
+	species := config.Get(kSpecies)
-	name := Get(kName)
+	name := config.Get(kName)
 
 	if order != fOrder {
 		t.Errorf("want %s, have %s", fOrder, order)

config/iniconf/iniconf.go

@@ -2,6 +2,7 @@ package iniconf
 
 import (
 	"bufio"
+	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -23,86 +24,115 @@ var (
 var DefaultSection = "default"
 
 // ParseFile attempts to load the named config file.
-func ParseFile(fileName string) (cfg ConfigMap, err error) {
+func ParseFile(fileName string) (ConfigMap, error) {
-	var file *os.File
+	file, err := os.Open(fileName)
-	file, err = os.Open(fileName)
 	if err != nil {
-		return
+		return nil, err
 	}
 	defer file.Close()
+
 	return ParseReader(file)
 }
 
 // ParseReader reads a configuration from an io.Reader.
-func ParseReader(r io.Reader) (cfg ConfigMap, err error) {
+func ParseReader(r io.Reader) (ConfigMap, error) {
-	cfg = ConfigMap{}
+	cfg := ConfigMap{}
 	buf := bufio.NewReader(r)
 
 	var (
 		line           string
 		longLine       bool
 		currentSection string
-		lineBytes      []byte
+		err            error
-		isPrefix       bool
 	)
 
 	for {
-		err = nil
+		line, longLine, err = readConfigLine(buf, line, longLine)
-		lineBytes, isPrefix, err = buf.ReadLine()
+		if errors.Is(err, io.EOF) {
-		if io.EOF == err {
 			err = nil
 			break
 		} else if err != nil {
 			break
-		} else if isPrefix {
-			line += string(lineBytes)
-
-			longLine = true
-			continue
-		} else if longLine {
-			line += string(lineBytes)
-			longLine = false
-		} else {
-			line = string(lineBytes)
 		}
 
-		if commentLine.MatchString(line) {
+		if line == "" {
 			continue
-		} else if blankLine.MatchString(line) {
+		}
-			continue
+
-		} else if configSection.MatchString(line) {
+		currentSection, err = processConfigLine(cfg, line, currentSection)
-			section := configSection.ReplaceAllString(line,
+		if err != nil {
-				"$1")
-			if section == "" {
-				err = fmt.Errorf("invalid structure in file")
 			break
-			} else if !cfg.SectionInConfig(section) {
+		}
+	}
+
+	return cfg, err
+}
+
+// readConfigLine reads and assembles a complete configuration line, handling long lines.
+func readConfigLine(buf *bufio.Reader, currentLine string, longLine bool) (string, bool, error) {
+	lineBytes, isPrefix, err := buf.ReadLine()
+	if err != nil {
+		return "", false, err
+	}
+
+	if isPrefix {
+		return currentLine + string(lineBytes), true, nil
+	} else if longLine {
+		return currentLine + string(lineBytes), false, nil
+	}
+	return string(lineBytes), false, nil
+}
+
+// processConfigLine processes a single line and updates the configuration map.
+func processConfigLine(cfg ConfigMap, line string, currentSection string) (string, error) {
+	if commentLine.MatchString(line) || blankLine.MatchString(line) {
+		return currentSection, nil
+	}
+
+	if configSection.MatchString(line) {
+		return handleSectionLine(cfg, line)
+	}
+
+	if configLine.MatchString(line) {
+		return handleConfigLine(cfg, line, currentSection)
+	}
+
+	return currentSection, errors.New("invalid config file")
+}
+
+// handleSectionLine processes a section header line.
+func handleSectionLine(cfg ConfigMap, line string) (string, error) {
+	section := configSection.ReplaceAllString(line, "$1")
+	if section == "" {
+		return "", errors.New("invalid structure in file")
+	}
+	if !cfg.SectionInConfig(section) {
 		cfg[section] = make(map[string]string, 0)
 	}
-			currentSection = section
+	return section, nil
-		} else if configLine.MatchString(line) {
+}
+
+// handleConfigLine processes a key=value configuration line.
+func handleConfigLine(cfg ConfigMap, line string, currentSection string) (string, error) {
 	regex := configLine
 	if quotedConfigLine.MatchString(line) {
 		regex = quotedConfigLine
 	}
+
 	if currentSection == "" {
 		currentSection = DefaultSection
 		if !cfg.SectionInConfig(currentSection) {
 			cfg[currentSection] = map[string]string{}
 		}
 	}
+
 	key := regex.ReplaceAllString(line, "$1")
 	val := regex.ReplaceAllString(line, "$2")
-			if key == "" {
+	if key != "" {
-				continue
-			}
 		cfg[currentSection][key] = val
-		} else {
-			err = fmt.Errorf("invalid config file")
-			break
 	}
-	}
+
-	return
+	return currentSection, nil
 }
 
 // SectionInConfig determines whether a section is in the configuration.
@@ -112,41 +142,39 @@ func (c ConfigMap) SectionInConfig(section string) bool {
 }
 
 // ListSections returns the list of sections in the config map.
-func (c ConfigMap) ListSections() (sections []string) {
+func (c ConfigMap) ListSections() []string {
+	sections := make([]string, 0, len(c))
 	for section := range c {
 		sections = append(sections, section)
 	}
-	return
+	return sections
 }
 
 // WriteFile writes out the configuration to a file.
-func (c ConfigMap) WriteFile(filename string) (err error) {
+func (c ConfigMap) WriteFile(filename string) error {
 	file, err := os.Create(filename)
 	if err != nil {
-		return
+		return err
 	}
 	defer file.Close()
 
 	for _, section := range c.ListSections() {
 		sName := fmt.Sprintf("[ %s ]\n", section)
-		_, err = file.Write([]byte(sName))
+		if _, err = file.WriteString(sName); err != nil {
-		if err != nil {
+			return err
-			return
 		}
 
 		for k, v := range c[section] {
 			line := fmt.Sprintf("%s = %s\n", k, v)
-			_, err = file.Write([]byte(line))
+			if _, err = file.WriteString(line); err != nil {
-			if err != nil {
+				return err
-				return
 			}
 		}
-		_, err = file.Write([]byte{0x0a})
+		if _, err = file.Write([]byte{0x0a}); err != nil {
-		if err != nil {
+			return err
-			return
 		}
 	}
-	return
+	return nil
 }
 
 // AddSection creates a new section in the config map.
@@ -170,27 +198,26 @@ func (c ConfigMap) AddKeyVal(section, key, val string) {
 }
 
 // GetValue retrieves the value from a key map.
-func (c ConfigMap) GetValue(section, key string) (val string, present bool) {
+func (c ConfigMap) GetValue(section, key string) (string, bool) {
 	if c == nil {
-		return
+		return "", false
 	}
 
 	if section == "" {
 		section = DefaultSection
 	}
 
-	_, ok := c[section]
+	if _, ok := c[section]; !ok {
-	if !ok {
+		return "", false
-		return
 	}
 
-	val, present = c[section][key]
+	val, present := c[section][key]
-	return
+	return val, present
 }
 
 // GetValueDefault retrieves the value from a key map if present,
 // otherwise the default value.
-func (c ConfigMap) GetValueDefault(section, key, value string) (val string) {
+func (c ConfigMap) GetValueDefault(section, key, value string) string {
 	kval, ok := c.GetValue(section, key)
 	if !ok {
 		return value
@@ -199,7 +226,7 @@ func (c ConfigMap) GetValueDefault(section, key, value string) (val string) {
 }
 
 // SectionKeys returns the sections in the config map.
-func (c ConfigMap) SectionKeys(section string) (keys []string, present bool) {
+func (c ConfigMap) SectionKeys(section string) ([]string, bool) {
 	if c == nil {
 		return nil, false
 	}
@@ -208,13 +235,12 @@ func (c ConfigMap) SectionKeys(section string) (keys []string, present bool) {
 		section = DefaultSection
 	}
 
-	cm := c
+	s, ok := c[section]
-	s, ok := cm[section]
 	if !ok {
 		return nil, false
 	}
 
-	keys = make([]string, 0, len(s))
+	keys := make([]string, 0, len(s))
 	for key := range s {
 		keys = append(keys, key)
 	}

config/iniconf/iniconf_test.go

@@ -1,18 +1,19 @@
-package iniconf
+package iniconf_test
 
 import (
 	"errors"
-	"fmt"
 	"os"
 	"sort"
 	"testing"
+
+	"git.wntrmute.dev/kyle/goutils/config/iniconf"
 )
 
