654 lines
26 KiB
Python
654 lines
26 KiB
Python
from __future__ import annotations
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import base64
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import io
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import json
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import logging
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import os
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import secrets
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import subprocess
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import sys
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from dataclasses import dataclass
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from pathlib import Path
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from typing import Any, BinaryIO, Dict, Generator, Optional
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from cryptography.hazmat.primitives.ciphers.aead import AESGCM
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from cryptography.hazmat.primitives.kdf.hkdf import HKDF
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from cryptography.hazmat.primitives import hashes
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if sys.platform != "win32":
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import fcntl
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try:
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import myfsio_core as _rc
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if not all(hasattr(_rc, f) for f in (
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"encrypt_stream_chunked", "decrypt_stream_chunked",
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)):
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raise ImportError("myfsio_core is outdated, rebuild with: cd myfsio_core && maturin develop --release")
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_HAS_RUST = True
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except ImportError:
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_rc = None
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_HAS_RUST = False
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logger = logging.getLogger(__name__)
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def _set_secure_file_permissions(file_path: Path) -> None:
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"""Set restrictive file permissions (owner read/write only)."""
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if sys.platform == "win32":
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try:
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username = os.environ.get("USERNAME", "")
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if username:
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subprocess.run(
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["icacls", str(file_path), "/inheritance:r",
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"/grant:r", f"{username}:F"],
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check=True, capture_output=True
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)
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else:
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logger.warning("Could not set secure permissions on %s: USERNAME not set", file_path)
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except (subprocess.SubprocessError, OSError) as exc:
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logger.warning("Failed to set secure permissions on %s: %s", file_path, exc)
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else:
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os.chmod(file_path, 0o600)
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class EncryptionError(Exception):
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"""Raised when encryption/decryption fails."""
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@dataclass
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class EncryptionResult:
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"""Result of encrypting data."""
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ciphertext: bytes
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nonce: bytes
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key_id: str
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encrypted_data_key: bytes
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@dataclass
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class EncryptionMetadata:
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"""Metadata stored with encrypted objects."""
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algorithm: str
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key_id: str
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nonce: bytes
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encrypted_data_key: bytes
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def to_dict(self) -> Dict[str, str]:
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return {
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"x-amz-server-side-encryption": self.algorithm,
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"x-amz-encryption-key-id": self.key_id,
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"x-amz-encryption-nonce": base64.b64encode(self.nonce).decode(),
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"x-amz-encrypted-data-key": base64.b64encode(self.encrypted_data_key).decode(),
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}
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@classmethod
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def from_dict(cls, data: Dict[str, str]) -> Optional["EncryptionMetadata"]:
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algorithm = data.get("x-amz-server-side-encryption")
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if not algorithm:
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return None
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try:
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return cls(
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algorithm=algorithm,
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key_id=data.get("x-amz-encryption-key-id", "local"),
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nonce=base64.b64decode(data.get("x-amz-encryption-nonce", "")),
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encrypted_data_key=base64.b64decode(data.get("x-amz-encrypted-data-key", "")),
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)
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except Exception:
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return None
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class EncryptionProvider:
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"""Base class for encryption providers."""
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def encrypt(self, plaintext: bytes, context: Dict[str, str] | None = None) -> EncryptionResult:
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raise NotImplementedError
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def decrypt(self, ciphertext: bytes, nonce: bytes, encrypted_data_key: bytes,
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key_id: str, context: Dict[str, str] | None = None) -> bytes:
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raise NotImplementedError
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def generate_data_key(self) -> tuple[bytes, bytes]:
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"""Generate a data key and its encrypted form.
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Returns:
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Tuple of (plaintext_key, encrypted_key)
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"""
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raise NotImplementedError
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def decrypt_data_key(self, encrypted_data_key: bytes, key_id: str | None = None) -> bytes:
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"""Decrypt an encrypted data key.
