Finished authenticator (now it works!)

utils/aes.py

@@ -0,0 +1,61 @@
+import pyaes
+
+
+class AES:
+    @staticmethod
+    def decrypt_ige(cipher_text, key, iv):
+        iv1 = iv[:len(iv)//2]
+        iv2 = iv[len(iv)//2:]
+
+        aes = pyaes.AES(key)
+
+        plain_text = [0] * len(cipher_text)
+        blocks_count = len(cipher_text) // 16
+
+        cipher_text_block = [0] * 16
+        for block_index in range(blocks_count):
+            for i in range(16):
+                cipher_text_block[i] = cipher_text[block_index * 16 + i] ^ iv2[i]
+
+            plain_text_block = aes.decrypt(cipher_text_block)
+
+            for i in range(16):
+                plain_text_block[i] ^= iv1[i]
+
+            iv1 = cipher_text[block_index * 16:block_index * 16 + 16]
+            iv2 = plain_text_block[0:16]
+
+            plain_text[block_index * 16:block_index * 16 + 16] = plain_text_block[:16]
+
+        return bytes(plain_text)
+
+    @staticmethod
+    def encrypt_ige(plain_text, key, iv):
+        # TODO: Random padding
+        padding = bytes(16 - len(plain_text) % 16)
+        plain_text += padding
+
+        iv1 = iv[:len(iv)//2]
+        iv2 = iv[len(iv)//2:]
+
+        aes = pyaes.AES(key)
+
+        blocks_count = len(plain_text) // 16
+        cipher_text = [0] * len(plain_text)
+
+        for block_index in range(blocks_count):
+            plain_text_block = list(plain_text[block_index * 16:block_index * 16 + 16])
+            for i in range(16):
+                plain_text_block[i] ^= iv1[i]
+
+            cipher_text_block = aes.encrypt(plain_text_block)
+
+            for i in range(16):
+                cipher_text_block[i] ^= iv2[i]
+
+            iv1 = cipher_text_block[0:16]
+            iv2 = plain_text[block_index * 16:block_index * 16 + 16]
+
+            cipher_text[block_index * 16:block_index * 16 + 16] = cipher_text_block[:16]
+
+        return bytes(cipher_text)