 // FailWithError is a utility for dumping errors and failing the test.
 func FailWithError(t *testing.T, err error) {
-	fmt.Println("failed")
+	t.Log("failed")
 	if err != nil {
-		fmt.Println("[!] ", err.Error())
+		t.Log("[!] ", err.Error())
 	}
 	t.FailNow()
 }
@@ -49,47 +50,50 @@ func stringSlicesEqual(slice1, slice2 []string) bool {
 
 func TestGoodConfig(t *testing.T) {
 	testFile := "testdata/test.conf"
-	fmt.Printf("[+] validating known-good config... ")
+	t.Logf("[+] validating known-good config... ")
-	cmap, err := ParseFile(testFile)
+	cmap, err := iniconf.ParseFile(testFile)
 	if err != nil {
 		FailWithError(t, err)
 	} else if len(cmap) != 2 {
 		FailWithError(t, err)
 	}
-	fmt.Println("ok")
+	t.Log("ok")
 }
 
 func TestGoodConfig2(t *testing.T) {
 	testFile := "testdata/test2.conf"
-	fmt.Printf("[+] validating second known-good config... ")
+	t.Logf("[+] validating second known-good config... ")
-	cmap, err := ParseFile(testFile)
+	cmap, err := iniconf.ParseFile(testFile)
-	if err != nil {
+	switch {
+	case err != nil:
 		FailWithError(t, err)
-	} else if len(cmap) != 1 {
+	case len(cmap) != 1:
 		FailWithError(t, err)
-	} else if len(cmap["default"]) != 3 {
+	case len(cmap["default"]) != 3:
 		FailWithError(t, err)
+	default:
+		// nothing to do here
 	}
-	fmt.Println("ok")
+	t.Log("ok")
 }
 
 func TestBadConfig(t *testing.T) {
 	testFile := "testdata/bad.conf"
-	fmt.Printf("[+] ensure invalid config file fails... ")
+	t.Logf("[+] ensure invalid config file fails... ")
-	_, err := ParseFile(testFile)
+	_, err := iniconf.ParseFile(testFile)
 	if err == nil {
-		err = fmt.Errorf("invalid config file should fail")
+		err = errors.New("invalid config file should fail")
 		FailWithError(t, err)
 	}
-	fmt.Println("ok")
+	t.Log("ok")
 }
 
 func TestWriteConfigFile(t *testing.T) {
-	fmt.Printf("[+] ensure config file is written properly... ")
+	t.Logf("[+] ensure config file is written properly... ")
 	const testFile = "testdata/test.conf"
 	const testOut = "testdata/test.out"
 
-	cmap, err := ParseFile(testFile)
+	cmap, err := iniconf.ParseFile(testFile)
 	if err != nil {
 		FailWithError(t, err)
 	}
@@ -100,7 +104,7 @@ func TestWriteConfigFile(t *testing.T) {
 		FailWithError(t, err)
 	}
 
-	cmap2, err := ParseFile(testOut)
+	cmap2, err := iniconf.ParseFile(testOut)
 	if err != nil {
 		FailWithError(t, err)
 	}
@@ -110,25 +114,25 @@ func TestWriteConfigFile(t *testing.T) {
 	sort.Strings(sectionList1)
 	sort.Strings(sectionList2)
 	if !stringSlicesEqual(sectionList1, sectionList2) {
-		err = fmt.Errorf("section lists don't match")
+		err = errors.New("section lists don't match")
 		FailWithError(t, err)
 	}
 
 	for _, section := range sectionList1 {
 		for _, k := range cmap[section] {
 			if cmap[section][k] != cmap2[section][k] {
-				err = fmt.Errorf("config key doesn't match")
+				err = errors.New("config key doesn't match")
 				FailWithError(t, err)
 			}
 		}
 	}
-	fmt.Println("ok")
+	t.Log("ok")
 }
 
 func TestQuotedValue(t *testing.T) {
 	testFile := "testdata/test.conf"
-	fmt.Printf("[+] validating quoted value... ")
+	t.Logf("[+] validating quoted value... ")
-	cmap, _ := ParseFile(testFile)
+	cmap, _ := iniconf.ParseFile(testFile)
 	val := cmap["sectionName"]["key4"]
 	if val != " space at beginning and end " {
 		FailWithError(t, errors.New("Wrong value in double quotes ["+val+"]"))
@@ -138,5 +142,5 @@ func TestQuotedValue(t *testing.T) {
 	if val != " is quoted with single quotes " {
 		FailWithError(t, errors.New("Wrong value in single quotes ["+val+"]"))
 	}
-	fmt.Println("ok")
+	t.Log("ok")
 }

config/path.go

@@ -1,5 +1,4 @@
 //go:build !linux
-// +build !linux
 
 package config
 

config/path_test.go

@@ -1,7 +1,11 @@
-package config
+package config_test
 
-import "testing"
+import (
+	"testing"
+
+	"git.wntrmute.dev/kyle/goutils/config"
+)
 
 func TestDefaultPath(t *testing.T) {
-	t.Log(DefaultConfigPath("demoapp", "app.conf"))
+	t.Log(config.DefaultConfigPath("demoapp", "app.conf"))
 }

dbg/dbg.go

@@ -47,7 +47,7 @@ func ToFile(path string) (*DebugPrinter, error) {
 	}, nil
 }
 
-// To sets up a new DebugPrint to an io.WriteCloser.
+// To will set up a new DebugPrint to an io.WriteCloser.
 func To(w io.WriteCloser) *DebugPrinter {
 	return &DebugPrinter{
 		out: w,
@@ -55,21 +55,21 @@ func To(w io.WriteCloser) *DebugPrinter {
 }
 
 // Print calls fmt.Print if Enabled is true.
-func (dbg *DebugPrinter) Print(v ...interface{}) {
+func (dbg *DebugPrinter) Print(v ...any) {
 	if dbg.Enabled {
 		fmt.Fprint(dbg.out, v...)
 	}
 }
 
 // Println calls fmt.Println if Enabled is true.
-func (dbg *DebugPrinter) Println(v ...interface{}) {
+func (dbg *DebugPrinter) Println(v ...any) {
 	if dbg.Enabled {
 		fmt.Fprintln(dbg.out, v...)
 	}
 }
 
 // Printf calls fmt.Printf if Enabled is true.
-func (dbg *DebugPrinter) Printf(format string, v ...interface{}) {
+func (dbg *DebugPrinter) Printf(format string, v ...any) {
 	if dbg.Enabled {
 		fmt.Fprintf(dbg.out, format, v...)
 	}

dbg/dbg_test.go

@@ -2,7 +2,6 @@ package dbg
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"testing"
 
@@ -50,7 +49,7 @@ func TestTo(t *testing.T) {
 }
 
 func TestToFile(t *testing.T) {
-	testFile, err := ioutil.TempFile("", "dbg")
+	testFile, err := os.CreateTemp(t.TempDir(), "dbg")
 	assert.NoErrorT(t, err)
 	err = testFile.Close()
 	assert.NoErrorT(t, err)
@@ -103,7 +102,7 @@ func TestWriting(t *testing.T) {
 }
 
 func TestToFileError(t *testing.T) {
-	testFile, err := ioutil.TempFile("", "dbg")
+	testFile, err := os.CreateTemp(t.TempDir(), "dbg")
 	assert.NoErrorT(t, err)
 	err = testFile.Chmod(0400)
 	assert.NoErrorT(t, err)

die/README.md

@@ -1,12 +0,0 @@
-Simple fatal utilities for Go programs.
-
-```
-	result, err := doSomething()
-	die.If(err)
-
-	ok := processResult(result)
-	if !ok {
-		die.With("failed to process result %s", result.Name)
-	}
-```
-

die/die.go

@@ -1,4 +1,5 @@
-// Package die contains utilities for fatal error handling.
+// Package die contains utilities for fatal error handling. It
+// presents simple fatal utilities for Go programs.
 package die
 
 import (
@@ -15,14 +16,14 @@ func If(err error) {
 }
 
 // With prints the message to stderr, appending a newline, and exits.
-func With(fstr string, args ...interface{}) {
+func With(fstr string, args ...any) {
 	out := fmt.Sprintf("[!] %s\n", fstr)
 	fmt.Fprintf(os.Stderr, out, args...)
 	os.Exit(1)
 }
 
 // When prints the error to stderr and exits if cond is true.
-func When(cond bool, fstr string, args ...interface{}) {
+func When(cond bool, fstr string, args ...any) {
 	if cond {
 		With(fstr, args...)
 	}

fileutil/fileutil.go

@@ -1,10 +1,10 @@
 //go:build !windows
-// +build !windows
 
 // Package fileutil contains common file functions.
 package fileutil
 
 import (
+	"math"
 	"os"
 
