From: Sergey Matveev <stargrave@stargrave.org>
Date: Wed, 12 Apr 2023 12:23:12 +0000 (+0300)
Subject: Fixed incorrect digest calculation
X-Git-Tag: 5.12^0
X-Git-Url: http://www.git.cypherpunks.ru/?p=pygost.git;a=commitdiff_plain;h=63d5c5a81f29bfbb2e6eff3d8dc730a33ef80427

Fixed incorrect digest calculation
---

diff --git a/news.texi b/news.texi
index ed7795d..1dabeea 100644
--- a/news.texi
+++ b/news.texi
@@ -3,6 +3,11 @@
 
 @table @strong
 
+@anchor{Release 5.12}
+@item 5.12
+Fixed incorrect digest calculation when using @code{GOST34112012*.update()}
+method.
+
 @anchor{Release 5.11}
 @item 5.11
 @code{gost34112012}'s @code{update()}/@code{digest()} methods are
diff --git a/pygost/__init__.py b/pygost/__init__.py
index 54bee02..c0695ad 100644
--- a/pygost/__init__.py
+++ b/pygost/__init__.py
@@ -3,4 +3,4 @@
 PyGOST is free software: see the file COPYING for copying conditions.
 """
 
-__version__ = "5.11"
+__version__ = "5.12"
diff --git a/pygost/gost3410.py b/pygost/gost3410.py
index 6e1bf84..cdb5b03 100644
--- a/pygost/gost3410.py
+++ b/pygost/gost3410.py
@@ -55,6 +55,7 @@ class GOST3410Curve(object):
                       the twisted Edwards form
     :param str name: human-readable curve name
     """
+
     def __init__(self, p, q, a, b, x, y, cofactor=1, e=None, d=None, name=None):
         self.p = p
         self.q = q
diff --git a/pygost/gost34112012.py b/pygost/gost34112012.py
index 64ed3b6..91782de 100644
--- a/pygost/gost34112012.py
+++ b/pygost/gost34112012.py
@@ -268,8 +268,9 @@ class GOST34112012(PEP247):
         """Update state with the new data
         """
         if len(self.buf) > 0:
-            self.buf += data[:BLOCKSIZE - len(self.buf)]
-            data = data[BLOCKSIZE - len(self.buf):]
+            chunk_len = BLOCKSIZE - len(self.buf)
+            self.buf += data[:chunk_len]
+            data = data[chunk_len:]
             if len(self.buf) == BLOCKSIZE:
                 self._update_block(self.buf)
                 self.buf = b""
diff --git a/pygost/test_gost34112012.py b/pygost/test_gost34112012.py
index fdec31a..c7c2df9 100644
--- a/pygost/test_gost34112012.py
+++ b/pygost/test_gost34112012.py
@@ -14,6 +14,8 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+from os import urandom
+from random import randint
 from unittest import skip
 from unittest import TestCase
 import hmac
@@ -37,6 +39,20 @@ class TestCopy(TestCase):
         self.assertSequenceEqual(m.digest(), c.digest())
 
 
+class TestSymmetric(TestCase):
+    def runTest(self):
+        chunks = []
+        for _ in range(randint(1, 10)):
+            chunks.append(urandom(randint(20, 80)))
+        m = GOST34112012256()
+        for chunk in chunks:
+            m.update(chunk)
+        self.assertSequenceEqual(
+            m.hexdigest(),
+            GOST34112012256(b"".join(chunks)).hexdigest(),
+        )
+
+
 class TestHMAC(TestCase):
     """RFC 7836
     """