Files
deploy-felhom-compose/controller/internal/crypto/crypto.go
T
admin 44f7fd2f19 feat: encrypt sensitive values in app.yaml with AES-256-GCM
Passwords and secrets from deploy fields (type: password/secret) are now
encrypted at rest in app.yaml using a per-node 32-byte key. Values stored
as ENC:base64(nonce+ciphertext), decrypted transparently for docker-compose
and web UI. Key included in infra backup bundle for disaster recovery.
Existing plaintext values migrated automatically on startup.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-02-23 19:12:24 +01:00

117 lines
2.9 KiB
Go

// Package crypto provides AES-256-GCM encryption for sensitive app config values.
package crypto
import (
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"encoding/base64"
"fmt"
"os"
"strings"
)
const (
keySize = 32 // AES-256
prefix = "ENC:"
)
// LoadOrCreateKey reads a 32-byte encryption key from path, or generates one if it doesn't exist.
func LoadOrCreateKey(path string) ([]byte, error) {
data, err := os.ReadFile(path)
if err == nil {
if len(data) != keySize {
return nil, fmt.Errorf("encryption key file %s has invalid size %d (expected %d)", path, len(data), keySize)
}
return data, nil
}
if !os.IsNotExist(err) {
return nil, fmt.Errorf("reading encryption key %s: %w", path, err)
}
// Generate new key
key := make([]byte, keySize)
if _, err := rand.Read(key); err != nil {
return nil, fmt.Errorf("generating encryption key: %w", err)
}
if err := os.WriteFile(path, key, 0600); err != nil {
return nil, fmt.Errorf("writing encryption key %s: %w", path, err)
}
return key, nil
}
// Encrypt encrypts plaintext with AES-256-GCM and returns "ENC:<base64(nonce+ciphertext)>".
func Encrypt(key []byte, plaintext string) (string, error) {
block, err := aes.NewCipher(key)
if err != nil {
return "", err
}
gcm, err := cipher.NewGCM(block)
if err != nil {
return "", err
}
nonce := make([]byte, gcm.NonceSize())
if _, err := rand.Read(nonce); err != nil {
return "", err
}
ciphertext := gcm.Seal(nonce, nonce, []byte(plaintext), nil) // nonce prepended
return prefix + base64.StdEncoding.EncodeToString(ciphertext), nil
}
// Decrypt decrypts a value produced by Encrypt. Returns error if value is not encrypted or decryption fails.
func Decrypt(key []byte, value string) (string, error) {
if !IsEncrypted(value) {
return "", fmt.Errorf("value is not encrypted")
}
data, err := base64.StdEncoding.DecodeString(value[len(prefix):])
if err != nil {
return "", fmt.Errorf("base64 decode: %w", err)
}
block, err := aes.NewCipher(key)
if err != nil {
return "", err
}
gcm, err := cipher.NewGCM(block)
if err != nil {
return "", err
}
nonceSize := gcm.NonceSize()
if len(data) < nonceSize {
return "", fmt.Errorf("ciphertext too short")
}
plaintext, err := gcm.Open(nil, data[:nonceSize], data[nonceSize:], nil)
if err != nil {
return "", fmt.Errorf("decrypt: %w", err)
}
return string(plaintext), nil
}
// IsEncrypted returns true if the value has the encryption prefix.
func IsEncrypted(value string) bool {
return strings.HasPrefix(value, prefix)
}
// DecryptMap decrypts all encrypted values in a map, returning a new map with plaintext values.
func DecryptMap(key []byte, env map[string]string) map[string]string {
if key == nil || env == nil {
return env
}
result := make(map[string]string, len(env))
for k, v := range env {
if IsEncrypted(v) {
if dec, err := Decrypt(key, v); err == nil {
result[k] = dec
continue
}
}
result[k] = v
}
return result
}