 	"golang.org/x/sys/unix"
@@ -46,5 +46,9 @@ const (
 // Access returns a boolean indicating whether the mode being checked
 // for is valid.
 func Access(path string, mode int) error {
-	return unix.Access(path, uint32(mode))
+	// Validate the conversion to avoid potential integer overflow (gosec G115).
+	if mode < 0 || uint64(mode) > uint64(math.MaxUint32) {
+		return unix.EINVAL
+	}
+	return unix.Access(path, uint32(mode)) // #nosec G115 - handled above.
 }

fileutil/fileutil_windows.go

@@ -1,5 +1,4 @@
 //go:build windows
-// +build windows
 
 // Package fileutil contains common file functions.
 package fileutil

go.mod

@@ -1,18 +1,18 @@
 module git.wntrmute.dev/kyle/goutils
 
-go 1.20
+go 1.24.0
 
 require (
 	github.com/hashicorp/go-syslog v1.0.0
 	github.com/kr/text v0.2.0
-	github.com/pkg/errors v0.9.1
 	github.com/pkg/sftp v1.12.0
-	golang.org/x/crypto v0.0.0-20220314234659-1baeb1ce4c0b
+	golang.org/x/crypto v0.44.0
-	golang.org/x/sys v0.0.0-20220412211240-33da011f77ad
+	golang.org/x/sys v0.38.0
 	gopkg.in/yaml.v2 v2.4.0
 )
 
 require (
+	github.com/benbjohnson/clock v1.3.5
 	github.com/davecgh/go-spew v1.1.1
 	github.com/google/certificate-transparency-go v1.0.21
 )
@@ -20,5 +20,6 @@ require (
 require (
 	github.com/kr/fs v0.1.0 // indirect
 	github.com/kr/pretty v0.1.0 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
 	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
 )

go.sum

@@ -1,3 +1,5 @@
+github.com/benbjohnson/clock v1.3.5 h1:VvXlSJBzZpA/zum6Sj74hxwYI2DIxRWuNIoXAzHZz5o=
+github.com/benbjohnson/clock v1.3.5/go.mod h1:J11/hYXuz8f4ySSvYwY0FKfm+ezbsZBKZxNJlLklBHA=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
@@ -25,14 +27,15 @@ github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20200820211705-5c72a883971a/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
-golang.org/x/crypto v0.0.0-20220314234659-1baeb1ce4c0b h1:Qwe1rC8PSniVfAFPFJeyUkB+zcysC3RgJBAGk7eqBEU=
+golang.org/x/crypto v0.44.0 h1:A97SsFvM3AIwEEmTBiaxPPTYpDC47w720rdiiUvgoAU=
-golang.org/x/crypto v0.0.0-20220314234659-1baeb1ce4c0b/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
+golang.org/x/crypto v0.44.0/go.mod h1:013i+Nw79BMiQiMsOPcVCB5ZIJbYkerPrGnOa00tvmc=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20220412211240-33da011f77ad h1:ntjMns5wyP/fN65tdBD4g8J5w8n015+iIIs9rtjXkY0=
+golang.org/x/sys v0.38.0 h1:3yZWxaJjBmCWXqhN1qh02AkOnCQ1poK6oF+a7xWL6Gc=
-golang.org/x/sys v0.0.0-20220412211240-33da011f77ad/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.38.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
-golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1 h1:v+OssWQX+hTHEmOBgwxdZxK4zHq3yOs8F9J7mk0PY8E=
+golang.org/x/term v0.37.0 h1:8EGAD0qCmHYZg6J17DvsMy9/wJ7/D/4pV/wfnld5lTU=
+golang.org/x/term v0.37.0/go.mod h1:5pB4lxRNYYVZuTLmy8oR2BH8dflOR+IbTYFD8fi3254=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=

lib/lib.go

@@ -11,7 +11,7 @@ import (
 var progname = filepath.Base(os.Args[0])
 
 // ProgName returns what lib thinks the program name is, namely the
-// basename of of argv0.
+// basename of argv0.
 //
 // It is similar to the Linux __progname function.
 func ProgName() string {

log/logger.go

@@ -1,4 +1,4 @@
-// Package syslog is a syslog-type facility for logging.
+// Package log is a syslog-type facility for logging.
 package log
 
 import (
@@ -17,7 +17,7 @@ type logger struct {
 	writeConsole bool
 }
 
-func (log *logger) printf(p gsyslog.Priority, format string, args ...interface{}) {
+func (log *logger) printf(p gsyslog.Priority, format string, args ...any) {
 	if !strings.HasSuffix(format, "\n") {
 		format += "\n"
 	}
@@ -28,33 +28,33 @@ func (log *logger) printf(p gsyslog.Priority, format string, args ...interface{}
 	}
 
 	if log.l != nil {
-		log.l.WriteLevel(p, []byte(fmt.Sprintf(format, args...)))
+		_ = log.l.WriteLevel(p, fmt.Appendf(nil, format, args...))
 	}
 }
 
-func (log *logger) print(p gsyslog.Priority, args ...interface{}) {
+func (log *logger) print(p gsyslog.Priority, args ...any) {
 	if p <= log.p && log.writeConsole {
 		fmt.Printf("%s [%s] ", prioritiev[p], timestamp())
 		fmt.Print(args...)
 	}
 
 	if log.l != nil {
-		log.l.WriteLevel(p, []byte(fmt.Sprint(args...)))
+		_ = log.l.WriteLevel(p, fmt.Append(nil, args...))
 	}
 }
 
-func (log *logger) println(p gsyslog.Priority, args ...interface{}) {
+func (log *logger) println(p gsyslog.Priority, args ...any) {
 	if p <= log.p && log.writeConsole {
 		fmt.Printf("%s [%s] ", prioritiev[p], timestamp())
 		fmt.Println(args...)
 	}
 
 	if log.l != nil {
-		log.l.WriteLevel(p, []byte(fmt.Sprintln(args...)))
+		_ = log.l.WriteLevel(p, fmt.Appendln(nil, args...))
 	}
 }
 
-func (log *logger) spew(args ...interface{}) {
+func (log *logger) spew(args ...any) {
 	if log.p == gsyslog.LOG_DEBUG {
 		spew.Dump(args...)
 	}
@@ -160,109 +160,109 @@ func Setup(opts *Options) error {
 	return nil
 }
 
-func Debug(args ...interface{}) {
+func Debug(args ...any) {
 	log.print(gsyslog.LOG_DEBUG, args...)
 }
 
-func Info(args ...interface{}) {
+func Info(args ...any) {
 	log.print(gsyslog.LOG_INFO, args...)
 }
 
-func Notice(args ...interface{}) {
+func Notice(args ...any) {
 	log.print(gsyslog.LOG_NOTICE, args...)
 }
 
-func Warning(args ...interface{}) {
+func Warning(args ...any) {
 	log.print(gsyslog.LOG_WARNING, args...)
 }
 
-func Err(args ...interface{}) {
+func Err(args ...any) {
 	log.print(gsyslog.LOG_ERR, args...)
 }
 
-func Crit(args ...interface{}) {
+func Crit(args ...any) {
 	log.print(gsyslog.LOG_CRIT, args...)
 }
 
-func Alert(args ...interface{}) {
+func Alert(args ...any) {
 	log.print(gsyslog.LOG_ALERT, args...)
 }
 
-func Emerg(args ...interface{}) {
+func Emerg(args ...any) {
 	log.print(gsyslog.LOG_EMERG, args...)
 }
 
-func Debugln(args ...interface{}) {
+func Debugln(args ...any) {
 	log.println(gsyslog.LOG_DEBUG, args...)
 }
 
-func Infoln(args ...interface{}) {
+func Infoln(args ...any) {
 	log.println(gsyslog.LOG_INFO, args...)
 }
 
-func Noticeln(args ...interface{}) {
+func Noticeln(args ...any) {
 	log.println(gsyslog.LOG_NOTICE, args...)
 }
 
-func Warningln(args ...interface{}) {
+func Warningln(args ...any) {
 	log.print(gsyslog.LOG_WARNING, args...)
 }
 
-func Errln(args ...interface{}) {
+func Errln(args ...any) {
 	log.println(gsyslog.LOG_ERR, args...)
 }
 
-func Critln(args ...interface{}) {
+func Critln(args ...any) {
 	log.println(gsyslog.LOG_CRIT, args...)
 }
 
-func Alertln(args ...interface{}) {
+func Alertln(args ...any) {
 	log.println(gsyslog.LOG_ALERT, args...)
 }
 
-func Emergln(args ...interface{}) {
+func Emergln(args ...any) {
 	log.println(gsyslog.LOG_EMERG, args...)
 }
 
-func Debugf(format string, args ...interface{}) {
+func Debugf(format string, args ...any) {
 	log.printf(gsyslog.LOG_DEBUG, format, args...)
 }
 
-func Infof(format string, args ...interface{}) {
+func Infof(format string, args ...any) {
 	log.printf(gsyslog.LOG_INFO, format, args...)
 }
 
-func Noticef(format string, args ...interface{}) {
+func Noticef(format string, args ...any) {
 	log.printf(gsyslog.LOG_NOTICE, format, args...)
 }
 
-func Warningf(format string, args ...interface{}) {
+func Warningf(format string, args ...any) {
 	log.printf(gsyslog.LOG_WARNING, format, args...)
 }
 
