Merge lp:~vomun-security/anonplus/security-trunk into lp:anonplus

[aj00200]

Completed the AES code with random padding.

Completed the AES code with random padding.

[aj00200 (aj00200)]

Everything seems to function and the random padding works as expected.

review: Approve (security)

[al1ce (al1ce)]

review: Approve (security)

=== modified file 'src/libs/encryption/aes.py'
--- src/libs/encryption/aes.py	2011-10-23 15:41:09 +0000
+++ src/libs/encryption/aes.py	2011-12-30 01:31:24 +0000
@@ -1,7 +1,35 @@
 '''Handles all AES (Advanced Encryption Standard) encryption. This module is
 not being used yet, but it will be in a later version.'''
+import Crypto
+from Crypto import Random
+from Crypto.Cipher import AES
 import libs.encryption.base
 
 class Encryption(libs.encryption.base.Encryption):
     '''Hold the AES encryption state.'''
-    pass
+    def __init__(self, key):
+        self.aes = AES.new(key)
+        self.rng = Random.new()
+
+    def encrypt(self, data):
+        '''Pad `data` with random bytes so that it is a multiple of 16
+        bytes in length. Then encrypt the data and return it.
+        '''
+        return self.aes.encrypt(self.pad(data))
+
+    def decrypt(self, data):
+        '''Decrypt the data.'''
+        return self.aes.decrypt(data)
+
+    # AES only methods
+    def rekey(self, key):
+        '''Switch to a different key. The key should be 16 bytes in length and
+        contain purely random data.
+        '''
+        self.aes = AES.new(key)
+        
+    def pad(self, data):
+        count = 16 - len(data) % 16
+        data += self.rng.read(count)
+        return data
+        
\ No newline at end of file