minor updates

Builds certificate bundles.

.circleci/config.yml

@@ -0,0 +1,42 @@
+# Use the latest 2.1 version of CircleCI pipeline process engine.
+# See: https://circleci.com/docs/2.0/configuration-reference
+version: 2.1
+
+# Define a job to be invoked later in a workflow.
+# See: https://circleci.com/docs/2.0/configuration-reference/#jobs
+jobs:
+  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: cimg/go:1.22.2
+    # Add steps to the job
+    # See: https://circleci.com/docs/2.0/configuration-reference/#steps
+    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: Run tests
+          command: go test ./...
+      - run:
+          name: Run 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
+workflows:
+  testbuild:
+    jobs:
+      - testbuild

.idea/.gitignore

@@ -0,0 +1,8 @@
+# Default ignored files
+/shelf/
+/workspace.xml
+# Editor-based HTTP Client requests
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml

.idea/goutils.iml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="WEB_MODULE" version="4">
+  <component name="Go" enabled="true" />
+  <component name="NewModuleRootManager">
+    <content url="file://$MODULE_DIR$" />
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

.idea/modules.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/.idea/goutils.iml" filepath="$PROJECT_DIR$/.idea/goutils.iml" />
+    </modules>
+  </component>
+</project>

.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+  </component>
+</project>

BUILD.bazel

@@ -1,12 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_library")
-load("@bazel_gazelle//:def.bzl", "gazelle")
-
-# gazelle:prefix git.wntrmute.dev/kyle/goutils
-gazelle(name = "gazelle")
-
-go_library(
-    name = "goutils",
-    srcs = ["doc.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils",
-    visibility = ["//visibility:public"],
-)

LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2015 Kyle Isom <kyle@tyrfingr.is>
+Copyright (c) 2015-2023 Kyle Isom <kyle@tyrfingr.is>
 
 Permission to use, copy, modify, and distribute this software for any
 purpose with or without fee is hereby granted, provided that the above 
@@ -11,3 +11,34 @@ 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. 
+
+
+=======================================================================
+The backoff package (written during my time at Cloudflare) is released
+under the following license:
+
+Copyright (c) 2016 CloudFlare Inc.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+Redistributions of source code must retain the above copyright notice,
+this list of conditions and the following disclaimer.
+
+Redistributions in binary form must reproduce the above copyright notice,
+this list of conditions and the following disclaimer in the documentation
+and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+

README.md

@@ -1,15 +1,18 @@
 GOUTILS
 
-### Note: this repo is archived and not being maintained here anymore.
-
 This is a collection of small utility code I've written in Go; the `cmd/`
 directory has a number of command-line utilities. Rather than keep all
-of these in superfluous repositories of their own, I'm putting them here.
+of these in superfluous repositories of their own, or rewriting them
+for each project, I'm putting them here.
+
+The project can be built with the standard Go tooling, or it can be built
+with Bazel.
 
 Contents:
 
     ahash/          Provides hashes from string algorithm specifiers.
     assert/         Error handling, assertion-style.
+    backoff/        Implementation of an intelligent backoff strategy.
     cmd/
         atping/     Automated TCP ping, meant for putting in cronjobs.
         certchain/  Display the certificate chain from a
@@ -25,33 +28,47 @@ Contents:
         cruntar/    Untar an archive with hard links, copying instead of
                     linking.
         csrpubdump/ Dump the public key from an X.509 certificate request.
+        data_sync/  Sync the user's homedir to external storage.
+        diskimg/    Write a disk image to a device.
+        eig/        EEPROM image generator.
         fragment/   Print a fragment of a file.
         jlp/        JSON linter/prettifier.
         kgz/        Custom gzip compressor / decompressor that handles 99%
                     of my use cases.
+        parts/      Simple parts database management for my collection of
+                    electronic components.
         pem2bin/    Dump the binary body of a PEM-encoded block.
         pembody/    Print the body of a PEM certificate.
         pemit/      Dump data to a PEM file.
-        showimp/    List the external (e.g. non-stdlib and outside the
-                    current working directory) imports for a Go file.
         readchain/  Print the common name for the certificates
                     in a bundle.
         renfnv/     Rename a file to base32-encoded 64-bit FNV-1a hash.
         rhash/      Compute the digest of remote files.
-        showimp     Display the external imports in a package.
+        showimp/    List the external (e.g. non-stdlib and outside the
+                    current working directory) imports for a Go file.
         ski         Display the SKI for PEM-encoded TLS material.
+        sprox/      Simple TCP proxy.
         stealchain/ Dump the verified chain from a TLS
-                    connection.
+                    connection to a server.
+        stealchain- Dump the verified chain from a TLS
+          server/   connection from a client.
         subjhash/   Print or match subject info from a certificate.
         tlskeypair/ Check whether a TLS certificate and key file match.
         utc/        Convert times to UTC.
         yamll/      A small YAML linter.
+    config/         A simple global configuration system where configuration
+                    data is pulled from a file or an environment variable
+                    transparently.
+    dbg/            A debug printer.
     die/            Death of a program.
     fileutil/       Common file functions.
     lib/            Commonly-useful functions for writing Go programs.
     logging/        A logging library.
     mwc/            MultiwriteCloser implementation.
+    rand/           Utilities for working with math/rand.
     sbuf/           A byte buffer that can be wiped.
+    seekbuf/        A read-seekable byte buffer.
+    syslog/         Syslog-type logging.
     tee/            Emulate tee(1)'s functionality in io.Writers.
     testio/         Various I/O utilities useful during testing.
     testutil/       Various utility functions useful during testing.
@@ -60,4 +77,4 @@ Contents:
 Each program should have a small README in the directory with more
 information.
 
-All code here is licensed under the MIT license.
+All code here is licensed under the ISC license.

WORKSPACE

@@ -1,39 +0,0 @@
-load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
-
-http_archive(
-    name = "io_bazel_rules_go",
-    sha256 = "6b65cb7917b4d1709f9410ffe00ecf3e160edf674b78c54a894471320862184f",
-    urls = [
-        "https://mirror.bazel.build/github.com/bazelbuild/rules_go/releases/download/v0.39.0/rules_go-v0.39.0.zip",
-        "https://github.com/bazelbuild/rules_go/releases/download/v0.39.0/rules_go-v0.39.0.zip",
-    ],
-)
-
-http_archive(
-    name = "bazel_gazelle",
-    sha256 = "ecba0f04f96b4960a5b250c8e8eeec42281035970aa8852dda73098274d14a1d",
-    urls = [
-        "https://mirror.bazel.build/github.com/bazelbuild/bazel-gazelle/releases/download/v0.29.0/bazel-gazelle-v0.29.0.tar.gz",
-        "https://github.com/bazelbuild/bazel-gazelle/releases/download/v0.29.0/bazel-gazelle-v0.29.0.tar.gz",
-    ],
-)
-
-load("@io_bazel_rules_go//go:deps.bzl", "go_register_toolchains", "go_rules_dependencies")
-load("@bazel_gazelle//:deps.bzl", "gazelle_dependencies")
-
-############################################################
-# Define your own dependencies here using go_repository.
-# Else, dependencies declared by rules_go/gazelle will be used.
-# The first declaration of an external repository "wins".
-############################################################
-
-load("//:deps.bzl", "go_dependencies")
-
-# gazelle:repository_macro deps.bzl%go_dependencies
-go_dependencies()
-
-go_rules_dependencies()
-
-go_register_toolchains(version = "1.20.4")
-
-gazelle_dependencies()

ahash/BUILD.bazel

@@ -1,23 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
-
-go_library(
-    name = "ahash",
-    srcs = ["ahash.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/ahash",
-    visibility = ["//visibility:public"],
-    deps = [
-        "@ht_sr_git_kisom_goutils//assert:go_default_library",
-        "@org_golang_x_crypto//blake2b",
-        "@org_golang_x_crypto//blake2s",
-        "@org_golang_x_crypto//md4",
-        "@org_golang_x_crypto//ripemd160",
-        "@org_golang_x_crypto//sha3",
-    ],
-)
-
-go_test(
-    name = "ahash_test",
-    srcs = ["ahash_test.go"],
-    embed = [":ahash"],
-    deps = ["@ht_sr_git_kisom_goutils//assert:go_default_library"],
-)

ahash/ahash.go

@@ -45,13 +45,6 @@ func sha512Slicer(bs []byte) []byte {
 	return sum[:]
 }
 
-var sliceFunctions = map[string]func([]byte) []byte{
-	"sha224": sha224Slicer,
-	"sha256": sha256Slicer,
-	"sha384": sha384Slicer,
-	"sha512": sha512Slicer,
-}
-
 // Hash represents a generic hash function that may or may not be secure. It
 // satisfies the hash.Hash interface.
 type Hash struct {

assert/BUILD.bazel

@@ -1,8 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_library")
-
-go_library(
-    name = "assert",
-    srcs = ["assert.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/assert",
-    visibility = ["//visibility:public"],
-)

assert/assert.go

@@ -94,7 +94,7 @@ func NoError(err error, s ...string) {
 	}
 
 	if nil != err {
-		die(err.Error())
+		die(err.Error(), s...)
 	}
 }
 
@@ -170,5 +170,5 @@ func ErrorEqT(t *testing.T, expected, actual error) {
 		should = fmt.Sprintf("have '%s'", actual)
 	}
 
-	die(fmt.Sprintf("assert.Error2: expected '%s', but %s", expected, should))
+	t.Fatalf("assert.Error2: expected '%s', but %s", expected, should)
 }

backoff/LICENSE

@@ -0,0 +1,24 @@
+Copyright (c) 2016 CloudFlare Inc.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+Redistributions of source code must retain the above copyright notice,
+this list of conditions and the following disclaimer.
+
+Redistributions in binary form must reproduce the above copyright notice,
+this list of conditions and the following disclaimer in the documentation
+and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

backoff/README.md

@@ -0,0 +1,83 @@
+# backoff
+## Go implementation of "Exponential Backoff And Jitter"
+
+This package implements the backoff strategy described in the AWS
+Architecture Blog article
+["Exponential Backoff And Jitter"](http://www.awsarchitectureblog.com/2015/03/backoff.html). Essentially,
+the backoff has an interval `time.Duration`; the *n<sup>th</sup>* call
+to backoff will return an a `time.Duration` that is *2 <sup>n</sup> *
+interval*. If jitter is enabled (which is the default behaviour), the
+duration is a random value between 0 and *2 <sup>n</sup> * interval*.
+The backoff is configured with a maximum duration that will not be
+exceeded; e.g., by default, the longest duration returned is
+`backoff.DefaultMaxDuration`.
+
+## Usage
+
+A `Backoff` is initialised with a call to `New`. Using zero values
+causes it to use `DefaultMaxDuration` and `DefaultInterval` as the
+maximum duration and interval.
+
+```
+package something
+
+import "github.com/cloudflare/backoff"
+
+func retryable() {
+        b := backoff.New(0, 0)
+        for {
+                err := someOperation()
+                if err == nil {
+                    break
+                }
+
+                log.Printf("error in someOperation: %v", err)
+                <-time.After(b.Duration())
+        }
+
+        log.Printf("succeeded after %d tries", b.Tries()+1)
+        b.Reset()
+}
+```
+
+It can also be used to rate limit code that should retry infinitely, but which does not
+use `Backoff` itself.
+
+```
+package something
+
+import (
+    "time"
+
+    "github.com/cloudflare/backoff"
+)
+
+func retryable() {
+        b := backoff.New(0, 0)
+        b.SetDecay(30 * time.Second)
+
+        for {
+                // b will reset if someOperation returns later than
+                // the last call to b.Duration() + 30s.
+                err := someOperation()
+                if err == nil {
+                    break
+                }
+
+                log.Printf("error in someOperation: %v", err)
+                <-time.After(b.Duration())
+        }
+}
+```
+
+## Tunables
+
+* `NewWithoutJitter` creates a Backoff that doesn't use jitter.
+
+The default behaviour is controlled by two variables:
+
+* `DefaultInterval` sets the base interval for backoffs created with
+  the zero `time.Duration` value in the `Interval` field.
+* `DefaultMaxDuration` sets the maximum duration for backoffs created
+  with the zero `time.Duration` value in the `MaxDuration` field.
+

backoff/backoff.go

@@ -0,0 +1,197 @@
+// Package backoff contains an implementation of an intelligent backoff
+// strategy. It is based on the approach in the AWS architecture blog
+// article titled "Exponential Backoff And Jitter", which is found at
+// http://www.awsarchitectureblog.com/2015/03/backoff.html.
+//
+// Essentially, the backoff has an interval `time.Duration`; the nth
+// call to backoff will return a `time.Duration` that is 2^n *
+// interval. If jitter is enabled (which is the default behaviour),
+// the duration is a random value between 0 and 2^n * interval.  The
+// backoff is configured with a maximum duration that will not be
+// exceeded.
+//
+// The `New` function will attempt to use the system's cryptographic
+// random number generator to seed a Go math/rand random number
+// source. If this fails, the package will panic on startup.
+package backoff
+
+import (
+	"crypto/rand"
+	"encoding/binary"
+	"io"
+	"math"
+	mrand "math/rand"
+	"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
+// delay for.
+var DefaultMaxDuration = 6 * time.Hour
+
+// A Backoff contains the information needed to intelligently backoff
+// and retry operations using an exponential backoff algorithm. It should
+// be initialised with a call to `New`.
+//
+// Only use a Backoff from a single goroutine, it is not safe for concurrent
+// access.
+type Backoff struct {
+	// maxDuration is the largest possible duration that can be
+	// returned from a call to Duration.
+	maxDuration time.Duration
+
+	// interval controls the time step for backing off.
+	interval time.Duration
+
+	// noJitter controls whether to use the "Full Jitter"
+	// improvement to attempt to smooth out spikes in a high
+	// contention scenario. If noJitter is set to true, no
+	// jitter will be introduced.
+	noJitter bool
+
+	// decay controls the decay of n. If it is non-zero, n is
+	// reset if more than the last backoff + decay has elapsed since
+	// the last try.
+	decay time.Duration
+
+	n       uint64
+	lastTry time.Time
+}
+
+// New creates a new backoff with the specified max duration and
+// interval. Zero values may be used to use the default values.
+//
+// Panics if either max or interval is negative.
+func New(max time.Duration, interval time.Duration) *Backoff {
+	if max < 0 || interval < 0 {
+		panic("backoff: max or interval is negative")
+	}
+
+	b := &Backoff{
+		maxDuration: max,
+		interval:    interval,
+	}
+	b.setup()
+	return b
+}
+
+// NewWithoutJitter works similarly to New, except that the created
+// Backoff will not use jitter.
+func NewWithoutJitter(max time.Duration, interval time.Duration) *Backoff {
+	b := New(max, 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
+	}
+
+	if b.maxDuration == 0 {
+		b.maxDuration = DefaultMaxDuration
+	}
+}
+
+// Duration returns a time.Duration appropriate for the backoff,
+// incrementing the attempt counter.
+func (b *Backoff) Duration() time.Duration {
+	b.setup()
+
+	b.decayN()
+
+	t := b.duration(b.n)
+
+	if b.n < math.MaxUint64 {
+		b.n++
+	}
+
+	if !b.noJitter {
+		prngMu.Lock()
+		t = time.Duration(prng.Int63n(int64(t)))
+		prngMu.Unlock()
+	}
+
+	return t
+}
+
+// requires b to be locked.
+func (b *Backoff) duration(n uint64) (t time.Duration) {
+	// Saturate pow
+	pow := time.Duration(math.MaxInt64)
+	if n < 63 {
+		pow = 1 << n
+	}
+
+	t = b.interval * pow
+	if t/pow != b.interval || t > b.maxDuration {
+		t = b.maxDuration
+	}
+
+	return
+}
+
+// Reset resets the attempt counter of a backoff.
+//
+// It should be called when the rate-limited action succeeds.
+func (b *Backoff) Reset() {
+	b.lastTry = time.Time{}
+	b.n = 0
+}
+
+// SetDecay sets the duration after which the try counter will be reset.
+// Panics if decay is smaller than 0.
+//
+// The decay only kicks in if at least the last backoff + decay has elapsed
+// since the last try.
+func (b *Backoff) SetDecay(decay time.Duration) {
+	if decay < 0 {
+		panic("backoff: decay < 0")
+	}
+
+	b.decay = decay
+}
+
+// requires b to be locked
+func (b *Backoff) decayN() {
+	if b.decay == 0 {
+		return
+	}
+
+	if b.lastTry.IsZero() {
+		b.lastTry = time.Now()
+		return
+	}
+
+	lastDuration := b.duration(b.n - 1)
+	decayed := time.Since(b.lastTry) > lastDuration+b.decay
+	b.lastTry = time.Now()
+
+	if !decayed {
+		return
+	}
+
+	b.n = 0
+}

