chore: 初始化 Cloudreve 源码仓库

pkg/filemanager/encrypt/encrypt.go

@@ -0,0 +1,97 @@
+package encrypt
+
+import (
+	"context"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"fmt"
+	"io"
+
+	"github.com/cloudreve/Cloudreve/v4/inventory/types"
+)
+
+type (
+	Cryptor interface {
+		io.ReadCloser
+		io.Seeker
+		// LoadMetadata loads and decrypts the encryption metadata using the master key
+		LoadMetadata(ctx context.Context, encryptedMetadata *types.EncryptMetadata) error
+		// SetSource sets the encrypted data source and initializes the cipher stream
+		SetSource(src io.ReadCloser, seeker io.Seeker, size, counterOffset int64) error
+		// GenerateMetadata generates a new encryption metadata
+		GenerateMetadata(ctx context.Context) (*types.EncryptMetadata, error)
+	}
+
+	CryptorFactory func(algorithm types.Cipher) (Cryptor, error)
+)
+
+func NewCryptorFactory(masterKeyVault MasterEncryptKeyVault) CryptorFactory {
+	return func(algorithm types.Cipher) (Cryptor, error) {
+		switch algorithm {
+		case types.CipherAES256CTR:
+			return NewAES256CTR(masterKeyVault), nil
+		default:
+			return nil, fmt.Errorf("unknown algorithm: %s", algorithm)
+		}
+	}
+}
+
+// EncryptWithMasterKey encrypts data using the master key with AES-256-CTR
+// Returns: [16-byte IV] + [encrypted data]
+func EncryptWithMasterKey(masterKey, data []byte) ([]byte, error) {
+	// Create AES cipher with master key
+	block, err := aes.NewCipher(masterKey)
+	if err != nil {
+		return nil, err
+	}
+
+	// Generate random IV for encryption
+	iv := make([]byte, 16)
+	if _, err := io.ReadFull(rand.Reader, iv); err != nil {
+		return nil, err
+	}
+
+	// Encrypt data
+	stream := cipher.NewCTR(block, iv)
+	encrypted := make([]byte, len(data))
+	stream.XORKeyStream(encrypted, data)
+
+	// Return IV + encrypted data
+	result := append(iv, encrypted...)
+	return result, nil
+}
+
+func DecriptKey(ctx context.Context, keyVault MasterEncryptKeyVault, encryptedKey []byte) ([]byte, error) {
+	masterKey, err := keyVault.GetMasterKey(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get master key: %w", err)
+	}
+	return DecryptWithMasterKey(masterKey, encryptedKey)
+}
+
+// DecryptWithMasterKey decrypts data using the master key with AES-256-CTR
+// Input format: [16-byte IV] + [encrypted data]
+func DecryptWithMasterKey(masterKey, encryptedData []byte) ([]byte, error) {
+	// Validate input length
+	if len(encryptedData) < 16 {
+		return nil, aes.KeySizeError(len(encryptedData))
+	}
+
+	// Extract IV and encrypted data
+	iv := encryptedData[:16]
+	encrypted := encryptedData[16:]
+
+	// Create AES cipher with master key
+	block, err := aes.NewCipher(masterKey)
+	if err != nil {
+		return nil, err
+	}
+
+	// Decrypt data
+	stream := cipher.NewCTR(block, iv)
+	decrypted := make([]byte, len(encrypted))
+	stream.XORKeyStream(decrypted, encrypted)
+
+	return decrypted, nil
+}