-func Errf(format string, args ...interface{}) {
+func Errf(format string, args ...any) {
 	log.printf(gsyslog.LOG_ERR, format, args...)
 }
 
-func Critf(format string, args ...interface{}) {
+func Critf(format string, args ...any) {
 	log.printf(gsyslog.LOG_CRIT, format, args...)
 }
 
-func Alertf(format string, args ...interface{}) {
+func Alertf(format string, args ...any) {
 	log.printf(gsyslog.LOG_ALERT, format, args...)
 }
 
-func Emergf(format string, args ...interface{}) {
+func Emergf(format string, args ...any) {
 	log.printf(gsyslog.LOG_EMERG, format, args...)
 	os.Exit(1)
 }
 
-func Fatal(args ...interface{}) {
+func Fatal(args ...any) {
 	log.println(gsyslog.LOG_ERR, args...)
 	os.Exit(1)
 }
 
-func Fatalf(format string, args ...interface{}) {
+func Fatalf(format string, args ...any) {
 	log.printf(gsyslog.LOG_ERR, format, args...)
 	os.Exit(1)
 }
@@ -279,7 +279,7 @@ func FatalError(err error, message string) {
 }
 
 // Spew will pretty print the args if the logger is set to DEBUG priority.
-func Spew(args ...interface{}) {
+func Spew(args ...any) {
 	log.spew(args...)
 }
 

logging/doc.go

@@ -11,5 +11,4 @@
 // This produces the output message
 //
 //	[2016-04-01T15:04:30-0700] [ERROR] [actor:serialiser event:failed to open file] error=is a directory path=data.bin
-//
 package logging

logging/example/example.go

@@ -25,8 +25,8 @@ func main() {
 
 	log.Info("example", "filelog test", nil)
 	exampleNewFromFile()
-	os.Remove("example.log")
+	_ = os.Remove("example.log")
-	os.Remove("example.err")
+	_ = os.Remove("example.err")
 }
 
 func exampleNewFromFile() {

logging/example_test.go

@@ -23,7 +23,7 @@ func Example() {
 		map[string]string{"when": time.Now().String()})
 }
 
-func ExampleNewFromFile() {
+func ExampleNewSplitFile() {
 	flog, err := logging.NewSplitFile("example.log", "example.err", true)
 	if err != nil {
 		log.Fatal("filelog", "failed to open logger",

logging/file.go

@@ -1,6 +1,9 @@
 package logging
 
-import "os"
+import (
+    "fmt"
+    "os"
+)
 
 // File writes its logs to file.
 type File struct {
@@ -8,22 +11,6 @@ type File struct {
 	*LogWriter
 }
 
-// Close calls close on the underlying log files.
-func (fl *File) Close() error {
-	if fl.fo != nil {
-		if err := fl.fo.Close(); err != nil {
-			return err
-		}
-		fl.fo = nil
-	}
-
-	if fl.fe != nil {
-		return fl.fe.Close()
-	}
-
-	return nil
-}
-
 // NewFile creates a new Logger that writes all logs to the file
 // specified by path. If overwrite is specified, the log file will be
 // truncated before writing. Otherwise, the log file will be appended
@@ -36,7 +23,7 @@ func NewFile(path string, overwrite bool) (*File, error) {
 	if overwrite {
 		fl.fo, err = os.Create(path)
 	} else {
-		fl.fo, err = os.OpenFile(path, os.O_WRONLY|os.O_APPEND, 0644)
+		fl.fo, err = os.OpenFile(path, os.O_WRONLY|os.O_APPEND, 0600) // #nosec G302
 	}
 
 	if err != nil {
@@ -59,7 +46,7 @@ func NewSplitFile(outpath, errpath string, overwrite bool) (*File, error) {
 	if overwrite {
 		fl.fo, err = os.Create(outpath)
 	} else {
-		fl.fo, err = os.OpenFile(outpath, os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0644)
+		fl.fo, err = os.OpenFile(outpath, os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0600)
 	}
 
 	if err != nil {
@@ -69,14 +56,51 @@ func NewSplitFile(outpath, errpath string, overwrite bool) (*File, error) {
 	if overwrite {
 		fl.fe, err = os.Create(errpath)
 	} else {
-		fl.fe, err = os.OpenFile(errpath, os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0644)
+		fl.fe, err = os.OpenFile(errpath, os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0600)
 	}
 
  if err != nil {
-		fl.Close()
+        if closeErr := fl.Close(); closeErr != nil {
+            return nil, fmt.Errorf("failed to open error log: cleanup close failed: %v: %w", closeErr, err)
+        }
         return nil, err
     }
 
 	fl.LogWriter = NewLogWriter(fl.fo, fl.fe)
 	return fl, nil
 }
+
+// Close calls close on the underlying log files.
+func (fl *File) Close() error {
+	if fl.fo != nil {
+		if err := fl.fo.Close(); err != nil {
+			return err
+		}
+		fl.fo = nil
+	}
+
+	if fl.fe != nil {
+		return fl.fe.Close()
+	}
+
+	return nil
+}
+
+func (fl *File) Flush() error {
+	if err := fl.fo.Sync(); err != nil {
+		return err
+	}
+	return fl.fe.Sync()
+}
+
+func (fl *File) Chmod(mode os.FileMode) error {
+    if err := fl.fo.Chmod(mode); err != nil {
+        return fmt.Errorf("failed to chmod output log: %w", err)
+    }
+
+    if err := fl.fe.Chmod(mode); err != nil {
+        return fmt.Errorf("failed to chmod error log: %w", err)
+    }
+
+    return nil
+}

logging/levels.go

@@ -32,31 +32,6 @@ const (
 // DefaultLevel is the default logging level when none is provided.
 const DefaultLevel = LevelInfo
 
-// Cheap integer to fixed-width decimal ASCII.  Give a negative width
-// to avoid zero-padding. (From log/log.go in the standard library).
-func itoa(i int, wid int) string {
-	// Assemble decimal in reverse order.
-	var b [20]byte
-	bp := len(b) - 1
-	for i >= 10 || wid > 1 {
-		wid--
-		q := i / 10
-		b[bp] = byte('0' + i - q*10)
-		bp--
-		i = q
-	}
-	// i < 10
-	b[bp] = byte('0' + i)
-	return string(b[bp:])
-}
-
-func writeToOut(level Level) bool {
-	if level < LevelWarning {
-		return true
-	}
-	return false
-}
-
 var levelPrefix = [...]string{
 	LevelDebug:    "DEBUG",
 	LevelInfo:     "INFO",

logging/log.go

@@ -1,6 +1,7 @@
 package logging
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -14,7 +15,7 @@ import (
 //  1. The **level** attaches a notion of priority to the log message.
 //     Several log levels are available:
 //
-//    + FATAL (32): the system is in an unsuable state, and cannot
+//     + FATAL (32): the system is in an unusable state and cannot
 //     continue to run. Most of the logging for this will cause the
 //     program to exit with an error code.
 //     + CRITICAL (16): critical conditions. The error, if uncorrected, is
@@ -34,9 +35,9 @@ import (
 //     typically much higher than errors). For example, repeated
 //     warnings might be a sign that the system is under attack.
 //     + INFO (2): informational message. This is a normal log message
-//      that is used to deliver information, such as recording
+//     used to deliver information, such as recording requests. Ops
-//      requests. Ops teams are never paged for informational
+//     teams are never paged for informational messages. This is the
-//      messages. This is the default log level.
+//     default log level.
 //     + DEBUG (1): debug-level message. These are only used during
 //     development or if a deployed system repeatedly sees abnormal
 //     errors.
@@ -65,10 +66,10 @@ import (
 //
 // will cover the header:
 //
-// + ``$1`` contains the timestamp
+// + “$1“ contains the timestamp
-// + ``$2`` contains the level
+// + “$2“ contains the level
-// + ``$3`` contains the actor
+// + “$3“ contains the actor
-// + ``$4`` contains the event
+// + “$4“ contains the event.
 type Logger interface {
 	// SetLevel sets the minimum log level.
 	SetLevel(Level)
@@ -131,7 +132,7 @@ func (lw *LogWriter) output(w io.Writer, lvl Level, actor, event string, attrs m
 }
 
 // Debug emits a debug-level message. These are only used during
-// development or if a deployed system repeatedly sees abnormal
+// development, or if a deployed system repeatedly sees abnormal
 // errors.
 //
 // Actor specifies the component emitting the message; event indicates
@@ -213,7 +214,7 @@ func (lw *LogWriter) Critical(actor, event string, attrs map[string]string) {
 	lw.output(lw.we, LevelCritical, actor, event, attrs)
 }
 
-// Fatal emits a message indicating that the system is in an unsuable
+// Fatal emits a message indicating that the system is in an unusable
 // state, and cannot continue to run. The program will exit with exit
 // code 1.
 //
@@ -229,9 +230,9 @@ func (lw *LogWriter) Fatal(actor, event string, attrs map[string]string) {
 	os.Exit(1)
 }
 
