# coding: utf-8
# PyGOST -- Pure Python GOST cryptographic functions library
-# Copyright (C) 2015-2021 Sergey Matveev <stargrave@stargrave.org>
+# Copyright (C) 2015-2024 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
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
CURVES["id-tc26-gost-3410-2012-512-paramSetA"] = CURVES["id-tc26-gost-3410-12-512-paramSetA"]
CURVES["id-tc26-gost-3410-2012-512-paramSetB"] = CURVES["id-tc26-gost-3410-12-512-paramSetB"]
CURVES["id-tc26-gost-3410-2012-512-paramSetC"] = CURVES["id-tc26-gost-3410-12-512-paramSetC"]
-for name, curve in CURVES.items():
- curve.name = name
+for _name, _curve in CURVES.items():
+ _curve.name = _name
DEFAULT_CURVE = CURVES["id-tc26-gost-3410-12-256-paramSetB"]
-def public_key(curve, prv):
+def public_key(curve, prv, mask=None):
"""Generate public key from the private one
:param GOST3410Curve curve: curve to use
:returns: public key's parts, X and Y
:rtype: (long, long)
"""
- return curve.exp(prv)
+ pub = curve.exp(prv)
+ if mask is not None:
+ pub = curve.exp(mask, pub[0], pub[1])
+ return pub
-def sign(curve, prv, digest, rand=None):
+def sign(curve, prv, digest, rand=None, mask=None):
"""Calculate signature for provided digest
:param GOST3410Curve curve: curve to use
k = bytes2long(rand) % q
if k == 0:
continue
- r, _ = curve.exp(k)
+ r, y = curve.exp(k)
+ if mask is not None:
+ r, y = curve.exp(mask, x=r, y=y)
r %= q
if r == 0:
continue
d = prv * r
k *= e
- s = (d + k) % q
+ s = d + k
+ if mask is not None:
+ s *= mask
+ s %= q
if s == 0:
continue
break