backoff/backoff_test.go

@@ -0,0 +1,175 @@
+package backoff
+
+import (
+	"fmt"
+	"math"
+	"testing"
+	"time"
+)
+
+// If given New with 0's and no jitter, ensure that certain invariants are met:
+//
+//   - the default max 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
+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)
+	}
+
+	if b.interval != DefaultInterval {
+		t.Fatalf("exepcted new backoff to use the default interval (%s), but have %s", DefaultInterval, b.interval)
+	}
+
+	if b.noJitter != true {
+		t.Fatal("backoff should have been initialised without jitter")
+	}
+
+	dur := b.Duration()
+	if dur != DefaultInterval {
+		t.Fatalf("expected first duration to be %s, have %s", DefaultInterval, dur)
+	}
+}
+
+// Given a zero-value initialised Backoff, it should be transparently
+// setup.
+func TestSetup(t *testing.T) {
+	b := new(Backoff)
+	dur := b.Duration()
+	if dur < 0 || dur > (5*time.Minute) {
+		t.Fatalf("want duration between 0 and 5 minutes, have %s", dur)
+	}
+}
+
+// Ensure that tries incremenets as expected.
+func TestTries(t *testing.T) {
+	b := NewWithoutJitter(5, 1)
+
+	for i := uint64(0); i < 3; i++ {
+		if b.n != i {
+			t.Fatalf("want tries=%d, have tries=%d", i, b.n)
+		}
+
+		pow := 1 << i
+		expected := time.Duration(pow)
+		dur := b.Duration()
+		if dur != expected {
+			t.Fatalf("want duration=%d, have duration=%d at i=%d", expected, dur, i)
+		}
+	}
+
+	for i := uint(3); i < 5; i++ {
+		dur := b.Duration()
+		if dur != 5 {
+			t.Fatalf("want duration=5, have %d at i=%d", dur, i)
+		}
+	}
+}
+
+// Ensure that a call to Reset will actually reset the Backoff.
+func TestReset(t *testing.T) {
+	const iter = 10
+	b := New(1000, 1)
+	for i := 0; i < iter; i++ {
+		_ = b.Duration()
+	}
+
+	if b.n != iter {
+		t.Fatalf("expected tries=%d, have tries=%d", iter, b.n)
+	}
+
+	b.Reset()
+	if b.n != 0 {
+		t.Fatalf("expected tries=0 after reset, have tries=%d", b.n)
+	}
+}
+
+const decay = 5 * time.Millisecond
+const max = 10 * time.Millisecond
+const interval = time.Millisecond
+
+func TestDecay(t *testing.T) {
+	const iter = 10
+
+	b := NewWithoutJitter(max, 1)
+	b.SetDecay(decay)
+
+	var backoff time.Duration
+	for i := 0; i < iter; i++ {
+		backoff = b.Duration()
+	}
+
+	if b.n != iter {
+		t.Fatalf("expected tries=%d, have tries=%d", iter, b.n)
+	}
+
+	// Don't decay below backoff
+	b.lastTry = time.Now().Add(-backoff + 1)
+	backoff = b.Duration()
+	if b.n != iter+1 {
+		t.Fatalf("expected tries=%d, have tries=%d", iter+1, b.n)
+	}
+
+	// Reset after backoff + decay
+	b.lastTry = time.Now().Add(-backoff - decay)
+	b.Duration()
+	if b.n != 1 {
+		t.Fatalf("expected tries=%d, have tries=%d", 1, b.n)
+	}
+}
+
+// Ensure that decay works even if the retry counter is saturated.
+func TestDecaySaturation(t *testing.T) {
+	b := NewWithoutJitter(1<<2, 1)
+	b.SetDecay(decay)
+
+	var duration time.Duration
+	for i := 0; i <= 2; i++ {
+		duration = b.Duration()
+	}
+
+	if duration != 1<<2 {
+		t.Fatalf("expected duration=%v, have duration=%v", 1<<2, duration)
+	}
+
+	b.lastTry = time.Now().Add(-duration - decay)
+	b.n = math.MaxUint64
+
+	duration = b.Duration()
+	if duration != 1 {
+		t.Errorf("expected duration=%v, have duration=%v", 1, duration)
+	}
+}
+
+func ExampleBackoff_SetDecay() {
+	b := NewWithoutJitter(max, interval)
+	b.SetDecay(decay)
+
+	// try 0
+	fmt.Println(b.Duration())
+
+	// try 1
+	fmt.Println(b.Duration())
+
+	// try 2
+	duration := b.Duration()
+	fmt.Println(duration)
+
+	// try 3, below decay
+	time.Sleep(duration)
+	duration = b.Duration()
+	fmt.Println(duration)
+
+	// try 4, resets
+	time.Sleep(duration + decay)
+	fmt.Println(b.Duration())
+
+	// Output: 1ms
+	// 2ms
+	// 4ms
+	// 8ms
+	// 1ms
+}

certlib/certerr/errors.go

@@ -0,0 +1,79 @@
+package certerr
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+)
+
+// ErrEmptyCertificate indicates that a certificate could not be processed
+// because there was no data to process.
+var ErrEmptyCertificate = errors.New("certlib: empty certificate")
+
+type ErrorSourceType uint8
+
+func (t ErrorSourceType) String() string {
+	switch t {
+	case ErrorSourceCertificate:
+		return "certificate"
+	case ErrorSourcePrivateKey:
+		return "private key"
+	case ErrorSourceCSR:
+		return "CSR"
+	case ErrorSourceSCTList:
+		return "SCT list"
+	case ErrorSourceKeypair:
+		return "TLS keypair"
+	default:
+		panic(fmt.Sprintf("unknown error source %d", t))
+	}
+}
+
+const (
+	ErrorSourceCertificate ErrorSourceType = 1
+	ErrorSourcePrivateKey  ErrorSourceType = 2
+	ErrorSourceCSR         ErrorSourceType = 3
+	ErrorSourceSCTList     ErrorSourceType = 4
+	ErrorSourceKeypair     ErrorSourceType = 5
+)
+
+// InvalidPEMType is used to indicate that we were expecting one type of PEM
+// file, but saw another.
+type InvalidPEMType struct {
+	have string
+	want []string
+}
+
+func (err *InvalidPEMType) 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.
+func ErrInvalidPEMType(have string, want ...string) error {
+	return &InvalidPEMType{
+		have: have,
+		want: want,
+	}
+}
+
+func LoadingError(t ErrorSourceType, err error) error {
+	return fmt.Errorf("failed to load %s from disk: %w", t, err)
+}
+
+func ParsingError(t ErrorSourceType, err error) error {
+	return fmt.Errorf("failed to parse %s: %w", t, err)
+}
+
+func DecodeError(t ErrorSourceType, err error) error {
+	return fmt.Errorf("failed to decode %s: %w", t, err)
+}
+
+func VerifyError(t ErrorSourceType, err error) error {
+	return fmt.Errorf("failed to verify %s: %w", t, err)
+}
+
+var ErrEncryptedPrivateKey = errors.New("private key is encrypted")

certlib/certlib.go

@@ -0,0 +1,85 @@
+package certlib
+
+import (
+	"crypto/x509"
+	"encoding/pem"
+	"errors"
+	"io/ioutil"
+
+	"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) {
+	if len(in) == 0 {
+		err = certerr.ErrEmptyCertificate
+		return
+	}
+
+	if in[0] == '-' {
+		p, remaining := pem.Decode(in)
+		if p == nil {
+			err = errors.New("certlib: invalid PEM file")
+			return
+		}
+
+		rest = remaining
+		if p.Type != "CERTIFICATE" {
+			err = certerr.ErrInvalidPEMType(p.Type, "CERTIFICATE")
+			return
+		}
+
+		in = p.Bytes
+	}
+
+	cert, err = x509.ParseCertificate(in)
+	return
+}
+
+// ReadCertificates tries to read all the certificates in a
+// PEM-encoded collection.
+func ReadCertificates(in []byte) (certs []*x509.Certificate, err error) {
+	var cert *x509.Certificate
+	for {
+		cert, in, err = ReadCertificate(in)
+		if err != nil {
+			break
+		}
+
+		if cert == nil {
+			break
+		}
+
+		certs = append(certs, cert)
+		if len(in) == 0 {
+			break
+		}
+	}
+
+	return certs, err
+}
+
+// LoadCertificate tries to read a single certificate from disk. If
+// 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)
+	if err != nil {
+		return nil, err
+	}
+
+	cert, _, err := ReadCertificate(in)
+	return cert, err
+}
+
+// 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)
+	if err != nil {
+		return nil, err
+	}
+
+	return ReadCertificates(in)
+}

certlib/certlib_test.go

@@ -1,4 +1,4 @@
-package lib
+package certlib
 
 import (
 	"fmt"

certlib/der_helpers.go

@@ -0,0 +1,75 @@
+package certlib
+
+// Originally from CFSSL, mostly written by me originally, and licensed under:
+
+/*
+Copyright (c) 2014 CloudFlare Inc.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+Redistributions of source code must retain the above copyright notice,
+this list of conditions and the following disclaimer.
+
+Redistributions in binary form must reproduce the above copyright notice,
+this list of conditions and the following disclaimer in the documentation
+and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+// I've modified it for use in my own code e.g. by removing the CFSSL errors
+// and replacing them with sane ones.
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/ed25519"
+	"crypto/rsa"
+	"crypto/x509"
+	"fmt"
+
+	"git.wntrmute.dev/kyle/goutils/certlib/certerr"
+)
+
+// ParsePrivateKeyDER parses a PKCS #1, PKCS #8, ECDSA, or Ed25519 DER-encoded
+// 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) {
+	generalKey, err := x509.ParsePKCS8PrivateKey(keyDER)
+	if err != nil {
+		generalKey, err = x509.ParsePKCS1PrivateKey(keyDER)
+		if err != nil {
+			generalKey, err = x509.ParseECPrivateKey(keyDER)
+			if err != nil {
+				generalKey, err = ParseEd25519PrivateKey(keyDER)
+				if err != nil {
+					return nil, certerr.ParsingError(certerr.ErrorSourcePrivateKey, err)
+				}
+			}
+		}
+	}
+
+	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

@@ -0,0 +1,164 @@
+package certlib
+
+import (
+	"crypto"
+	"crypto/ed25519"
+	"crypto/x509/pkix"
+	"encoding/asn1"
+	"errors"
+)
+
+// Originally from CFSSL, mostly written by me originally, and licensed under:
+
+/*
+Copyright (c) 2014 CloudFlare Inc.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+Redistributions of source code must retain the above copyright notice,
+this list of conditions and the following disclaimer.
+
+Redistributions in binary form must reproduce the above copyright notice,
+this list of conditions and the following disclaimer in the documentation
+and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+// I've modified it for use in my own code e.g. by removing the CFSSL errors
+// and replacing them with sane ones.
+
+var errEd25519WrongID = errors.New("incorrect object identifier")
+var errEd25519WrongKeyType = errors.New("incorrect key type")
+
+// ed25519OID is the OID for the Ed25519 signature scheme: see
+// https://datatracker.ietf.org/doc/draft-ietf-curdle-pkix-04.
+var ed25519OID = asn1.ObjectIdentifier{1, 3, 101, 112}
+
+// subjectPublicKeyInfo reflects the ASN.1 object defined in the X.509 standard.
+//
+// This is defined in crypto/x509 as "publicKeyInfo".
+type subjectPublicKeyInfo struct {
+	Algorithm pkix.AlgorithmIdentifier
+	PublicKey asn1.BitString
+}
+
+// MarshalEd25519PublicKey creates a DER-encoded SubjectPublicKeyInfo for an
+// ed25519 public key, as defined in
+// https://tools.ietf.org/html/draft-ietf-curdle-pkix-04. This is analogous to
+// MarshalPKIXPublicKey in crypto/x509, which doesn't currently support Ed25519.
+func MarshalEd25519PublicKey(pk crypto.PublicKey) ([]byte, error) {
+	pub, ok := pk.(ed25519.PublicKey)
+	if !ok {
+		return nil, errEd25519WrongKeyType
+	}
+
+	spki := subjectPublicKeyInfo{
+		Algorithm: pkix.AlgorithmIdentifier{
+			Algorithm: ed25519OID,
+		},
+		PublicKey: asn1.BitString{
+			BitLength: len(pub) * 8,
+			Bytes:     pub,
+		},
+	}
+
+	return asn1.Marshal(spki)
+}
+
+// ParseEd25519PublicKey returns the Ed25519 public key encoded by the input.
+func ParseEd25519PublicKey(der []byte) (crypto.PublicKey, error) {
+	var spki subjectPublicKeyInfo
+	if rest, err := asn1.Unmarshal(der, &spki); err != nil {
+		return nil, err
+	} else if len(rest) > 0 {
+		return nil, errors.New("SubjectPublicKeyInfo too long")
+	}
+
+	if !spki.Algorithm.Algorithm.Equal(ed25519OID) {
+		return nil, errEd25519WrongID
+	}
+
+	if spki.PublicKey.BitLength != ed25519.PublicKeySize*8 {
+		return nil, errors.New("SubjectPublicKeyInfo PublicKey length mismatch")
+	}
+
+	return ed25519.PublicKey(spki.PublicKey.Bytes), nil
+}
+
+// oneAsymmetricKey reflects the ASN.1 structure for storing private keys in
+// https://tools.ietf.org/html/draft-ietf-curdle-pkix-04, excluding the optional
+// fields, which we don't use here.
+//
+// This is identical to pkcs8 in crypto/x509.
+type oneAsymmetricKey struct {
+	Version    int
+	Algorithm  pkix.AlgorithmIdentifier
+	PrivateKey []byte
+}
+
+// curvePrivateKey is the innter type of the PrivateKey field of
+// oneAsymmetricKey.
+type curvePrivateKey []byte
+
+// MarshalEd25519PrivateKey returns a DER encoding of the input private key as
+// specified in https://tools.ietf.org/html/draft-ietf-curdle-pkix-04.
+func MarshalEd25519PrivateKey(sk crypto.PrivateKey) ([]byte, error) {
+	priv, ok := sk.(ed25519.PrivateKey)
+	if !ok {
+		return nil, errEd25519WrongKeyType
+	}
+
+	// Marshal the innter CurvePrivateKey.
+	curvePrivateKey, err := asn1.Marshal(priv.Seed())
+	if err != nil {
+		return nil, err
+	}
+
+	// Marshal the OneAsymmetricKey.
+	asym := oneAsymmetricKey{
+		Version: 0,
+		Algorithm: pkix.AlgorithmIdentifier{
+			Algorithm: ed25519OID,
+		},
+		PrivateKey: curvePrivateKey,
+	}
+	return asn1.Marshal(asym)
+}
+
+// ParseEd25519PrivateKey returns the Ed25519 private key encoded by the input.
+func ParseEd25519PrivateKey(der []byte) (crypto.PrivateKey, error) {
+	asym := new(oneAsymmetricKey)
+	if rest, err := asn1.Unmarshal(der, asym); err != nil {
+		return nil, err
+	} else if len(rest) > 0 {
+		return nil, errors.New("OneAsymmetricKey too long")
+	}
+
+	// Check that the key type is correct.
+	if !asym.Algorithm.Algorithm.Equal(ed25519OID) {
+		return nil, errEd25519WrongID
+	}
+
+	// Unmarshal the inner CurvePrivateKey.
+	seed := new(curvePrivateKey)
+	if rest, err := asn1.Unmarshal(asym.PrivateKey, seed); err != nil {
+		return nil, err
+	} else if len(rest) > 0 {
+		return nil, errors.New("CurvePrivateKey too long")
+	}
+
+	return ed25519.NewKeyFromSeed(*seed), nil
+}