-// FatalCode emits a message indicating that the system is in an unsuable
+// FatalCode emits a message indicating that the system is in an unusable
 // state, and cannot continue to run. The program will exit with the
-// exit code speicfied in the exitcode argument.
+// exit code specified in the exitcode argument.
 //
 // Actor specifies the component emitting the message; event indicates
 // the event that caused the log message to be emitted. attrs is a map
@@ -245,7 +246,7 @@ func (lw *LogWriter) FatalCode(exitcode int, actor, event string, attrs map[stri
 	os.Exit(exitcode)
 }
 
-// FatalNoDie emits a message indicating that the system is in an unsuable
+// FatalNoDie emits a message indicating that the system is in an unusable
 // state, and cannot continue to run. The program will not exit; it is
 // assumed that the caller has some final clean up to perform.
 //
@@ -314,12 +315,18 @@ func (m *Multi) Status() error {
 }
 
 func (m *Multi) Close() error {
+	var errs []error
 	for _, l := range m.loggers {
-		l.Close()
+		if err := l.Close(); err != nil {
+			errs = append(errs, err)
+		}
 	}
 
+	if len(errs) == 0 {
 		return nil
 	}
+	return errors.Join(errs...)
+}
 
 func (m *Multi) Debug(actor, event string, attrs map[string]string) {
 	for _, l := range m.loggers {

logging/log_test.go

@@ -1,30 +1,32 @@
-package logging
+package logging_test
 
 import (
 	"bytes"
 	"fmt"
 	"os"
 	"testing"
+
+	"git.wntrmute.dev/kyle/goutils/logging"
 )
 
 // A list of implementations that should be tested.
-var implementations []Logger
+var implementations []logging.Logger
 
 func init() {
-	lw := NewLogWriter(&bytes.Buffer{}, nil)
+	lw := logging.NewLogWriter(&bytes.Buffer{}, nil)
-	cw := NewConsole()
+	cw := logging.NewConsole()
 
 	implementations = append(implementations, lw)
 	implementations = append(implementations, cw)
 }
 
 func TestFileSetup(t *testing.T) {
-	fw1, err := NewFile("fw1.log", true)
+	fw1, err := logging.NewFile("fw1.log", true)
 	if err != nil {
 		t.Fatalf("failed to create new file logger: %v", err)
 	}
 
-	fw2, err := NewSplitFile("fw2.log", "fw2.err", true)
+	fw2, err := logging.NewSplitFile("fw2.log", "fw2.err", true)
 	if err != nil {
 		t.Fatalf("failed to create new split file logger: %v", err)
 	}
@@ -33,7 +35,7 @@ func TestFileSetup(t *testing.T) {
 	implementations = append(implementations, fw2)
 }
 
-func TestImplementations(t *testing.T) {
+func TestImplementations(_ *testing.T) {
 	for _, l := range implementations {
 		l.Info("TestImplementations", "Info message",
 			map[string]string{"type": fmt.Sprintf("%T", l)})
@@ -44,20 +46,30 @@ func TestImplementations(t *testing.T) {
 
 func TestCloseLoggers(t *testing.T) {
 	for _, l := range implementations {
-		l.Close()
+		if err := l.Close(); err != nil {
+			t.Errorf("failed to close logger: %v", err)
+		}
 	}
 }
 
 func TestDestroyLogFiles(t *testing.T) {
-	os.Remove("fw1.log")
+	if err := os.Remove("fw1.log"); err != nil {
-	os.Remove("fw2.log")
+		t.Errorf("failed to remove fw1.log: %v", err)
-	os.Remove("fw2.err")
+	}
+
+	if err := os.Remove("fw2.log"); err != nil {
+		t.Errorf("failed to remove fw2.log: %v", err)
+	}
+
+	if err := os.Remove("fw2.err"); err != nil {
+		t.Errorf("failed to remove fw2.err: %v", err)
+	}
 }
 
 func TestMulti(t *testing.T) {
-	c1 := NewConsole()
+	c1 := logging.NewConsole()
-	c2 := NewConsole()
+	c2 := logging.NewConsole()
-	m := NewMulti(c1, c2)
+	m := logging.NewMulti(c1, c2)
 	if !m.Good() {
 		t.Fatal("failed to set up multi logger")
 	}

mwc/mwc.go

@@ -8,15 +8,15 @@ type mwc struct {
 }
 
 // Write implements the Writer interface.
-func (t *mwc) Write(p []byte) (n int, err error) {
+func (t *mwc) Write(p []byte) (int, error) {
 	for _, w := range t.wcs {
-		n, err = w.Write(p)
+		n, err := w.Write(p)
 		if err != nil {
-			return
+			return n, err
 		}
 		if n != len(p) {
 			err = io.ErrShortWrite
-			return
+			return n, err
 		}
 	}
 	return len(p), nil

mwc/mwc_test.go

@@ -1,10 +1,11 @@
-package mwc
+package mwc_test
 
 import (
 	"bytes"
 	"testing"
 
 	"git.wntrmute.dev/kyle/goutils/assert"
+	"git.wntrmute.dev/kyle/goutils/mwc"
 	"git.wntrmute.dev/kyle/goutils/testio"
 )
 
@@ -12,7 +13,7 @@ func TestMWC(t *testing.T) {
 	buf1 := testio.NewBufCloser(nil)
 	buf2 := testio.NewBufCloser(nil)
 
-	mwc := MultiWriteCloser(buf1, buf2)
+	mwc := mwc.MultiWriteCloser(buf1, buf2)
 
 	_, err := mwc.Write([]byte("hello, world"))
 	assert.NoErrorT(t, err)
@@ -30,15 +31,15 @@ func TestMWCShort(t *testing.T) {
 	buf3 := testio.NewBrokenWriter(5)
 	buf4 := testio.NewSilentBrokenWriter(5)
 
-	mwc := MultiWriteCloser(buf1, buf2, buf3)
+	multiWriter := mwc.MultiWriteCloser(buf1, buf2, buf3)
-	defer mwc.Close()
+	defer multiWriter.Close()
 
-	_, err := mwc.Write([]byte("hello, world"))
+	_, err := multiWriter.Write([]byte("hello, world"))
 	assert.ErrorT(t, err, "expected a short write error", "but no error occurred")
-	mwc.Close()
+	multiWriter.Close()
 
-	mwc = MultiWriteCloser(buf1, buf2, buf4)
+	multiWriter = mwc.MultiWriteCloser(buf1, buf2, buf4)
-	_, err = mwc.Write([]byte("hello, world"))
+	_, err = multiWriter.Write([]byte("hello, world"))
 	assert.ErrorT(t, err, "expected a short write error", "but no error occurred")
 }
 
@@ -47,7 +48,7 @@ func TestMWCClose(t *testing.T) {
 	buf2 := testio.NewBufCloser(nil)
 	buf3 := testio.NewBrokenCloser(nil)
 
-	mwc := MultiWriteCloser(buf1, buf2, buf3)
+	mwc := mwc.MultiWriteCloser(buf1, buf2, buf3)
 	_, err := mwc.Write([]byte("hello, world"))
 	assert.NoErrorT(t, err)
 

rand/rand.go

@@ -1,49 +0,0 @@
-// Package rand contains utilities for interacting with math/rand, including
-// seeding from a random sed.
-package rand
-
-import (
-	"crypto/rand"
-	"encoding/binary"
-	mrand "math/rand"
-)
-
-// CryptoUint64 generates a cryptographically-secure 64-bit integer.
-func CryptoUint64() (uint64, error) {
-	bs := make([]byte, 8)
-	_, err := rand.Read(bs)
-	if err != nil {
-		return 0, err
-	}
-
-	return binary.BigEndian.Uint64(bs), nil
-}
-
-// Seed initialises the non-cryptographic PRNG with a random,
-// cryptographically secure value. This is done just as a good
-// way to make this random. The returned 64-bit value is the seed.
-func Seed() (uint64, error) {
-	seed, err := CryptoUint64()
-	if err != nil {
-		return 0, err
-	}
-
-	// NB: this is permitted.
-	mrand.Seed(int64(seed))
-	return seed, nil
-}
-
-// Int is a wrapper for math.Int so only one package needs to be imported.
-func Int() int {
-	return mrand.Int()
-}
-
-// Intn is a wrapper for math.Intn so only one package needs to be imported.
-func Intn(max int) int {
-	return mrand.Intn(max)
-}
-
-// Intn2 returns a random value between min and max, inclusive.
-func Intn2(min, max int) int {
-	return Intn(max-min) + min
-}

