Separate 34.11-94 PBKDF2 function could be useful

diff --git a/NEWS b/NEWS
index 8726c5dc6aa16e4da8584e442cf221bf7c0aa828..e2887cc5e27643b7e044f7b347290e2bbd45e043 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -11,6 +11,7 @@
       helpers added, removing the need of x509 module at all
     * gost3410.verify expects (pubX, pubY) tuple, instead of two separate
       pubX, pubY arguments
+    * 34.11-94 based PBKDF2 function added
 
 2.4:
     Fixed 34.13 mypy stub

diff --git a/README b/README
index 54cc0c9fde75a3e303e619d1fd4b4f9831074659..3e98f1109d89bc28c64578c44278b376ec8ed846 100644 (file)
--- a/README
+++ b/README
@@ -6,6 +6,7 @@ GOST is GOvernment STandard of Russian Federation (and Soviet Union).
   CBC (RFC 4357) modes of operation
 * various 28147-89-related S-boxes included
 * GOST R 34.11-94 hash function (RFC 5831)
+* GOST R 34.11-94 based PBKDF2 function
 * GOST R 34.11-2012 Стрибог (Streebog) hash function (RFC 6986)
 * GOST R 34.10-2001 (RFC 5832) public key signature function
 * GOST R 34.10-2012 (RFC 7091) public key signature function

diff --git a/pygost/gost341194.py b/pygost/gost341194.py
index adc0925f6e53e32cbbb909dfc978f9b08dd87530..0a71518cb445d6c733eb2b24237dcb8409d3420c 100644 (file)
--- a/pygost/gost341194.py
+++ b/pygost/gost341194.py
@@ -29,8 +29,10 @@ from pygost.gost28147 import encrypt
 from pygost.gost28147 import ns2block
 from pygost.gost28147 import validate_sbox
 from pygost.iface import PEP247
+from pygost.utils import bytes2long
 from pygost.utils import hexdec
 from pygost.utils import hexenc
+from pygost.utils import long2bytes
 from pygost.utils import strxor
 from pygost.utils import xrange
 
@@ -183,3 +185,36 @@ class GOST341194(PEP247):
 
 def new(data=b"", sbox=DEFAULT_SBOX):
     return GOST341194(data, sbox)
+
+
+# This implementation is based on Python 3.5.2 source code's one.
+# PyGOST does not register itself in hashlib anyway, so use it instead.
+def pbkdf2(password, salt, iterations, dklen):
+    """PBKDF2 implementation for GOST R 34.11-94
+
+    Based on http://tc26.ru/methods/containers_v1/Addition_to_PKCS5_v1_0.pdf
+    """
+    inner = GOST341194(sbox="GostR3411_94_CryptoProParamSet")
+    outer = GOST341194(sbox="GostR3411_94_CryptoProParamSet")
+    password = password + b"\x00" * (inner.block_size - len(password))
+    inner.update(strxor(password, len(password) * b"\x36"))
+    outer.update(strxor(password, len(password) * b"\x5C"))
+
+    def prf(msg):
+        icpy = inner.copy()
+        ocpy = outer.copy()
+        icpy.update(msg)
+        ocpy.update(icpy.digest())
+        return ocpy.digest()
+
+    dkey = b''
+    loop = 1
+    while len(dkey) < dklen:
+        prev = prf(salt + long2bytes(loop, 4))
+        rkey = bytes2long(prev)
+        for _ in xrange(iterations - 1):
+            prev = prf(prev)
+            rkey ^= bytes2long(prev)
+        loop += 1
+        dkey += long2bytes(rkey, inner.digest_size)
+    return dkey[:dklen]

diff --git a/pygost/stubs/pygost/gost341194.pyi b/pygost/stubs/pygost/gost341194.pyi
index 18e04d4c4759f53a611fa2b6273ff7945f964796..1432fad29422e6ed39859a4a07c675859759ff5c 100644 (file)
--- a/pygost/stubs/pygost/gost341194.pyi
+++ b/pygost/stubs/pygost/gost341194.pyi
@@ -14,3 +14,6 @@ class GOST341194:
 
 
 def new(data: bytes=..., sbox: str=...) -> GOST341194: ...
+
+
+def pbkdf2(password: bytes, salt: bytes, iterations: int, dklen: int) -> bytes: ...