certlib/helpers.go

@@ -0,0 +1,630 @@
+package certlib
+
+// Originally from CFSSL, mostly written by me originally, and licensed under:
+
+/*
+Copyright (c) 2014 CloudFlare Inc.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+Redistributions of source code must retain the above copyright notice,
+this list of conditions and the following disclaimer.
+
+Redistributions in binary form must reproduce the above copyright notice,
+this list of conditions and the following disclaimer in the documentation
+and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+// I've modified it for use in my own code e.g. by removing the CFSSL errors
+// and replacing them with sane ones.
+
+import (
+	"bytes"
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rsa"
+	"crypto/tls"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/asn1"
+	"encoding/pem"
+	"errors"
+	"fmt"
+	"os"
+	"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"
+)
+
+// OneYear is a time.Duration representing a year's worth of seconds.
+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
+var DelegationUsage = asn1.ObjectIdentifier{1, 3, 6, 1, 4, 1, 44363, 44}
+
+// DelegationExtension
+var DelegationExtension = pkix.Extension{
+	Id:       DelegationUsage,
+	Critical: false,
+	Value:    []byte{0x05, 0x00}, // ASN.1 NULL
+}
+
+// InclusiveDate returns the time.Time representation of a date - 1
+// nanosecond. This allows time.After to be used inclusively.
+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)
+}
+
+// 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)
+
+// 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)
+
+// KeyLength returns the bit size of ECDSA or RSA PublicKey
+func KeyLength(key interface{}) int {
+	if key == nil {
+		return 0
+	}
+	if ecdsaKey, ok := key.(*ecdsa.PublicKey); ok {
+		return ecdsaKey.Curve.Params().BitSize
+	} else if rsaKey, ok := key.(*rsa.PublicKey); ok {
+		return rsaKey.N.BitLen()
+	}
+
+	return 0
+}
+
+// ExpiryTime returns the time when the certificate chain is expired.
+func ExpiryTime(chain []*x509.Certificate) (notAfter time.Time) {
+	if len(chain) == 0 {
+		return
+	}
+
+	notAfter = chain[0].NotAfter
+	for _, cert := range chain {
+		if notAfter.After(cert.NotAfter) {
+			notAfter = cert.NotAfter
+		}
+	}
+	return
+}
+
+// MonthsValid returns the number of months for which a certificate is valid.
+func MonthsValid(c *x509.Certificate) int {
+	issued := c.NotBefore
+	expiry := c.NotAfter
+	years := (expiry.Year() - issued.Year())
+	months := years*12 + int(expiry.Month()) - int(issued.Month())
+
+	// Round up if valid for less than a full month
+	if expiry.Day() > issued.Day() {
+		months++
+	}
+	return months
+}
+
+// ValidExpiry determines if a certificate is valid for an acceptable
+// length of time per the CA/Browser Forum baseline requirements.
+// See https://cabforum.org/wp-content/uploads/CAB-Forum-BR-1.3.0.pdf
+func ValidExpiry(c *x509.Certificate) bool {
+	issued := c.NotBefore
+
+	var maxMonths int
+	switch {
+	case issued.After(Apr2015):
+		maxMonths = 39
+	case issued.After(Jul2012):
+		maxMonths = 60
+	case issued.Before(Jul2012):
+		maxMonths = 120
+	}
+
+	if MonthsValid(c) > maxMonths {
+		return false
+	}
+	return true
+}
+
+// SignatureString returns the TLS signature string corresponding to
+// an X509 signature algorithm.
+func SignatureString(alg x509.SignatureAlgorithm) string {
+	switch alg {
+	case x509.MD2WithRSA:
+		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.
+func HashAlgoString(alg x509.SignatureAlgorithm) string {
+	switch alg {
+	case x509.MD2WithRSA:
+		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"
+	}
+}
+
+// StringTLSVersion returns underlying enum values from human names for TLS
+// versions, defaults to current golang default of TLS 1.0
+func StringTLSVersion(version string) uint16 {
+	switch version {
+	case "1.2":
+		return tls.VersionTLS12
+	case "1.1":
+		return tls.VersionTLS11
+	default:
+		return tls.VersionTLS10
+	}
+}
+
+// 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{
+			Type:  "CERTIFICATE",
+			Bytes: cert.Raw,
+		})
+	}
+
+	return buffer.Bytes()
+}
+
+// EncodeCertificatePEM encodes a single x509 certificates to PEM
+func EncodeCertificatePEM(cert *x509.Certificate) []byte {
+	return EncodeCertificatesPEM([]*x509.Certificate{cert})
+}
+
+// ParseCertificatesPEM parses a sequence of PEM-encoded certificate and returns them,
+// can handle PEM encoded PKCS #7 structures.
+func ParseCertificatesPEM(certsPEM []byte) ([]*x509.Certificate, error) {
+	var certs []*x509.Certificate
+	var err error
+	certsPEM = bytes.TrimSpace(certsPEM)
+	for len(certsPEM) > 0 {
+		var cert []*x509.Certificate
+		cert, certsPEM, err = ParseOneCertificateFromPEM(certsPEM)
+		if err != nil {
+			return nil, certerr.ParsingError(certerr.ErrorSourceCertificate, err)
+		} else if cert == nil {
+			break
+		}
+
+		certs = append(certs, cert...)
+	}
+	if len(certsPEM) > 0 {
+		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) {
+	certsDER = bytes.TrimSpace(certsDER)
+	pkcs7data, err := pkcs7.ParsePKCS7(certsDER)
+	if err != nil {
+		var pkcs12data interface{}
+		certs = make([]*x509.Certificate, 1)
+		pkcs12data, certs[0], err = pkcs12.Decode(certsDER, password)
+		if err != nil {
+			certs, err = x509.ParseCertificates(certsDER)
+			if err != nil {
+				return nil, nil, certerr.DecodeError(certerr.ErrorSourceCertificate, err)
+			}
+		} else {
+			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.
+func ParseSelfSignedCertificatePEM(certPEM []byte) (*x509.Certificate, error) {
+	cert, err := ParseCertificatePEM(certPEM)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := cert.CheckSignature(cert.SignatureAlgorithm, cert.RawTBSCertificate, cert.Signature); err != nil {
+		return nil, certerr.VerifyError(certerr.ErrorSourceCertificate, err)
+	}
+	return cert, nil
+}
+
+// ParseCertificatePEM parses and returns a PEM-encoded certificate,
+// can handle PEM encoded PKCS #7 structures.
+func ParseCertificatePEM(certPEM []byte) (*x509.Certificate, error) {
+	certPEM = bytes.TrimSpace(certPEM)
+	cert, 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
+}
+
+// ParseOneCertificateFromPEM attempts to parse one PEM encoded certificate object,
+// either a raw x509 certificate or a PKCS #7 structure possibly containing
+// 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
+	}
+
+	cert, err := x509.ParseCertificate(block.Bytes)
+	if err != nil {
+		pkcs7data, err := pkcs7.ParsePKCS7(block.Bytes)
+		if err != nil {
+			return nil, rest, err
+		}
+		if pkcs7data.ContentInfo != "SignedData" {
+			return nil, rest, errors.New("only PKCS #7 Signed Data Content Info supported for certificate parsing")
+		}
+		certs := pkcs7data.Content.SignedData.Certificates
+		if certs == nil {
+			return nil, rest, errors.New("PKCS #7 structure contains no certificates")
+		}
+		return certs, rest, nil
+	}
+	var certs = []*x509.Certificate{cert}
+	return certs, rest, nil
+}
+
+// LoadPEMCertPool loads a pool of PEM certificates from file.
+func LoadPEMCertPool(certsFile string) (*x509.CertPool, error) {
+	if certsFile == "" {
+		return nil, nil
+	}
+	pemCerts, err := os.ReadFile(certsFile)
+	if err != nil {
+		return nil, err
+	}
+
+	return PEMToCertPool(pemCerts)
+}
+
+// PEMToCertPool concerts PEM certificates to a CertPool.
+func PEMToCertPool(pemCerts []byte) (*x509.CertPool, error) {
+	if len(pemCerts) == 0 {
+		return nil, nil
+	}
+
+	certPool := x509.NewCertPool()
+	if !certPool.AppendCertsFromPEM(pemCerts) {
+		return nil, errors.New("failed to load cert pool")
+	}
+
+	return certPool, nil
+}
+
+// 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) {
+	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) {
+	keyDER, err := GetKeyDERFromPEM(keyPEM, password)
+	if err != nil {
+		return nil, err
+	}
+
+	return ParsePrivateKeyDER(keyDER)
+}
+
+// GetKeyDERFromPEM parses a PEM-encoded private key and returns DER-format key bytes.
+func GetKeyDERFromPEM(in []byte, password []byte) ([]byte, error) {
+	// Ignore any EC PARAMETERS blocks when looking for a key (openssl includes
+	// them by default).
+	var keyDER *pem.Block
+	for {
+		keyDER, in = pem.Decode(in)
+		if keyDER == nil || keyDER.Type != "EC PARAMETERS" {
+			break
+		}
+	}
+	if keyDER != nil {
+		if procType, ok := keyDER.Headers["Proc-Type"]; ok {
+			if strings.Contains(procType, "ENCRYPTED") {
+				if password != nil {
+					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) {
+	in = bytes.TrimSpace(in)
+	p, rest := pem.Decode(in)
+	if p != 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"))
+		}
+
+		csr, err = x509.ParseCertificateRequest(p.Bytes)
+	} else {
+		csr, err = x509.ParseCertificateRequest(in)
+	}
+
+	if err != nil {
+		return nil, rest, err
+	}
+
+	err = csr.CheckSignature()
+	if err != nil {
+		return nil, rest, err
+	}
+
+	return csr, rest, nil
+}
+
+// ParseCSRPEM parses a PEM-encoded certificate signing request.
+// 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))
+	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 csrObject, nil
+}
+
+// SignerAlgo returns an X.509 signature algorithm from a crypto.Signer.
+func SignerAlgo(priv crypto.Signer) x509.SignatureAlgorithm {
+	switch pub := priv.Public().(type) {
+	case *rsa.PublicKey:
+		bitLength := pub.N.BitLen()
+		switch {
+		case bitLength >= 4096:
+			return x509.SHA512WithRSA
+		case bitLength >= 3072:
+			return x509.SHA384WithRSA
+		case bitLength >= 2048:
+			return x509.SHA256WithRSA
+		default:
+			return x509.SHA1WithRSA
+		}
+	case *ecdsa.PublicKey:
+		switch pub.Curve {
+		case elliptic.P521():
+			return x509.ECDSAWithSHA512
+		case elliptic.P384():
+			return x509.ECDSAWithSHA384
+		case elliptic.P256():
+			return x509.ECDSAWithSHA256
+		default:
+			return x509.ECDSAWithSHA1
+		}
+	default:
+		return x509.UnknownSignatureAlgorithm
+	}
+}
+
+// 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)
+		if err != nil {
+			return nil, certerr.LoadingError(certerr.ErrorSourceKeypair, err)
+		}
+		return &cert, nil
+	}
+	return nil, nil
+}
+
+// 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 {
+		certs = []tls.Certificate{*cert}
+	}
+	return &tls.Config{
+		Certificates: certs,
+		RootCAs:      remoteCAs,
+	}
+}
+
+// SerializeSCTList serializes a list of SCTs.
+func SerializeSCTList(sctList []ct.SignedCertificateTimestamp) ([]byte, error) {
+	list := ctx509.SignedCertificateTimestampList{}
+	for _, sct := range sctList {
+		sctBytes, err := cttls.Marshal(sct)
+		if err != nil {
+			return nil, err
+		}
+		list.SCTList = append(list.SCTList, ctx509.SerializedSCT{Val: sctBytes})
+	}
+	return cttls.Marshal(list)
+}
+
+// DeserializeSCTList deserializes a list of SCTs.
+func DeserializeSCTList(serializedSCTList []byte) ([]ct.SignedCertificateTimestamp, error) {
+	var sctList ctx509.SignedCertificateTimestampList
+	rest, err := cttls.Unmarshal(serializedSCTList, &sctList)
+	if err != nil {
+		return nil, err
+	}
+	if len(rest) != 0 {
+		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)
+		if err != nil {
+			return nil, err
+		}
+		if len(rest) != 0 {
+			return nil, certerr.ParsingError(certerr.ErrorSourceSCTList, errors.New("serialized SCT list contained trailing garbage"))
+		}
+		list[i] = sct
+	}
+	return list, nil
+}
+
+// SCTListFromOCSPResponse extracts the SCTList from an ocsp.Response,
+// returning an empty list if the SCT extension was not found or could not be
+// unmarshalled.
+func SCTListFromOCSPResponse(response *ocsp.Response) ([]ct.SignedCertificateTimestamp, error) {
+	// This loop finds the SCTListExtension in the OCSP response.
+	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
+			break
+		}
+	}
+
+	// This code block extracts the sctList from the SCT extension.
+	var sctList []ct.SignedCertificateTimestamp
+	var err error
+	if numBytes := len(SCTListExtension.Value); numBytes != 0 {
+		var serializedSCTList []byte
+		rest := make([]byte, numBytes)
+		copy(rest, SCTListExtension.Value)
+		for len(rest) != 0 {
+			rest, err = asn1.Unmarshal(rest, &serializedSCTList)
+			if err != nil {
+				return nil, certerr.ParsingError(certerr.ErrorSourceSCTList, err)
+			}
+		}
+		sctList, err = DeserializeSCTList(serializedSCTList)
+	}
+	return sctList, err
+}
+
+// ReadBytes reads a []byte either from a file or an environment variable.
+// If valFile has a prefix of 'env:', the []byte is read from the environment
+// using the subsequent name. If the prefix is 'file:' the []byte is read from
+// 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) {
+	case 1:
+		return os.ReadFile(valFile)
+	case 2:
+		switch splitVal[0] {
+		case "env":
+			return []byte(os.Getenv(splitVal[1])), nil
+		case "file":
+			return os.ReadFile(splitVal[1])
+		default:
+			return nil, fmt.Errorf("unknown prefix: %s", splitVal[0])
+		}
+	default:
+		return nil, fmt.Errorf("multiple prefixes: %s",
+			strings.Join(splitVal[:len(splitVal)-1], ", "))
+	}
+}

certlib/hosts/hosts.go

@@ -0,0 +1,82 @@
+package hosts
+
+import (
+	"errors"
+	"fmt"
+	"net"
+	"net/url"
+	"strconv"
+	"strings"
+)
+
+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(), 443, nil
+	}
+
+	port, err := strconv.ParseInt(url.Port(), 10, 16)
+	if err != nil {
+		return "", 0, fmt.Errorf("certlib/hosts: invalid port: %s", url.Port())
+	}
+
+	return url.Hostname(), int(port), nil
+}
+
+func parseHostPort(host string) (string, int, error) {
+	host, sport, err := net.SplitHostPort(host)
+	if err == nil {
+		port, err := strconv.ParseInt(sport, 10, 16)
+		if err != nil {
+			return "", 0, fmt.Errorf("certlib/hosts: invalid port: %s", sport)
+		}
+
+		return host, int(port), nil
+	}
+
+	return host, 443, 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

