new_size = len(aes.ecb_encrypt(msg))
if new_size > size:
break
return size
data = b64decode('Um9sbGluJyBpbiBteSA1LjAKV2l0aCBteSByYWctdG9wIGRvd24gc28gbXkgaGFpciBjYW4gYmxvdwpUaGUgZ2lybGllcyBvbiBzdGFuZGJ5IHdhdmluZyBqdXN0IHRvIHNheSBoaQpEaWQgeW91IHN0b3A/IE5vLCBJIGp1c3QgZHJvdmUgYnkK')
key = generate_key()
a = AESCipher(key)
bs = determine_block_size(a)
print "Block size: %s" % bs
known_data = ""
char_dict = {}
for i in range(1, 176):
short_str = "A" * (bs-i) + known_data
for j in range(256):
str = short_str + known_data + chr(j)
char_dict[str] = a.ecb_encrypt(str)
enc = short_str + data[:i]
msg = a.ecb_encrypt(enc)
for k,v in char_dict.iteritems():
if v == msg:
known_data += k[-1]
print known_data
dupe_count = find_duplicate_blocks(data) if dupe_count > 2: return 2 elif dupe_count == 0: return 1 else: return -1 success = 0 fail = 0 msg = "111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111" for i in range(200): enc_msg = generate_jibber_jabber(msg) mode = randint(1,2) if mode == 1: a = AESCipher(key=generate_key(), bs=16, iv=generate_key()) enc = a.cbc_encrypt(enc_msg) elif mode == 2: a = AESCipher(key=generate_key(), bs=16, iv=generate_key()) enc = a.ecb_encrypt(enc_msg) computed_mode = encryption_oracle(enc) if mode == computed_mode: success += 1 else: fail += 1 print "Success rate: %.3f" % float(float(success)/float((success + fail)))
