Pulse/internal/crypto/crypto.go
2025-12-29 17:25:21 +00:00

290 lines
9 KiB
Go

package crypto
import (
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"encoding/base64"
"fmt"
"io"
"os"
"path/filepath"
"github.com/rcourtman/pulse-go-rewrite/internal/utils"
"github.com/rs/zerolog/log"
)
var defaultDataDirFn = utils.GetDataDir
var legacyKeyPath = "/etc/pulse/.encryption.key"
var randReader = rand.Reader
var newCipher = aes.NewCipher
var newGCM = cipher.NewGCM
// CryptoManager handles encryption/decryption of sensitive data
type CryptoManager struct {
key []byte
keyPath string // Path to the encryption key file for runtime validation
}
// NewCryptoManagerAt creates a new crypto manager with an explicit data directory override.
func NewCryptoManagerAt(dataDir string) (*CryptoManager, error) {
if dataDir == "" {
dataDir = defaultDataDirFn()
}
keyPath := filepath.Join(dataDir, ".encryption.key")
key, err := getOrCreateKeyAt(dataDir)
if err != nil {
return nil, fmt.Errorf("failed to get encryption key: %w", err)
}
return &CryptoManager{
key: key,
keyPath: keyPath,
}, nil
}
// getOrCreateKeyAt gets the encryption key or creates one if it doesn't exist
func getOrCreateKeyAt(dataDir string) ([]byte, error) {
if dataDir == "" {
dataDir = defaultDataDirFn()
}
keyPath := filepath.Join(dataDir, ".encryption.key")
oldKeyPath := legacyKeyPath
oldKeyDir := filepath.Dir(oldKeyPath)
log.Debug().
Str("dataDir", dataDir).
Str("keyPath", keyPath).
Msg("Looking for encryption key")
// Try to read existing key from new location
if data, err := os.ReadFile(keyPath); err == nil {
// Use DecodedLen to allocate sufficient space, then slice to actual length
// This prevents panics if the file contains more data than expected
decoded := make([]byte, base64.StdEncoding.DecodedLen(len(data)))
n, err := base64.StdEncoding.Decode(decoded, data)
if err == nil {
if n == 32 {
log.Debug().Msg("Found and loaded existing encryption key")
return decoded[:n], nil
}
log.Warn().
Int("decodedBytes", n).
Msg("Encryption key has invalid length (expected 32 bytes)")
} else {
log.Warn().
Err(err).
Msg("Failed to decode encryption key")
}
} else {
log.Debug().Err(err).Str("path", keyPath).Msg("Could not read encryption key file")
}
// Check for key in old location and migrate if found (only if paths differ)
// CRITICAL: This code deletes the encryption key at oldKeyPath after migrating it.
// Adding extensive logging to diagnose recurring key deletion bug.
if dataDir != oldKeyDir && keyPath != oldKeyPath {
log.Warn().
Str("dataDir", dataDir).
Str("keyPath", keyPath).
Str("oldKeyPath", oldKeyPath).
Msg("ENCRYPTION KEY MIGRATION: Checking if old key exists for migration (this code path CAN delete the key!)")
if data, err := os.ReadFile(oldKeyPath); err == nil {
decoded := make([]byte, base64.StdEncoding.DecodedLen(len(data)))
n, err := base64.StdEncoding.Decode(decoded, data)
if err == nil && n == 32 {
key := decoded[:n]
// Migrate key to new location
if err := os.MkdirAll(filepath.Dir(keyPath), 0700); err != nil {
// Migration failed, but we can still use the old key
log.Warn().Err(err).Msg("Failed to create directory for key migration, using old location")
return key, nil
}
if err := os.WriteFile(keyPath, data, 0600); err != nil {
// Migration failed, but we can still use the old key
log.Warn().Err(err).Msg("Failed to migrate encryption key, using old location")
return key, nil
}
log.Info().
Str("from", oldKeyPath).
Str("to", keyPath).
Msg("Successfully migrated encryption key to data directory")
// CRITICAL: This is the ONLY place in the codebase that deletes the encryption key!
// BUG FIX: Disabling key deletion to prevent key loss.
// Keeping both copies is safe - the old key at /etc/pulse will just be unused.
log.Info().
Str("oldKeyPath", oldKeyPath).
Str("newKeyPath", keyPath).
Str("dataDir", dataDir).
Msg("Key migration complete - PRESERVING old key at original location for safety")
// DISABLED: Key deletion was causing mysterious key loss bugs.
// The old key is now preserved. This is safe because:
// 1. We just successfully wrote the key to the new location
// 2. Future reads will use the new location (checked first)
// 3. Keeping the backup prevents data loss if something goes wrong
//
// if err := os.Remove(oldKeyPath); err != nil {
// log.Debug().Err(err).Msg("Could not remove old encryption key (may lack permissions)")
// } else {
// log.Error().
// Str("deletedPath", oldKeyPath).
