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Support for memoryview for SIV

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This commit is contained in:
Helder Eijs 2018-04-03 15:26:10 +02:00
parent 53be0708d7
commit 6fd65d491f
3 changed files with 104 additions and 41 deletions
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34
lib/Crypto/Protocol/KDF.py
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@ -23,7 +23,7 @@
import struct
from Crypto.Util.py3compat import *
from Crypto.Util.py3compat import tobytes, bord, _copy_bytes
from Crypto.Hash import SHA1, SHA256, HMAC, CMAC
from Crypto.Util.strxor import strxor
@ -144,7 +144,7 @@ def PBKDF2(password, salt, dkLen=16, count=1000, prf=None, hmac_hash_module=None
s[0], s[1] = s[1], prf(password, s[1])
return s[0]
key = b('')
key = b''
i = 1
while len(key)<dkLen:
s = [ prf(password, salt + struct.pack(">I", i)) ] * 2
@ -153,10 +153,10 @@ def PBKDF2(password, salt, dkLen=16, count=1000, prf=None, hmac_hash_module=None
else:
# Optimized implementation
key = b('')
key = b''
i = 1
while len(key)<dkLen:
base = HMAC.new(password, b(""), hmac_hash_module)
base = HMAC.new(password, b"", hmac_hash_module)
first_digest = base.copy().update(salt + struct.pack(">I", i)).digest()
key += base._pbkdf2_hmac_assist(first_digest, count)
i += 1
@ -186,10 +186,10 @@ class _S2V(object):
A set of extra parameters to use to create a cipher instance.
"""
self._key = key
self._key = _copy_bytes(None, None, key)
self._ciphermod = ciphermod
self._last_string = self._cache = bchr(0)*ciphermod.block_size
self._n_updates = ciphermod.block_size*8-1
self._last_string = self._cache = b'\x00' * ciphermod.block_size
self._n_updates = ciphermod.block_size * 8 - 1
if cipher_params is None:
self._cipher_params = {}
else:
@ -230,7 +230,7 @@ class _S2V(object):
if not item:
raise ValueError("A component cannot be empty")
if self._n_updates==0:
if self._n_updates == 0:
raise TypeError("Too many components passed to S2V")
self._n_updates -= 1
@ -239,7 +239,7 @@ class _S2V(object):
ciphermod=self._ciphermod,
cipher_params=self._cipher_params)
self._cache = strxor(self._double(self._cache), mac.digest())
self._last_string = item
self._last_string = _copy_bytes(None, None, item)
def derive(self):
""""Derive a secret from the vector of components.
@ -247,10 +247,10 @@ class _S2V(object):
:Return: a byte string, as long as the block length of the cipher.
"""
if len(self._last_string)>=16:
if len(self._last_string) >= 16:
final = self._last_string[:-16] + strxor(self._last_string[-16:], self._cache)
else:
padded = (self._last_string + bchr(0x80)+ bchr(0)*15)[:16]
padded = (self._last_string + b'\x80' + b'\x00' * 15)[:16]
final = strxor(padded, self._double(self._cache))
mac = CMAC.new(self._key,
msg=final,
@ -301,24 +301,24 @@ def HKDF(master, key_len, salt, hashmod, num_keys=1, context=None):
if output_len > (255 * hashmod.digest_size):
raise ValueError("Too much secret data to derive")
if not salt:
salt = bchr(0) * hashmod.digest_size
salt = b'\x00' * hashmod.digest_size
if context is None:
context = b("")
context = b""
# Step 1: extract
hmac = HMAC.new(salt, master, digestmod=hashmod)
prk = hmac.digest()
# Step 2: expand
t = [b("")]
t = [ b"" ]
n = 1
tlen = 0
while tlen < output_len:
hmac = HMAC.new(prk, t[-1] + context + bchr(n), digestmod=hashmod)
hmac = HMAC.new(prk, t[-1] + context + struct.pack('B', n), digestmod=hashmod)
t.append(hmac.digest())
tlen += hashmod.digest_size
n += 1
derived_output = b("").join(t)
derived_output = b"".join(t)
if num_keys == 1:
return derived_output[:key_len]
kol = [derived_output[idx:idx + key_len]
@ -403,7 +403,7 @@ def scrypt(password, salt, key_len, N, r, p, num_keys=1):
data_out += [ get_raw_buffer(buffer_out) ]
dk = PBKDF2(password,
b("").join(data_out),
b"".join(data_out),
key_len * num_keys, 1,
prf=prf_hmac_sha256)