@@ -0,0 +1,220 @@
+package pkcs7
+
+// Originally from CFSSL, and licensed under:
+
+/*
+Copyright (c) 2014 CloudFlare Inc.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+Redistributions of source code must retain the above copyright notice,
+this list of conditions and the following disclaimer.
+
+Redistributions in binary form must reproduce the above copyright notice,
+this list of conditions and the following disclaimer in the documentation
+and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+// I've modified it for use in my own code e.g. by removing the CFSSL errors
+// and replacing them with sane ones.
+
+// Package pkcs7 implements the subset of the CMS PKCS #7 datatype that is typically
+// used to package certificates and CRLs.  Using openssl, every certificate converted
+// to PKCS #7 format from another encoding such as PEM conforms to this implementation.
+// reference: https://www.openssl.org/docs/man1.1.0/apps/crl2pkcs7.html
+//
+// PKCS #7 Data type, reference: https://tools.ietf.org/html/rfc2315
+//
+// The full pkcs#7 cryptographic message syntax allows for cryptographic enhancements,
+// for example data can be encrypted and signed and then packaged through pkcs#7 to be
+// sent over a network and then verified and decrypted.  It is asn1, and the type of
+// PKCS #7 ContentInfo, which comprises the PKCS #7 structure, is:
+//
+//	ContentInfo ::= SEQUENCE {
+//		contentType ContentType,
+//		content [0] EXPLICIT ANY DEFINED BY contentType OPTIONAL
+//	}
+//
+// There are 6 possible ContentTypes, data, signedData, envelopedData,
+// signedAndEnvelopedData, digestedData, and encryptedData.  Here signedData, Data, and encrypted
+// Data are implemented, as the degenerate case of signedData without a signature is the typical
+// format for transferring certificates and CRLS, and Data and encryptedData are used in PKCS #12
+// formats.
+// The ContentType signedData has the form:
+//
+//	signedData ::= SEQUENCE {
+//		version Version,
+//		digestAlgorithms DigestAlgorithmIdentifiers,
+//		contentInfo ContentInfo,
+//		certificates [0] IMPLICIT ExtendedCertificatesAndCertificates OPTIONAL
+//		crls [1] IMPLICIT CertificateRevocationLists OPTIONAL,
+//		signerInfos SignerInfos
+//	}
+//
+// As of yet signerInfos and digestAlgorithms are not parsed, as they are not relevant to
+// this system's use of PKCS #7 data.  Version is an integer type, note that PKCS #7 is
+// recursive, this second layer of ContentInfo is similar ignored for our degenerate
+// usage.  The ExtendedCertificatesAndCertificates type consists of a sequence of choices
+// between PKCS #6 extended certificates and x509 certificates.  Any sequence consisting
+// of any number of extended certificates is not yet supported in this implementation.
+//
+// The ContentType Data is simply a raw octet string and is parsed directly into a Go []byte slice.
+//
+// The ContentType encryptedData is the most complicated and its form can be gathered by
+// the go type below.  It essentially contains a raw octet string of encrypted data and an
+// algorithm identifier for use in decrypting this data.
+
+import (
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/asn1"
+	"errors"
+
+	"git.wntrmute.dev/kyle/goutils/certlib/certerr"
+)
+
+// Types used for asn1 Unmarshaling.
+
+type signedData struct {
+	Version          int
+	DigestAlgorithms asn1.RawValue
+	ContentInfo      asn1.RawValue
+	Certificates     asn1.RawValue `asn1:"optional" asn1:"tag:0"`
+	Crls             asn1.RawValue `asn1:"optional"`
+	SignerInfos      asn1.RawValue
+}
+
+type initPKCS7 struct {
+	Raw         asn1.RawContent
+	ContentType asn1.ObjectIdentifier
+	Content     asn1.RawValue `asn1:"tag:0,explicit,optional"`
+}
+
+// Object identifier strings of the three implemented PKCS7 types.
+const (
+	ObjIDData          = "1.2.840.113549.1.7.1"
+	ObjIDSignedData    = "1.2.840.113549.1.7.2"
+	ObjIDEncryptedData = "1.2.840.113549.1.7.6"
+)
+
+// PKCS7 represents the ASN1 PKCS #7 Content type.  It contains one of three
+// possible types of Content objects, as denoted by the object identifier in
+// the ContentInfo field, the other two being nil.  SignedData
+// is the degenerate SignedData Content info without signature used
+// to hold certificates and crls.  Data is raw bytes, and EncryptedData
+// is as defined in PKCS #7 standard.
+type PKCS7 struct {
+	Raw         asn1.RawContent
+	ContentInfo string
+	Content     Content
+}
+
+// Content implements three of the six possible PKCS7 data types.  Only one is non-nil.
+type Content struct {
+	Data          []byte
+	SignedData    SignedData
+	EncryptedData EncryptedData
+}
+
+// SignedData defines the typical carrier of certificates and crls.
+type SignedData struct {
+	Raw          asn1.RawContent
+	Version      int
+	Certificates []*x509.Certificate
+	Crl          *x509.RevocationList
+}
+
+// Data contains raw bytes.  Used as a subtype in PKCS12.
+type Data struct {
+	Bytes []byte
+}
+
+// EncryptedData contains encrypted data.  Used as a subtype in PKCS12.
+type EncryptedData struct {
+	Raw                  asn1.RawContent
+	Version              int
+	EncryptedContentInfo EncryptedContentInfo
+}
+
+// EncryptedContentInfo is a subtype of PKCS7EncryptedData.
+type EncryptedContentInfo struct {
+	Raw                        asn1.RawContent
+	ContentType                asn1.ObjectIdentifier
+	ContentEncryptionAlgorithm pkix.AlgorithmIdentifier
+	EncryptedContent           []byte `asn1:"tag:0,optional"`
+}
+
+// ParsePKCS7 attempts to parse the DER encoded bytes of a
+// PKCS7 structure.
+func ParsePKCS7(raw []byte) (msg *PKCS7, err error) {
+
+	var pkcs7 initPKCS7
+	_, err = asn1.Unmarshal(raw, &pkcs7)
+	if err != nil {
+		return nil, certerr.ParsingError(certerr.ErrorSourceCertificate, err)
+	}
+
+	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
+
+	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 msg, nil
+
+}

certlib/revoke/revoke.go

@@ -0,0 +1,363 @@
+// Package revoke provides functionality for checking the validity of
+// a cert. Specifically, the temporal validity of the certificate is
+// checked first, then any CRL and OCSP url in the cert is checked.
+package revoke
+
+import (
+	"bytes"
+	"crypto"
+	"crypto/x509"
+	"encoding/base64"
+	"encoding/pem"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	neturl "net/url"
+	"sync"
+	"time"
+
+	"git.wntrmute.dev/kyle/goutils/certlib"
+	"git.wntrmute.dev/kyle/goutils/log"
+	"golang.org/x/crypto/ocsp"
+)
+
+// Originally from CFSSL, mostly written by me originally, and licensed under:
+
+/*
+Copyright (c) 2014 CloudFlare Inc.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+Redistributions of source code must retain the above copyright notice,
+this list of conditions and the following disclaimer.
+
+Redistributions in binary form must reproduce the above copyright notice,
+this list of conditions and the following disclaimer in the documentation
+and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+// I've modified it for use in my own code e.g. by removing the CFSSL errors
+// and replacing them with sane ones.
+
+// HTTPClient is an instance of http.Client that will be used for all HTTP requests.
+var HTTPClient = http.DefaultClient
+
+// HardFail determines whether the failure to check the revocation
+// status of a certificate (i.e. due to network failure) causes
+// verification to fail (a hard failure).
+var HardFail = false
+
+// CRLSet associates a PKIX certificate list with the URL the CRL is
+// fetched from.
+var CRLSet = map[string]*x509.RevocationList{}
+var crlLock = new(sync.Mutex)
+
+// We can't handle LDAP certificates, so this checks to see if the
+// URL string points to an LDAP resource so that we can ignore it.
+func ldapURL(url string) bool {
+	u, err := neturl.Parse(url)
+	if err != nil {
+		log.Warningf("error parsing url %s: %v", url, err)
+		return false
+	}
+	if u.Scheme == "ldap" {
+		return true
+	}
+	return false
+}
+
+// revCheck should check the certificate for any revocations. It
+// returns a pair of booleans: the first indicates whether the certificate
+// is revoked, the second indicates whether the revocations were
+// successfully checked.. This leads to the following combinations:
+//
+// - 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
+func revCheck(cert *x509.Certificate) (revoked, ok bool, err 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 {
+			log.Warning("error checking revocation via CRL")
+			if HardFail {
+				return true, false, err
+			}
+			return false, false, err
+		} else if revoked {
+			log.Info("certificate is revoked via CRL")
+			return true, true, err
+		}
+	}
+
+	if revoked, ok, err := certIsRevokedOCSP(cert, HardFail); !ok {
+		log.Warning("error checking revocation via OCSP")
+		if HardFail {
+			return true, false, err
+		}
+		return false, false, err
+	} else if revoked {
+		log.Info("certificate is revoked via OCSP")
+		return true, true, err
+	}
+
+	return false, true, nil
+}
+
+// fetchCRL fetches and parses a CRL.
+func fetchCRL(url string) (*x509.RevocationList, error) {
+	resp, err := HTTPClient.Get(url)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode >= 300 {
+		return nil, errors.New("failed to retrieve CRL")
+	}
+
+	body, err := crlRead(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+	return x509.ParseRevocationList(body)
+}
+
+func getIssuer(cert *x509.Certificate) *x509.Certificate {
+	var issuer *x509.Certificate
+	var err error
+	for _, issuingCert := range cert.IssuingCertificateURL {
+		issuer, err = fetchRemote(issuingCert)
+		if err != nil {
+			continue
+		}
+		break
+	}
+
+	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) {
+	crlLock.Lock()
+	crl, ok := CRLSet[url]
+	if ok && crl == nil {
+		ok = false
+		delete(CRLSet, url)
+	}
+	crlLock.Unlock()
+
+	var shouldFetchCRL = true
+	if ok {
+		if time.Now().After(crl.ThisUpdate) {
+			shouldFetchCRL = false
+		}
+	}
+
+	issuer := getIssuer(cert)
+
+	if shouldFetchCRL {
+		var err error
+		crl, err = fetchCRL(url)
+		if err != nil {
+			log.Warningf("failed to fetch CRL: %v", err)
+			return false, false, err
+		}
+
+		// check CRL signature
+		if issuer != nil {
+			err = crl.CheckSignatureFrom(issuer)
+			if err != nil {
+				log.Warningf("failed to verify CRL: %v", err)
+				return false, false, err
+			}
+		}
+
+		crlLock.Lock()
+		CRLSet[url] = crl
+		crlLock.Unlock()
+	}
+
+	for _, revoked := range crl.RevokedCertificates {
+		if cert.SerialNumber.Cmp(revoked.SerialNumber) == 0 {
+			log.Info("Serial number match: intermediate is revoked.")
+			return true, true, err
+		}
+	}
+
+	return false, true, err
+}
+
+// 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) {
+	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) {
+	if !time.Now().Before(cert.NotAfter) {
+		msg := fmt.Sprintf("Certificate expired %s\n", cert.NotAfter)
+		log.Info(msg)
+		return true, true, fmt.Errorf(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 revCheck(cert)
+}
+
+func fetchRemote(url string) (*x509.Certificate, error) {
+	resp, err := HTTPClient.Get(url)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	in, err := remoteRead(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	p, _ := pem.Decode(in)
+	if p != nil {
+		return certlib.ParseCertificatePEM(in)
+	}
+
+	return x509.ParseCertificate(in)
+}
+
+var ocspOpts = ocsp.RequestOptions{
+	Hash: crypto.SHA1,
+}
+
+func certIsRevokedOCSP(leaf *x509.Certificate, strict bool) (revoked, ok bool, e error) {
+	var err error
+
+	ocspURLs := leaf.OCSPServer
+	if len(ocspURLs) == 0 {
+		// OCSP not enabled for this certificate.
+		return false, true, nil
+	}
+
+	issuer := getIssuer(leaf)
+
+	if issuer == nil {
+		return false, false, nil
+	}
+
+	ocspRequest, err := ocsp.CreateRequest(leaf, issuer, &ocspOpts)
+	if err != nil {
+		return revoked, ok, err
+	}
+
+	for _, server := range ocspURLs {
+		resp, err := sendOCSPRequest(server, ocspRequest, leaf, issuer)
+		if err != nil {
+			if strict {
+				return revoked, ok, err
+			}
+			continue
+		}
+
+		// There wasn't an error fetching the OCSP status.
+		ok = true
+
+		if resp.Status != ocsp.Good {
+			// The certificate was revoked.
+			revoked = true
+		}
+
+		return revoked, ok, err
+	}
+	return revoked, ok, err
+}
+
+// sendOCSPRequest attempts to request an OCSP response from the
+// server. The error only indicates a failure to *fetch* the
+// certificate, and *does not* mean the certificate is valid.
+func sendOCSPRequest(server string, req []byte, leaf, issuer *x509.Certificate) (*ocsp.Response, error) {
+	var resp *http.Response
+	var err error
+	if len(req) > 256 {
+		buf := bytes.NewBuffer(req)
+		resp, err = HTTPClient.Post(server, "application/ocsp-request", buf)
+	} else {
+		reqURL := server + "/" + neturl.QueryEscape(base64.StdEncoding.EncodeToString(req))
+		resp, err = HTTPClient.Get(reqURL)
+	}
+
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, errors.New("failed to retrieve OSCP")
+	}
+
+	body, err := ocspRead(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	switch {
+	case bytes.Equal(body, ocsp.UnauthorizedErrorResponse):
+		return nil, errors.New("OSCP unauthorized")
+	case bytes.Equal(body, ocsp.MalformedRequestErrorResponse):
+		return nil, errors.New("OSCP malformed")
+	case bytes.Equal(body, ocsp.InternalErrorErrorResponse):
+		return nil, errors.New("OSCP internal error")
+	case bytes.Equal(body, ocsp.TryLaterErrorResponse):
+		return nil, errors.New("OSCP try later")
+	case bytes.Equal(body, ocsp.SigRequredErrorResponse):
+		return nil, errors.New("OSCP signature required")
+	}
+
+	return ocsp.ParseResponseForCert(body, leaf, issuer)
+}
+
+var crlRead = io.ReadAll
+
+// 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
+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
+func SetOCSPFetcher(fn func(io.Reader) ([]byte, error)) {
+	ocspRead = fn
+}

