X-Git-Url: http://www.git.cypherpunks.ru/?a=blobdiff_plain;f=pygost%2Ftest_mgm.py;h=c84be2b682e50cef5c775eb9514be714d1ab2dc1;hb=ade04d6c0456bb39793e8b3547ac99aeffe8af73;hp=56cfda0a30cf9421b2af0ddc5b7ce32678e13322;hpb=a63f78066756e6959b7bcbc52738f2ff4a03a308;p=pygost.git

diff --git a/pygost/test_mgm.py b/pygost/test_mgm.py
index 56cfda0..c84be2b 100644
--- a/pygost/test_mgm.py
+++ b/pygost/test_mgm.py
@@ -1,6 +1,6 @@
 # coding: utf-8
 # PyGOST -- Pure Python GOST cryptographic functions library
-# Copyright (C) 2015-2020 Sergey Matveev <stargrave@stargrave.org>
+# Copyright (C) 2015-2021 Sergey Matveev <stargrave@stargrave.org>
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -20,6 +20,7 @@ from unittest import TestCase
 
 from pygost.gost3412 import GOST3412Kuznechik
 from pygost.gost3412 import GOST3412Magma
+from pygost.gost3412 import KEYSIZE
 from pygost.mgm import MGM
 from pygost.mgm import nonce_prepare
 from pygost.utils import hexdec
@@ -30,7 +31,7 @@ class TestVector(TestCase):
         key = hexdec("8899AABBCCDDEEFF0011223344556677FEDCBA98765432100123456789ABCDEF")
         ad = hexdec("0202020202020202010101010101010104040404040404040303030303030303EA0505050505050505")
         plaintext = hexdec("1122334455667700FFEEDDCCBBAA998800112233445566778899AABBCCEEFF0A112233445566778899AABBCCEEFF0A002233445566778899AABBCCEEFF0A0011AABBCC")
-        mgm = MGM(GOST3412Kuznechik(key).encrypt, 16)
+        mgm = MGM(GOST3412Kuznechik(key).encrypt, GOST3412Kuznechik.blocksize)
         ciphertext = mgm.seal(plaintext[:16], plaintext, ad)
         self.assertSequenceEqual(ciphertext[:len(plaintext)], hexdec("A9757B8147956E9055B8A33DE89F42FC8075D2212BF9FD5BD3F7069AADC16B39497AB15915A6BA85936B5D0EA9F6851CC60C14D4D3F883D0AB94420695C76DEB2C7552"))
         self.assertSequenceEqual(ciphertext[len(plaintext):], hexdec("CF5D656F40C34F5C46E8BB0E29FCDB4C"))
@@ -38,7 +39,7 @@ class TestVector(TestCase):
 
 
 class TestSymmetric(TestCase):
-    def _itself(self, mgm, bs):
+    def _itself(self, mgm, bs, tag_size):
         for _ in range(1000):
             nonce = nonce_prepare(urandom(bs))
             ad = urandom(randint(0, 20))
@@ -46,12 +47,29 @@ class TestSymmetric(TestCase):
             if len(ad) + len(pt) == 0:
                 continue
             ct = mgm.seal(nonce, pt, ad)
+            self.assertEqual(len(ct) - tag_size, len(pt))
             self.assertSequenceEqual(mgm.open(nonce, ct, ad), pt)
 
     def test_magma(self):
-        mgm = MGM(GOST3412Magma(urandom(32)).encrypt, 8)
-        self._itself(mgm, 8)
+        for tag_size in (
+                GOST3412Magma.blocksize,
+                GOST3412Magma.blocksize - 2,
+        ):
+            mgm = MGM(
+                GOST3412Magma(urandom(KEYSIZE)).encrypt,
+                GOST3412Magma.blocksize,
+                tag_size,
+            )
+            self._itself(mgm, GOST3412Magma.blocksize, tag_size)
 
     def test_kuznechik(self):
-        mgm = MGM(GOST3412Kuznechik(urandom(32)).encrypt, 16)
-        self._itself(mgm, 16)
+        for tag_size in (
+                GOST3412Kuznechik.blocksize,
+                GOST3412Kuznechik.blocksize - 2,
+        ):
+            mgm = MGM(
+                GOST3412Kuznechik(urandom(KEYSIZE)).encrypt,
+                GOST3412Kuznechik.blocksize,
+                tag_size,
+            )
+            self._itself(mgm, GOST3412Kuznechik.blocksize, tag_size)