added tests for crypto

tests/test_core_crypto.py

@@ -0,0 +1,72 @@
+import unittest
+import mock
+
+from steam.core import crypto
+
+
+class crypto_testcase(unittest.TestCase):
+    def setUp(self):
+        class NotRandom:
+            def read(self, n):
+                return '1' * n
+
+        def fakeNew():
+            return NotRandom()
+
+        self._oldnew = crypto.Random.new
+        crypto.Random.new = fakeNew
+
+    def tearDown(self):
+        crypto.Random.new = self._oldnew
+
+    def test_keygen(self):
+        expected_key = '1' * 32
+        expected_ekey = ('82a5d4d6de38e443ed3e6f0a1701a2c47bc98e0860e7883638ea5263a1744d02'
+                         'f733f09bc6b0f9b2a371bbb79b639208521f88658aab38c23e181d39a58ae39e'
+                         'c4e207fba822d523028d3c04e812abdc2247aa8d8e6e4a89c7a65671c5bcb329'
+                         '51c6d721ccf57cc2920d6ff3b69bfb2c611b1275badcd3e37fe024c9a25bf4b0'
+                         )
+
+        key, ekey = crypto.generate_session_key()
+        ekey = ekey.encode('hex')
+
+        self.assertEqual(key, expected_key)
+        self.assertEqual(ekey, expected_ekey)
+
+    def test_keygen_with_challenge(self):
+        expected_key = '1' * 32
+        expected_ekey = ('d710c55122f9bf772ec9c0f21d75c05055764d5445902577340029b4707e1725'
+                         'd61bec77f41b17faed6577d08c812cef76dca8b0b0b2329e1f33ea4cfa31f1e6'
+                         '0babc859c55b6ac94497b5dc9b0bc89629290dc038274af4377771e088e92887'
+                         '30d3906f6b698fd113ba36e3d28a5e1ce0283b27a1adda538df5dc5b179cf84f'
+                         )
+
+        key, ekey = crypto.generate_session_key('5'*16)
+        ekey = ekey.encode('hex')
+
+        self.assertEqual(key, expected_key)
+        self.assertEqual(ekey, expected_ekey)
+
+
+    def test_encryption(self):
+        message = "My secret message"
+        key = '9' * 32
+        hmac = '3' * 16
+
+        # legacy
+        cyphertext = crypto.symmetric_encrypt(message, key)
+        dmessage = crypto.symmetric_decrypt(cyphertext, key)
+
+        self.assertEqual(message, dmessage)
+
+        # with HMAC
+        cyphertext = crypto.symmetric_encrypt_HMAC(message, key, hmac)
+        dmessage = crypto.symmetric_decrypt_HMAC(cyphertext, key, hmac)
+
+        self.assertEqual(message, dmessage)
+
+        # failing HMAC check
+        with self.assertRaises(RuntimeError):
+            crypto.symmetric_decrypt_HMAC(cyphertext, key, '4'*16)
+
+