certlib/revoke/revoke_test.go

@@ -0,0 +1,262 @@
+package revoke
+
+import (
+	"crypto/x509"
+	"encoding/pem"
+	"fmt"
+	"os"
+	"testing"
+	"time"
+)
+
+// Originally from CFSSL, mostly written by me originally, and licensed under:
+
+/*
+Copyright (c) 2014 CloudFlare Inc.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+Redistributions of source code must retain the above copyright notice,
+this list of conditions and the following disclaimer.
+
+Redistributions in binary form must reproduce the above copyright notice,
+this list of conditions and the following disclaimer in the documentation
+and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+// I've modified it for use in my own code e.g. by removing the CFSSL errors
+// and replacing them with sane ones.
+
+// The first three test cases represent known revoked, expired, and good
+// certificates that were checked on the date listed in the log. The
+// good certificate will eventually need to be replaced in year 2029.
+
+// If there is a soft-fail, the test will pass to mimic the default
+// behaviour used in this software. However, it will print a warning
+// 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
+var expiredCert = mustParse(`-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----`)
+
+// 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
+var revokedCert = mustParse(`-----BEGIN CERTIFICATE-----
+MIIEEzCCAvugAwIBAgILBAAAAAABGMGjftYwDQYJKoZIhvcNAQEFBQAwcTEoMCYG
+A1UEAxMfR2xvYmFsU2lnbiBSb290U2lnbiBQYXJ0bmVycyBDQTEdMBsGA1UECxMU
+Um9vdFNpZ24gUGFydG5lcnMgQ0ExGTAXBgNVBAoTEEdsb2JhbFNpZ24gbnYtc2Ex
+CzAJBgNVBAYTAkJFMB4XDTA4MDMxODEyMDAwMFoXDTE4MDMxODEyMDAwMFowJTEj
+MCEGA1UEAxMaTW9iaWxlIEFybW9yIEVudGVycHJpc2UgQ0EwggEiMA0GCSqGSIb3
+DQEBAQUAA4IBDwAwggEKAoIBAQCaEjeDR73jSZVlacRn5bc5VIPdyouHvGIBUxyS
+C6483HgoDlWrWlkEndUYFjRPiQqJFthdJxfglykXD+btHixMIYbz/6eb7hRTdT9w
+HKsfH+wTBIdb5AZiNjkg3QcCET5HfanJhpREjZWP513jM/GSrG3VwD6X5yttCIH1
+NFTDAr7aqpW/UPw4gcPfkwS92HPdIkb2DYnsqRrnKyNValVItkxJiotQ1HOO3YfX
+ivGrHIbJdWYg0rZnkPOgYF0d+aIA4ZfwvdW48+r/cxvLevieuKj5CTBZZ8XrFt8r
+JTZhZljbZvnvq/t6ZIzlwOj082f+lTssr1fJ3JsIPnG2lmgTAgMBAAGjgfcwgfQw
+DgYDVR0PAQH/BAQDAgEGMBIGA1UdEwEB/wQIMAYBAf8CAQEwHQYDVR0OBBYEFIZw
+ns4uzXdLX6xDRXUzFgZxWM7oME0GA1UdIARGMEQwQgYJKwYBBAGgMgE8MDUwMwYI
+KwYBBQUHAgIwJxolaHR0cDovL3d3dy5nbG9iYWxzaWduLmNvbS9yZXBvc2l0b3J5
+LzA/BgNVHR8EODA2MDSgMqAwhi5odHRwOi8vY3JsLmdsb2JhbHNpZ24ubmV0L1Jv
+b3RTaWduUGFydG5lcnMuY3JsMB8GA1UdIwQYMBaAFFaE7LVxpedj2NtRBNb65vBI
+UknOMA0GCSqGSIb3DQEBBQUAA4IBAQBZvf+2xUJE0ekxuNk30kPDj+5u9oI3jZyM
+wvhKcs7AuRAbcxPtSOnVGNYl8By7DPvPun+U3Yci8540y143RgD+kz3jxIBaoW/o
+c4+X61v6DBUtcBPEt+KkV6HIsZ61SZmc/Y1I2eoeEt6JYoLjEZMDLLvc1cK/+wpg
+dUZSK4O9kjvIXqvsqIOlkmh/6puSugTNao2A7EIQr8ut0ZmzKzMyZ0BuQhJDnAPd
+Kz5vh+5tmytUPKA8hUgmLWe94lMb7Uqq2wgZKsqun5DAWleKu81w7wEcOrjiiB+x
+jeBHq7OnpWm+ccTOPCE6H4ZN4wWVS7biEBUdop/8HgXBPQHWAdjL
+-----END CERTIFICATE-----`)
+
+// A Comodo intermediate CA certificate with issuer url, CRL url and OCSP url
+var goodComodoCA = (`-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----`)
+
+var goodCert = mustParse(goodComodoCA)
+
+func mustParse(pemData string) *x509.Certificate {
+	block, _ := pem.Decode([]byte(pemData))
+	if block == nil {
+		panic("Invalid PEM data.")
+	} else if block.Type != "CERTIFICATE" {
+		panic("Invalid PEM type.")
+	}
+
+	cert, err := x509.ParseCertificate([]byte(block.Bytes))
+	if err != nil {
+		panic(err.Error())
+	}
+	return cert
+}
+
+func TestRevoked(t *testing.T) {
+	if revoked, ok := VerifyCertificate(revokedCert); !ok {
+		fmt.Fprintf(os.Stderr, "Warning: soft fail checking revocation")
+	} else if !revoked {
+		t.Fatalf("revoked certificate should have been marked as revoked")
+	}
+}
+
+func TestExpired(t *testing.T) {
+	if revoked, ok := VerifyCertificate(expiredCert); !ok {
+		fmt.Fprintf(os.Stderr, "Warning: soft fail checking revocation")
+	} else if !revoked {
+		t.Fatalf("expired certificate should have been marked as revoked")
+	}
+}
+
+func TestGood(t *testing.T) {
+	if revoked, ok := VerifyCertificate(goodCert); !ok {
+		fmt.Fprintf(os.Stderr, "Warning: soft fail checking revocation")
+	} else if revoked {
+		t.Fatalf("good certificate should not have been marked as revoked")
+	}
+
+}
+
+func TestLdap(t *testing.T) {
+	ldapCert := mustParse(goodComodoCA)
+	ldapCert.CRLDistributionPoints = append(ldapCert.CRLDistributionPoints, "ldap://myldap.example.com")
+	if revoked, ok := VerifyCertificate(ldapCert); revoked || !ok {
+		t.Fatalf("ldap certificate should have been recognized")
+	}
+}
+
+func TestLdapURLErr(t *testing.T) {
+	if ldapURL(":") {
+		t.Fatalf("bad url does not cause error")
+	}
+}
+
+func TestCertNotYetValid(t *testing.T) {
+	notReadyCert := expiredCert
+	notReadyCert.NotBefore = time.Date(3000, time.January, 1, 1, 1, 1, 1, time.Local)
+	notReadyCert.NotAfter = time.Date(3005, time.January, 1, 1, 1, 1, 1, time.Local)
+	if revoked, _ := VerifyCertificate(expiredCert); !revoked {
+		t.Fatalf("not yet verified certificate should have been marked as revoked")
+	}
+}
+
+func TestCRLFetchError(t *testing.T) {
+	ldapCert := mustParse(goodComodoCA)
+	ldapCert.CRLDistributionPoints[0] = ""
+	if revoked, ok := VerifyCertificate(ldapCert); ok || revoked {
+		t.Fatalf("Fetching error not encountered")
+	}
+	HardFail = true
+	if revoked, ok := VerifyCertificate(ldapCert); ok || !revoked {
+		t.Fatalf("Fetching error not encountered, hardfail not registered")
+	}
+	HardFail = false
+}
+
+func TestBadCRLSet(t *testing.T) {
+	ldapCert := mustParse(goodComodoCA)
+	ldapCert.CRLDistributionPoints[0] = ""
+	CRLSet[""] = nil
+	certIsRevokedCRL(ldapCert, "")
+	if _, ok := CRLSet[""]; ok {
+		t.Fatalf("key emptystring should be deleted from CRLSet")
+	}
+	delete(CRLSet, "")
+
+}
+
+func TestCachedCRLSet(t *testing.T) {
+	VerifyCertificate(goodCert)
+	if revoked, ok := VerifyCertificate(goodCert); !ok || revoked {
+		t.Fatalf("Previously fetched CRL's should be read smoothly and unrevoked")
+	}
+}
+
+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) {
+	badIssuer := goodCert
+	badIssuer.IssuingCertificateURL = []string{" "}
+	certIsRevokedOCSP(badIssuer, true)
+	noOCSPCert := goodCert
+	noOCSPCert.OCSPServer = make([]string, 0)
+	if revoked, ok, _ := certIsRevokedOCSP(noOCSPCert, true); revoked || !ok {
+		t.Fatalf("OCSP falsely registered as enabled for this certificate")
+	}
+}

cmd/atping/BUILD.bazel

@@ -1,14 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "atping_lib",
-    srcs = ["main.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/atping",
-    visibility = ["//visibility:private"],
-)
-
-go_binary(
-    name = "atping",
-    embed = [":atping_lib"],
-    visibility = ["//visibility:public"],
-)

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 +1,287 @@
+package main
+
+import (
+	"crypto/x509"
+	"embed"
+	"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) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+
+	// Try PEM first
+	if certs, err := certlib.ParseCertificatesPEM(data); err == nil {
+		return certs, nil
+	}
+
+	// Try DER/PKCS7/PKCS12 (with no password)
+	if certs, _, err := certlib.ParseCertificatesDER(data, ""); err == nil {
+		return certs, nil
+	} else {
+		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) {
+	// Try PEM first
+	if certs, err := certlib.ParseCertificatesPEM(data); err == nil {
+		return certs, nil
+	}
+	// Try DER/PKCS7/PKCS12 (with no password)
+	if certs, _, err := certlib.ParseCertificatesDER(data, ""); err == nil {
+		return certs, nil
+	} else {
+		return nil, err
+	}
+}
+
+func makePoolFromBytes(data []byte) (*x509.CertPool, error) {
+    certs, err := loadCertsFromBytes(data)
+    if err != nil || len(certs) == 0 {
+        return nil, fmt.Errorf("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) (ok bool, expiry 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) (ok bool, expiry 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")
+}
+
+// selftest runs built-in validation using embedded certificates.
+func selftest() int {
+	type testCase struct {
+		name     string
+		caFile   string
+		certFile string
+		expectOK bool
+	}
+
+ 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},
+    }
+
+    failures := 0
+    for _, tc := range cases {
+		caBytes, err := embeddedTestdata.ReadFile(tc.caFile)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "selftest: failed to read embedded %s: %v\n", tc.caFile, err)
+			failures++
+			continue
+		}
+		certBytes, err := embeddedTestdata.ReadFile(tc.certFile)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "selftest: failed to read embedded %s: %v\n", tc.certFile, err)
+			failures++
+			continue
+		}
+		pool, err := makePoolFromBytes(caBytes)
+		if err != nil || pool == nil {
+			fmt.Fprintf(os.Stderr, "selftest: failed to build CA pool for %s: %v\n", tc.caFile, err)
+			failures++
+			continue
+		}
+		ok, exp := verifyAgainstCABytes(pool, certBytes)
+		if ok != tc.expectOK {
+			fmt.Printf("%s: unexpected result: got %v, want %v\n", tc.name, ok, tc.expectOK)
+			failures++
+		} else {
+			if ok {
+				fmt.Printf("%s: OK (expires %s)\n", tc.name, exp)
+			} else {
+				fmt.Printf("%s: INVALID (as expected)\n", tc.name)
+			}
+		}
+    }
+
+    // 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
+}
+
+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:] {
+        ok, exp := verifyAgainstCA(caPool, certPath)
+        name := filepath.Base(certPath)
+        // Load the leaf once for self-signed detection and potential expiry fallback
+        var leaf *x509.Certificate
+        if certs, err := loadCertsFromFile(certPath); err == nil && len(certs) > 0 {
+            leaf = certs[0]
+        }
+
+        // If the certificate is self-signed, prefer the SELF-SIGNED label
+        if isSelfSigned(leaf) {
+            fmt.Printf("%s: SELF-SIGNED\n", name)
+            continue
+        }
+
+        if ok {
+            // Display with the requested format
+            // Example: file: OK (expires 2031-01-01)
+            // Ensure deterministic date formatting
+            // Note: no timezone displayed; date only as per example
+            // If exp ended up empty for some reason, recompute safely
+            if exp == "" {
+                if leaf != nil {
+                    exp = leaf.NotAfter.Format("2006-01-02")
+                } else {
+                    // fallback to the current date to avoid empty; though shouldn't happen
+                    exp = time.Now().Format("2006-01-02")
+                }
+            }
+            fmt.Printf("%s: OK (expires %s)\n", name, exp)
+        } else {
+            fmt.Printf("%s: INVALID\n", name)
+        }
+    }
+}

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-----
+MIIFazCCA1OgAwIBAgIRAIIQz7DSQONZRGPgu2OCiwAwDQYJKoZIhvcNAQELBQAw
+TzELMAkGA1UEBhMCVVMxKTAnBgNVBAoTIEludGVybmV0IFNlY3VyaXR5IFJlc2Vh
+cmNoIEdyb3VwMRUwEwYDVQQDEwxJU1JHIFJvb3QgWDEwHhcNMTUwNjA0MTEwNDM4
+WhcNMzUwNjA0MTEwNDM4WjBPMQswCQYDVQQGEwJVUzEpMCcGA1UEChMgSW50ZXJu
+ZXQgU2VjdXJpdHkgUmVzZWFyY2ggR3JvdXAxFTATBgNVBAMTDElTUkcgUm9vdCBY
+MTCCAiIwDQYJKoZIhvcNAQEBBQADggIPADCCAgoCggIBAK3oJHP0FDfzm54rVygc
+h77ct984kIxuPOZXoHj3dcKi/vVqbvYATyjb3miGbESTtrFj/RQSa78f0uoxmyF+
+0TM8ukj13Xnfs7j/EvEhmkvBioZxaUpmZmyPfjxwv60pIgbz5MDmgK7iS4+3mX6U
+A5/TR5d8mUgjU+g4rk8Kb4Mu0UlXjIB0ttov0DiNewNwIRt18jA8+o+u3dpjq+sW
+T8KOEUt+zwvo/7V3LvSye0rgTBIlDHCNAymg4VMk7BPZ7hm/ELNKjD+Jo2FR3qyH
+B5T0Y3HsLuJvW5iB4YlcNHlsdu87kGJ55tukmi8mxdAQ4Q7e2RCOFvu396j3x+UC
+B5iPNgiV5+I3lg02dZ77DnKxHZu8A/lJBdiB3QW0KtZB6awBdpUKD9jf1b0SHzUv
+KBds0pjBqAlkd25HN7rOrFleaJ1/ctaJxQZBKT5ZPt0m9STJEadao0xAH0ahmbWn
+OlFuhjuefXKnEgV4We0+UXgVCwOPjdAvBbI+e0ocS3MFEvzG6uBQE3xDk3SzynTn
+jh8BCNAw1FtxNrQHusEwMFxIt4I7mKZ9YIqioymCzLq9gwQbooMDQaHWBfEbwrbw
+qHyGO0aoSCqI3Haadr8faqU9GY/rOPNk3sgrDQoo//fb4hVC1CLQJ13hef4Y53CI
+rU7m2Ys6xt0nUW7/vGT1M0NPAgMBAAGjQjBAMA4GA1UdDwEB/wQEAwIBBjAPBgNV
+HRMBAf8EBTADAQH/MB0GA1UdDgQWBBR5tFnme7bl5AFzgAiIyBpY9umbbjANBgkq
+hkiG9w0BAQsFAAOCAgEAVR9YqbyyqFDQDLHYGmkgJykIrGF1XIpu+ILlaS/V9lZL
+ubhzEFnTIZd+50xx+7LSYK05qAvqFyFWhfFQDlnrzuBZ6brJFe+GnY+EgPbk6ZGQ
+3BebYhtF8GaV0nxvwuo77x/Py9auJ/GpsMiu/X1+mvoiBOv/2X/qkSsisRcOj/KK
+NFtY2PwByVS5uCbMiogziUwthDyC3+6WVwW6LLv3xLfHTjuCvjHIInNzktHCgKQ5
+ORAzI4JMPJ+GslWYHb4phowim57iaztXOoJwTdwJx4nLCgdNbOhdjsnvzqvHu7Ur
+TkXWStAmzOVyyghqpZXjFaH3pO3JLF+l+/+sKAIuvtd7u+Nxe5AW0wdeRlN8NwdC
+jNPElpzVmbUq4JUagEiuTDkHzsxHpFKVK7q4+63SM1N95R1NbdWhscdCb+ZAJzVc
+oyi3B43njTOQ5yOf+1CceWxG1bQVs5ZufpsMljq4Ui0/1lvh+wjChP4kqKOJ2qxq
+4RgqsahDYVvTH9w7jXbyLeiNdd8XM2w9U/t7y0Ff/9yi0GE44Za4rF2LN9d11TPA
+mRGunUHBcnWEvgJBQl9nJEiU0Zsnvgc/ubhPgXRR4Xq37Z0j4r7g1SgEEzwxA57d
+emyPxgcYxn/eR44/KJ4EBs+lVDR3veyJm+kXQ99b21/+jh5Xos1AnX5iItreGCc=
+-----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 +1,489 @@
+package main
+
+import (
+	"archive/tar"
+	"archive/zip"
+	"compress/gzip"
+	"crypto/sha256"
+	"crypto/x509"
+	_ "embed"
+	"encoding/pem"
+	"flag"
+	"fmt"
+	"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
+	if err := os.MkdirAll(outputDir, 0755); err != nil {
+		fmt.Fprintf(os.Stderr, "Error creating output directory: %v\n", err)
+		os.Exit(1)
+	}
+
+	// Process each chain group
+	createdFiles := []string{}
+	for groupName, group := range cfg.Chains {
+		files, err := processChainGroup(groupName, group, expiryDuration)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Error processing chain group %s: %v\n", groupName, err)
+			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 err := generateHashFile(hashFile, createdFiles); err != nil {
+			fmt.Fprintf(os.Stderr, "Error generating hash file: %v\n", err)
+			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 err := yaml.Unmarshal(data, &cfg); err != nil {
+		return nil, err
+	}
+
+	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) {
+	var createdFiles []string
+
+	// Default encoding to "pem" if not specified
+	encoding := group.Outputs.Encoding
+	if encoding == "" {
+		encoding = "pem"
+	}
+
+	// Collect data from all chains in the group
+	var singleFileCerts []*x509.Certificate
+	var individualCerts []certWithPath
+
+	for _, chain := range group.Certs {
+		// Step 1: Load all certificates for this chain
+		allCerts := make(map[string]*x509.Certificate)
+
+		// Load root certificate
+		rootCert, err := certlib.LoadCertificate(chain.Root)
+		if err != nil {
+			return nil, fmt.Errorf("failed to load root certificate %s: %v", chain.Root, err)
+		}
+		allCerts[chain.Root] = rootCert
+
+		// Check expiry for root
+		checkExpiry(chain.Root, rootCert, expiryDuration)
+
+		// Add root to single file if needed
+		if group.Outputs.IncludeSingle {
+			singleFileCerts = append(singleFileCerts, rootCert)
+		}
+
+		// Add root to individual files if needed
+		if group.Outputs.IncludeIndividual {
+			individualCerts = append(individualCerts, certWithPath{
+				cert: rootCert,
+				path: chain.Root,
+			})
+		}
+
+		// Step 2: Load and validate intermediates
+		for _, intPath := range chain.Intermediates {
+			intCert, err := certlib.LoadCertificate(intPath)
+			if err != nil {
+				return nil, fmt.Errorf("failed to load intermediate certificate %s: %v", intPath, err)
+			}
+			allCerts[intPath] = intCert
+
+			// Validate that intermediate is signed by root
+			if err := intCert.CheckSignatureFrom(rootCert); err != nil {
+				return nil, fmt.Errorf("intermediate %s is not properly signed by root %s: %v", intPath, chain.Root, err)
+			}
+
+			// Check expiry for intermediate
+			checkExpiry(intPath, intCert, expiryDuration)
+
+			// Add intermediate to a single file if needed
+			if group.Outputs.IncludeSingle {
+				singleFileCerts = append(singleFileCerts, intCert)
+			}
+
+			// Add intermediate to individual files if needed
+			if group.Outputs.IncludeIndividual {
+				individualCerts = append(individualCerts, certWithPath{
+					cert: intCert,
+					path: intPath,
+				})
+			}
+		}
+	}
+
+	// Prepare files for inclusion in archives for the entire group.
+	var archiveFiles []fileEntry
+
+	// Handle a single bundle file.
+	if group.Outputs.IncludeSingle && len(singleFileCerts) > 0 {
+		files, err := encodeCertsToFiles(singleFileCerts, "bundle", encoding, true)
+		if err != nil {
+			return nil, fmt.Errorf("failed to encode single bundle: %v", err)
+		}
+		archiveFiles = append(archiveFiles, files...)
+	}
+
+	// Handle individual files
+	if group.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: %v", cp.path, err)
+			}
+			archiveFiles = append(archiveFiles, files...)
+		}
+	}
+
+	// Generate manifest if requested
+	if group.Outputs.Manifest {
+		manifestContent := generateManifest(archiveFiles)
+		archiveFiles = append(archiveFiles, fileEntry{
+			name:    "MANIFEST",
+			content: manifestContent,
+		})
+	}
+
+	// Create archives for the entire group
+	for _, format := range group.Outputs.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: %v", err)
+			}
+		case "tgz":
+			if err := createTarGzArchive(archivePath, archiveFiles); err != nil {
+				return nil, fmt.Errorf("failed to create tar.gz archive: %v", 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, err := encodeCertsToPEM(certs, isSingle)
+		if err != nil {
+			return nil, err
+		}
+		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 {
+			// Individual DER file (should only have one cert)
+			if len(certs) > 0 {
+				files = append(files, fileEntry{
+					name:    baseName + ".crt",
+					content: certs[0].Raw,
+				})
+			}
+		}
+	case "both":
+		// Add PEM version
+		pemContent, err := encodeCertsToPEM(certs, isSingle)
+		if err != nil {
+			return nil, err
+		}
+		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, concatenate bool) ([]byte, error) {
+	var pemContent []byte
+	for _, cert := range certs {
+		pemBlock := &pem.Block{
+			Type:  "CERTIFICATE",
+			Bytes: cert.Raw,
+		}
+		pemContent = append(pemContent, pem.EncodeToMemory(pemBlock)...)
+	}
+	return pemContent, nil
+}
+
+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())
+}
+
+func createZipArchive(path string, files []fileEntry) error {
+	f, err := os.Create(path)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	w := zip.NewWriter(f)
+	defer w.Close()
+
+	for _, file := range files {
+		fw, err := w.Create(file.name)
+		if err != nil {
+			return err
+		}
+		if _, err := fw.Write(file.content); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func createTarGzArchive(path string, files []fileEntry) error {
+	f, err := os.Create(path)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	gw := gzip.NewWriter(f)
+	defer gw.Close()
+
+	tw := tar.NewWriter(gw)
+	defer tw.Close()
+
+	for _, file := range files {
+		hdr := &tar.Header{
+			Name: file.name,
+			Mode: 0644,
+			Size: int64(len(file.content)),
+		}
+		if err := tw.WriteHeader(hdr); err != nil {
+			return err
+		}
+		if _, err := tw.Write(file.content); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+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, err := os.ReadFile(file)
+		if err != nil {
+			return err
+		}
+
+		hash := sha256.Sum256(data)
+		fmt.Fprintf(f, "%x  %s\n", hash, filepath.Base(file))
+	}
+
+	return nil
+}