rand/rand_test.go

@@ -1,74 +0,0 @@
-package rand
-
-import (
-	"fmt"
-	mrand "math/rand"
-	"testing"
-)
-
-func TestCryptoUint64(t *testing.T) {
-	n1, err := CryptoUint64()
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	n2, err := CryptoUint64()
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	// This has such a low chance of occurring that it's likely to be
-	// indicative of a bad CSPRNG.
-	if n1 == n2 {
-		t.Fatalf("repeated random uint64s: %d", n1)
-	}
-}
-
-func TestIntn(t *testing.T) {
-	expected := []int{3081, 4887, 4847, 1059, 3081}
-	mrand.Seed(1)
-	for i := 0; i < 5; i++ {
-		n := Intn2(1000, 5000)
-
-		if n != expected[i] {
-			fmt.Printf("invalid sequence at %d: expected %d, have %d", i, expected[i], n)
-		}
-	}
-}
-
-func TestSeed(t *testing.T) {
-	seed1, err := Seed()
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	var seed2 uint64
-	n1 := Int()
-	tries := 0
-
-	for {
-		seed2, err = Seed()
-		if err != nil {
-			t.Fatal(err)
-		}
-
-		if seed1 != seed2 {
-			break
-		}
-
-		tries++
-
-		if tries > 3 {
-			t.Fatal("can't generate two unique seeds")
-		}
-	}
-
-	n2 := Int()
-
-	// Again, this not impossible, merely statistically improbably and a
-	// potential canary for RNG issues.
-	if n1 == n2 {
-		t.Fatalf("repeated integers fresh from two unique seeds: %d/%d -> %d",
-			seed1, seed2, n1)
-	}
-}

sbuf/sbuf.go

@@ -15,7 +15,7 @@ func zero(in []byte, n int) {
 		stop = len(in)
 	}
 
-	for i := 0; i < stop; i++ {
+	for i := range stop {
 		in[i] ^= in[i]
 	}
 }
@@ -37,7 +37,10 @@ func NewBuffer(n int) *Buffer {
 // original data will be wiped.
 func NewBufferFrom(p []byte) *Buffer {
 	buf := NewBuffer(len(p))
-	buf.Write(p)
+	_, err := buf.Write(p)
+	if err != nil {
+		return nil
+	}
 	zero(p, len(p))
 	return buf
 }
@@ -54,10 +57,7 @@ func (buf *Buffer) Read(p []byte) (int, error) {
 		return 0, io.EOF
 	}
 
-	copyLength := len(p)
+	copyLength := min(len(p), len(buf.buf))
-	if copyLength > len(buf.buf) {
-		copyLength = len(buf.buf)
-	}
 
 	copy(p, buf.buf)
 	zero(buf.buf, len(p))
@@ -91,10 +91,7 @@ func (buf *Buffer) Write(p []byte) (int, error) {
 	r := len(buf.buf) + len(p)
 	if cap(buf.buf) < r {
 		l := r
-		for {
+		for l <= r {
-			if l > r {
-				break
-			}
 			l *= 2
 		}
 		buf.grow(l - cap(buf.buf))
@@ -107,7 +104,7 @@ func (buf *Buffer) Write(p []byte) (int, error) {
 func (buf *Buffer) WriteByte(c byte) error {
 	r := len(buf.buf) + 1
 	if cap(buf.buf) < r {
-		l := r * 2
+		l := r << 1
 		buf.grow(l - cap(buf.buf))
 	}
 	buf.buf = append(buf.buf, c)
@@ -138,7 +135,7 @@ func (buf *Buffer) Bytes() []byte {
 	}
 
 	p := make([]byte, buf.Len())
-	buf.Read(p)
+	_, _ = buf.Read(p)
 	buf.Close()
 	return p
 }

sbuf/sbuf_test.go

@@ -1,15 +1,16 @@
-package sbuf
+package sbuf_test
 
 import (
 	"bytes"
 	"crypto/rand"
 	"testing"
 
+	"git.wntrmute.dev/kyle/goutils/sbuf"
 	"golang.org/x/crypto/nacl/box"
 )
 
 var (
-	buf          = &Buffer{}
+	buf          = &sbuf.Buffer{}
 	testMessage1 = []byte("round and round and round we go, where we stop, no one knows")
 	testMessage2 = []byte("the deconstruction of falling stars")
 )
@@ -113,23 +114,23 @@ func TestShortRead(t *testing.T) {
 }
 
 func TestNewBuffer(t *testing.T) {
-	buf := NewBuffer(32)
+	testBuffer := sbuf.NewBuffer(32)
-	if len(buf.buf) != 0 {
+	if testBuffer.Len() != 0 {
 		t.Fatalf("expected new buffer length to be 0, have %d",
-			len(buf.buf))
+			testBuffer.Len())
 	}
 
-	if cap(buf.buf) != 32 {
+	if testBuffer.Cap() != 32 {
 		t.Fatalf("expected new buffer capacity to be 0, have %d",
-			cap(buf.buf))
+			testBuffer.Cap())
 	}
 }
 
 func TestNewBufferFrom(t *testing.T) {
 	p := make([]byte, len(testMessage1))
 	copy(p, testMessage1)
-	buf := NewBufferFrom(p)
+	testBuffer := sbuf.NewBufferFrom(p)
-	if !bytes.Equal(buf.buf, testMessage1) {
+	if !bytes.Equal(testBuffer.Bytes(), testMessage1) {
 		t.Fatal("new buffer wasn't constructed properly")
 	}
 }
@@ -137,10 +138,10 @@ func TestNewBufferFrom(t *testing.T) {
 func TestBytes(t *testing.T) {
 	p := make([]byte, len(testMessage1))
 	copy(p, testMessage1)
-	buf := NewBufferFrom(p)
+	testBuffer := sbuf.NewBufferFrom(p)
 
-	out := buf.Bytes()
+	out := testBuffer.Bytes()
-	if buf.buf != nil {
+	if testBuffer.Len() != 0 {
 		t.Fatal("buffer was not closed")
 	}
 
@@ -148,21 +149,21 @@ func TestBytes(t *testing.T) {
 		t.Fatal("buffer did not return the right data")
 	}
 
-	out = buf.Bytes()
+	out = testBuffer.Bytes()
 	if out != nil {
 		t.Fatal("a closed buffer should return nil for Bytes")
 	}
 }
 
 func TestRWByte(t *testing.T) {
-	buf := NewBuffer(0)
+	testBuffer := sbuf.NewBuffer(0)
 	c := byte(42)
-	err := buf.WriteByte(c)
+	err := testBuffer.WriteByte(c)
 	if err != nil {
 		t.Fatalf("%v", err)
 	}
 
-	c, err = buf.ReadByte()
+	c, err = testBuffer.ReadByte()
 	if err != nil {
 		t.Fatalf("%v", err)
 	}
@@ -171,22 +172,21 @@ func TestRWByte(t *testing.T) {
 		t.Fatalf("Expected 42, have %d", c)
 	}
 
-	_, err = buf.ReadByte()
+	_, err = testBuffer.ReadByte()
 	if err == nil {
 		t.Fatal("Expected EOF")
 	}
 }
 
 func BenchmarkRead(b *testing.B) {
-	b.N = 2000
 	pub, priv, err := box.GenerateKey(rand.Reader)
 	if err != nil {
 		b.Fatalf("%v", err)
 	}
 	b.ReportAllocs()
 
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
-		_, err := buf.Write(priv[:])
+		_, err = buf.Write(priv[:])
 		if err != nil {
 			b.Fatalf("%v", err)
 		}
@@ -204,11 +204,11 @@ func BenchmarkFixed(b *testing.B) {
 		b.Fatalf("%v", err)
 	}
 
-	buf = NewBuffer(64 * b.N)
+	buf = sbuf.NewBuffer(64 * b.N)
 	b.ReportAllocs()
 
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
-		_, err := buf.Write(priv[:])
+		_, err = buf.Write(priv[:])
 		if err != nil {
 			b.Fatalf("%v", err)
 		}

seekbuf/seekbuf_test.go

@@ -1,18 +1,20 @@
-package seekbuf
+package seekbuf_test
 
 import (
 	"fmt"
 	"testing"
 
 	"git.wntrmute.dev/kyle/goutils/assert"
+	"git.wntrmute.dev/kyle/goutils/seekbuf"
 )
 
 func TestSeeking(t *testing.T) {
 	partA := []byte("hello, ")
 	partB := []byte("world!")
 
