first test

backend/utils/encryption.go

@@ -0,0 +1,160 @@
+package utils
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/base64"
+	"fmt"
+	"io"
+	"os"
+)
+
+// GetEncryptionKey returns the encryption key from environment
+func GetEncryptionKey() ([]byte, error) {
+	key := os.Getenv("ENCRYPTION_KEY")
+	if key == "" {
+		return nil, fmt.Errorf("ENCRYPTION_KEY environment variable not set")
+	}
+
+	// Hash the key to ensure it's exactly 32 bytes for AES-256
+	hash := sha256.Sum256([]byte(key))
+	return hash[:], nil
+}
+
+// Encrypt encrypts plaintext using AES-GCM
+func Encrypt(plaintext string) (string, error) {
+	key, err := GetEncryptionKey()
+	if err != nil {
+		return "", err
+	}
+
+	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 := io.ReadFull(rand.Reader, nonce); err != nil {
+		return "", err
+	}
+
+	ciphertext := gcm.Seal(nonce, nonce, []byte(plaintext), nil)
+	return base64.StdEncoding.EncodeToString(ciphertext), nil
+}
+
+// Decrypt decrypts ciphertext using AES-GCM
+func Decrypt(ciphertext string) (string, error) {
+	key, err := GetEncryptionKey()
+	if err != nil {
+		return "", err
+	}
+
+	data, err := base64.StdEncoding.DecodeString(ciphertext)
+	if err != nil {
+		return "", 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")
+	}
+
+	nonce, ciphertext_bytes := data[:nonceSize], data[nonceSize:]
+	plaintext, err := gcm.Open(nil, nonce, ciphertext_bytes, nil)
+	if err != nil {
+		return "", err
+	}
+
+	return string(plaintext), nil
+}
+
+// EncryptFile encrypts file content and returns the encrypted data
+func EncryptFile(content []byte) ([]byte, error) {
+	key, err := GetEncryptionKey()
+	if err != nil {
+		return nil, err
+	}
+
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+
+	gcm, err := cipher.NewGCM(block)
+	if err != nil {
+		return nil, err
+	}
+
+	nonce := make([]byte, gcm.NonceSize())
+	if _, err := io.ReadFull(rand.Reader, nonce); err != nil {
+		return nil, err
+	}
+
+	// Prepend nonce to encrypted content
+	encrypted := gcm.Seal(nonce, nonce, content, nil)
+	return encrypted, nil
+}
+
+// DecryptFile decrypts file content
+func DecryptFile(encryptedContent []byte) ([]byte, error) {
+	key, err := GetEncryptionKey()
+	if err != nil {
+		return nil, err
+	}
+
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+
+	gcm, err := cipher.NewGCM(block)
+	if err != nil {
+		return nil, err
+	}
+
+	nonceSize := gcm.NonceSize()
+	if len(encryptedContent) < nonceSize {
+		return nil, fmt.Errorf("encrypted content too short")
+	}
+
+	nonce, ciphertext := encryptedContent[:nonceSize], encryptedContent[nonceSize:]
+	plaintext, err := gcm.Open(nil, nonce, ciphertext, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	return plaintext, nil
+}
+
+// IsEncrypted checks if content appears to be encrypted (base64 encoded)
+func IsEncrypted(content string) bool {
+	// Simple check: try to base64 decode and see if it looks like encrypted content
+	_, err := base64.StdEncoding.DecodeString(content)
+	return err == nil && len(content) > 32 // Encrypted content should be longer than 32 chars
+}
+
+// GenerateEncryptionKey generates a new random encryption key
+func GenerateEncryptionKey() (string, error) {
+	key := make([]byte, 32)
+	if _, err := rand.Read(key); err != nil {
+		return "", err
+	}
+	return base64.StdEncoding.EncodeToString(key), nil
+}