class ECB_RANDKEY_ORACLE:
cipher = ECB()
key = Random.new().read(block_size)
thispkcs7 = PKCS7()
def encrypt_ECB(self, plaintext):
encrypted = self.cipher.encryptECB(self.thispkcs7.PKCS7_padding(plaintext, len(self.key)), self.key)
return encrypted
def make_profile_from_encrypted(cipher, encrypted_profile, key):
pkcs = PKCS7()
decrypted_profile = pkcs.unpadPKCS7(
cipher.decryptECB(encrypted_profile, key))
for i in range(0, len(decrypted_profile)):
partial_plaintext = decrypted_profile[:len(decrypted_profile) - i]
if chr(partial_plaintext[-1]) == "=":
return cipher.encryptECB(
pkcs.PKCS7_padding(partial_plaintext + b"admin", block_size),
key)
def decrypt(self, ciphertext, key, IV):
mypkcs7 = PKCS7()
ecb_cipher = ECB()
plaintext = b""
for i in range(0, len(ciphertext), block_size):
pre_plaintext_block = mypkcs7.unpadPKCS7(
ecb_cipher.decryptECB(ciphertext[i:i + block_size], key))
plaintext_block = bytes(
[x ^ y for x, y in zip(IV, pre_plaintext_block)])
plaintext += plaintext_block
IV = ciphertext[i:i + block_size]
return mypkcs7.unpadPKCS7(plaintext).decode('utf-8')
def encrypt(self, plaintext, key, IV):
mypkcs7 = PKCS7()
ecb_cipher = ECB()
answer = b""
for i in range(0, len(plaintext), block_size):
pre_block = mypkcs7.PKCS7_padding(
bytes([x ^ y
for x, y in zip(IV, plaintext[i:i + block_size])]),
block_size)
ciphertext_block = ecb_cipher.encryptECB(pre_block, key)
answer += ciphertext_block
IV = ciphertext_block
return answer
class HARDER_ECB_BREAKING_ORACLE:
target = base64.b64decode(
"Um9sbGluJyBpbiBteSA1LjAKV2l0aCBteSByYWctdG9wIGRvd24gc28gbXkgaGFpciBjYW4gYmxvdwpUaGUgZ2lybGllcyBvbiBzdGFuZGJ5IHdhdmluZyBqdXN0IHRvIHNheSBoaQpEaWQgeW91IHN0b3A/IE5vLCBJIGp1c3QgZHJvdmUgYnkK"
)
cipher = ECB()
rand_padding = Random.new().read(
Random.random.randrange(block_size, block_size * 4))
key = Random.new().read(block_size)
thispkcs7 = PKCS7()
def encrypt_ECB(self, plaintext):
encrypted = self.cipher.encryptECB(
self.thispkcs7.PKCS7_padding(
self.rand_padding + plaintext + self.target, len(self.key)),
self.key)
return encrypted
def prep_plaintext(self, plaintext):
mypkcs7 = PKCS7()
key = self.random_key(block_size)
return (mypkcs7.PKCS7_padding(
Random.new().read(random.randrange(5, 11)) + plaintext +
Random.new().read(random.randrange(5, 11)), len(key)))
def check_padding(text):
my_pkcs7 = PKCS7()
return my_pkcs7.is_it_padded(text)
def make_profile_from_encrypted(cipher, encrypted_profile, key):
pkcs = PKCS7()
decrypted_profile = pkcs.unpadPKCS7(
cipher.decryptECB(encrypted_profile, key))
for i in range(0, len(decrypted_profile)):
partial_plaintext = decrypted_profile[:len(decrypted_profile) - i]
if chr(partial_plaintext[-1]) == "=":
return cipher.encryptECB(
pkcs.PKCS7_padding(partial_plaintext + b"admin", block_size),
key)
if __name__ == "__main__":
cipher = ECB()
pkcs = PKCS7()
key = Random.new().read(block_size)
encoded_profile = profile_for("*****@*****.**", 100)
profile_json_object = parse_profile(profile_for("*****@*****.**",
100))
encrypted_profile = cipher.encryptECB(
pkcs.PKCS7_padding(str.encode(encoded_profile), block_size), key)
decrypted_profile = pkcs.unpadPKCS7(
cipher.decryptECB(encrypted_profile, key))
pasted_and_encrypted = make_profile_from_encrypted(cipher,
encrypted_profile, key)
decrypted_pasted_profile = pkcs.unpadPKCS7(
cipher.decryptECB(pasted_and_encrypted, key))
parsed_admin = parse_profile(decrypted_pasted_profile.decode())
print(encrypted_profile)
print(parse_profile(decrypted_profile.decode()))