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Args:
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encrypted_data_key: The encrypted data key bytes
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key_id: Optional key identifier (used by KMS providers)
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Returns:
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The decrypted data key
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"""
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raise NotImplementedError
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class LocalKeyEncryption(EncryptionProvider):
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"""SSE-S3 style encryption using a local master key.
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Uses envelope encryption:
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1. Generate a unique data key for each object
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2. Encrypt the data with the data key (AES-256-GCM)
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3. Encrypt the data key with the master key
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4. Store the encrypted data key alongside the ciphertext
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"""
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KEY_ID = "local"
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def __init__(self, master_key_path: Path):
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self.master_key_path = master_key_path
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self._master_key: bytes | None = None
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@property
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def master_key(self) -> bytes:
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if self._master_key is None:
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self._master_key = self._load_or_create_master_key()
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return self._master_key
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def _load_or_create_master_key(self) -> bytes:
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"""Load master key from file or generate a new one (with file locking)."""
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lock_path = self.master_key_path.with_suffix(".lock")
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lock_path.parent.mkdir(parents=True, exist_ok=True)
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try:
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with open(lock_path, "w") as lock_file:
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if sys.platform == "win32":
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import msvcrt
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msvcrt.locking(lock_file.fileno(), msvcrt.LK_LOCK, 1)
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else:
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fcntl.flock(lock_file.fileno(), fcntl.LOCK_EX)
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try:
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if self.master_key_path.exists():
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try:
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return base64.b64decode(self.master_key_path.read_text().strip())
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except Exception as exc:
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raise EncryptionError(f"Failed to load master key: {exc}") from exc
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key = secrets.token_bytes(32)
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try:
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self.master_key_path.write_text(base64.b64encode(key).decode())
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_set_secure_file_permissions(self.master_key_path)
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except OSError as exc:
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raise EncryptionError(f"Failed to save master key: {exc}") from exc
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return key
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finally:
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if sys.platform == "win32":
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import msvcrt
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msvcrt.locking(lock_file.fileno(), msvcrt.LK_UNLCK, 1)
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else:
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fcntl.flock(lock_file.fileno(), fcntl.LOCK_UN)
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except OSError as exc:
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raise EncryptionError(f"Failed to acquire lock for master key: {exc}") from exc
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DATA_KEY_AAD = b'{"purpose":"data_key","version":1}'
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def _encrypt_data_key(self, data_key: bytes) -> bytes:
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"""Encrypt the data key with the master key."""
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aesgcm = AESGCM(self.master_key)
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nonce = secrets.token_bytes(12)
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encrypted = aesgcm.encrypt(nonce, data_key, self.DATA_KEY_AAD)
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return nonce + encrypted
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def _decrypt_data_key(self, encrypted_data_key: bytes) -> bytes:
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"""Decrypt the data key using the master key."""
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if len(encrypted_data_key) < 12 + 32 + 16: # nonce + key + tag
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raise EncryptionError("Invalid encrypted data key")
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aesgcm = AESGCM(self.master_key)
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nonce = encrypted_data_key[:12]
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ciphertext = encrypted_data_key[12:]
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try:
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return aesgcm.decrypt(nonce, ciphertext, self.DATA_KEY_AAD)
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except Exception:
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try:
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return aesgcm.decrypt(nonce, ciphertext, None)
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except Exception as exc:
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raise EncryptionError(f"Failed to decrypt data key: {exc}") from exc
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def decrypt_data_key(self, encrypted_data_key: bytes, key_id: str | None = None) -> bytes:
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"""Decrypt an encrypted data key (key_id ignored for local encryption)."""
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return self._decrypt_data_key(encrypted_data_key)
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def generate_data_key(self) -> tuple[bytes, bytes]:
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"""Generate a data key and its encrypted form."""
