Dump libssl bindings in favour of the new optional cryptg module

telethon/crypto/aes.py

@@ -3,15 +3,14 @@ AES IGE implementation in Python. This module may use libssl if available.
 """
 import os
 import pyaes
-from . import libssl
+
+try:
+    import cryptg
+except ImportError:
+    cryptg = None
 
 
-if libssl.AES is not None:
+class AES:
-    # Use libssl if available, since it will be faster
-    AES = libssl.AES
-else:
-    # Fallback to a pure Python implementation
-    class AES:
     """
     Class that servers as an interface to encrypt and decrypt
     text through the AES IGE mode.
@@ -22,6 +21,9 @@ else:
         Decrypts the given text in 16-bytes blocks by using the
         given key and 32-bytes initialization vector.
         """
+        if cryptg:
+            return cryptg.decrypt_ige(cipher_text, key, iv)
+
         iv1 = iv[:len(iv) // 2]
         iv2 = iv[len(iv) // 2:]
 
@@ -54,12 +56,14 @@ else:
         Encrypts the given text in 16-bytes blocks by using the
         given key and 32-bytes initialization vector.
         """
-
         # Add random padding iff it's not evenly divisible by 16 already
         if len(plain_text) % 16 != 0:
             padding_count = 16 - len(plain_text) % 16
             plain_text += os.urandom(padding_count)
 
+        if cryptg:
+            return cryptg.encrypt_ige(plain_text, key, iv)
+
         iv1 = iv[:len(iv) // 2]
         iv2 = iv[len(iv) // 2:]
 

telethon/crypto/libssl.py

@@ -1,107 +0,0 @@
-"""
-This module holds an AES IGE class, if libssl is available on the system.
-"""
-import os
-import ctypes
-from ctypes.util import find_library
-
-lib = find_library('ssl')
-if not lib:
-    AES = None
-else:
-    """ <aes.h>
-    # define AES_ENCRYPT     1
-    # define AES_DECRYPT     0
-    # define AES_MAXNR 14
-    struct aes_key_st {
-    # ifdef AES_LONG
-        unsigned long rd_key[4 * (AES_MAXNR + 1)];
-    # else
-        unsigned int rd_key[4 * (AES_MAXNR + 1)];
-    # endif
-        int rounds;
-    };
-    typedef struct aes_key_st AES_KEY;
-
-    int AES_set_encrypt_key(const unsigned char *userKey, const int bits,
-                            AES_KEY *key);
-    int AES_set_decrypt_key(const unsigned char *userKey, const int bits,
-                            AES_KEY *key);
-    void AES_ige_encrypt(const unsigned char *in, unsigned char *out,
-                         size_t length, const AES_KEY *key,
-                         unsigned char *ivec, const int enc);
-    """
-    _libssl = ctypes.cdll.LoadLibrary(lib)
-
-    AES_MAXNR = 14
-    AES_ENCRYPT = ctypes.c_int(1)
-    AES_DECRYPT = ctypes.c_int(0)
-
-    class AES_KEY(ctypes.Structure):
-        """Helper class representing an AES key"""
-        _fields_ = [
-            ('rd_key', ctypes.c_uint32 * (4*(AES_MAXNR + 1))),
-            ('rounds', ctypes.c_uint),
-        ]
-
-    class AES:
-        """
-        Class that servers as an interface to encrypt and decrypt
-        text through the AES IGE mode, using the system's libssl.
-        """
-        @staticmethod
-        def decrypt_ige(cipher_text, key, iv):
-            """
-            Decrypts the given text in 16-bytes blocks by using the
-            given key and 32-bytes initialization vector.
-            """
-            aeskey = AES_KEY()
-            ckey = (ctypes.c_ubyte * len(key))(*key)
-            cklen = ctypes.c_int(len(key)*8)
-            cin = (ctypes.c_ubyte * len(cipher_text))(*cipher_text)
-            ctlen = ctypes.c_size_t(len(cipher_text))
-            cout = (ctypes.c_ubyte * len(cipher_text))()
-            civ = (ctypes.c_ubyte * len(iv))(*iv)
-
-            _libssl.AES_set_decrypt_key(ckey, cklen, ctypes.byref(aeskey))
-            _libssl.AES_ige_encrypt(
-                ctypes.byref(cin),
-                ctypes.byref(cout),
-                ctlen,
-                ctypes.byref(aeskey),
-                ctypes.byref(civ),
-                AES_DECRYPT
-            )
-
-            return bytes(cout)
-
-        @staticmethod
-        def encrypt_ige(plain_text, key, iv):
-            """
-            Encrypts the given text in 16-bytes blocks by using the
-            given key and 32-bytes initialization vector.
-            """
-            # Add random padding iff it's not evenly divisible by 16 already
-            if len(plain_text) % 16 != 0:
-                padding_count = 16 - len(plain_text) % 16
-                plain_text += os.urandom(padding_count)
-
-            aeskey = AES_KEY()
-            ckey = (ctypes.c_ubyte * len(key))(*key)
-            cklen = ctypes.c_int(len(key)*8)
-            cin = (ctypes.c_ubyte * len(plain_text))(*plain_text)
-            ctlen = ctypes.c_size_t(len(plain_text))
-            cout = (ctypes.c_ubyte * len(plain_text))()
-            civ = (ctypes.c_ubyte * len(iv))(*iv)
-
-            _libssl.AES_set_encrypt_key(ckey, cklen, ctypes.byref(aeskey))
-            _libssl.AES_ige_encrypt(
-                ctypes.byref(cin),
-                ctypes.byref(cout),
-                ctlen,
-                ctypes.byref(aeskey),
-                ctypes.byref(civ),
-                AES_ENCRYPT
-            )
-
-            return bytes(cout)