Pure Python 3.x GOST cryptographic functions library.

GOST is GOvernment STandard of Russian Federation (and Soviet Union).

* GOST 28147-89 (RFC 5830) block cipher with ECB, CNT (CTR), CFB, MAC,
  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 34.11-2012 based PBKDF2 function (ТК26 Р 50.1.111-2016)
* GOST R 34.10-2001 (RFC 5832) public key signature function
* GOST R 34.10-2012 (RFC 7091) public key signature function
* various 34.10 curve parameters included
* Coordinates conversion from twisted Edwards to Weierstrass form and
  vice versa
* VKO GOST R 34.10-2001 VKO key agreement function (RFC 4357)
* VKO GOST R 34.10-2012 VKO key agreement function (RFC 7836)
* 28147-89 and CryptoPro key wrapping (RFC 4357)
* 28147-89 CryptoPro key meshing for CFB and CBC modes (RFC 4357)
* RFC 4491 (using GOST algorithms with X.509) compatibility helpers
* GOST R 34.12-2015 128-bit block cipher Кузнечик (Kuznechik) (RFC 7801)
* GOST R 34.12-2015 64-bit block cipher Магма (Magma)
* GOST R 34.13-2015 padding methods and block cipher modes of operation
  (ECB, CTR, OFB, CBC, CFB, MAC), ISO 10126 padding
* MGM AEAD mode for 64 and 128 bit ciphers (RFC 9058)
* SESPAKE password-authenticated key exchange protocol
  (RFC 8133, ТК26 Р 50.1.115-2016)
* CTR-ACPKM, OMAC-ACPKM-Master modes of operation (ТК26 Р 1323565.1.017-2018)
* KExp15/KImp15 key export/import functions (ТК26 Р 1323565.1.017-2018)
* KDF_GOSTR3411_2012_256, KDF_TREE_GOSTR3411_2012_256 (ТК26 Р 50.1.113-2016)
* KEG export key generation function (ТК26 Р 1323565.1.020-2018)
* PEP247-compatible hash/MAC functions

Known problems: low performance and non time-constant calculations.

Example 34.10-2012 keypair generation, signing and verifying:

    >>> from pygost.gost3410 import CURVES
    >>> curve = CURVES["id-tc26-gost-3410-12-512-paramSetA"]
    >>> from os import urandom
    >>> prv_raw = urandom(64)
    >>> from pygost.gost3410 import prv_unmarshal
    >>> from pygost.gost3410 import prv_marshal
    >>> prv = prv_unmarshal(prv_raw)
    >>> prv_raw = prv_marshal(curve, prv)
    >>> from pygost.gost3410 import public_key
    >>> pub = public_key(curve, prv)
    >>> from pygost.gost3410 import pub_marshal
    >>> print "Public key is:", pub_marshal(pub).hex()
    >>> from pygost import gost34112012512
    >>> data_for_signing = b"some data"
    >>> dgst = gost34112012512.new(data_for_signing).digest()
    >>> from pygost.gost3410 import sign
    >>> signature = sign(curve, prv, dgst)
    >>> from pygost.gost3410 import verify
    >>> verify(curve, pub, dgst, signature)
    True

Other examples can be found in docstrings and unittests.
Example self-signed X.509 certificate creation can be found in
pygost/asn1schemas/cert-selfsigned-example.py.

PyGOST is free software: see the file COPYING for copying conditions.

PyGOST'es home page is: http://www.pygost.stargrave.org/
You can read about GOST algorithms more: http://www.gost.stargrave.org/

Please send questions, bug reports and patches to
http://lists.stargrave.org/gost.html mailing list.
Announcements also go to this mailing list.

Development Git source code repository currently is located here:
http://www.git.stargrave.org/?p=pygost.git
