Files
gemini-banlancer/internal/crypto/crypto.go
2025-11-20 12:24:05 +08:00

77 lines
2.2 KiB
Go

// Filename: internal/crypto/crypto.go
package crypto
import (
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"encoding/hex"
"fmt"
"gemini-balancer/internal/config" // [NEW] Crypto service now depends on Config
"io"
"os"
)
type Service struct {
gcm cipher.AEAD
}
func NewService(cfg *config.Config) (*Service, error) {
keyHex := cfg.EncryptionKey
if keyHex == "" {
// Fallback to environment variable if not in config file
keyHex = os.Getenv("ENCRYPTION_KEY")
if keyHex == "" {
return nil, fmt.Errorf("encryption key is not configured: please set 'encryption_key' in config.yaml or the ENCRYPTION_KEY environment variable")
}
}
key, err := hex.DecodeString(keyHex)
if err != nil {
return nil, fmt.Errorf("failed to decode encryption key from hex: %w", err)
}
if len(key) != 32 {
return nil, fmt.Errorf("invalid encryption key length: must be 32 bytes (64 hex characters), got %d bytes", len(key))
}
block, err := aes.NewCipher(key)
if err != nil { // ... (rest is the same)
return nil, fmt.Errorf("failed to create AES cipher block: %w", err)
}
gcm, err := cipher.NewGCM(block)
if err != nil {
return nil, fmt.Errorf("failed to create GCM block cipher: %w", err)
}
return &Service{gcm: gcm}, nil
}
// Encrypt encrypts plaintext and returns hex-encoded ciphertext.
func (s *Service) Encrypt(plaintext string) (string, error) {
nonce := make([]byte, s.gcm.NonceSize())
if _, err := io.ReadFull(rand.Reader, nonce); err != nil {
return "", fmt.Errorf("failed to generate nonce: %w", err)
}
ciphertext := s.gcm.Seal(nonce, nonce, []byte(plaintext), nil)
return hex.EncodeToString(ciphertext), nil
}
// Decrypt decrypts a hex-encoded ciphertext and returns the plaintext.
func (s *Service) Decrypt(hexCiphertext string) (string, error) {
ciphertext, err := hex.DecodeString(hexCiphertext)
if err != nil {
return "", fmt.Errorf("ciphertext hex decode error: %w", err)
}
nonceSize := s.gcm.NonceSize()
if len(ciphertext) < nonceSize {
return "", fmt.Errorf("invalid ciphertext: too short")
}
nonce, encryptedMessage := ciphertext[:nonceSize], ciphertext[nonceSize:]
plaintext, err := s.gcm.Open(nil, nonce, encryptedMessage, nil)
if err != nil {
return "", fmt.Errorf("failed to decrypt: %w", err)
}
return string(plaintext), nil
}