def encryption_oracle(plaintext):
paddedPlaintext = addPKCS7Padding(urandom(randint(5,10))+plaintext+urandom(randint(5,10)), AES.block_size)
if randint(0, 1):
return encryptAES_ECB(paddedPlaintext, urandom(AES.block_size))
else:
return encryptAES_ECB_CBC(paddedPlaintext, urandom(AES.block_size), urandom(AES.block_size))
def encryptAES_ECB_CBC(plaintext, key, iv):
plaintext = addPKCS7Padding(plaintext, AES.block_size)
ciphertext = bytearray(len(plaintext))
for n in range(0, len(plaintext), AES.block_size):
ciphertext[n: n+AES.block_size] = encryptAES_ECB(xor(plaintext[n: n+AES.block_size], iv), key)
iv = ciphertext[n: n+AES.block_size]
return ciphertext
def cryptAES_CTR(key, nonce, plaintext):
counter = 0
nonce = bytearray(pack('<Q', nonce))
ciphertext = bytearray()
for n in range(0, len(plaintext), AES.block_size):
cipher = encryptAES_ECB(nonce + bytearray(pack('<Q', counter)), key)
ciphertext += xor(plaintext[n:n + AES.block_size], cipher)
counter += 1
return ciphertext
def oracle(knownText):
return encryptAES_ECB(
addPKCS7Padding(randomPrefix + knownText + unknownText,
AES.block_size), RandomAESKey)
def profileFor(email): # oracle
assert not ("&".encode('utf-8') in email) and not ("=".encode('utf-8') in email)
encoded = ("email=".encode('utf-8'))+email+("&uid=10&role=user".encode('utf-8'))
return bytearray(encryptAES_ECB(addPKCS7Padding(encoded, AES.block_size), AESKey))