def final(self, output=True):
"""Return hashed data as bytestring.
`output` is primarily for internal use. It should only be False
if you have a clear reason for doing so.
This function can be called as either ``final`` or ``digest``.
"""
self.tf.tweak[1] |= bigint(0x8000000000000000) # SKEIN_T1_FLAG_FINAL
buflen = len(self.buf)
self.buf += zero_bytes[:64 - buflen]
self._process_block(self.buf, buflen)
if not output:
hash_val = words2bytes(self.tf.key)
else:
hash_val = empty_bytes
self.buf = zero_bytes[:]
key = self.tf.key[:] # temporary copy
i = 0
while i * 64 < self.digest_size:
self.buf = words_format[1].pack(i) + self.buf[8:]
self.tf.tweak = [0, self.block_type['out_final']]
self._process_block(self.buf, 8)
n = self.digest_size - i * 64
if n >= 64:
n = 64
hash_val += words2bytes(self.tf.key)[0:n]
self.tf.key = key
i += 1
return hash_val
def final(self, output=True):
"""Return hashed data as bytestring.
`output` is primarily for internal use. It should only be False
if you have a clear reason for doing so.
This function can be called as either ``final`` or ``digest``.
"""
self.tf.tweak[1] |= bigint(0x8000000000000000) # SKEIN_T1_FLAG_FINAL
buflen = len(self.buf)
self.buf += zero_bytes[:64-buflen]
self._process_block(self.buf, buflen)
if not output:
hash_val = words2bytes(self.tf.key)
else:
hash_val = empty_bytes
self.buf = zero_bytes[:]
key = self.tf.key[:] # temporary copy
i=0
while i*64 < self.digest_size:
self.buf = words_format[1].pack(i) + self.buf[8:]
self.tf.tweak = [0, self.block_type['out_final']]
self._process_block(self.buf, 8)
n = self.digest_size - i*64
if n >= 64:
n = 64
hash_val += words2bytes(self.tf.key)[0:n]
self.tf.key = key
i+=1
return hash_val
def _process_block(self, block, byte_count_add):
"""Encrypt internal state using Threefish.
Primarily for internal use.
"""
block_len = len(block)
for i in xrange(0, block_len, 64):
w = bytes2words(block[i:i + 64])
self.tf.tweak[0] = add64(self.tf.tweak[0], byte_count_add)
self.tf.prepare_tweak()
self.tf.prepare_key()
self.tf.key = self.tf.encrypt_block(w)
self.tf._feed_forward(self.tf.key, w)
# set second tweak value to ~SKEIN_T1_FLAG_FIRST:
self.tf.tweak[1] &= bigint(0xbfffffffffffffff)
def _process_block(self, block, byte_count_add):
"""Encrypt internal state using Threefish.
Primarily for internal use.
"""
block_len = len(block)
for i in xrange(0,block_len,64):
w = bytes2words(block[i:i+64])
self.tf.tweak[0] = add64(self.tf.tweak[0], byte_count_add)
self.tf.prepare_tweak()
self.tf.prepare_key()
self.tf.key = self.tf.encrypt_block(w)
self.tf._feed_forward(self.tf.key, w)
# set second tweak value to ~SKEIN_T1_FLAG_FIRST:
self.tf.tweak[1] &= bigint(0xbfffffffffffffff)