def encrypt_fp(secret_key, plaintext_fp, cipher_fp, init_vec=''):
encrypt('\x00' * 16, secret_key)
while True:
block = plaintext_fp.read(block_size)
block_len = len(block)
if 0 < block_len < block_size:
block += padding(block_len)
cipher_fp.write(''.join([encrypt(block[start:start + 16]) for start in rng[:block_len / 16 + 1]]))
break
cipher_fp.write(''.join([encrypt(block[start:start + 16]) for start in rng]))
return cipher_fp
def protocrypt_fp(func, secret_key, in_fp, out_fp, init_vector='\x00' * 16):
encrypt('\x00' * 16, secret_key)
in_fp.seek(0, os.SEEK_END)
rest_size = in_fp.tell()
in_fp.seek(0, os.SEEK_SET)
while True:
if not rest_size:
break
elif rest_size > block_size_and_a_byte:
size = block_size
else:
size = rest_size
out_text, init_vector = func(in_fp.read(size),
init_vector)
out_fp.write(out_text)
rest_size -= size
return out_fp
def decrypt_fp(secret_key, cipher_fp, plaintext_fp, init_vec=''):
encrypt('\x00' * 16, secret_key)
length = len_fp(cipher_fp)
while True:
block = cipher_fp.read(block_size)
block_len = len(block)
if block_len < block_size:
plaintext_block = ''.join([decrypt(block[start:start + 16]) for start in rng[:block_len / 16]])
else:
plaintext_block = ''.join([decrypt(block[start:start + 16]) for start in rng])
if cipher_fp.tell() == length:
plaintext_block = plaintext_block[:-ord(plaintext_block[-1])]
plaintext_fp.write(plaintext_block)
break
plaintext_fp.write(plaintext_block)
return plaintext_fp
