def c12():
# Find block size
length = crypto.detect_cipher_block_size(crypto.encrypt_append_secret_ECB)
print('Determined block size to be {0}.'.format(length))
# Check the cipher uses ECB mode
ecb = crypto.detect_ECB(crypto.encrypt_append_secret_ECB)
if ecb:
print('The cipher uses ECB mode')
else:
raise ValueError('The cipher does not use ECB mode')
# Find number of blocks to crack for the secret
num_blocks = int(len(crypto.encrypt_append_secret_ECB(b'')) / length)
print ('There are {0} blocks to crack'.format(num_blocks))
print('Finding the secret...')
print()
secret = bytes(0)
for j in range(num_blocks):
for i in range(length):
block = {}
for b in range(0, 255):
plain = crypto.str_to_bytes('A' * (length - (i + 1))) + secret + b.to_bytes(1, byteorder='big')
block[b] = crypto.encrypt_append_secret_ECB(plain)[j*length:(j+1)*length]
match = crypto.encrypt_append_secret_ECB(b'A' * (length - (i + 1)))[j*length:(j+1)*length]
byte = [k for k,v in block.items() if v == match]
if not byte:
# Done - or failed to find a match (i.e padding)
break
secret += byte[0].to_bytes(1, byteorder='big')
print(secret.decode())
def c11():
cipher = crypto.encrypt_ECB_or_CBC
result = crypto.detect_ECB(cipher)
if result:
print('Cipher used ECB')
else:
print('Cipher used CBC')