cmd/cert-bundler/prompt.txt

@@ -0,0 +1,189 @@
+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.
+
+

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-----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=
+-----END CERTIFICATE-----

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

@@ -0,0 +1,31 @@
+-----BEGIN CERTIFICATE-----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+-----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/certchain/BUILD.bazel

@@ -1,15 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "certchain_lib",
-    srcs = ["certchain.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/certchain",
-    visibility = ["//visibility:private"],
-    deps = ["@ht_sr_git_kisom_goutils//die:go_default_library"],
-)
-
-go_binary(
-    name = "certchain",
-    embed = [":certchain_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/certdump/BUILD.bazel

@@ -1,22 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "certdump_lib",
-    srcs = [
-        "certdump.go",
-        "util.go",
-    ],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/certdump",
-    visibility = ["//visibility:private"],
-    deps = [
-        "@com_github_cloudflare_cfssl//errors",
-        "@com_github_cloudflare_cfssl//helpers",
-        "@com_github_kr_text//:text",
-    ],
-)
-
-go_binary(
-    name = "certdump",
-    embed = [":certdump_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/certdump/certdump.go

@@ -12,12 +12,13 @@ import (
 	"crypto/x509/pkix"
 	"flag"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"os"
 	"sort"
 	"strings"
 
-	"github.com/cloudflare/cfssl/helpers"
+	"git.wntrmute.dev/kyle/goutils/certlib"
+	"git.wntrmute.dev/kyle/goutils/lib"
 )
 
 func certPublic(cert *x509.Certificate) string {
@@ -109,6 +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) {
@@ -208,17 +217,17 @@ func displayCert(cert *x509.Certificate) {
 }
 
 func displayAllCerts(in []byte, leafOnly bool) {
-	certs, err := helpers.ParseCertificatesPEM(in)
+	certs, err := certlib.ParseCertificatesPEM(in)
 	if err != nil {
-		certs, _, err = helpers.ParseCertificatesDER(in, "")
+		certs, _, err = certlib.ParseCertificatesDER(in, "")
 		if err != nil {
-			Warn(TranslateCFSSLError(err), "failed to parse certificates")
+			lib.Warn(err, "failed to parse certificates")
 			return
 		}
 	}
 
 	if len(certs) == 0 {
-		Warnx("no certificates found")
+		lib.Warnx("no certificates found")
 		return
 	}
 
@@ -236,7 +245,7 @@ func displayAllCertsWeb(uri string, leafOnly bool) {
 	ci := getConnInfo(uri)
 	conn, err := tls.Dial("tcp", ci.Addr, permissiveConfig())
 	if err != nil {
-		Warn(err, "couldn't connect to %s", ci.Addr)
+		lib.Warn(err, "couldn't connect to %s", ci.Addr)
 		return
 	}
 	defer conn.Close()
@@ -252,11 +261,11 @@ func displayAllCertsWeb(uri string, leafOnly bool) {
 		}
 		conn.Close()
 	} else {
-		Warn(err, "TLS verification error with server name %s", ci.Host)
+		lib.Warn(err, "TLS verification error with server name %s", ci.Host)
 	}
 
 	if len(state.PeerCertificates) == 0 {
-		Warnx("no certificates found")
+		lib.Warnx("no certificates found")
 		return
 	}
 
@@ -266,7 +275,7 @@ func displayAllCertsWeb(uri string, leafOnly bool) {
 	}
 
 	if len(state.VerifiedChains) == 0 {
-		Warnx("no verified chains found; using peer chain")
+		lib.Warnx("no verified chains found; using peer chain")
 		for i := range state.PeerCertificates {
 			displayCert(state.PeerCertificates[i])
 		}
@@ -289,9 +298,9 @@ func main() {
 	flag.Parse()
 
 	if flag.NArg() == 0 || (flag.NArg() == 1 && flag.Arg(0) == "-") {
-		certs, err := ioutil.ReadAll(os.Stdin)
+		certs, err := io.ReadAll(os.Stdin)
 		if err != nil {
-			Warn(err, "couldn't read certificates from standard input")
+			lib.Warn(err, "couldn't read certificates from standard input")
 			os.Exit(1)
 		}
 
@@ -306,9 +315,9 @@ func main() {
 			if strings.HasPrefix(filename, "https://") {
 				displayAllCertsWeb(filename, leafOnly)
 			} else {
-				in, err := ioutil.ReadFile(filename)
+				in, err := os.ReadFile(filename)
 				if err != nil {
-					Warn(err, "couldn't read certificate")
+					lib.Warn(err, "couldn't read certificate")
 					continue
 				}
 

cmd/certdump/util.go

@@ -3,13 +3,10 @@ package main
 import (
 	"crypto/tls"
 	"crypto/x509"
-	"errors"
 	"fmt"
 	"net"
-	"os"
 	"strings"
 
-	cferr "github.com/cloudflare/cfssl/errors"
 	"github.com/kr/text"
 )
 
@@ -89,34 +86,6 @@ func sigAlgoHash(a x509.SignatureAlgorithm) string {
 	}
 }
 
-// TranslateCFSSLError turns a CFSSL error into a more readable string.
-func TranslateCFSSLError(err error) error {
-	if err == nil {
-		return nil
-	}
-
-	// printing errors as json is terrible
-	if cfsslError, ok := err.(*cferr.Error); ok {
-		err = errors.New(cfsslError.Message)
-	}
-	return err
-}
-
-// Warnx displays a formatted error message to standard error, à la
-// warnx(3).
-func Warnx(format string, a ...interface{}) (int, error) {
-	format += "\n"
-	return fmt.Fprintf(os.Stderr, format, a...)
-}
-
-// Warn displays a formatted error message to standard output,
-// appending the error string, à la warn(3).
-func Warn(err error, format string, a ...interface{}) (int, error) {
-	format += ": %v\n"
-	a = append(a, err)
-	return fmt.Fprintf(os.Stderr, format, a...)
-}
-
 const maxLine = 78
 
 func makeIndent(n int) string {

cmd/certexpiry/BUILD.bazel

@@ -1,19 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "certexpiry_lib",
-    srcs = ["main.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/certexpiry",
-    visibility = ["//visibility:private"],
-    deps = [
-        "@com_github_cloudflare_cfssl//helpers",
-        "@ht_sr_git_kisom_goutils//die:go_default_library",
-        "@ht_sr_git_kisom_goutils//lib:go_default_library",
-    ],
-)
-
-go_binary(
-    name = "certexpiry",
-    embed = [":certexpiry_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/certexpiry/main.go

@@ -10,7 +10,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/cloudflare/cfssl/helpers"
+	"git.wntrmute.dev/kyle/goutils/certlib"
 	"git.wntrmute.dev/kyle/goutils/die"
 	"git.wntrmute.dev/kyle/goutils/lib"
 )
@@ -87,7 +87,7 @@ func main() {
 			continue
 		}
 
-		certs, err := helpers.ParseCertificatesPEM(in)
+		certs, err := certlib.ParseCertificatesPEM(in)
 		if err != nil {
 			lib.Warn(err, "while parsing certificates")
 			continue

cmd/certverify/BUILD.bazel

@@ -1,20 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "certverify_lib",
-    srcs = ["main.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/certverify",
-    visibility = ["//visibility:private"],
-    deps = [
-        "@com_github_cloudflare_cfssl//helpers",
-        "@com_github_cloudflare_cfssl//revoke",
-        "@ht_sr_git_kisom_goutils//die:go_default_library",
-        "@ht_sr_git_kisom_goutils//lib:go_default_library",
-    ],
-)
-
-go_binary(
-    name = "certverify",
-    embed = [":certverify_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/certverify/main.go

@@ -8,14 +8,14 @@ import (
 	"os"
 	"time"
 
-	"github.com/cloudflare/cfssl/helpers"
-	"github.com/cloudflare/cfssl/revoke"
+	"git.wntrmute.dev/kyle/goutils/certlib"
+	"git.wntrmute.dev/kyle/goutils/certlib/revoke"
 	"git.wntrmute.dev/kyle/goutils/die"
 	"git.wntrmute.dev/kyle/goutils/lib"
 )
 
 func printRevocation(cert *x509.Certificate) {
-	remaining := cert.NotAfter.Sub(time.Now())
+	remaining := time.Until(cert.NotAfter)
 	fmt.Printf("certificate expires in %s.\n", lib.Duration(remaining))
 
 	revoked, ok := revoke.VerifyCertificate(cert)
@@ -47,7 +47,7 @@ func main() {
 		if verbose {
 			fmt.Println("[+] loading root certificates from", caFile)
 		}
-		roots, err = helpers.LoadPEMCertPool(caFile)
+		roots, err = certlib.LoadPEMCertPool(caFile)
 		die.If(err)
 	}
 
@@ -57,7 +57,7 @@ func main() {
 		if verbose {
 			fmt.Println("[+] loading intermediate certificates from", intFile)
 		}
-		ints, err = helpers.LoadPEMCertPool(caFile)
+		ints, err = certlib.LoadPEMCertPool(caFile)
 		die.If(err)
 	} else {
 		ints = x509.NewCertPool()
@@ -71,7 +71,7 @@ func main() {
 	fileData, err := ioutil.ReadFile(flag.Arg(0))
 	die.If(err)
 
-	chain, err := helpers.ParseCertificatesPEM(fileData)
+	chain, err := certlib.ParseCertificatesPEM(fileData)
 	die.If(err)
 	if verbose {
 		fmt.Printf("[+] %s has %d certificates\n", flag.Arg(0), len(chain))

cmd/clustersh/BUILD.bazel

@@ -1,20 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "clustersh_lib",
-    srcs = ["main.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/clustersh",
-    visibility = ["//visibility:private"],
-    deps = [
-        "@com_github_pkg_sftp//:sftp",
-        "@ht_sr_git_kisom_goutils//lib:go_default_library",
-        "@org_golang_x_crypto//ssh",
-        "@org_golang_x_crypto//ssh/agent",
-    ],
-)
-
-go_binary(
-    name = "clustersh",
-    embed = [":clustersh_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/cruntar/BUILD.bazel

@@ -1,15 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "cruntar_lib",
-    srcs = ["main.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/cruntar",
-    visibility = ["//visibility:private"],
-    deps = ["@ht_sr_git_kisom_goutils//die:go_default_library"],
-)
-
-go_binary(
-    name = "cruntar",
-    embed = [":cruntar_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/cruntar/main.go

@@ -12,6 +12,7 @@ import (
 	"path/filepath"
 
 	"git.wntrmute.dev/kyle/goutils/die"
+	"git.wntrmute.dev/kyle/goutils/fileutil"
 )
 
 var (
@@ -56,7 +57,7 @@ func processFile(tfr *tar.Reader, hdr *tar.Header, top string) error {
 	}
 	filePath := filepath.Clean(filepath.Join(top, hdr.Name))
 	switch hdr.Typeflag {
-	case tar.TypeReg, tar.TypeRegA:
+	case tar.TypeReg:
 		file, err := os.Create(filePath)
 		if err != nil {
 			return err
@@ -92,6 +93,17 @@ func processFile(tfr *tar.Reader, hdr *tar.Header, top string) error {
 			return err
 		}
 	case tar.TypeSymlink:
+		if !fileutil.ValidateSymlink(hdr.Linkname, top) {
+			return fmt.Errorf("symlink %s is outside the top-level %s",
+				hdr.Linkname, top)
+		}
+		path := linkTarget(hdr.Linkname, top)
+		if ok, err := filepath.Match(top+"/*", filepath.Clean(path)); !ok {
+			return fmt.Errorf("symlink %s isn't in %s", hdr.Linkname, top)
+		} else if err != nil {
+			return err
+		}
+
 		err := os.Symlink(linkTarget(hdr.Linkname, top), filePath)
 		if err != nil {
 			return err

cmd/csrpubdump/BUILD.bazel

@@ -1,15 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "csrpubdump_lib",
-    srcs = ["pubdump.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/csrpubdump",
-    visibility = ["//visibility:private"],
-    deps = ["@ht_sr_git_kisom_goutils//die:go_default_library"],
-)
-
-go_binary(
-    name = "csrpubdump",
-    embed = [":csrpubdump_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/data_sync/README

