def encryptParams(userdata):
userdata = userdata.replace(';', '%3B').replace('=', '%3D')
x1 = b'comment1=cooking%20MCs;userdata='
x2 = b';comment2=%20like%20a%20pound%20of%20bacon'
params = x1 + userdata.encode('ascii') + x2
cipher = challenge10.CBC(AES.new(key, AES.MODE_ECB), iv)
return cipher.encrypt(util.padPKCS7(params, 16))
def decryptParamsAndCheckAdmin(encryptedParams):
cipher = challenge10.CBC(AES.new(key, AES.MODE_ECB), key)
paddedParams = cipher.decrypt(encryptedParams)
params = challenge15.unpadPKCS7(paddedParams)
if any([x > 127 for x in params]):
raise ValueError(params)
return params.find(b';admin=true;') != -1
def padding_oracle(iv, s):
cipher = challenge10.CBC(AES.new(key, AES.MODE_ECB), iv)
paddedT = cipher.decrypt(s)
try:
t = challenge15.unpadPKCS7(paddedT)
except ValueError:
return False
return True
def encryption_oracle(s):
key = util.randbytes(16)
cipher = AES.new(key, AES.MODE_ECB)
if random.randint(0, 1) == 0:
print('Encrypting with ECB')
else:
print('Encrypting with CBC')
IV = util.randbytes(16)
cipher = challenge10.CBC(cipher, IV)
s = util.randbytes(random.randint(5, 10)) + s + util.randbytes(random.randint(5, 10))
s = util.padPKCS7(s, 16)
return cipher.encrypt(s)
def decryptParamsAndCheckAdmin(encryptedParams):
cipher = challenge10.CBC(AES.new(key, AES.MODE_ECB), iv)
paddedParams = cipher.decrypt(encryptedParams)
params = challenge15.unpadPKCS7(paddedParams)
return params.find(b';admin=true;') != -1
def ciphertext_oracle():
s = base64.b64decode(random.choice(strings))
iv = util.randbytes(16)
cipher = challenge10.CBC(AES.new(key, AES.MODE_ECB), iv)
return (iv, cipher.encrypt(util.padPKCS7(s, 16)))