{"repo": "tgalal/python-axolotl", "pull_number": 22, "instance_id": "tgalal__python-axolotl-22", "issue_numbers": "", "base_commit": "37c5c552f6c7dd2c47f6d76bcde7648f058d7457", "patch": "diff --git a/axolotl/sessioncipher.py b/axolotl/sessioncipher.py\n--- a/axolotl/sessioncipher.py\n+++ b/axolotl/sessioncipher.py\n@@ -1,9 +1,10 @@\n # -*- coding: utf-8 -*-\n \n import sys\n+import os\n \n-import Crypto.Cipher.AES as AES\n-from Crypto.Util import Counter\n+from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes\n+from cryptography.hazmat.backends import default_backend\n \n from .ecc.curve import Curve\n from .sessionbuilder import SessionBuilder\n@@ -203,7 +204,7 @@ def getCiphertext(self, version, messageKeys, plainText):\n         if version >= 3:\n             cipher = self.getCipher(messageKeys.getCipherKey(), messageKeys.getIv())\n         else:\n-            cipher = self.getCipher_v2(messageKeys.getCipherKey(), messageKeys.getCounter())\n+            cipher = self.getCipher_v2(messageKeys.getCipherKey())\n \n         return cipher.encrypt(bytes(plainText))\n \n@@ -212,7 +213,7 @@ def getPlaintext(self, version, messageKeys, cipherText):\n         if version >= 3:\n             cipher = self.getCipher(messageKeys.getCipherKey(), messageKeys.getIv())\n         else:\n-            cipher = self.getCipher_v2(messageKeys.getCipherKey(), messageKeys.getCounter())\n+            cipher = self.getCipher_v2(messageKeys.getCipherKey())\n \n         return cipher.decrypt(cipherText)\n \n@@ -222,20 +223,9 @@ def getCipher(self, key, iv):\n         # return cipher\n         return AESCipher(key, iv)\n \n-    def getCipher_v2(self, key, counter):\n+    def getCipher_v2(self, key):\n         # AES/CTR/NoPadding\n-        # counterbytes = struct.pack('>L', counter) + (b'\\x00' * 12)\n-        # counterint = struct.unpack(\">L\", counterbytes)[0]\n-        # counterint = int.from_bytes(counterbytes, byteorder='big')\n-        ctr = Counter.new(128, initial_value=counter)\n-\n-        # cipher = AES.new(key, AES.MODE_CTR, counter=ctr)\n-        ivBytes = bytearray(16)\n-        ByteUtil.intToByteArray(ivBytes, 0, counter)\n-\n-        cipher = AES.new(key, AES.MODE_CTR, IV=bytes(ivBytes), counter=ctr)\n-\n-        return cipher\n+        return AESCipherV2(key)\n \n \n BS = 16\n@@ -251,7 +241,7 @@ class AESCipher:\n     def __init__(self, key, iv):\n         self.key = key\n         self.iv = iv\n-        self.cipher = AES.new(key, AES.MODE_CBC, IV = iv)\n+        self.cipher = Cipher(algorithms.AES(key), modes.CBC(iv), backend=default_backend())\n \n     def unpad(self, data):\n         unpadLength = data[-1]\n@@ -270,10 +260,30 @@ def encrypt(self, raw):\n         #     rawPadded = pad(raw.decode()).encode()\n         # else:\n         rawPadded = pad(raw)\n+        encryptor = self.cipher.encryptor()\n+        try:\n+            return encryptor.update(rawPadded) + encryptor.finalize()\n+        except ValueError:\n+            raise\n+\n+    def decrypt(self, enc):\n+        decryptor = self.cipher.decryptor()\n+        return self.unpad(decryptor.update(enc) + decryptor.finalize())\n+\n+\n+class AESCipherV2:\n+    def __init__(self, key):\n+        self.key = key\n+        random = os.urandom(16)\n+        self.cipher = Cipher(algorithms.AES(key), modes.CTR(random), backend=default_backend())\n+\n+    def encrypt(self, raw):\n+        encryptor = self.cipher.encryptor()\n         try:\n-            return self.cipher.encrypt(rawPadded)\n+            return encryptor.update(raw) + encryptor.finalize()\n         except ValueError:\n             raise\n \n     def decrypt(self, enc):\n-        return self.unpad(self.cipher.decrypt(enc))\n+        decryptor = self.cipher.decryptor()\n+        return decryptor.update(enc) + decryptor.finalize()\ndiff --git a/setup.py b/setup.py\n--- a/setup.py\n+++ b/setup.py\n@@ -5,7 +5,7 @@\n import axolotl\n from setuptools import find_packages, setup\n \n-deps = ['pycrypto', 'python-axolotl-curve25519', 'protobuf>=3.0.0.b2']\n+deps = ['cryptography', 'python-axolotl-curve25519', 'protobuf>=3.0.0.b2']\n \n setup(\n     name='python-axolotl',\n", "test_patch": "", "problem_statement": "", "hints_text": "", "created_at": "2017-11-19T21:47:26Z"}