// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package secp256k1
import (
"bytes"
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rand"
"encoding/hex"
"testing"
"github.com/ethereum/go-ethereum/common/math"
"github.com/ethereum/go-ethereum/crypto/randentropy"
)
const TestCount = 1000
func generateKeyPair() (pubkey, privkey []byte) {
key, err := ecdsa.GenerateKey(S256(), rand.Reader)
if err != nil {
panic(err)
}
pubkey = elliptic.Marshal(S256(), key.X, key.Y)
return pubkey, math.PaddedBigBytes(key.D, 32)
}
func randSig() []byte {
sig := randentropy.GetEntropyCSPRNG(65)
sig[32] &= 0x70
sig[64] %= 4
return sig
}
// tests for malleability
// highest bit of signature ECDSA s value must be 0, in the 33th byte
func compactSigCheck(t *testing.T, sig []byte) {
var b = int(sig[32])
if b < 0 {
t.Errorf("highest bit is negative: %d", b)
}
if ((b >> 7) == 1) != ((b & 0x80) == 0x80) {
t.Errorf("highest bit: %d bit >> 7: %d", b, b>>7)
}
if (b & 0x80) == 0x80 {
t.Errorf("highest bit: %d bit & 0x80: %d", b, b&0x80)
}
}
func TestSignatureValidity(t *testing.T) {
pubkey, seckey := generateKeyPair()
msg := randentropy.GetEntropyCSPRNG(32)
sig, err := Sign(msg, seckey)
if err != nil {
t.Errorf("signature error: %s", err)
}
compactSigCheck(t, sig)
if len(pubkey) != 65 {
t.Errorf("pubkey length mismatch: want: 65 have: %d", len(pubkey))
}
if len(seckey) != 32 {
t.Errorf("seckey length mismatch: want: 32 have: %d", len(seckey))
}
if len(sig) != 65 {
t.Errorf("sig length mismatch: want: 65 have: %d", len(sig))
}
recid := int(sig[64])
if recid > 4 || recid < 0 {
t.Errorf("sig recid mismatch: want: within 0 to 4 have: %d", int(sig[64]))
}
}
func TestInvalidRecoveryID(t *testing.T) {
_, seckey := generateKeyPair()
msg := randentropy.GetEntropyCSPRNG(32)
sig, _ := Sign(msg, seckey)
sig[64] = 99
_, err := RecoverPubkey(msg, sig)
if err != ErrInvalidRecoveryID {
t.Fatalf("got %q, want %q", err, ErrInvalidRecoveryID)
}
}
func TestSignAndRecover(t *testing.T) {
pubkey1, seckey := generateKeyPair()
msg := randentropy.GetEntropyCSPRNG(32)
sig, err := Sign(msg, seckey)
if err != nil {
t.Errorf("signature error: %s", err)
}
pubkey2, err := RecoverPubkey(msg, sig)
if err != nil {
t.Errorf("recover error: %s", err)
}
if !bytes.Equal(pubkey1, pubkey2) {
t.Errorf("pubkey mismatch: want: %x have: %x", pubkey1, pubkey2)
}
}
func TestSignDeterministic(t *testing.T) {
_, seckey := generateKeyPair()
msg := make([]byte, 32)
copy(msg, "hi there")
sig1, err := Sign(msg, seckey)
if err != nil {
t.Fatal(err)
}
sig2, err := Sign(msg, seckey)
if err != nil {
t.Fatal(err)
}
if !bytes.Equal(sig1, sig2) {
t.Fatal("signatures not equal")
}
}
func TestRandomMessagesWithSameKey(t *testing.T) {
pubkey, seckey := generateKeyPair()
keys := func() ([]byte, []byte) {
return pubkey, seckey
}
signAndRecoverWithRandomMessages(t, keys)
}
func TestRandomMessagesWithRandomKeys(t *testing.T) {
keys := func() ([]byte, []byte) {
pubkey, seckey := generateKeyPair()
return pubkey, seckey
}
signAndRecoverWithRandomMessages(t, keys)
}
func signAndRecoverWithRandomMessages(t *testing.T, keys func() ([]byte, []byte)) {
for i := 0; i < TestCount; i++ {
pubkey1, seckey := keys()
msg := randentropy.GetEntropyCSPRNG(32)
sig, err := Sign(msg, seckey)
if err != nil {
t.Fatalf("signature error: %s", err)
}
if sig == nil {
t.Fatal("signature is nil")
}
compactSigCheck(t, sig)
// TODO: why do we flip around the recovery id?
