avoid losing the key (old crypto)

if we just have a pointer to a bytes object which might go out of scope, we can lose it.

also: cython can directly assign a bytes object into a same-size char array.
This commit is contained in:
Thomas Waldmann 2022-03-20 05:31:47 +01:00
parent 6d6d3caa24
commit 0b5a21275f
1 changed files with 7 additions and 9 deletions

View File

@ -187,7 +187,7 @@ cdef class AES256_CTR_BASE:
# Layout: HEADER + MAC 32 + IV 8 + CT (same as attic / borg < 1.3 IF HEADER = TYPE_BYTE, no AAD)
cdef EVP_CIPHER_CTX *ctx
cdef unsigned char *enc_key
cdef unsigned char enc_key[32]
cdef int cipher_blk_len
cdef int iv_len, iv_len_short
cdef int aad_offset
@ -335,8 +335,7 @@ cdef class AES256_CTR_BASE:
if isinstance(iv, int):
iv = iv.to_bytes(self.iv_len, byteorder='big')
assert isinstance(iv, bytes) and len(iv) == self.iv_len
for i in range(self.iv_len):
self.iv[i] = iv[i]
self.iv = iv
self.blocks = 0 # how many AES blocks got encrypted with this IV?
def next_iv(self):
@ -360,7 +359,7 @@ cdef class AES256_CTR_BASE:
cdef class AES256_CTR_HMAC_SHA256(AES256_CTR_BASE):
cdef unsigned char *mac_key
cdef unsigned char mac_key[32]
def __init__(self, mac_key, enc_key, iv=None, header_len=1, aad_offset=1):
assert isinstance(mac_key, bytes) and len(mac_key) == 32
@ -377,7 +376,7 @@ cdef class AES256_CTR_HMAC_SHA256(AES256_CTR_BASE):
const unsigned char *data2, int data2_len,
unsigned char *mac_buf):
data = data1[:data1_len] + data2[:data2_len]
mac = hmac.HMAC(self.mac_key, data, hashlib.sha256).digest()
mac = hmac.HMAC(self.mac_key[:self.mac_len], data, hashlib.sha256).digest()
for i in range(self.mac_len):
mac_buf[i] = mac[i]
@ -390,7 +389,7 @@ cdef class AES256_CTR_HMAC_SHA256(AES256_CTR_BASE):
cdef class AES256_CTR_BLAKE2b(AES256_CTR_BASE):
cdef unsigned char *mac_key
cdef unsigned char mac_key[128]
def __init__(self, mac_key, enc_key, iv=None, header_len=1, aad_offset=1):
assert isinstance(mac_key, bytes) and len(mac_key) == 128
@ -638,7 +637,7 @@ cdef class AES:
"""A thin wrapper around the OpenSSL EVP cipher API - for legacy code, like key file encryption"""
cdef CIPHER cipher
cdef EVP_CIPHER_CTX *ctx
cdef unsigned char *enc_key
cdef unsigned char enc_key[32]
cdef int cipher_blk_len
cdef int iv_len
cdef unsigned char iv[16]
@ -726,8 +725,7 @@ cdef class AES:
if isinstance(iv, int):
iv = iv.to_bytes(self.iv_len, byteorder='big')
assert isinstance(iv, bytes) and len(iv) == self.iv_len
for i in range(self.iv_len):
self.iv[i] = iv[i]
self.iv = iv
self.blocks = 0 # number of cipher blocks encrypted with this IV
def next_iv(self):