// Msg("CRITICAL: ENCRYPTION KEY HAS BEEN DELETED")
// }
return key, nil
}
}
} else {
log.Debug().
Str("dataDir", dataDir).
Str("keyPath", keyPath).
Bool("sameAsOldPath", dataDir == oldKeyDir).
Msg("Skipping key migration check (dataDir is /etc/pulse or paths match)")
}
// Before generating a new key, check if encrypted data exists OR if there are any backup/corrupted files
// This prevents silently orphaning existing encrypted configurations
// CRITICAL: Also check for .backup and .corrupted files to prevent data loss
checkPatterns := []string{
"nodes.enc*",
"email.enc*",
"webhooks.enc*",
"oidc.enc*",
}
hasEncryptedData := false
var foundFiles []string
for _, pattern := range checkPatterns {
matches, _ := filepath.Glob(filepath.Join(dataDir, pattern))
for _, file := range matches {
if info, err := os.Stat(file); err == nil && info.Size() > 0 {
hasEncryptedData = true
foundFiles = append(foundFiles, filepath.Base(file))
}
}
}
if hasEncryptedData {
log.Error().
Strs("foundFiles", foundFiles).
Str("dataDir", dataDir).
Msg("CRITICAL: Encryption key not found but encrypted/backup/corrupted files exist")
return nil, fmt.Errorf("encryption key not found but encrypted data exists (%v) - cannot generate new key as it would orphan existing data. Please restore the encryption key from backup or delete ALL .enc* files to start fresh", foundFiles)
}
// Generate new key (only if no encrypted data exists)
key := make([]byte, 32) // AES-256
if _, err := io.ReadFull(randReader, key); err != nil {
return nil, fmt.Errorf("failed to generate key: %w", err)
}
// Ensure directory exists
if err := os.MkdirAll(filepath.Dir(keyPath), 0700); err != nil {
return nil, fmt.Errorf("failed to create directory: %w", err)
}
// Save key with restricted permissions
encoded := base64.StdEncoding.EncodeToString(key)
if err := os.WriteFile(keyPath, []byte(encoded), 0600); err != nil {
return nil, fmt.Errorf("failed to save key: %w", err)
}
log.Info().Msg("Generated new encryption key")
return key, nil
}
// Encrypt encrypts data using AES-GCM
// SAFETY: Verifies the encryption key file still exists on disk before encrypting.
// This prevents orphaned encrypted data if the key was deleted while Pulse was running.
func (c *CryptoManager) Encrypt(plaintext []byte) ([]byte, error) {
// CRITICAL: Verify the key file still exists on disk before encrypting
// This prevents creating orphaned encrypted data that can never be decrypted
if c.keyPath != "" {
if _, err := os.Stat(c.keyPath); os.IsNotExist(err) {
log.Error().
Str("keyPath", c.keyPath).
Msg("CRITICAL: Encryption key file has been deleted - refusing to encrypt to prevent orphaned data")
return nil, fmt.Errorf("encryption key file deleted - cannot encrypt (would create orphaned data)")
}
}
block, err := newCipher(c.key)
if err != nil {
return nil, err
}
gcm, err := newGCM(block)
if err != nil {
return nil, err
}
nonce := make([]byte, gcm.NonceSize())
if _, err := io.ReadFull(randReader, nonce); err != nil {
return nil, err
}
ciphertext := gcm.Seal(nonce, nonce, plaintext, nil)
return ciphertext, nil
}
// Decrypt decrypts data using AES-GCM
func (c *CryptoManager) Decrypt(ciphertext []byte) ([]byte, error) {
block, err := newCipher(c.key)
if err != nil {
return nil, err
}
gcm, err := newGCM(block)
if err != nil {
return nil, err
}
nonceSize := gcm.NonceSize()
if len(ciphertext) < nonceSize {
return nil, fmt.Errorf("ciphertext too short")
}
nonce, ciphertext := ciphertext[:nonceSize], ciphertext[nonceSize:]
plaintext, err := gcm.Open(nil, nonce, ciphertext, nil)
if err != nil {
return nil, err
}
return plaintext, nil
}
// EncryptString encrypts a string and returns base64
func (c *CryptoManager) EncryptString(plaintext string) (string, error) {
encrypted, err := c.Encrypt([]byte(plaintext))
if err != nil {
return "", err
}
return base64.StdEncoding.EncodeToString(encrypted), nil
}
// DecryptString decrypts a base64 string
func (c *CryptoManager) DecryptString(ciphertext string) (string, error) {
data, err := base64.StdEncoding.DecodeString(ciphertext)
if err != nil {
return "", err
}
decrypted, err := c.Decrypt(data)
if err != nil {
return "", err
}
return string(decrypted), nil
}
// Note: Password hashing has been moved to the auth package
// which uses bcrypt for secure password hashing.
// Never use SHA256 or other fast hashes for passwords!