cmd: add cert-bundler

Builds certificate bundles.
This commit is contained in:
2025-11-14 21:59:03 -08:00
parent e375963243
commit 289c9d2343
12 changed files with 801 additions and 0 deletions

489
cmd/cert-bundler/main.go Normal file
View File

@@ -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
}