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plaintext_key = secrets.token_bytes(32)
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encrypted_key = self._encrypt_data_key(plaintext_key)
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return plaintext_key, encrypted_key
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def encrypt(self, plaintext: bytes, context: Dict[str, str] | None = None) -> EncryptionResult:
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"""Encrypt data using envelope encryption."""
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data_key, encrypted_data_key = self.generate_data_key()
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aesgcm = AESGCM(data_key)
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nonce = secrets.token_bytes(12)
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aad = json.dumps(context, sort_keys=True).encode() if context else None
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ciphertext = aesgcm.encrypt(nonce, plaintext, aad)
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return EncryptionResult(
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ciphertext=ciphertext,
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nonce=nonce,
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key_id=self.KEY_ID,
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encrypted_data_key=encrypted_data_key,
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)
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def decrypt(self, ciphertext: bytes, nonce: bytes, encrypted_data_key: bytes,
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key_id: str, context: Dict[str, str] | None = None) -> bytes:
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"""Decrypt data using envelope encryption."""
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data_key = self._decrypt_data_key(encrypted_data_key)
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aesgcm = AESGCM(data_key)
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aad = json.dumps(context, sort_keys=True).encode() if context else None
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try:
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return aesgcm.decrypt(nonce, ciphertext, aad)
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except Exception as exc:
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raise EncryptionError("Failed to decrypt data") from exc
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class StreamingEncryptor:
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"""Encrypts/decrypts data in streaming fashion for large files.
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For large files, we encrypt in chunks. Each chunk is encrypted with the
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same data key but a unique nonce derived from the base nonce + chunk index.
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"""
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CHUNK_SIZE = 64 * 1024
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HEADER_SIZE = 4
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def __init__(self, provider: EncryptionProvider, chunk_size: int = CHUNK_SIZE):
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self.provider = provider
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self.chunk_size = chunk_size
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def _derive_chunk_nonce(self, base_nonce: bytes, chunk_index: int) -> bytes:
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"""Derive a unique nonce for each chunk using HKDF."""
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hkdf = HKDF(
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algorithm=hashes.SHA256(),
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length=12,
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salt=base_nonce,
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info=chunk_index.to_bytes(4, "big"),
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)
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return hkdf.derive(b"chunk_nonce")
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def encrypt_stream(self, stream: BinaryIO,
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context: Dict[str, str] | None = None) -> tuple[BinaryIO, EncryptionMetadata]:
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"""Encrypt a stream and return encrypted stream + metadata.
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Performance: Writes chunks directly to output buffer instead of accumulating in list.
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"""
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data_key, encrypted_data_key = self.provider.generate_data_key()
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base_nonce = secrets.token_bytes(12)
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aesgcm = AESGCM(data_key)
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# Performance: Write directly to BytesIO instead of accumulating chunks
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output = io.BytesIO()
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output.write(b"\x00\x00\x00\x00") # Placeholder for chunk count
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chunk_index = 0
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while True:
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chunk = stream.read(self.chunk_size)
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if not chunk:
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break
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chunk_nonce = self._derive_chunk_nonce(base_nonce, chunk_index)
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encrypted_chunk = aesgcm.encrypt(chunk_nonce, chunk, None)
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# Write size prefix + encrypted chunk directly
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output.write(len(encrypted_chunk).to_bytes(self.HEADER_SIZE, "big"))
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output.write(encrypted_chunk)
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chunk_index += 1
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# Write actual chunk count to header
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output.seek(0)
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output.write(chunk_index.to_bytes(4, "big"))
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output.seek(0)
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metadata = EncryptionMetadata(
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algorithm="AES256",
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key_id=self.provider.KEY_ID if hasattr(self.provider, "KEY_ID") else "local",
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nonce=base_nonce,
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encrypted_data_key=encrypted_data_key,
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)
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return output, metadata
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def decrypt_stream(self, stream: BinaryIO, metadata: EncryptionMetadata) -> BinaryIO:
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"""Decrypt a stream using the provided metadata.
