upstream/borgbackup
1
0
Fork 0
mirror of https://github.com/borgbackup/borg.git synced 2026-06-04 06:07:48 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions 6

legacy: move pbkdf2 key file encryption to borg.legacy.crypto.key, refs #9556

Browse source
This commit is contained in:
Mrityunjay Raj 2026-05-23 13:58:02 +05:30
parent f58732290a
commit b4821255f4
3 changed files with 56 additions and 31 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

26
src/borg/crypto/key.py
View file

@ -28,7 +28,7 @@ from ..platform import SaveFile
from ..repoobj import RepoObj
from .low_level import AES, bytes_to_int, num_cipher_blocks, hmac_sha256, blake2b_256
from .low_level import bytes_to_int, num_cipher_blocks, hmac_sha256, blake2b_256
from .low_level import AES256_OCB, CHACHA20_POLY1305
from . import low_level
@ -438,9 +438,7 @@ class FlexiKey:
raise UnsupportedKeyFormatError()
else:
self._encrypted_key_algorithm = encrypted_key.algorithm
if encrypted_key.algorithm == "sha256":
return self.decrypt_key_file_pbkdf2(encrypted_key, passphrase)
elif encrypted_key.algorithm == "argon2 chacha20-poly1305":
if encrypted_key.algorithm == "argon2 chacha20-poly1305":
return self.decrypt_key_file_argon2(encrypted_key, passphrase)
else:
raise UnsupportedKeyFormatError()
@ -478,13 +476,6 @@ class FlexiKey:
)
return key
def decrypt_key_file_pbkdf2(self, encrypted_key, passphrase):
key = self.pbkdf2(passphrase, encrypted_key.salt, encrypted_key.iterations, 32)
data = AES(key, b"\0" * 16).decrypt(encrypted_key.data)
if hmac.compare_digest(hmac_sha256(key, data), encrypted_key.hash):
return data
return None
def decrypt_key_file_argon2(self, encrypted_key, passphrase):
key = self.argon2(
passphrase,
@ -502,22 +493,11 @@ class FlexiKey:
return None
def encrypt_key_file(self, data, passphrase, algorithm):
if algorithm == "sha256":
return self.encrypt_key_file_pbkdf2(data, passphrase)
elif algorithm == "argon2 chacha20-poly1305":
if algorithm == "argon2 chacha20-poly1305":
return self.encrypt_key_file_argon2(data, passphrase)
else:
raise ValueError(f"Unexpected algorithm: {algorithm}")
def encrypt_key_file_pbkdf2(self, data, passphrase):
salt = os.urandom(32)
iterations = PBKDF2_ITERATIONS
key = self.pbkdf2(passphrase, salt, iterations, 32)
hash = hmac_sha256(key, data)
cdata = AES(key, b"\0" * 16).encrypt(data)
enc_key = EncryptedKey(version=1, salt=salt, iterations=iterations, algorithm="sha256", hash=hash, data=cdata)
return msgpack.packb(enc_key.as_dict())
def encrypt_key_file_argon2(self, data, passphrase):
salt = os.urandom(ARGON2_SALT_BYTES)
key = self.argon2(passphrase, output_len_in_bytes=32, salt=salt, **ARGON2_ARGS)