-	buf := New(partA)
+	buf := seekbuf.New(partA)
-	assert.BoolT(t, buf.Len() == len(partA), fmt.Sprintf("on init: have length %d, want length %d", buf.Len(), len(partA)))
+	assert.BoolT(t, buf.Len() == len(partA),
+		fmt.Sprintf("on init: have length %d, want length %d", buf.Len(), len(partA)))
 
 	b := make([]byte, 32)
 
@@ -32,7 +34,8 @@ func TestSeeking(t *testing.T) {
 
 	partsLen := len(partA) + len(partB)
 	buf.Rewind()
-	assert.BoolT(t, buf.Len() == partsLen, fmt.Sprintf("after rewinding: have length %d, want length %d", buf.Len(), partsLen))
+	assert.BoolT(t, buf.Len() == partsLen,
+		fmt.Sprintf("after rewinding: have length %d, want length %d", buf.Len(), partsLen))
 
 	buf.Close()
 	assert.BoolT(t, buf.Len() == 0, fmt.Sprintf("after closing, have length %d, want length 0", buf.Len()))

tee/tee.go

@@ -17,23 +17,6 @@ type Tee struct {
 	Verbose bool
 }
 
-func (t *Tee) Write(p []byte) (int, error) {
-	n, err := os.Stdout.Write(p)
-	if err != nil {
-		return n, err
-	}
-
-	if t.f != nil {
-		return t.f.Write(p)
-	}
-	return n, nil
-}
-
-// Close calls Close on the underlying file.
-func (t *Tee) Close() error {
-	return t.f.Close()
-}
-
 // NewOut writes to standard output only. The file is created, not
 // appended to.
 func NewOut(logFile string) (*Tee, error) {
@@ -48,9 +31,32 @@ func NewOut(logFile string) (*Tee, error) {
 	return &Tee{f: f}, nil
 }
 
+func (t *Tee) Write(p []byte) (int, error) {
+	n, err := os.Stdout.Write(p)
+	if err != nil {
+		return n, err
+	}
+
+	if t.f != nil {
+		return t.f.Write(p)
+	}
+	return n, nil
+}
+
+// Close calls Close on the underlying file if present.
+// It is safe to call Close on a Tee with no file; in that case, it returns nil.
+func (t *Tee) Close() error {
+	if t == nil || t.f == nil {
+		return nil
+	}
+	err := t.f.Close()
+	t.f = nil
+	return err
+}
+
 // Printf formats according to a format specifier and writes to the
 // tee instance.
-func (t *Tee) Printf(format string, args ...interface{}) (int, error) {
+func (t *Tee) Printf(format string, args ...any) (int, error) {
 	s := fmt.Sprintf(format, args...)
 	n, err := os.Stdout.WriteString(s)
 	if err != nil {
@@ -66,7 +72,7 @@ func (t *Tee) Printf(format string, args ...interface{}) (int, error) {
 
 // VPrintf is a variant of Printf that only prints if the Tee's
 // Verbose flag is set.
-func (t *Tee) VPrintf(format string, args ...interface{}) (int, error) {
+func (t *Tee) VPrintf(format string, args ...any) (int, error) {
 	if t.Verbose {
 		return t.Printf(format, args...)
 	}
@@ -87,12 +93,12 @@ func Open(logFile string) error {
 
 // Printf formats according to a format specifier and writes to the
 // global tee.
-func Printf(format string, args ...interface{}) (int, error) {
+func Printf(format string, args ...any) (int, error) {
 	return globalTee.Printf(format, args...)
 }
 
 // VPrintf calls VPrintf on the global tee instance.
-func VPrintf(format string, args ...interface{}) (int, error) {
+func VPrintf(format string, args ...any) (int, error) {
 	return globalTee.VPrintf(format, args...)
 }
 

tee/tee_test.go

@@ -0,0 +1,197 @@
+package tee_test
+
+import (
+	"io"
+	"os"
+	"path/filepath"
+	"testing"
+
+	tee "git.wntrmute.dev/kyle/goutils/tee"
+)
+
+// captureStdout redirects os.Stdout for the duration of fn and returns what was written.
+func captureStdout(t *testing.T, fn func()) string {
+	t.Helper()
+	r, w, err := os.Pipe()
+	if err != nil {
+		t.Fatalf("pipe: %v", err)
+	}
+	old := os.Stdout
+	os.Stdout = w
+	defer func() { os.Stdout = old }()
+
+	fn()
+
+	// Close writer to unblock reader and restore stdout
+	_ = w.Close()
+	b, _ := io.ReadAll(r)
+	_ = r.Close()
+	return string(b)
+}
+
+func TestNewOutEmpty_WritesToStdoutOnly(t *testing.T) {
+	teeInst, err := tee.NewOut("")
+	if err != nil {
+		t.Fatalf("NewOut: %v", err)
+	}
+
+	out := captureStdout(t, func() {
+		var n int
+		if n, err = teeInst.Write([]byte("abc")); err != nil || n != 3 {
+			t.Fatalf("Write got n=%d err=%v", n, err)
+		}
+
+		if n, err = teeInst.Printf("-%d-", 7); err != nil || n != len("-7-") {
+			t.Fatalf("Printf got n=%d err=%v", n, err)
+		}
+	})
+
+	if out != "abc-7-" {
+		t.Fatalf("stdout = %q, want %q", out, "abc-7-")
+	}
+}
+
+func TestNewOutWithFile_WritesToBoth(t *testing.T) {
+	dir := t.TempDir()
+	logPath := filepath.Join(dir, "log.txt")
+
+	teeInst, err := tee.NewOut(logPath)
+	if err != nil {
+		t.Fatalf("NewOut: %v", err)
+	}
+	defer func() { _ = teeInst.Close() }()
+
+	out := captureStdout(t, func() {
+		if _, err = teeInst.Write([]byte("x")); err != nil {
+			t.Fatalf("Write: %v", err)
+		}
+		if _, err = teeInst.Printf("%s", "y"); err != nil {
+			t.Fatalf("Printf: %v", err)
+		}
+	})
+
+	if out != "xy" {
+		t.Fatalf("stdout = %q, want %q", out, "xy")
+	}
+
+	// Close to flush and release the file before reading
+	if err = teeInst.Close(); err != nil {
+		t.Fatalf("Close: %v", err)
+	}
+
+	data, err := os.ReadFile(logPath)
+	if err != nil {
+		t.Fatalf("ReadFile: %v", err)
+	}
+	if string(data) != "xy" {
+		t.Fatalf("file content = %q, want %q", string(data), "xy")
+	}
+}
+
+func TestVPrintf_VerboseToggle(t *testing.T) {
+	teeInst := &tee.Tee{} // stdout only
+
+	out := captureStdout(t, func() {
+		if n, err := teeInst.VPrintf("hello"); err != nil || n != 0 {
+			t.Fatalf("VPrintf (quiet) got n=%d err=%v", n, err)
+		}
+	})
+	if out != "" {
+		t.Fatalf("stdout = %q, want empty when not verbose", out)
+	}
+
+	teeInst.Verbose = true
+	out = captureStdout(t, func() {
+		if n, err := teeInst.VPrintf("%s", "hello"); err != nil || n != len("hello") {
+			t.Fatalf("VPrintf (verbose) got n=%d err=%v", n, err)
+		}
+	})
+	if out != "hello" {
+		t.Fatalf("stdout = %q, want %q", out, "hello")
+	}
+}
+
+func TestWrite_StdoutErrorDoesNotWriteToFile(t *testing.T) {
+	dir := t.TempDir()
+	logPath := filepath.Join(dir, "log.txt")
+	teeInst, err := tee.NewOut(logPath)
+	if err != nil {
+		t.Fatalf("NewOut: %v", err)
+	}
+	defer func() { _ = teeInst.Close() }()
+
+	// Replace stdout with a closed pipe writer to force write error.
+	r, w, err := os.Pipe()
+	if err != nil {
+		t.Fatalf("pipe: %v", err)
+	}
+	old := os.Stdout
+	os.Stdout = w
+	_ = w.Close() // immediately close to cause EPIPE on write
+	defer func() {
+		os.Stdout = old
+		_ = r.Close()
+	}()
+
+	var n int
+	if n, err = teeInst.Write([]byte("abc")); err == nil {
+		t.Fatalf("expected error writing to closed stdout, got n=%d err=nil", n)
+	}
+
+	// Ensure file remained empty because stdout write failed first.
+	_ = teeInst.Close()
+	data, err := os.ReadFile(logPath)
+	if err != nil {
+		t.Fatalf("ReadFile: %v", err)
+	}
+	if len(data) != 0 {
+		t.Fatalf("file content = %q, want empty due to stdout failure", string(data))
+	}
+}
+
+func TestGlobal_OpenPrintfVPrintfClose(t *testing.T) {
+	// Ensure a clean slate for global tee
+	_ = tee.Close()
+	tee.SetVerbose(false)
+
+	dir := t.TempDir()
+	logPath := filepath.Join(dir, "glog.txt")
+
+	if err := tee.Open(logPath); err != nil {
+		t.Fatalf("Open: %v", err)
+	}
+
+	out := captureStdout(t, func() {
+		if _, err := tee.Printf("A"); err != nil {
+			t.Fatalf("Printf: %v", err)
+		}
+		// Not verbose yet, should not print
+		if n, err := tee.VPrintf("B"); err != nil || n != 0 {
+			t.Fatalf("VPrintf (quiet) n=%d err=%v", n, err)
+		}
+		tee.SetVerbose(true)
+		if _, err := tee.VPrintf("C%d", 1); err != nil {
+			t.Fatalf("VPrintf (verbose): %v", err)
+		}
+	})
+
+	if out != "AC1" {
+		t.Fatalf("stdout = %q, want %q", out, "AC1")
+	}
+
+	if err := tee.Close(); err != nil {
+		t.Fatalf("Close: %v", err)
+	}
+
+	data, err := os.ReadFile(logPath)
+	if err != nil {
+		t.Fatalf("ReadFile: %v", err)
+	}
+	if string(data) != "AC1" {
+		t.Fatalf("file content = %q, want %q", string(data), "AC1")
+	}
+
+	// Reset global tee for other tests/packages
+	_ = tee.Close()
+	tee.SetVerbose(false)
+}