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Performance: Writes chunks directly to output buffer instead of accumulating in list.
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"""
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data_key = self.provider.decrypt_data_key(metadata.encrypted_data_key, metadata.key_id)
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aesgcm = AESGCM(data_key)
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base_nonce = metadata.nonce
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chunk_count_bytes = stream.read(4)
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if len(chunk_count_bytes) < 4:
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raise EncryptionError("Invalid encrypted stream: missing header")
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chunk_count = int.from_bytes(chunk_count_bytes, "big")
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# Performance: Write directly to BytesIO instead of accumulating chunks
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output = io.BytesIO()
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for chunk_index in range(chunk_count):
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size_bytes = stream.read(self.HEADER_SIZE)
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if len(size_bytes) < self.HEADER_SIZE:
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raise EncryptionError(f"Invalid encrypted stream: truncated at chunk {chunk_index}")
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chunk_size = int.from_bytes(size_bytes, "big")
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encrypted_chunk = stream.read(chunk_size)
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if len(encrypted_chunk) < chunk_size:
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raise EncryptionError(f"Invalid encrypted stream: incomplete chunk {chunk_index}")
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chunk_nonce = self._derive_chunk_nonce(base_nonce, chunk_index)
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try:
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decrypted_chunk = aesgcm.decrypt(chunk_nonce, encrypted_chunk, None)
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output.write(decrypted_chunk) # Write directly instead of appending to list
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except Exception as exc:
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raise EncryptionError(f"Failed to decrypt chunk {chunk_index}: {exc}") from exc
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output.seek(0)
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return output
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def encrypt_file(self, input_path: str, output_path: str) -> EncryptionMetadata:
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data_key, encrypted_data_key = self.provider.generate_data_key()
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base_nonce = secrets.token_bytes(12)
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if _HAS_RUST:
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_rc.encrypt_stream_chunked(
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input_path, output_path, data_key, base_nonce, self.chunk_size
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)
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else:
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with open(input_path, "rb") as stream:
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aesgcm = AESGCM(data_key)
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with open(output_path, "wb") as out:
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out.write(b"\x00\x00\x00\x00")
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chunk_index = 0
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while True:
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chunk = stream.read(self.chunk_size)
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if not chunk:
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break
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chunk_nonce = self._derive_chunk_nonce(base_nonce, chunk_index)
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encrypted_chunk = aesgcm.encrypt(chunk_nonce, chunk, None)
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out.write(len(encrypted_chunk).to_bytes(self.HEADER_SIZE, "big"))
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out.write(encrypted_chunk)
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chunk_index += 1
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out.seek(0)
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out.write(chunk_index.to_bytes(4, "big"))
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return EncryptionMetadata(
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algorithm="AES256",
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key_id=self.provider.KEY_ID if hasattr(self.provider, "KEY_ID") else "local",
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nonce=base_nonce,
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encrypted_data_key=encrypted_data_key,
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)
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def decrypt_file(self, input_path: str, output_path: str,
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metadata: EncryptionMetadata) -> None:
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data_key = self.provider.decrypt_data_key(metadata.encrypted_data_key, metadata.key_id)
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base_nonce = metadata.nonce
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if _HAS_RUST:
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_rc.decrypt_stream_chunked(input_path, output_path, data_key, base_nonce)
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else:
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with open(input_path, "rb") as stream:
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chunk_count_bytes = stream.read(4)
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if len(chunk_count_bytes) < 4:
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raise EncryptionError("Invalid encrypted stream: missing header")
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chunk_count = int.from_bytes(chunk_count_bytes, "big")
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aesgcm = AESGCM(data_key)
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with open(output_path, "wb") as out:
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for chunk_index in range(chunk_count):
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size_bytes = stream.read(self.HEADER_SIZE)
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if len(size_bytes) < self.HEADER_SIZE:
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raise EncryptionError(f"Invalid encrypted stream: truncated at chunk {chunk_index}")
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chunk_size = int.from_bytes(size_bytes, "big")
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encrypted_chunk = stream.read(chunk_size)
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if len(encrypted_chunk) < chunk_size:
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raise EncryptionError(f"Invalid encrypted stream: incomplete chunk {chunk_index}")
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chunk_nonce = self._derive_chunk_nonce(base_nonce, chunk_index)
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try:
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decrypted_chunk = aesgcm.decrypt(chunk_nonce, encrypted_chunk, None)
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out.write(decrypted_chunk)
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except Exception as exc:
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raise EncryptionError(f"Failed to decrypt chunk {chunk_index}: {exc}") from exc
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class EncryptionManager:
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"""Manages encryption providers and operations."""
