Merge pull request #138 from binance-chain/side_slash

expose RecoverPubkey from internal secp256k1

crypto/secp256k1/secp256k1.go

@@ -12,7 +12,9 @@ import (
 
 	secp256k1 "github.com/btcsuite/btcd/btcec"
 
-	amino "github.com/tendermint/go-amino"
+	insecp256k1 "github.com/tendermint/tendermint/crypto/secp256k1/internal/secp256k1"
+
+	"github.com/tendermint/go-amino"
 
 	"github.com/tendermint/tendermint/crypto"
 )
@@ -65,6 +67,14 @@ func (privKey PrivKeySecp256k1) Equals(other crypto.PrivKey) bool {
 	return false
 }
 
+// RecoverPubkey returns the public key of the signer.
+// msg must be the 32-byte hash of the message to be signed.
+// sig must be a 65-byte compact ECDSA signature containing the
+// recovery id as the last element.
+func RecoverPubkey(msg []byte, sig []byte) ([]byte, error) {
+	return insecp256k1.RecoverPubkey(msg, sig)
+}
+
 // GenPrivKey generates a new ECDSA private key on curve secp256k1 private key.
 // It uses OS randomness to generate the private key.
 func GenPrivKey() PrivKeySecp256k1 {