def root_output_bytes(self, output):
output_block_counter = 0
for out_block_ind in range(0, len(output), 2*self.OUTPUT_LENGTH):
remaining_block_bytes = min(2*self.OUTPUT_LENGTH, len(output)- out_block_ind)
words = compress(self.input_chaining_value, self.block_words, output_block_counter, self.block_length, self.flags | self.ROOT)
for (word, out_word_ind) in zip(words, range(0, remaining_block_bytes, 4)):
remaining_word_bytes = min(remaining_block_bytes - out_word_ind, 4)
output[out_block_ind + out_word_ind : out_block_ind + out_word_ind + remaining_word_bytes] = word.to_bytes(4, byteorder="little")[:remaining_word_bytes]
output_block_counter += 1
def update(self, input):
while len(input) > 0:
if self.block_length == self.BLOCK_SIZE:
#We need to pack the little-endian bytes into 32-bit words
block_words = self.convert_block_to_words()
#Get the chaining_value
self.chaining_value = compress(self.chaining_value, block_words, self.chunk_counter, self.BLOCK_SIZE, self.flags | self.start_flag())[:8]
self.blocks_compressed += 1
self.block = [0] * self.BLOCK_SIZE
self.block_length = 0
missing_bytes = self.BLOCK_SIZE - self.block_length
taken_bytes = min(len(input), missing_bytes)
self.block[self.block_length:self.block_length+taken_bytes] = input[:taken_bytes]
self.block_length += taken_bytes
input = input[taken_bytes:]
def chaining_value(self):
return compress(self.input_chaining_value, self.block_words, self.counter, self.block_length, self.flags)[:8]