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def __init__(self, config: Dict[str, Any]):
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self.config = config
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self._local_provider: LocalKeyEncryption | None = None
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self._kms_provider: Any = None # Set by KMS module
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self._streaming_encryptor: StreamingEncryptor | None = None
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@property
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def enabled(self) -> bool:
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return self.config.get("encryption_enabled", False)
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@property
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def default_algorithm(self) -> str:
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return self.config.get("default_encryption_algorithm", "AES256")
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def get_local_provider(self) -> LocalKeyEncryption:
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if self._local_provider is None:
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key_path = Path(self.config.get("encryption_master_key_path", "data/.myfsio.sys/keys/master.key"))
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self._local_provider = LocalKeyEncryption(key_path)
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return self._local_provider
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def set_kms_provider(self, kms_provider: Any) -> None:
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"""Set the KMS provider (injected from kms module)."""
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self._kms_provider = kms_provider
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def get_provider(self, algorithm: str, kms_key_id: str | None = None) -> EncryptionProvider:
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"""Get the appropriate encryption provider for the algorithm."""
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if algorithm == "AES256":
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return self.get_local_provider()
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elif algorithm == "aws:kms":
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if self._kms_provider is None:
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raise EncryptionError("KMS is not configured")
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return self._kms_provider.get_provider(kms_key_id)
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else:
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raise EncryptionError(f"Unsupported encryption algorithm: {algorithm}")
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def get_streaming_encryptor(self) -> StreamingEncryptor:
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if self._streaming_encryptor is None:
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chunk_size = self.config.get("encryption_chunk_size_bytes", 64 * 1024)
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self._streaming_encryptor = StreamingEncryptor(self.get_local_provider(), chunk_size=chunk_size)
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return self._streaming_encryptor
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def encrypt_object(self, data: bytes, algorithm: str = "AES256",
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kms_key_id: str | None = None,
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context: Dict[str, str] | None = None) -> tuple[bytes, EncryptionMetadata]:
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"""Encrypt object data."""
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provider = self.get_provider(algorithm, kms_key_id)
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result = provider.encrypt(data, context)
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metadata = EncryptionMetadata(
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algorithm=algorithm,
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key_id=result.key_id,
|
|
nonce=result.nonce,
|
|
encrypted_data_key=result.encrypted_data_key,
|
|
)
|
|
|
|
return result.ciphertext, metadata
|
|
|
|
def decrypt_object(self, ciphertext: bytes, metadata: EncryptionMetadata,
|
|
context: Dict[str, str] | None = None) -> bytes:
|
|
"""Decrypt object data."""
|
|
provider = self.get_provider(metadata.algorithm, metadata.key_id)
|
|
return provider.decrypt(
|
|
ciphertext,
|
|
metadata.nonce,
|
|
metadata.encrypted_data_key,
|
|
metadata.key_id,
|
|
context,
|
|
)
|
|
|
|
def encrypt_stream(self, stream: BinaryIO, algorithm: str = "AES256",
|
|
context: Dict[str, str] | None = None) -> tuple[BinaryIO, EncryptionMetadata]:
|
|
"""Encrypt a stream for large files."""
