def findCollision(message, prefix):
extra = (7 - len(prefix))%16
if extra == 0:
extra = 16
for extraPadding in itertools.product([chr(c) for c in xrange(0x30, 0x7b)], repeat=extra):
new_prefix = prefix + "".join(list(extraPadding))
print new_prefix
prefixHash = h2a(hash(new_prefix))
mid_part = h2a(xor_ascii_strings(prefixHash, message[:16]))
if not all(ord(c)>=32 and ord(c)<127 for c in mid_part):
continue
mal_message = h2a(pad_pkcs_7(a2h(new_prefix)) + h2a(xor_ascii_strings(prefixHash, message[:16])) + message[16:]
return mal_message
return ""
def solver():
message = "alert('MZA who was that?');\n"
h = hash(message)
prefix = b"alert('Ayo, the Wu is back!'); //"
collision = findCollision(message, prefix)
print "[+] Found one."
print a2h(collision)
return
if __name__=='__main__':
solver()
def oracle(msg):
key = generate_key()
iv = generate_key()
request = build_request(msg)
compressed_request = zlib.compress(request)
encrypted_request = aes_cbc.infra.encrypt_manual(pad_pkcs_7(a2h(compressed_request)), key, iv)
return len(encrypted_request)
def encryption_oracle(plaintext):
global KEY
global prefix
if KEY is None:
KEY = crypty.generate_key()
if prefix is None:
# I am getting integer between 0 to 100
prefix = crypty.generate_key(key_size=randint(0, 100))
print "[*] Using Prefix of size : %d" % (len(prefix) / 2)
plaintext = crypty.pad_pkcs_7(prefix + plaintext +
crypty.convert_b64_to_hex(suffix))
return aes_ecb.infra.encrypt(plaintext, KEY)
def encrypt_manual(hex_string, key, iv):
"""
Manually AES-128-CBC Encrypts the input hex string using key, iv and AES-128-ECB
:param hex_string: Hex string
:param key: Hex string
:param iv: Hex string
:return: hex string
"""
assert len(iv) == len(key)
blocks = crypty.get_blocks(hex_string, block_size=16)
ciphertext = ""
for block in blocks:
if len(crypty.h2a(block)) % 16 is not 0:
block = crypty.pad_pkcs_7(block, block_size=16)
xor_block = crypty.xor_hex_strings(block, iv)
iv = ecb_cipher.infra.encrypt(xor_block, key)
ciphertext += iv
return ciphertext
def simplePadMessageFn(message_hex):
return h2a(pad_pkcs_7(message_hex, block_size=8))
def hash(message):
message = pad_pkcs_7(a2h(message))
return aes_cbc.infra.encrypt_manual(message, a2h("YELLOW SUBMARINE"), "00"*16)
def solve():
print crypty.pad_pkcs_7(crypty.a2h("YELLOW SUBMARINE"), block_size=20)
def encrypt_profile(profile):
global key
if key is None:
key = crypty.generate_key()
ciphertext = ecb_cipher.infra.encrypt(crypty.pad_pkcs_7(crypty.a2h(profile)), key)
return (key,ciphertext)
def encryption_oracle(plaintext):
global KEY
if KEY is None:
KEY = crypty.generate_key()
plaintext = crypty.pad_pkcs_7(plaintext+crypty.convert_b64_to_hex(suffix))
return aes_ecb.infra.encrypt(plaintext, KEY)