From 893152e52ba69edc047ca16b25e9a04724792f62 Mon Sep 17 00:00:00 2001
From: Anton Evangelatov <anton.evangelatov@gmail.com>
Date: Fri, 1 Dec 2017 18:40:16 +0100
Subject: [PATCH] p2p/enr: using btcec library for signing and verifying of
 signature, instead of crypto

---
 p2p/enr/enr.go | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/p2p/enr/enr.go b/p2p/enr/enr.go
index b1ccf78d6d..a4b4ac1ab0 100644
--- a/p2p/enr/enr.go
+++ b/p2p/enr/enr.go
@@ -222,10 +222,12 @@ func (r *Record) signAndEncode(privkey *ecdsa.PrivateKey) error {
 
 	digest := crypto.Keccak256Hash(sigcontent)
 
-	r.signature, err = crypto.Sign(digest.Bytes(), privkey)
+	key := btcec.PrivateKey(*privkey)
+	signature, err := key.Sign(digest.Bytes())
 	if err != nil {
 		return err
 	}
+	r.signature = signature.Serialize()
 
 	blob, err := rlp.EncodeToBytes(r.signature)
 	if err != nil {
@@ -263,7 +265,6 @@ func (r *Record) verifySignature() error {
 	if err != nil {
 		return err
 	}
-	pubkey1 := pk.SerializeUncompressed()
 
 	// get publickey from message and signature
 	sigcontent, err := r.serialisedContent()
@@ -273,13 +274,13 @@ func (r *Record) verifySignature() error {
 
 	digest := crypto.Keccak256Hash(sigcontent)
 
-	pubkey2, err := crypto.Ecrecover(digest.Bytes(), r.signature)
+	sign, err := btcec.ParseSignature(r.signature, btcec.S256())
 	if err != nil {
 		return err
 	}
 
-	if bytes.Compare(pubkey1, pubkey2) != 0 {
-		return errors.New("public key mismatch")
+	if !sign.Verify(digest.Bytes(), pk) {
+		return errors.New("signature is not valid")
 	}
 
 	return nil