import CA
#TODO Comments
#TODO Split this into two steps
block_size = 0
for i in range(2,257):
plain = 'A' * i
ciphertext = CA.ecb_oracle(plain)
if CA.detect_ecb_cbc(ciphertext) == 'ECB':
block_size = i/2
break
BLOCK_COUNT = (len(ciphertext) - block_size)/block_size
block_dictionary={}
decrypted = ''
while(len(decrypted) < block_size):
front_buffer = ('A'*(block_size-1-len(decrypted))+decrypted)
for query_byte in range(0,256):
front_buffer+=chr(query_byte)
guess_block = CA.ecb_oracle(front_buffer)[0:block_size]
block_dictionary[guess_block] = front_buffer
front_buffer = front_buffer[0:-1]
plain = ('A'*(block_size-1-len(decrypted)))
byte_search_block = CA.ecb_oracle(plain)[0:block_size]
byte = block_dictionary[byte_search_block][-1:]
decrypted += byte
print decrypted
plain_text = decrypted
for block_i in range(1,BLOCK_COUNT-1):