sig[len(sig)-1] %= 4
pubkey2, err := RecoverPubkey(msg, sig)
if err != nil {
t.Fatalf("recover error: %s", err)
}
if pubkey2 == nil {
t.Error("pubkey is nil")
}
if !bytes.Equal(pubkey1, pubkey2) {
t.Fatalf("pubkey mismatch: want: %x have: %x", pubkey1, pubkey2)
}
}
}
func TestRecoveryOfRandomSignature(t *testing.T) {
pubkey1, _ := generateKeyPair()
msg := randentropy.GetEntropyCSPRNG(32)
for i := 0; i < TestCount; i++ {
// recovery can sometimes work, but if so should always give wrong pubkey
pubkey2, _ := RecoverPubkey(msg, randSig())
if bytes.Equal(pubkey1, pubkey2) {
t.Fatalf("iteration: %d: pubkey mismatch: do NOT want %x: ", i, pubkey2)
}
}
}
func TestRandomMessagesAgainstValidSig(t *testing.T) {
pubkey1, seckey := generateKeyPair()
msg := randentropy.GetEntropyCSPRNG(32)
sig, _ := Sign(msg, seckey)
for i := 0; i < TestCount; i++ {
msg = randentropy.GetEntropyCSPRNG(32)
pubkey2, _ := RecoverPubkey(msg, sig)
// recovery can sometimes work, but if so should always give wrong pubkey
if bytes.Equal(pubkey1, pubkey2) {
t.Fatalf("iteration: %d: pubkey mismatch: do NOT want %x: ", i, pubkey2)
}
}
}
// Useful when the underlying libsecp256k1 API changes to quickly
// check only recover function without use of signature function
func TestRecoverSanity(t *testing.T) {
msg, _ := hex.DecodeString("ce0677bb30baa8cf067c88db9811f4333d131bf8bcf12fe7065d211dce971008")
sig, _ := hex.DecodeString("90f27b8b488db00b00606796d2987f6a5f59ae62ea05effe84fef5b8b0e549984a691139ad57a3f0b906637673aa2f63d1f55cb1a69199d4009eea23ceaddc9301")
pubkey1, _ := hex.DecodeString("04e32df42865e97135acfb65f3bae71bdc86f4d49150ad6a440b6f15878109880a0a2b2667f7e725ceea70c673093bf67663e0312623c8e091b13cf2c0f11ef652")
pubkey2, err := RecoverPubkey(msg, sig)
if err != nil {
t.Fatalf("recover error: %s", err)
}
if !bytes.Equal(pubkey1, pubkey2) {
t.Errorf("pubkey mismatch: want: %x have: %x", pubkey1, pubkey2)
}
}
func BenchmarkSign(b *testing.B) {
_, seckey := generateKeyPair()
msg := randentropy.GetEntropyCSPRNG(32)
b.ResetTimer()
for i := 0; i < b.N; i++ {
Sign(msg, seckey)
}
}
func BenchmarkRecover(b *testing.B) {
msg := randentropy.GetEntropyCSPRNG(32)
_, seckey := generateKeyPair()
sig, _ := Sign(msg, seckey)
b.ResetTimer()
for i := 0; i < b.N; i++ {
RecoverPubkey(msg, sig)
}
}
