Add RSA support for sending strings. Chops strings into single charac…

…ters and encrypts each character, then returns a list of chiffres.

encryption_algorithms/asymmetric/rsa.py

@@ -53,7 +53,20 @@ def _random_prime_of_length(k):
     while not isPrime(candidate):
         candidate = get_odd_random(k)
     return candidate
-
+
+def encrypt_string(public_key, str_to_send):
+    message = [ord(c) for c in str_to_send]
+    chiffre = []
+    for ordc in message:
+        chiffre.append(RSA.encryption(public_key, ordc))
+    return chiffre
+
+def decrypt_string(private_key, list_of_chiffres):
+    cleartext = []
+    for chiff in list_of_chiffres:
+        cleartext.append(RSA.decryption(private_key, chiff))
+    return ''.join(chr(ordc) for ordc in cleartext)
+
 class RSA(object):
     """implements the RSA encryption algorithm. Please do not use this to encrypt anything remotely serious."""
     @classmethod

encryption_algorithms/test/test_encryption.py

@@ -1,4 +1,4 @@
-from asymmetric.rsa import RSA
+from asymmetric.rsa import RSA, encrypt_string, decrypt_string
 
 import random
 import os
@@ -102,6 +102,10 @@ def send_messages(self, scenario):
     def test_send_messages_rsa(self):
         self.send_messages(self.scenario_rsa)
 
+    def test_send_strings_rsa(self):
+        message = "My super complicated test message.\n I love RSA!"
+        self.assertEquals(decrypt_string(self.scenario_rsa.sk_bob, encrypt_string(self.scenario_rsa.pk_bob, message)), message, "Error: Decryption of encryption does not match clear text!")
+
     @unittest.skip("not implemented")
     def test_send_messages_des(self):
         self.send_messages(self.scenario_des)