testio/testio.go

@@ -169,6 +169,26 @@ type BufCloser struct {
 	buf *bytes.Buffer
 }
 
+// NewBufCloser creates and initializes a new BufCloser using buf as
+// its initial contents. It is intended to prepare a BufCloser to read
+// existing data. It can also be used to size the internal buffer for
+// writing. To do that, buf should have the desired capacity but a
+// length of zero.
+func NewBufCloser(buf []byte) *BufCloser {
+	bc := new(BufCloser)
+	bc.buf = bytes.NewBuffer(buf)
+	return bc
+}
+
+// NewBufCloserString creates and initializes a new Buffer using
+// string s as its initial contents. It is intended to prepare a
+// buffer to read an existing string.
+func NewBufCloserString(s string) *BufCloser {
+	buf := new(BufCloser)
+	buf.buf = bytes.NewBufferString(s)
+	return buf
+}
+
 // Write writes the data to the BufCloser.
 func (buf *BufCloser) Write(p []byte) (int, error) {
 	return buf.buf.Write(p)
@@ -199,26 +219,6 @@ func (buf *BufCloser) Len() int {
 	return buf.buf.Len()
 }
 
-// NewBufCloser creates and initializes a new BufCloser using buf as
-// its initial contents. It is intended to prepare a BufCloser to read
-// existing data. It can also be used to size the internal buffer for
-// writing. To do that, buf should have the desired capacity but a
-// length of zero.
-func NewBufCloser(buf []byte) *BufCloser {
-	bc := new(BufCloser)
-	bc.buf = bytes.NewBuffer(buf)
-	return bc
-}
-
-// NewBufCloserString creates and initializes a new Buffer using
-// string s as its initial contents. It is intended to prepare a
-// buffer to read an existing string.
-func NewBufCloserString(s string) *BufCloser {
-	buf := new(BufCloser)
-	buf.buf = bytes.NewBufferString(s)
-	return buf
-}
-
 // A LoggingBuffer is an io.ReadWriter that prints the hex value of
 // the data for all reads and writes.
 type LoggingBuffer struct {
@@ -323,6 +323,26 @@ type BrokenCloser struct {
 	buf *bytes.Buffer
 }
 
+// NewBrokenCloser creates and initializes a new BrokenCloser using buf as
+// its initial contents. It is intended to prepare a BrokenCloser to read
+// existing data. It can also be used to size the internal buffer for
+// writing. To do that, buf should have the desired capacity but a
+// length of zero.
+func NewBrokenCloser(buf []byte) *BrokenCloser {
+	bc := new(BrokenCloser)
+	bc.buf = bytes.NewBuffer(buf)
+	return bc
+}
+
+// NewBrokenCloserString creates and initializes a new Buffer using
+// string s as its initial contents. It is intended to prepare a
+// buffer to read an existing string.
+func NewBrokenCloserString(s string) *BrokenCloser {
+	buf := new(BrokenCloser)
+	buf.buf = bytes.NewBufferString(s)
+	return buf
+}
+
 // Write writes the data to the BrokenCloser.
 func (buf *BrokenCloser) Write(p []byte) (int, error) {
 	return buf.buf.Write(p)
@@ -347,23 +367,3 @@ func (buf *BrokenCloser) Reset() {
 func (buf *BrokenCloser) Bytes() []byte {
 	return buf.buf.Bytes()
 }
-
-// NewBrokenCloser creates and initializes a new BrokenCloser using buf as
-// its initial contents. It is intended to prepare a BrokenCloser to read
-// existing data. It can also be used to size the internal buffer for
-// writing. To do that, buf should have the desired capacity but a
-// length of zero.
-func NewBrokenCloser(buf []byte) *BrokenCloser {
-	bc := new(BrokenCloser)
-	bc.buf = bytes.NewBuffer(buf)
-	return bc
-}
-
-// NewBrokenCloserString creates and initializes a new Buffer using
-// string s as its initial contents. It is intended to prepare a
-// buffer to read an existing string.
-func NewBrokenCloserString(s string) *BrokenCloser {
-	buf := new(BrokenCloser)
-	buf.buf = bytes.NewBufferString(s)
-	return buf
-}

testio/testio_test.go

@@ -1,13 +1,15 @@
-package testio
+package testio_test
 
 import (
 	"bytes"
 	"os"
 	"testing"
+
+	"git.wntrmute.dev/kyle/goutils/testio"
 )
 
 func TestBrokenWriter(t *testing.T) {
-	buf := NewBrokenWriter(2)
+	buf := testio.NewBrokenWriter(2)
 	data := []byte{1, 2}
 
 	n, err := buf.Write(data)
@@ -39,7 +41,7 @@ func TestBufCloser(t *testing.T) {
 	var data = []byte{1, 2}
 	var read = make([]byte, 2)
 
-	buf := NewBufCloser(data)
+	buf := testio.NewBufCloser(data)
 	_, err := buf.Read(read)
 	if err != nil {
 		t.Fatalf("%v", err)
@@ -54,7 +56,7 @@ func TestBufCloser(t *testing.T) {
 	buf.Reset()
 
 	s := "hi"
-	buf = NewBufCloserString(s)
+	buf = testio.NewBufCloserString(s)
 
 	read = buf.Bytes()
 	if string(read) != s {
@@ -65,7 +67,7 @@ func TestBufCloser(t *testing.T) {
 func TestLoggingBuffer(t *testing.T) {
 	src := &bytes.Buffer{}
 	data := []byte("AB")
-	lb := NewLoggingBuffer(src)
+	lb := testio.NewLoggingBuffer(src)
 	_, err := lb.Write(data)
 	if err != nil {
 		t.Fatalf("%v", err)
@@ -82,8 +84,8 @@ func TestLoggingBuffer(t *testing.T) {
 	}
 
 	expected := "[TEST] [WRITE] 4142\n"
-	if string(out.Bytes()) != expected {
+	if out.String() != expected {
-		t.Fatalf("expected '%s', have '%s'", expected, string(out.Bytes()))
+		t.Fatalf("expected '%s', have '%s'", expected, out.String())
 	}
 
 	out.Reset()
@@ -96,8 +98,8 @@ func TestLoggingBuffer(t *testing.T) {
 	}
 
 	expected = "[TEST] [READ] 4142\n"
-	if string(out.Bytes()) != expected {
+	if out.String() != expected {
-		t.Fatalf("expected '%s', have '%s'", expected, string(out.Bytes()))
+		t.Fatalf("expected '%s', have '%s'", expected, out.String())
 	}
 
 	out.Reset()
@@ -112,8 +114,8 @@ func TestLoggingBuffer(t *testing.T) {
 	}
 
 	expected = "[READ] 4142\n"
-	if string(out.Bytes()) != expected {
+	if out.String() != expected {
-		t.Fatalf("expected '%s', have '%s'", expected, string(out.Bytes()))
+		t.Fatalf("expected '%s', have '%s'", expected, out.String())
 	}
 
 	src.Reset()
@@ -124,8 +126,8 @@ func TestLoggingBuffer(t *testing.T) {
 }
 
 func TestBrokenReadWriter(t *testing.T) {
-	brw := NewBrokenReadWriter(0, 0)
+	brw := testio.NewBrokenReadWriter(0, 0)
-	lb := NewLoggingBuffer(brw)
+	lb := testio.NewLoggingBuffer(brw)
 
 	var p = make([]byte, 2)
 	var data = []byte("HI")
@@ -177,7 +179,7 @@ func TestBrokenReadWriter(t *testing.T) {
 }
 
 func TestBufferConn(t *testing.T) {
-	bc := NewBufferConn()
+	bc := testio.NewBufferConn()
 
 	client := []byte("AB")
 	peer := []byte("XY")

testutil/testutil.go

@@ -1,16 +0,0 @@
-package testutil
-
-import "io/ioutil"
-
-// TempName generates a new temporary file name. The caller should
-// remove the temporary file when done.
-func TempName() (string, error) {
-	tmpf, err := ioutil.TempFile("", "transport_cachedkp_")
-	if err != nil {
-		return "", err
-	}
-
-	name := tmpf.Name()
-	tmpf.Close()
-	return name, nil
-}