|
|
encryptor = self.get_streaming_encryptor()
|
|
return encryptor.encrypt_stream(stream, context)
|
|
|
|
def decrypt_stream(self, stream: BinaryIO, metadata: EncryptionMetadata) -> BinaryIO:
|
|
"""Decrypt a stream."""
|
|
encryptor = self.get_streaming_encryptor()
|
|
return encryptor.decrypt_stream(stream, metadata)
|
|
|
|
|
|
class SSECEncryption(EncryptionProvider):
|
|
"""SSE-C: Server-Side Encryption with Customer-Provided Keys.
|
|
|
|
The client provides the encryption key with each request.
|
|
Server encrypts/decrypts but never stores the key.
|
|
|
|
Required headers for PUT:
|
|
- x-amz-server-side-encryption-customer-algorithm: AES256
|
|
- x-amz-server-side-encryption-customer-key: Base64-encoded 256-bit key
|
|
- x-amz-server-side-encryption-customer-key-MD5: Base64-encoded MD5 of key
|
|
"""
|
|
|
|
KEY_ID = "customer-provided"
|
|
|
|
def __init__(self, customer_key: bytes):
|
|
if len(customer_key) != 32:
|
|
raise EncryptionError("Customer key must be exactly 256 bits (32 bytes)")
|
|
self.customer_key = customer_key
|
|
|
|
@classmethod
|
|
def from_headers(cls, headers: Dict[str, str]) -> "SSECEncryption":
|
|
algorithm = headers.get("x-amz-server-side-encryption-customer-algorithm", "")
|
|
if algorithm.upper() != "AES256":
|
|
raise EncryptionError(f"Unsupported SSE-C algorithm: {algorithm}. Only AES256 is supported.")
|
|
|
|
key_b64 = headers.get("x-amz-server-side-encryption-customer-key", "")
|
|
if not key_b64:
|
|
raise EncryptionError("Missing x-amz-server-side-encryption-customer-key header")
|
|
|
|
key_md5_b64 = headers.get("x-amz-server-side-encryption-customer-key-md5", "")
|
|
|
|
try:
|
|
customer_key = base64.b64decode(key_b64)
|
|
except Exception as e:
|
|
raise EncryptionError(f"Invalid base64 in customer key: {e}") from e
|
|
|
|
if len(customer_key) != 32:
|
|
raise EncryptionError(f"Customer key must be 256 bits, got {len(customer_key) * 8} bits")
|
|
|
|
if key_md5_b64:
|
|
import hashlib
|
|
expected_md5 = base64.b64encode(hashlib.md5(customer_key).digest()).decode()
|
|
if key_md5_b64 != expected_md5:
|
|
raise EncryptionError("Customer key MD5 mismatch")
|
|
|
|
return cls(customer_key)
|
|
|
|
def encrypt(self, plaintext: bytes, context: Dict[str, str] | None = None) -> EncryptionResult:
|
|
aesgcm = AESGCM(self.customer_key)
|
|
nonce = secrets.token_bytes(12)
|
|
aad = json.dumps(context, sort_keys=True).encode() if context else None
|
|
ciphertext = aesgcm.encrypt(nonce, plaintext, aad)
|
|
|
|
return EncryptionResult(
|
|
ciphertext=ciphertext,
|
|
nonce=nonce,
|
|
key_id=self.KEY_ID,
|
|
encrypted_data_key=b"",
|
|
)
|
|
|
|
def decrypt(self, ciphertext: bytes, nonce: bytes, encrypted_data_key: bytes,
|
|
key_id: str, context: Dict[str, str] | None = None) -> bytes:
|
|
aesgcm = AESGCM(self.customer_key)
|
|
aad = json.dumps(context, sort_keys=True).encode() if context else None
|
|
try:
|
|
return aesgcm.decrypt(nonce, ciphertext, aad)
|
|