55
src/borg/legacy/crypto/key.py
View file

@ -1,9 +1,52 @@
import hmac
import os
from ...constants import * # NOQA
from ...crypto.low_level import AES256_CTR_HMAC_SHA256, AES256_CTR_BLAKE2b
from ...crypto.key import ID_HMAC_SHA_256, ID_BLAKE2b_256, AESKeyBase, FlexiKey
from ...crypto.low_level import AES256_CTR_HMAC_SHA256, AES256_CTR_BLAKE2b, hmac_sha256
from ...crypto.key import ID_HMAC_SHA_256, ID_BLAKE2b_256, AESKeyBase, FlexiKey, UnsupportedKeyFormatError
from ...helpers import get_limited_unpacker, msgpack
from ...item import EncryptedKey
from .low_level import AES
class KeyfileKey(ID_HMAC_SHA_256, AESKeyBase, FlexiKey): # type: ignore[misc]
class Pbkdf2FileMixin:
"""Mixin for borg 1.x key files encrypted with PBKDF2 + AES-CTR."""
def decrypt_key_file(self, data, passphrase):
unpacker = get_limited_unpacker("key")
unpacker.feed(data)
unpacked = unpacker.unpack()
encrypted_key = EncryptedKey(internal_dict=unpacked)
if encrypted_key.version != 1:
raise UnsupportedKeyFormatError()
self._encrypted_key_algorithm = encrypted_key.algorithm
if encrypted_key.algorithm == "sha256":
return self.decrypt_key_file_pbkdf2(encrypted_key, passphrase)
return super().decrypt_key_file(data, passphrase)
def encrypt_key_file(self, data, passphrase, algorithm):
if algorithm == "sha256":
return self.encrypt_key_file_pbkdf2(data, passphrase)
return super().encrypt_key_file(data, passphrase, algorithm)
def decrypt_key_file_pbkdf2(self, encrypted_key, passphrase):
key = self.pbkdf2(passphrase, encrypted_key.salt, encrypted_key.iterations, 32)
data = AES(key, b"\0" * 16).decrypt(encrypted_key.data)
if hmac.compare_digest(hmac_sha256(key, data), encrypted_key.hash):
return data
return None
def encrypt_key_file_pbkdf2(self, data, passphrase):
salt = os.urandom(32)
iterations = PBKDF2_ITERATIONS
key = self.pbkdf2(passphrase, salt, iterations, 32)
hash = hmac_sha256(key, data)
cdata = AES(key, b"\0" * 16).encrypt(data)
enc_key = EncryptedKey(version=1, salt=salt, iterations=iterations, algorithm="sha256", hash=hash, data=cdata)
return msgpack.packb(enc_key.as_dict())
class KeyfileKey(Pbkdf2FileMixin, ID_HMAC_SHA_256, AESKeyBase, FlexiKey): # type: ignore[misc]
TYPES_ACCEPTABLE = {KeyType.KEYFILE, KeyType.REPO, KeyType.PASSPHRASE}
TYPE = KeyType.KEYFILE
NAME = "key file"
@ -12,7 +55,7 @@ class KeyfileKey(ID_HMAC_SHA_256, AESKeyBase, FlexiKey): # type: ignore[misc]
CIPHERSUITE = AES256_CTR_HMAC_SHA256
class RepoKey(ID_HMAC_SHA_256, AESKeyBase, FlexiKey): # type: ignore[misc]
class RepoKey(Pbkdf2FileMixin, ID_HMAC_SHA_256, AESKeyBase, FlexiKey): # type: ignore[misc]
TYPES_ACCEPTABLE = {KeyType.KEYFILE, KeyType.REPO, KeyType.PASSPHRASE}
TYPE = KeyType.REPO
NAME = "repokey"
@ -21,7 +64,7 @@ class RepoKey(ID_HMAC_SHA_256, AESKeyBase, FlexiKey): # type: ignore[misc]
CIPHERSUITE = AES256_CTR_HMAC_SHA256
class Blake2KeyfileKey(ID_BLAKE2b_256, AESKeyBase, FlexiKey): # type: ignore[misc]
class Blake2KeyfileKey(Pbkdf2FileMixin, ID_BLAKE2b_256, AESKeyBase, FlexiKey): # type: ignore[misc]
TYPES_ACCEPTABLE = {KeyType.BLAKE2KEYFILE, KeyType.BLAKE2REPO}
TYPE = KeyType.BLAKE2KEYFILE
NAME = "key file BLAKE2b"
@ -30,7 +73,7 @@ class Blake2KeyfileKey(ID_BLAKE2b_256, AESKeyBase, FlexiKey): # type: ignore[mi
CIPHERSUITE = AES256_CTR_BLAKE2b
class Blake2RepoKey(ID_BLAKE2b_256, AESKeyBase, FlexiKey): # type: ignore[misc]
class Blake2RepoKey(Pbkdf2FileMixin, ID_BLAKE2b_256, AESKeyBase, FlexiKey): # type: ignore[misc]
TYPES_ACCEPTABLE = {KeyType.BLAKE2KEYFILE, KeyType.BLAKE2REPO}
TYPE = KeyType.BLAKE2REPO
NAME = "repokey BLAKE2b"

6
src/borg/testsuite/crypto/crypto_test.py
View file

@ -6,9 +6,11 @@ import unittest
from ...crypto.low_level import AES256_CTR_HMAC_SHA256, AES256_OCB, CHACHA20_POLY1305, UNENCRYPTED, IntegrityError
from ...crypto.low_level import bytes_to_long, bytes_to_int, long_to_bytes
from ...crypto.low_level import AES, hmac_sha256
from ...crypto.low_level import hmac_sha256
from ...legacy.crypto.low_level import AES
from hashlib import sha256
from ...crypto.key import CHPOKeyfileKey, AESOCBRepoKey, FlexiKey, KeyBase, PlaintextKey
from ...legacy.crypto.key import KeyfileKey as LegacyKeyfileKey
from ...helpers import msgpack, bin_to_hex
from .. import BaseTestCase
@ -232,7 +234,7 @@ def test_decrypt_key_file_pbkdf2_sha256_aes256_ctr_hmac_sha256():
encrypted = msgpack.packb(
{"version": 1, "algorithm": "sha256", "iterations": 1, "salt": salt, "data": data, "hash": hash}
)
key = CHPOKeyfileKey(None)
key = LegacyKeyfileKey(None)
decrypted = key.decrypt_key_file(encrypted, passphrase)