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 encrypter():
plaintext = crypty.convert_b64_to_hex(plaintexts[randint(
0, len(plaintexts))])
#print plaintext.decode("hex")
iv = crypty.generate_key()
ciphertext = aes_cbc.infra.encrypt_manual(plaintext, key, iv)
return (iv, ciphertext)
def solve():
filename = "test.txt"
key = crypty.generate_key()
correct_hash = hmac.hmac(key.decode("hex"),
open(filename, 'r').read()).decode("hex")
print "[*] Key : %s" % (correct_hash.encode("hex"))
guessed_hash = ["\x00"] * 20
for i in xrange(20):
found_byte = b''
max_timetaken = 0
for c in xrange(256):
guessed_hash[i] = chr(c)
timetaken = 0
for j in xrange(5):
t1 = time.time()
insecure_compare("".join(guessed_hash), correct_hash)
t2 = time.time()
timetaken += (t2 - t1) * 1000
avg_timetaken = timetaken / 5.0
if avg_timetaken > max_timetaken:
found_byte = chr(c)
max_timetaken = avg_timetaken
print "Found next byte : %s" % (found_byte.encode("hex"))
guessed_hash[i] = found_byte
print "[+] Found Key : %s" % ("".join(guessed_hash).encode("hex"))
return
def step3(msg, B):
p = A_knows['p']
a = A_knows['a']
A_knows['B'] = B
k1 = getSHA1(format(pow(B, a, p), 'x'))[0:32]
A_knows['k1'] = k1
A_knows['msg'] = msg
iv = crypty.generate_key()
return aes_cbc.infra.encrypt_manual(msg.encode("hex"), k1, iv) + iv
def step4(msg):
p = B_knows['p']
A = B_knows['A']
b = B_knows['b']
k2 = getSHA1(format(pow(A, b, p), 'x'))[0:32]
B_knows['k2'] = k2
B_knows['msg2'] = msg
iv = crypty.generate_key()
return aes_cbc.infra.encrypt_manual(msg.encode("hex"), k2, iv) + iv
def step3_1(ciphertext, inject=None):
msg = aes_cbc.infra.decrypt_manual(ciphertext[0:-32], E_knows['k1'],
ciphertext[-32:])
E_knows['msg'] = msg.decode("hex")
iv = crypty.generate_key()
if inject:
E_knows['inject'] = inject
msg = inject.encode("hex")
return aes_cbc.infra.encrypt_manual(msg, E_knows['k2'], iv) + iv
def step3_1(ciphertext, inject=None):
if inject:
msg = aes_cbc.infra.decrypt_manual(ciphertext[0:-32],
getSHA1(format(0, 'x'))[:32],
ciphertext[-32:])
E_knows['msg'] = msg.decode("hex")
iv = crypty.generate_key()
if inject:
E_knows['inject'] = inject
msg = inject.encode("hex")
return aes_cbc.infra.encrypt_manual(msg,
getSHA1(format(0, 'x'))[:32],
iv) + iv
else:
return ciphertext
#!/usr/bin/python
"""
Main Code
"""
import crypty
from crypty.ciphers import cbc as aes_cbc
key = crypty.generate_key()
iv = crypty.generate_key()
def encrypter(userdata):
userdata = userdata.replace(";", "%3B").replace("=", "%3D")
prefix = "comment1=cooking%20MCs;userdata="
suffix = ";comment2=%20like%20a%20pound%20of%20bacon"
plaintext = prefix + userdata + suffix
ciphertext = aes_cbc.infra.encrypt_manual(crypty.a2h(plaintext), key, iv)
return ciphertext
def decrypter(ciphertext):
plaintext = aes_cbc.infra.decrypt_manual(ciphertext, key, iv)
return plaintext.decode("hex").find(";admin=true;") != -1
def solve():
ciphertext = encrypter('A' * 16)
blocks = crypty.get_blocks(ciphertext)
old_cipher_block = blocks[1]
new_cipher_block = crypty.xor_hex_strings(
#!/usr/bin/python
"""
Main Code
"""
from crypty.hash import sha1
import struct
import crypty
from random import randint
key = crypty.generate_key(key_size=randint(0, 40)).decode("hex")
def validate(message, key, digestMAC):
return sha1.authenticate(message, key, digestMAC)
def pad(message):
l = (len(message)) * 8
message += b'\x80'
message += b'\x00' * ((56 - (len(message) % 64)) % 64)
message += struct.pack('>Q', l)
return message
def solve():
message = "comment1=cooking%20MCs;userdata=foo;comment2=%20like%20a%20pound%20of%20bacon"
hash = sha1.sha1_hexdigest(key + message)
hasher = sha1.SHA1(crypty.get_sha1_regs(hash))
hasher.update(";admin=true;", len(pad(key + message) + ";admin=true;"))
new_hash = hasher.hexdigest()
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)
