From: Sergey Matveev <stargrave@stargrave.org>
Date: Tue, 17 Aug 2021 13:23:40 +0000 (+0300)
Subject: gost3410.PublicKey.Equal method, necessary for Go 1.17
X-Git-Tag: v5.7.0^0
X-Git-Url: http://www.git.cypherpunks.ru/?p=gogost.git;a=commitdiff_plain;h=6bb01904f8685018353233727eafceeb5a05ec64

gost3410.PublicKey.Equal method, necessary for Go 1.17
---

diff --git a/gogost.go b/gogost.go
index 068a449..6af0a23 100644
--- a/gogost.go
+++ b/gogost.go
@@ -1,4 +1,4 @@
 // Pure Go GOST cryptographic functions library.
 package gogost
 
-const Version = "5.6.0"
+const Version = "5.7.0"
diff --git a/gost3410/curve.go b/gost3410/curve.go
index 9ec14de..1aa783c 100644
--- a/gost3410/curve.go
+++ b/gost3410/curve.go
@@ -159,3 +159,15 @@ func (c *Curve) Exp(degree, xS, yS *big.Int) (*big.Int, *big.Int, error) {
 	}
 	return tx, ty, nil
 }
+
+func (our *Curve) Equal(their *Curve) bool {
+	return our.P.Cmp(their.P) == 0 &&
+		our.Q.Cmp(their.Q) == 0 &&
+		our.A.Cmp(their.A) == 0 &&
+		our.B.Cmp(their.B) == 0 &&
+		our.X.Cmp(their.X) == 0 &&
+		our.Y.Cmp(their.Y) == 0 &&
+		((our.E == nil && their.E == nil) || our.E.Cmp(their.E) == 0) &&
+		((our.D == nil && their.D == nil) || our.D.Cmp(their.D) == 0) &&
+		our.Co.Cmp(their.Co) == 0
+}
diff --git a/gost3410/public.go b/gost3410/public.go
index 79f00f4..8642a27 100644
--- a/gost3410/public.go
+++ b/gost3410/public.go
@@ -16,6 +16,7 @@
 package gost3410
 
 import (
+	"crypto"
 	"fmt"
 	"math/big"
 )
@@ -107,3 +108,11 @@ func (pub *PublicKey) VerifyDigest(digest, signature []byte) (bool, error) {
 	lm.Mod(lm, pub.C.Q)
 	return lm.Cmp(r) == 0, nil
 }
+
+func (our *PublicKey) Equal(theirKey crypto.PublicKey) bool {
+	their, ok := theirKey.(*PublicKey)
+	if !ok {
+		return false
+	}
+	return our.X.Cmp(their.X) == 0 && our.X.Cmp(their.Y) == 0 && our.C.Equal(their.C)
+}
diff --git a/news.texi b/news.texi
index a5aabeb..b91a0f1 100644
--- a/news.texi
+++ b/news.texi
@@ -3,6 +3,10 @@
 
 @table @strong
 
+@anchor{Release 5.7.0}
+@item 5.7.0
+Go 1.17 requires @code{gost3410.PublicKey} to have @code{Equal} method.
+
 @anchor{Release 5.6.0}
 @item 5.6.0
     @itemize