From d2b0d4b0f57745d7d09b9cea552235fe31e5db36 Mon Sep 17 00:00:00 2001
From: Sergey Matveev <stargrave@stargrave.org>
Date: Fri, 24 Jul 2020 14:51:52 +0300
Subject: [PATCH] Example 34.10-2012-256 signing/verifying

---
 README   | 25 +++++++++++++++++++++++++
 www.texi | 27 +++++++++++++++++++++++++++
 2 files changed, 52 insertions(+)

diff --git a/README b/README
index 68317a6..5d32fa0 100644
--- a/README
+++ b/README
@@ -32,6 +32,31 @@ Known problems:
 * intermediate calculation values are not zeroed
 * 34.10 is not time constant and slow
 
+Example 34.10-2012-256 keypair generation, signing and verifying:
+
+    import (
+        "crypto/rand"
+        "io"
+        "go.cypherpunks.ru/gogost/v4/gost3410"
+        "go.cypherpunks.ru/gogost/v4/gost34112012256"
+    )
+    func main() {
+        data := []byte("data to be signed")
+        hasher := gost34112012256.New()
+        _, err := hasher.Write(data)
+        dgst := hasher.Sum(nil)
+        curve := gost3410.CurveIdtc26gost34102012256paramSetB()
+        prvRaw := make([]byte, int(gost3410.Mode2001))
+        _, err = io.ReadFull(rand.Reader, prvRaw)
+        prv, err := gost3410.NewPrivateKey(curve, gost3410.Mode2001, prvRaw)
+        pub, err := prv.PublicKey()
+        pubRaw := pub.Raw()
+        sign, err := prv.Sign(rand.Reader, dgst, nil)
+        pub, err = gost3410.NewPublicKey(curve, gost3410.Mode2001, pubRaw)
+        isValid, err := pub.VerifyDigest(dgst, sign)
+        if !isValid { panic("signature is invalid") }
+    }
+
 GoGOST is free software: see the file COPYING for copying conditions.
 
 GoGOST'es home page is: http://www.gogost.cypherpunks.ru/
diff --git a/www.texi b/www.texi
index 541f896..94bf716 100644
--- a/www.texi
+++ b/www.texi
@@ -59,6 +59,33 @@ Currently supported algorithms are:
 Probably you could be interested in
 @url{//www.gostls13.cypherpunks.ru/, Go's support of GOST TLS 1.3}.
 
+Example 34.10-2012-256 keypair generation, signing and verifying:
+
+@verbatim
+import (
+    "crypto/rand"
+    "io"
+    "go.cypherpunks.ru/gogost/v4/gost3410"
+    "go.cypherpunks.ru/gogost/v4/gost34112012256"
+)
+func main() {
+    data := []byte("data to be signed")
+    hasher := gost34112012256.New()
+    _, err := hasher.Write(data)
+    dgst := hasher.Sum(nil)
+    curve := gost3410.CurveIdtc26gost34102012256paramSetB()
+    prvRaw := make([]byte, int(gost3410.Mode2001))
+    _, err = io.ReadFull(rand.Reader, prvRaw)
+    prv, err := gost3410.NewPrivateKey(curve, gost3410.Mode2001, prvRaw)
+    pub, err := prv.PublicKey()
+    pubRaw := pub.Raw()
+    sign, err := prv.Sign(rand.Reader, dgst, nil)
+    pub, err = gost3410.NewPublicKey(curve, gost3410.Mode2001, pubRaw)
+    isValid, err := pub.VerifyDigest(dgst, sign)
+    if !isValid { panic("signature is invalid") }
+}
+@end verbatim
+
 Please send questions, bug reports and patches to
 @url{https://lists.cypherpunks.ru/mailman/listinfo/gost, gost}
 mailing list. Announcements also go to this mailing list.
-- 
2.44.0