except Exception as exc:
|
|
raise EncryptionError("SSE-C decryption failed") from exc
|
|
|
|
def generate_data_key(self) -> tuple[bytes, bytes]:
|
|
return self.customer_key, b""
|
|
|
|
|
|
@dataclass
|
|
class SSECMetadata:
|
|
algorithm: str = "AES256"
|
|
nonce: bytes = b""
|
|
key_md5: str = ""
|
|
|
|
def to_dict(self) -> Dict[str, str]:
|
|
return {
|
|
"x-amz-server-side-encryption-customer-algorithm": self.algorithm,
|
|
"x-amz-encryption-nonce": base64.b64encode(self.nonce).decode(),
|
|
"x-amz-server-side-encryption-customer-key-MD5": self.key_md5,
|
|
}
|
|
|
|
@classmethod
|
|
def from_dict(cls, data: Dict[str, str]) -> Optional["SSECMetadata"]:
|
|
algorithm = data.get("x-amz-server-side-encryption-customer-algorithm")
|
|
if not algorithm:
|
|
return None
|
|
try:
|
|
nonce = base64.b64decode(data.get("x-amz-encryption-nonce", ""))
|
|
return cls(
|
|
algorithm=algorithm,
|
|
nonce=nonce,
|
|
key_md5=data.get("x-amz-server-side-encryption-customer-key-MD5", ""),
|
|
)
|
|
except Exception:
|
|
return None
|
|
|
|
|
|
class ClientEncryptionHelper:
|
|
"""Helpers for client-side encryption.
|
|
|
|
Client-side encryption is performed by the client, but this helper
|
|
provides key generation and materials for clients that need them.
|
|
"""
|
|
|
|
@staticmethod
|
|
def generate_client_key() -> Dict[str, str]:
|
|
"""Generate a new client encryption key."""
|
|
from datetime import datetime, timezone
|
|
key = secrets.token_bytes(32)
|
|
return {
|
|
"key": base64.b64encode(key).decode(),
|
|
"algorithm": "AES-256-GCM",
|
|
"created_at": datetime.now(timezone.utc).isoformat(),
|
|
}
|
|
|
|
@staticmethod
|
|
def encrypt_with_key(plaintext: bytes, key_b64: str, context: Dict[str, str] | None = None) -> Dict[str, str]:
|
|
"""Encrypt data with a client-provided key."""
|
|
key = base64.b64decode(key_b64)
|
|
if len(key) != 32:
|
|
raise EncryptionError("Key must be 256 bits (32 bytes)")
|
|
|
|
aesgcm = AESGCM(key)
|
|
nonce = secrets.token_bytes(12)
|
|
aad = json.dumps(context, sort_keys=True).encode() if context else None
|
|
ciphertext = aesgcm.encrypt(nonce, plaintext, aad)
|
|
|
|
return {
|
|
"ciphertext": base64.b64encode(ciphertext).decode(),
|
|
"nonce": base64.b64encode(nonce).decode(),
|
|
"algorithm": "AES-256-GCM",
|
|
}
|
|
|
|
@staticmethod
|
|
def decrypt_with_key(ciphertext_b64: str, nonce_b64: str, key_b64: str, context: Dict[str, str] | None = None) -> bytes:
|
|
"""Decrypt data with a client-provided key."""
|
|
key = base64.b64decode(key_b64)
|
|
nonce = base64.b64decode(nonce_b64)
|
|
ciphertext = base64.b64decode(ciphertext_b64)
|
|
|
|
if len(key) != 32:
|
|
raise EncryptionError("Key must be 256 bits (32 bytes)")
|
|
|
|
aesgcm = AESGCM(key)
|
|
aad = json.dumps(context, sort_keys=True).encode() if context else None
|
|
try:
|
|
return aesgcm.decrypt(nonce, ciphertext, aad)
|
|
except Exception as exc:
|
|
raise EncryptionError("Decryption failed") from exc
|