diff --git a/pygost/test_gost341194.py b/pygost/test_gost341194.py
index 4af684bb5379c48e60f9feae6a1c1a95f4367b18..aa9fc689d50d6593bbdf0c4b6d171c5d39122c30 100644 (file)
--- a/pygost/test_gost341194.py
+++ b/pygost/test_gost341194.py
@@ -21,11 +21,8 @@ import hmac
 
 from pygost import gost341194
 from pygost.gost341194 import GOST341194
-from pygost.utils import bytes2long
+from pygost.gost341194 import pbkdf2
 from pygost.utils import hexenc
-from pygost.utils import long2bytes
-from pygost.utils import strxor
-from pygost.utils import xrange
 
 
 class TestCopy(TestCase):
@@ -153,67 +150,37 @@ class TestVectorsCryptoPro(TestCase):
         )
 
 
-# This implementation is based on Python 3.5.2 source code.
-# PyGOST does not register itself in hashlib anyway, so use
-# pbkdf2_hmac directly.
-def pbkdf2_hmac(password, salt, iterations, dklen):
-    inner = GOST341194(sbox="GostR3411_94_CryptoProParamSet")
-    outer = GOST341194(sbox="GostR3411_94_CryptoProParamSet")
-    password = password + b'\x00' * (inner.block_size - len(password))
-    inner.update(strxor(password, len(password) * b"\x36"))
-    outer.update(strxor(password, len(password) * b"\x5C"))
-
-    def prf(msg):
-        icpy = inner.copy()
-        ocpy = outer.copy()
-        icpy.update(msg)
-        ocpy.update(icpy.digest())
-        return ocpy.digest()
-
-    dkey = b''
-    loop = 1
-    while len(dkey) < dklen:
-        prev = prf(salt + long2bytes(loop, 4))
-        rkey = bytes2long(prev)
-        for _ in xrange(iterations - 1):
-            prev = prf(prev)
-            rkey ^= bytes2long(prev)
-        loop += 1
-        dkey += long2bytes(rkey, inner.digest_size)
-    return dkey[:dklen]
-
-
 class TestPBKDF2(TestCase):
     """http://tc26.ru/methods/containers_v1/Addition_to_PKCS5_v1_0.pdf test vectors
     """
     def test_1(self):
         self.assertEqual(
-            hexenc(pbkdf2_hmac(b"password", b"salt", 1, 32)),
+            hexenc(pbkdf2(b"password", b"salt", 1, 32)),
             "7314e7c04fb2e662c543674253f68bd0b73445d07f241bed872882da21662d58",
         )
 
     def test_2(self):
         self.assertEqual(
-            hexenc(pbkdf2_hmac(b"password", b"salt", 2, 32)),
+            hexenc(pbkdf2(b"password", b"salt", 2, 32)),
             "990dfa2bd965639ba48b07b792775df79f2db34fef25f274378872fed7ed1bb3",
         )
 
     def test_3(self):
         self.assertEqual(
-            hexenc(pbkdf2_hmac(b"password", b"salt", 4096, 32)),
+            hexenc(pbkdf2(b"password", b"salt", 4096, 32)),
             "1f1829a94bdff5be10d0aeb36af498e7a97467f3b31116a5a7c1afff9deadafe",
         )
 
     @skip("it takes too long")
     def test_4(self):
         self.assertEqual(
-            hexenc(pbkdf2_hmac(b"password", b"salt", 16777216, 32)),
+            hexenc(pbkdf2(b"password", b"salt", 16777216, 32)),
             "a57ae5a6088396d120850c5c09de0a525100938a59b1b5c3f7810910d05fcd97",
         )
 
     def test_5(self):
         self.assertEqual(
-            hexenc(pbkdf2_hmac(
+            hexenc(pbkdf2(
                 b"passwordPASSWORDpassword",
                 b"saltSALTsaltSALTsaltSALTsaltSALTsalt",
                 4096,
@@ -224,7 +191,7 @@ class TestPBKDF2(TestCase):
 
     def test_6(self):
         self.assertEqual(
-            hexenc(pbkdf2_hmac(
+            hexenc(pbkdf2(
                 b"pass\x00word",
                 b"sa\x00lt",
                 4096,