@@ -0,0 +1,32 @@
+data_sync
+
+This is a tool I wrote primarily to sync my home directory to a backup
+drive plugged into my laptop. This system is provisioned by Ansible,
+and the goal is to be able to just copy my home directory back in the
+event of a failure without having lost a great deal of work or to wait
+for ansible to finish installing the right backup software. Specifically,
+I use a Framework laptop with the 1TB storage module, encrypted with
+LUKS, and run this twice daily (timed to correspond with my commute,
+though that's not really necessary). It started off as a shell script,
+then I decided to just write it as a program.
+
+Usage: data_sync [-d path] [-l level] [-m path] [-nqsv]
+                                  [-t path]
+        -d path         path to sync source directory
+                        (default "~")
+        -l level        log level to output (default "INFO"). Valid log
+                        levels are DEBUG, INFO, NOTICE, WARNING, ERR,
+                        CRIT, ALERT, EMERG. The default is INFO.
+        -m path         path to sync mount directory
+                        (default "/media/$USER/$(hostname -s)_data")
+        -n              dry-run mode: only check paths and print files to
+                        exclude
+        -q              suppress console output
+        -s              suppress syslog output
+        -t path         path to sync target directory
+                        (default "/media/$USER/$(hostname -s)_data/$USER")
+        -v              verbose rsync output
+
+data_sync rsyncs the tree at the sync source directory (-d) to the sync target
+directory (-t); it checks the mount directory (-m) exists; the sync target
+target directory must exist on the mount directory.

cmd/data_sync/main.go

@@ -0,0 +1,230 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"io/fs"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+
+	"git.wntrmute.dev/kyle/goutils/config"
+	"git.wntrmute.dev/kyle/goutils/fileutil"
+	"git.wntrmute.dev/kyle/goutils/log"
+)
+
+func mustHostname() string {
+	hostname, err := os.Hostname()
+	log.FatalError(err, "couldn't retrieve hostname")
+
+	if hostname == "" {
+		log.Fatal("no hostname returned")
+	}
+	return strings.Split(hostname, ".")[0]
+}
+
+var (
+	defaultDataDir   = mustHostname() + "_data"
+	defaultProgName  = defaultDataDir + "_sync"
+	defaultMountDir  = filepath.Join("/media", os.Getenv("USER"), defaultDataDir)
+	defaultSyncDir   = os.Getenv("HOME")
+	defaultTargetDir = filepath.Join(defaultMountDir, os.Getenv("USER"))
+)
+
+func usage(w io.Writer) {
+	prog := filepath.Base(os.Args[0])
+	fmt.Fprintf(w, `Usage: %s [-d path] [-l level] [-m path] [-nqsv]
+				  [-t path]
+	-d path		path to sync source directory
+			(default "%s")
+	-l level	log level to output (default "INFO"). Valid log
+			levels are DEBUG, INFO, NOTICE, WARNING, ERR,
+			CRIT, ALERT, EMERG. The default is INFO.
+	-m path		path to sync mount directory
+			(default "%s")
+	-n		dry-run mode: only check paths and print files to
+			exclude
+	-q		suppress console output
+	-s		suppress syslog output
+	-t path		path to sync target directory
+			(default "%s")
+	-v		verbose rsync output
+
+%s rsyncs the tree at the sync source directory (-d) to the sync target
+directory (-t); it checks the mount directory (-m) exists; the sync target
+target directory must exist on the mount directory.
+
+`, prog, defaultSyncDir, defaultMountDir, defaultTargetDir, prog)
+}
+
+func checkPaths(mount, target string, dryRun bool) error {
+	if !fileutil.DirectoryDoesExist(mount) {
+		return fmt.Errorf("sync dir %s isn't mounted", mount)
+	}
+
+	if !strings.HasPrefix(target, mount) {
+		return fmt.Errorf("target dir %s must exist in %s", target, mount)
+	}
+
+	if !fileutil.DirectoryDoesExist(target) {
+		if dryRun {
+			log.Infof("would mkdir %s", target)
+		} else {
+			log.Infof("mkdir %s", target)
+			if err := os.Mkdir(target, 0755); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func buildExcludes(syncDir string) ([]string, error) {
+	var excluded []string
+
+	walker := func(path string, info fs.FileInfo, err error) error {
+		if err != nil {
+			excluded = append(excluded, strings.TrimPrefix(path, syncDir))
+			if info != nil && info.IsDir() {
+				return filepath.SkipDir
+			}
+
+			return nil
+		}
+
+		if info.Mode().IsRegular() {
+			if err = fileutil.Access(path, fileutil.AccessRead); err != nil {
+				excluded = append(excluded, strings.TrimPrefix(path, syncDir))
+			}
+		}
+
+		if info.IsDir() {
+			if err = fileutil.Access(path, fileutil.AccessExec); err != nil {
+				excluded = append(excluded, strings.TrimPrefix(path, syncDir))
+			}
+		}
+
+		return nil
+	}
+
+	err := filepath.Walk(syncDir, walker)
+	return excluded, err
+}
+
+func writeExcludes(excluded []string) (string, error) {
+	if len(excluded) == 0 {
+		return "", nil
+	}
+
+	excludeFile, err := os.CreateTemp("", defaultProgName)
+	if err != nil {
+		return "", err
+	}
+
+	for _, name := range excluded {
+		fmt.Fprintln(excludeFile, name)
+	}
+
+	defer excludeFile.Close()
+	return excludeFile.Name(), nil
+}
+
+func rsync(syncDir, target, excludeFile string, verboseRsync bool) error {
+	var args []string
+
+	if excludeFile != "" {
+		args = append(args, "--exclude-from")
+		args = append(args, excludeFile)
+	}
+
+	if verboseRsync {
+		args = append(args, "--progress")
+		args = append(args, "-v")
+	}
+
+	args = append(args, []string{"-au", syncDir + "/", target + "/"}...)
+
+	path, err := exec.LookPath("rsync")
+	if err != nil {
+		return err
+	}
+
+	cmd := exec.Command(path, args...)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	return cmd.Run()
+}
+
+func init() {
+	flag.Usage = func() { usage(os.Stderr) }
+}
+
+func main() {
+
+	var logLevel, mountDir, syncDir, target string
+	var dryRun, quietMode, noSyslog, verboseRsync bool
+
+	flag.StringVar(&syncDir, "d", config.GetDefault("sync_dir", defaultSyncDir),
+		"`path to sync source directory`")
+	flag.StringVar(&logLevel, "l", config.GetDefault("log_level", "INFO"),
+		"log level to output")
+	flag.StringVar(&mountDir, "m", config.GetDefault("mount_dir", defaultMountDir),
+		"`path` to sync mount directory")
+	flag.BoolVar(&dryRun, "n", false, "dry-run mode: only check paths and print files to exclude")
+	flag.BoolVar(&quietMode, "q", quietMode, "suppress console output")
+	flag.BoolVar(&noSyslog, "s", noSyslog, "suppress syslog output")
+	flag.StringVar(&target, "t", config.GetDefault("sync_target", defaultTargetDir),
+		"`path` to sync target directory")
+	flag.BoolVar(&verboseRsync, "v", false, "verbose rsync output")
+	flag.Parse()
+
+	if quietMode && noSyslog {
+		fmt.Fprintln(os.Stderr, "both console and syslog output are suppressed")
+		fmt.Fprintln(os.Stderr, "errors will NOT be reported")
+	}
+
+	logOpts := &log.Options{
+		Level:        logLevel,
+		Tag:          defaultProgName,
+		Facility:     "user",
+		WriteSyslog:  !noSyslog,
+		WriteConsole: !quietMode,
+	}
+	err := log.Setup(logOpts)
+	log.FatalError(err, "failed to set up logging")
+
+	log.Infof("checking paths: mount=%s, target=%s", mountDir, target)
+	err = checkPaths(mountDir, target, dryRun)
+	log.FatalError(err, "target dir isn't ready")
+
+	log.Infof("checking for files to exclude from %s", syncDir)
+	excluded, err := buildExcludes(syncDir)
+	log.FatalError(err, "couldn't build excludes")
+
+	if dryRun {
+		fmt.Println("excluded files:")
+		for _, path := range excluded {
+			fmt.Printf("\t%s\n", path)
+		}
+		return
+	}
+
+	excludeFile, err := writeExcludes(excluded)
+	log.FatalError(err, "couldn't write exclude file")
+	log.Infof("excluding %d files via %s", len(excluded), excludeFile)
+
+	if excludeFile != "" {
+		defer func() {
+			log.Infof("removing exclude file %s", excludeFile)
+			if err := os.Remove(excludeFile); err != nil {
+				log.Warningf("failed to remove temp file %s", excludeFile)
+			}
+		}()
+	}
+
+	err = rsync(syncDir, target, excludeFile, verboseRsync)
+	log.FatalError(err, "couldn't sync data")
+}

cmd/diskimg/README

@@ -0,0 +1,34 @@
+diskimg: write disk images
+
+Usage:
+	diskimg [-a algo] [-v] image device
+
+Flags:
+	-a algo		Select the hashing algorithm to use. The default
+			is 'sha256'. Specifying an algorithm of 'list'
+			will print the supported algorithms to standard
+			output and exit with error code 2.
+	-v		Enable verbose (debug) output.
+
+Examples:
+	
+	Copying images/server.img to /dev/sda:
+
+	$ sudo diskimg images/server.img /dev/sda
+
+	Write a bladerunner node image to /dev/sda:
+
+	$ sudo diskimg -v ~/code/bladerunner/packer/build/cm4-cnode-ubuntu-22.04.2.img /dev/sda
+	opening image /home/kyle/code/bladerunner/packer/build/cm4-cnode-ubuntu-22.04.2.img for read
+	/home/kyle/code/bladerunner/packer/build/cm4-cnode-ubuntu-22.04.2.img  416d4c8f890904167419e3d488d097e9c847273376b650546fdb1f6f9809c184
+	opening device /dev/sda for rw
+	writing /home/kyle/code/bladerunner/packer/build/cm4-cnode-ubuntu-22.04.2.img -> /dev/sda
+	wrote 4151312384 bytes to /dev/sda
+	syncing /dev/sda
+	verifying the image was written successfully
+	OK
+
+Motivation:
+
+	I wanted to write something like balena's Etcher, but commandline only.
+

cmd/diskimg/main.go

@@ -0,0 +1,116 @@
+package main
+
+import (
+	"bytes"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+
+	"git.wntrmute.dev/kyle/goutils/ahash"
+	"git.wntrmute.dev/kyle/goutils/dbg"
+	"git.wntrmute.dev/kyle/goutils/die"
+)
+
+const defaultHashAlgorithm = "sha256"
+
+var (
+	hAlgo      string
+	debug = dbg.New()
+)
+
+
+func openImage(imageFile string) (image *os.File, hash []byte, err error) {
+	image, err = os.Open(imageFile)
+	if err != nil {
+		return
+	}
+
+	hash, err = ahash.SumReader(hAlgo, image)
+	if err != nil {
+		return
+	}
+
+	_, err = image.Seek(0, 0)
+	if err != nil {
+		return
+	}
+
+	debug.Printf("%s  %x\n", imageFile, hash)
+	return
+}
+
+func openDevice(devicePath string) (device *os.File, err error) {
+	fi, err := os.Stat(devicePath)
+	if err != nil {
+		return
+	}
+
+	device, err = os.OpenFile(devicePath, os.O_RDWR|os.O_SYNC, fi.Mode())
+	if err != nil {
+		return
+	}
+
+	return
+}
+
+func main() {
+	flag.StringVar(&hAlgo, "a", defaultHashAlgorithm, "default hash algorithm")
+	flag.BoolVar(&debug.Enabled, "v", false, "enable debug logging")
+	flag.Parse()
+
+	if hAlgo == "list" {
+		fmt.Println("Supported hashing algorithms:")
+		for _, algo := range ahash.SecureHashList() {
+			fmt.Printf("\t- %s\n", algo)
+		}
+		os.Exit(2)
+	}
+
+	if flag.NArg() != 2 {
+		die.With("usage: diskimg image device")
+	}
+
+	imageFile := flag.Arg(0)
+	devicePath := flag.Arg(1)
+
+	debug.Printf("opening image %s for read\n", imageFile)
+	image, hash, err := openImage(imageFile)
+	if image != nil {
+		defer image.Close()
+	}
+	die.If(err)
+
+	debug.Printf("opening device %s for rw\n", devicePath)
+	device, err := openDevice(devicePath)
+	if device != nil {
+		defer device.Close()
+	}
+	die.If(err)
+
+	debug.Printf("writing %s -> %s\n", imageFile, devicePath)
+	n, err := io.Copy(device, image)
+	die.If(err)
+	debug.Printf("wrote %d bytes to %s\n", n, devicePath)
+
+	debug.Printf("syncing %s\n", devicePath)
+	err = device.Sync()
+	die.If(err)
+
+	debug.Println("verifying the image was written successfully")
+	_, err = device.Seek(0, 0)
+	die.If(err)
+
+	deviceHash, err := ahash.SumLimitedReader(hAlgo, device, n)
+	die.If(err)
+
+	if !bytes.Equal(deviceHash, hash) {
+		fmt.Fprintln(os.Stderr, "Hash mismatch:")
+		fmt.Fprintf(os.Stderr, "\t%s: %s\n", imageFile, hash)
+		fmt.Fprintf(os.Stderr, "\t%s: %s\n", devicePath, deviceHash)
+		os.Exit(1)
+	}
+
+	debug.Println("OK")
+	os.Exit(0)
+}

cmd/dumpbytes/main.go

@@ -0,0 +1,71 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"git.wntrmute.dev/kyle/goutils/die"
+	"io"
+	"os"
+)
+
+func usage(w io.Writer, exc int) {
+	fmt.Fprintln(w, `usage: dumpbytes <file>`)
+	os.Exit(exc)
+}
+
+func printBytes(buf []byte) {
+	fmt.Printf("\t")
+	for i := 0; i < len(buf); i++ {
+		fmt.Printf("0x%02x, ", buf[i])
+	}
+	fmt.Println()
+}
+
+func dumpFile(path string, indentLevel int) error {
+	indent := ""
+	for i := 0; i < indentLevel; i++ {
+		indent += "\t"
+	}
+
+	file, err := os.Open(path)
+	if err != nil {
+		return err
+	}
+
+	defer file.Close()
+
+	fmt.Printf("%svar buffer = []byte{\n", indent)
+	for {
+		buf := make([]byte, 8)
+		n, err := file.Read(buf)
+		if err == io.EOF {
+			if n > 0 {
+				fmt.Printf("%s", indent)
+				printBytes(buf[:n])
+			}
+			break
+		}
+
+		if err != nil {
+			return err
+		}
+
+		fmt.Printf("%s", indent)
+		printBytes(buf[:n])
+	}
+
+	fmt.Printf("%s}\n", indent)
+	return nil
+}
+
+func main() {
+	indent := 0
+	flag.Usage = func() { usage(os.Stderr, 0) }
+	flag.IntVar(&indent, "n", 0, "indent level")
+	flag.Parse()
+
+	for _, file := range flag.Args() {
+		err := dumpFile(file, indent)
+		die.If(err)
+	}
+}

cmd/eig/BUILD.bazel

@@ -1,15 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "eig_lib",
-    srcs = ["main.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/eig",
-    visibility = ["//visibility:private"],
-    deps = ["@ht_sr_git_kisom_goutils//die:go_default_library"],
-)
-
-go_binary(
-    name = "eig",
-    embed = [":eig_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/fragment/BUILD.bazel

@@ -1,15 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "fragment_lib",
-    srcs = ["fragment.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/fragment",
-    visibility = ["//visibility:private"],
-    deps = ["@ht_sr_git_kisom_goutils//die:go_default_library"],
-)
-
-go_binary(
-    name = "fragment",
-    embed = [":fragment_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/host/README

@@ -0,0 +1,5 @@
+host
+
+This is a utility to display CNAME records and IPs for a hostname. It
+was born of my frustration in trying to figure out how to get the host(1)
+tool installed on Fedora.

