From a5f9732ba00df15025ca6c95909c8bcc432eb07f Mon Sep 17 00:00:00 2001
From: Daniel Cason <daniel.cason@informal.systems>
Date: Tue, 19 Apr 2022 14:54:29 +0200
Subject: [PATCH] BLS: simple sign and verify using ostracon library

   * FIXME: when a signature verification fails, an error is printed.
---
 crypto/bls/ostracon/bls_test.go |  2 +-
 crypto/bls/simple_sign_test.go  | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/crypto/bls/ostracon/bls_test.go b/crypto/bls/ostracon/bls_test.go
index 5ad9b95ab..9945df614 100644
--- a/crypto/bls/ostracon/bls_test.go
+++ b/crypto/bls/ostracon/bls_test.go
@@ -359,7 +359,7 @@ func TestSignAndValidateBLS12(t *testing.T) {
 	msg := crypto.CRandBytes(128)
 	sig, err := privKey.Sign(msg)
 	require.Nil(t, err)
-	fmt.Printf("restoring signature: %x\n", sig)
+	//fmt.Printf("restoring signature: %x\n", sig)
 
 	// Test the signature
 	assert.True(t, pubKey.VerifySignature(msg, sig))
diff --git a/crypto/bls/simple_sign_test.go b/crypto/bls/simple_sign_test.go
index b604cb90e..09003cfa3 100644
--- a/crypto/bls/simple_sign_test.go
+++ b/crypto/bls/simple_sign_test.go
@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"github.com/tendermint/tendermint/crypto/bls/blst"
+	"github.com/tendermint/tendermint/crypto/bls/ostracon"
 	"github.com/tendermint/tendermint/crypto/ed25519"
 )
 
@@ -47,6 +48,26 @@ func TestBlstSignVerify(t *testing.T) {
 	}
 }
 
+func TestOstraconSignVerify(t *testing.T) {
+	m := []byte("a test message to be signed")
+	privKey := ostracon.GenPrivKey()
+	pubKey := privKey.PubKey()
+
+	sig, err := privKey.Sign(m)
+	if err != nil {
+		t.Error("Unexpected nil signature or error", m, sig, err)
+	}
+	if !pubKey.VerifySignature(m, sig) {
+		t.Error("Failed to verify signature produced by the key", m, sig)
+	}
+	if pubKey.VerifySignature(scrambleBytes(m), sig) {
+		t.Error("Unexpected to verify scrambled message", scrambleBytes(m), sig)
+	}
+	if pubKey.VerifySignature(m, scrambleBytes(sig)) {
+		t.Error("Unexpected to verify scrambled signature", m, scrambleBytes(sig))
+	}
+}
+
 // Scrambles a byte array, currently just flipping a bit.
 // TODO: implement a more complex scrambling method.
 func scrambleBytes(b []byte) []byte {