cmd/host/main.go

@@ -0,0 +1,41 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"net"
+)
+
+func lookupHost(host string) error {
+	cname, err := net.LookupCNAME(host)
+	if err != nil {
+		return err
+	}
+
+	if cname != host {
+		fmt.Printf("%s is a CNAME for %s\n", host, cname)
+		host = cname
+	}
+
+	addrs, err := net.LookupHost(host)
+	if err != nil {
+		return err
+	}
+
+	for _, addr := range addrs {
+		fmt.Printf("\t%s\n", addr)
+	}
+
+	return nil
+}
+
+func main() {
+	flag.Parse()
+
+	for _, arg := range flag.Args() {
+		if err := lookupHost(arg); err != nil {
+			log.Printf("%s: %s", arg, err)
+		}
+	}
+}

cmd/jlp/BUILD.bazel

@@ -1,15 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "jlp_lib",
-    srcs = ["jlp.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/jlp",
-    visibility = ["//visibility:private"],
-    deps = ["@ht_sr_git_kisom_goutils//lib:go_default_library"],
-)
-
-go_binary(
-    name = "jlp",
-    embed = [":jlp_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/kgz/BUILD.bazel

@@ -1,15 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "kgz_lib",
-    srcs = ["main.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/kgz",
-    visibility = ["//visibility:private"],
-    deps = ["@com_github_pkg_errors//:errors"],
-)
-
-go_binary(
-    name = "kgz",
-    embed = [":kgz_lib"],
-    visibility = ["//visibility:public"],
-)

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/parts/BUILD.bazel

@@ -1,15 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "parts_lib",
-    srcs = ["main.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/parts",
-    visibility = ["//visibility:private"],
-    deps = ["@ht_sr_git_kisom_goutils//die:go_default_library"],
-)
-
-go_binary(
-    name = "parts",
-    embed = [":parts_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/pem2bin/BUILD.bazel

@@ -1,14 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "pem2bin_lib",
-    srcs = ["main.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/pem2bin",
-    visibility = ["//visibility:private"],
-)
-
-go_binary(
-    name = "pem2bin",
-    embed = [":pem2bin_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/pembody/BUILD.bazel

@@ -1,15 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "pembody_lib",
-    srcs = ["pembody.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/pembody",
-    visibility = ["//visibility:private"],
-    deps = ["@ht_sr_git_kisom_goutils//lib:go_default_library"],
-)
-
-go_binary(
-    name = "pembody",
-    embed = [":pembody_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/pemit/BUILD.bazel

@@ -1,19 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "pemit_lib",
-    srcs = ["main.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/pemit",
-    visibility = ["//visibility:private"],
-    deps = [
-        "@ht_sr_git_kisom_goutils//assert:go_default_library",
-        "@ht_sr_git_kisom_goutils//die:go_default_library",
-        "@ht_sr_git_kisom_goutils//lib:go_default_library",
-    ],
-)
-
-go_binary(
-    name = "pemit",
-    embed = [":pemit_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/readchain/BUILD.bazel

@@ -1,14 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "readchain_lib",
-    srcs = ["chain.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/readchain",
-    visibility = ["//visibility:private"],
-)
-
-go_binary(
-    name = "readchain",
-    embed = [":readchain_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/renfnv/BUILD.bazel

@@ -1,18 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "renfnv_lib",
-    srcs = ["renfnv.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/renfnv",
-    visibility = ["//visibility:private"],
-    deps = [
-        "@ht_sr_git_kisom_goutils//fileutil:go_default_library",
-        "@ht_sr_git_kisom_goutils//lib:go_default_library",
-    ],
-)
-
-go_binary(
-    name = "renfnv",
-    embed = [":renfnv_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/rhash/BUILD.bazel

@@ -1,19 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "rhash_lib",
-    srcs = ["main.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/rhash",
-    visibility = ["//visibility:private"],
-    deps = [
-        "@ht_sr_git_kisom_goutils//ahash:go_default_library",
-        "@ht_sr_git_kisom_goutils//die:go_default_library",
-        "@ht_sr_git_kisom_goutils//lib:go_default_library",
-    ],
-)
-
-go_binary(
-    name = "rhash",
-    embed = [":rhash_lib"],
-    visibility = ["//visibility:public"],
-)

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/showimp/BUILD.bazel

@@ -1,18 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "showimp_lib",
-    srcs = ["main.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/showimp",
-    visibility = ["//visibility:private"],
-    deps = [
-        "@ht_sr_git_kisom_goutils//die:go_default_library",
-        "@ht_sr_git_kisom_goutils//logging:go_default_library",
-    ],
-)
-
-go_binary(
-    name = "showimp",
-    embed = [":showimp_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/showimp/main.go

@@ -12,36 +12,23 @@ import (
 	"sort"
 	"strings"
 
+	"git.wntrmute.dev/kyle/goutils/dbg"
 	"git.wntrmute.dev/kyle/goutils/die"
-	"git.wntrmute.dev/kyle/goutils/logging"
 )
 
 var (
 	gopath  string
 	project string
-	debug   bool
 )
 
 var (
-	stdLibRegexp = regexp.MustCompile(`^\w+(/\w+)*$`)
-	sourceRegexp = regexp.MustCompile(`^[^.].*\.go$`)
-	log          = logging.NewConsole()
-	imports      = map[string]bool{}
+	debug        = dbg.New()
 	fset         = &token.FileSet{}
+	imports      = map[string]bool{}
+	sourceRegexp = regexp.MustCompile(`^[^.].*\.go$`)
+	stdLibRegexp = regexp.MustCompile(`^\w+(/\w+)*$`)
 )
 
-func debugf(format string, args ...interface{}) {
-	if debug {
-		fmt.Printf(format, args...)
-	}
-}
-
-func debugln(args ...interface{}) {
-	if debug {
-		fmt.Println(args...)
-	}
-}
-
 func init() {
 	gopath = os.Getenv("GOPATH")
 	if gopath == "" {
@@ -75,7 +62,7 @@ func walkFile(path string, info os.FileInfo, err error) error {
 		return nil
 	}
 
-	debugln(path)
+	debug.Println(path)
 
 	f, err := parser.ParseFile(fset, path, nil, parser.ImportsOnly)
 	if err != nil {
@@ -85,16 +72,16 @@ func walkFile(path string, info os.FileInfo, err error) error {
 	for _, importSpec := range f.Imports {
 		importPath := strings.Trim(importSpec.Path.Value, `"`)
 		if stdLibRegexp.MatchString(importPath) {
-			debugln("standard lib:", importPath)
+			debug.Println("standard lib:", importPath)
 			continue
 		} else if strings.HasPrefix(importPath, project) {
-			debugln("internal import:", importPath)
+			debug.Println("internal import:", importPath)
 			continue
 		} else if strings.HasPrefix(importPath, "golang.org/") {
-			debugln("extended lib:", importPath)
+			debug.Println("extended lib:", importPath)
 			continue
 		}
-		debugln("import:", importPath)
+		debug.Println("import:", importPath)
 		imports[importPath] = true
 	}
 
@@ -108,7 +95,7 @@ func main() {
 	var noVendor bool
 	flag.StringVar(&ignoreLine, "i", "", "comma-separated list of directories to ignore")
 	flag.BoolVar(&noVendor, "nv", false, "ignore the vendor directory")
-	flag.BoolVar(&debug, "v", false, "log debugging information")
+	flag.BoolVar(&debug.Enabled, "v", false, "log debugging information")
 	flag.Parse()
 
 	if noVendor {

cmd/ski/BUILD.bazel

@@ -1,18 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "ski_lib",
-    srcs = ["main.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/ski",
-    visibility = ["//visibility:private"],
-    deps = [
-        "@ht_sr_git_kisom_goutils//die:go_default_library",
-        "@ht_sr_git_kisom_goutils//lib:go_default_library",
-    ],
-)
-
-go_binary(
-    name = "ski",
-    embed = [":ski_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/sprox/BUILD.bazel

@@ -1,15 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "sprox_lib",
-    srcs = ["main.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/sprox",
-    visibility = ["//visibility:private"],
-    deps = ["@ht_sr_git_kisom_goutils//die:go_default_library"],
-)
-
-go_binary(
-    name = "sprox",
-    embed = [":sprox_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/stealchain-server/BUILD.bazel

@@ -1,15 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "stealchain-server_lib",
-    srcs = ["main.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/stealchain-server",
-    visibility = ["//visibility:private"],
-    deps = ["@ht_sr_git_kisom_goutils//die:go_default_library"],
-)
-
-go_binary(
-    name = "stealchain-server",
-    embed = [":stealchain-server_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/stealchain/BUILD.bazel

@@ -1,15 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "stealchain_lib",
-    srcs = ["thief.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/stealchain",
-    visibility = ["//visibility:private"],
-    deps = ["@ht_sr_git_kisom_goutils//die:go_default_library"],
-)
-
-go_binary(
-    name = "stealchain",
-    embed = [":stealchain_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/subjhash/BUILD.bazel

@@ -1,18 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "subjhash_lib",
-    srcs = ["main.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/subjhash",
-    visibility = ["//visibility:private"],
-    deps = [
-        "@ht_sr_git_kisom_goutils//die:go_default_library",
-        "@ht_sr_git_kisom_goutils//lib:go_default_library",
-    ],
-)
-
-go_binary(
-    name = "subjhash",
-    embed = [":subjhash_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/subjhash/main.go

@@ -9,6 +9,7 @@ import (
 	"io"
 	"os"
 
+	"git.wntrmute.dev/kyle/goutils/certlib"
 	"git.wntrmute.dev/kyle/goutils/die"
 	"git.wntrmute.dev/kyle/goutils/lib"
 )
@@ -57,7 +58,7 @@ func getSubjectInfoHash(cert *x509.Certificate, issuer bool) []byte {
 
 func printDigests(paths []string, issuer bool) {
 	for _, path := range paths {
-		cert, err := lib.LoadCertificate(path)
+		cert, err := certlib.LoadCertificate(path)
 		if err != nil {
 			lib.Warn(err, "failed to load certificate from %s", path)
 			continue
@@ -82,9 +83,9 @@ func matchDigests(paths []string, issuer bool) {
 		snd := paths[1]
 		paths = paths[2:]
 
-		fstCert, err := lib.LoadCertificate(fst)
+		fstCert, err := certlib.LoadCertificate(fst)
 		die.If(err)
-		sndCert, err := lib.LoadCertificate(snd)
+		sndCert, err := certlib.LoadCertificate(snd)
 		die.If(err)
 		if !bytes.Equal(getSubjectInfoHash(fstCert, issuer), getSubjectInfoHash(sndCert, issuer)) {
 			lib.Warnx("certificates don't match: %s and %s", fst, snd)

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/tlskeypair/BUILD.bazel

@@ -1,15 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "tlskeypair_lib",
-    srcs = ["main.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/tlskeypair",
-    visibility = ["//visibility:private"],
-    deps = ["@ht_sr_git_kisom_goutils//die:go_default_library"],
-)
-
-go_binary(
-    name = "tlskeypair",
-    embed = [":tlskeypair_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/utc/BUILD.bazel

@@ -1,14 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "utc_lib",
-    srcs = ["main.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/utc",
-    visibility = ["//visibility:private"],
-)
-
-go_binary(
-    name = "utc",
-    embed = [":utc_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/yamll/BUILD.bazel

@@ -1,15 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "yamll_lib",
-    srcs = ["main.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/cmd/yamll",
-    visibility = ["//visibility:private"],
-    deps = ["@in_gopkg_yaml_v2//:yaml_v2"],
-)
-
-go_binary(
-    name = "yamll",
-    embed = [":yamll_lib"],
-    visibility = ["//visibility:public"],
-)

cmd/zsearch/main.go

@@ -0,0 +1,136 @@
+// zsearch is a utility for searching zlib-compressed files for a
+// search string. It was really designed for use with the Git object
+// store, i.e. to aid in the recovery of files after Git does what Git
+// do.
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"compress/zlib"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"regexp"
+)
+
+const defaultDirectory = ".git/objects"
+
+func errorf(format string, a ...interface{}) {
+	fmt.Fprintf(os.Stderr, format, a...)
+	if format[len(format)-1] != '\n' {
+		fmt.Fprintf(os.Stderr, "\n")
+	}
+}
+
+func isDir(path string) bool {
+	fi, err := os.Stat(path)
+	if err != nil {
+		return false
+	}
+
+	return fi.IsDir()
+}
+
+func loadFile(path string) ([]byte, error) {
+	file, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	buf := new(bytes.Buffer)
+	zread, err := zlib.NewReader(file)
+	if err != nil {
+		return nil, err
+	}
+	defer zread.Close()
+
+	_, err = io.Copy(buf, zread)
+	if err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+func showFile(path string) {
+	fileData, err := loadFile(path)
+	if err != nil {
+		errorf("%v", err)
+		return
+	}
+
+	fmt.Printf("%s\n", fileData)
+}
+
+func searchFile(path string, search *regexp.Regexp) error {
+	file, err := os.Open(path)
+	if err != nil {
+		errorf("%v", err)
+		return err
+	}
+	defer file.Close()
+
+	zread, err := zlib.NewReader(file)
+	if err != nil {
+		errorf("%v", err)
+		return err
+	}
+	defer zread.Close()
+
+	zbuf := bufio.NewReader(zread)
+	if search.MatchReader(zbuf) {
+		fileData, err := loadFile(path)
+		if err != nil {
+			errorf("%v", err)
+			return err
+		}
+		fmt.Printf("%s:\n%s\n", path, fileData)
+	}
+	return nil
+}
+
+func buildWalker(searchExpr *regexp.Regexp) filepath.WalkFunc {
+	return func(path string, info os.FileInfo, err error) error {
+		if info.Mode().IsRegular() {
+			return searchFile(path, searchExpr)
+		}
+		return nil
+	}
+}
+
+func main() {
+	flSearch := flag.String("s", "", "search string (should be an RE2 regular expression)")
+	flag.Parse()
+
+	if *flSearch == "" {
+		for _, path := range flag.Args() {
+			showFile(path)
+		}
+	} else {
+		search, err := regexp.Compile(*flSearch)
+		if err != nil {
+			errorf("Bad regexp: %v", err)
+			return
+		}
+
+		pathList := flag.Args()
+		if len(pathList) == 0 {
+			pathList = []string{defaultDirectory}
+		}
+
+		for _, path := range pathList {
+			if isDir(path) {
+				err := filepath.Walk(path, buildWalker(search))
+				if err != nil {
+					errorf("%v", err)
+					return
+				}
+			} else {
+				searchFile(path, search)
+			}
+		}
+	}
+}

config/BUILD.bazel

@@ -1,22 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
-
-go_library(
-    name = "config",
-    srcs = [
-        "config.go",
-        "path_linux.go",
-    ],
-    importpath = "git.wntrmute.dev/kyle/goutils/config",
-    visibility = ["//visibility:public"],
-    deps = ["@ht_sr_git_kisom_goutils//config/iniconf:go_default_library"],
-)
-
-go_test(
-    name = "config_test",
-    srcs = [
-        "config_test.go",
-        "path_test.go",
-    ],
-    data = glob(["testdata/**"]),
-    embed = [":config"],
-)

config/config.go

@@ -13,6 +13,7 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"sort"
 	"strings"
 
 	"git.wntrmute.dev/kyle/goutils/config/iniconf"
@@ -139,3 +140,14 @@ func Require(key string) string {
 
 	return v
 }
+
+// ListKeys returns a slice of the currently known keys.
+func ListKeys() []string {
+	keyList := []string{}
+	for k := range vars {
+		keyList = append(keyList, k)
+	}
+
+	sort.Strings(keyList)
+	return keyList
+}

config/iniconf/BUILD.bazel

@@ -1,15 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
-
-go_library(
-    name = "iniconf",
-    srcs = ["iniconf.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/config/iniconf",
-    visibility = ["//visibility:public"],
-)
-
-go_test(
-    name = "iniconf_test",
-    srcs = ["iniconf_test.go"],
-    data = glob(["testdata/**"]),
-    embed = [":iniconf"],
-)

config/path.go

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

dbg/BUILD.bazel

@@ -1,18 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
-
-go_library(
-    name = "dbg",
-    srcs = ["dbg.go"],
-    importpath = "git.wntrmute.dev/kyle/goutils/dbg",
-    visibility = ["//visibility:public"],
-)
-
-go_test(
-    name = "dbg_test",
-    srcs = ["dbg_test.go"],
-    embed = [":dbg"],
-    deps = [
-        "@com_github_stretchr_testify//require",
-        "@ht_sr_git_kisom_goutils//testio:go_default_library",
-    ],
-)

dbg/dbg.go

@@ -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 ...interface{}) {
 	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 ...interface{}) {
 	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 ...interface{}) {
 	if dbg.Enabled {
 		fmt.Fprintf(dbg.out, format, v...)
 	}