core/vm, crypto/bn256: switch over to cloudflare library

crypto/bn256/bn256_amd64.go

@@ -0,0 +1,63 @@
+// Copyright 2018 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/>.
+
+// +build amd64,!appengine,!gccgo
+
+// Package bn256 implements the Optimal Ate pairing over a 256-bit Barreto-Naehrig curve.
+package bn256
+
+import (
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/crypto/bn256/cloudflare"
+)
+
+// G1 is an abstract cyclic group. The zero value is suitable for use as the
+// output of an operation, but cannot be used as an input.
+type G1 struct {
+	bn256.G1
+}
+
+// Add sets e to a+b and then returns e.
+func (e *G1) Add(a, b *G1) *G1 {
+	e.G1.Add(&a.G1, &b.G1)
+	return e
+}
+
+// ScalarMult sets e to a*k and then returns e.
+func (e *G1) ScalarMult(a *G1, k *big.Int) *G1 {
+	e.G1.ScalarMult(&a.G1, k)
+	return e
+}
+
+// G2 is an abstract cyclic group. The zero value is suitable for use as the
+// output of an operation, but cannot be used as an input.
+type G2 struct {
+	bn256.G2
+}
+
+// PairingCheck calculates the Optimal Ate pairing for a set of points.
+func PairingCheck(a []*G1, b []*G2) bool {
+	as := make([]*bn256.G1, len(a))
+	for i, p := range a {
+		as[i] = &p.G1
+	}
+	bs := make([]*bn256.G2, len(b))
+	for i, p := range b {
+		bs[i] = &p.G2
+	}
+	return bn256.PairingCheck(as, bs)
+}

crypto/bn256/bn256_other.go

@@ -0,0 +1,63 @@
+// Copyright 2018 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/>.
+
+// +build !amd64 appengine gccgo
+
+// Package bn256 implements the Optimal Ate pairing over a 256-bit Barreto-Naehrig curve.
+package bn256
+
+import (
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/crypto/bn256/google"
+)
+
+// G1 is an abstract cyclic group. The zero value is suitable for use as the
+// output of an operation, but cannot be used as an input.
+type G1 struct {
+	bn256.G1
+}
+
+// Add sets e to a+b and then returns e.
+func (e *G1) Add(a, b *G1) *G1 {
+	e.G1.Add(&a.G1, &b.G1)
+	return e
+}
+
+// ScalarMult sets e to a*k and then returns e.
+func (e *G1) ScalarMult(a *G1, k *big.Int) *G1 {
+	e.G1.ScalarMult(&a.G1, k)
+	return e
+}
+
+// G2 is an abstract cyclic group. The zero value is suitable for use as the
+// output of an operation, but cannot be used as an input.
+type G2 struct {
+	bn256.G2
+}
+
+// PairingCheck calculates the Optimal Ate pairing for a set of points.
+func PairingCheck(a []*G1, b []*G2) bool {
+	as := make([]*bn256.G1, len(a))
+	for i, p := range a {
+		as[i] = &p.G1
+	}
+	bs := make([]*bn256.G2, len(b))
+	for i, p := range b {
+		bs[i] = &p.G2
+	}
+	return bn256.PairingCheck(as, bs)
+}

crypto/bn256/bn256_test.go → crypto/bn256/cloudflare/bn256_test.go

@@ -1,3 +1,5 @@
+// +build amd64,!appengine,!gccgo
+
 package bn256
 
 import (

crypto/bn256/cloudflare/example_test.go

@@ -0,0 +1,45 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build amd64,!appengine,!gccgo
+
+package bn256
+
+import (
+	"crypto/rand"
+)
+
+func ExamplePair() {
+	// This implements the tripartite Diffie-Hellman algorithm from "A One
+	// Round Protocol for Tripartite Diffie-Hellman", A. Joux.
+	// http://www.springerlink.com/content/cddc57yyva0hburb/fulltext.pdf
+
+	// Each of three parties, a, b and c, generate a private value.
+	a, _ := rand.Int(rand.Reader, Order)
+	b, _ := rand.Int(rand.Reader, Order)
+	c, _ := rand.Int(rand.Reader, Order)
+
+	// Then each party calculates g₁ and g₂ times their private value.
+	pa := new(G1).ScalarBaseMult(a)
+	qa := new(G2).ScalarBaseMult(a)
+
+	pb := new(G1).ScalarBaseMult(b)
+	qb := new(G2).ScalarBaseMult(b)
+
+	pc := new(G1).ScalarBaseMult(c)
+	qc := new(G2).ScalarBaseMult(c)
+
+	// Now each party exchanges its public values with the other two and
+	// all parties can calculate the shared key.
+	k1 := Pair(pb, qc)
+	k1.ScalarMult(k1, a)
+
+	k2 := Pair(pc, qa)
+	k2.ScalarMult(k2, b)
+
+	k3 := Pair(pa, qb)
+	k3.ScalarMult(k3, c)
+
+	// k1, k2 and k3 will all be equal.
+}

crypto/bn256/cloudflare/gfp_pure.go

@@ -0,0 +1,19 @@
+//  +build !amd64 appengine gccgo
+
+package bn256
+
+func gfpNeg(c, a *gfP) {
+	panic("unsupported architecture")
+}
+
+func gfpAdd(c, a, b *gfP) {
+	panic("unsupported architecture")
+}
+
+func gfpSub(c, a, b *gfP) {
+	panic("unsupported architecture")
+}
+
+func gfpMul(c, a, b *gfP) {
+	panic("unsupported architecture")
+}

crypto/bn256/gfp_test.go → crypto/bn256/cloudflare/gfp_test.go

@@ -1,3 +1,5 @@
+// +build amd64,!appengine,!gccgo
+
 package bn256
 
 import (

crypto/bn256/cloudflare/main_test.go

@@ -0,0 +1,73 @@
+// +build amd64,!appengine,!gccgo
+
+package bn256
+
+import (
+	"testing"
+
+	"crypto/rand"
+)
+
+func TestRandomG2Marshal(t *testing.T) {
+	for i := 0; i < 10; i++ {
+		n, g2, err := RandomG2(rand.Reader)
+		if err != nil {
+			t.Error(err)
+			continue
+		}
+		t.Logf("%d: %x\n", n, g2.Marshal())
+	}
+}
+
+func TestPairings(t *testing.T) {
+	a1 := new(G1).ScalarBaseMult(bigFromBase10("1"))
+	a2 := new(G1).ScalarBaseMult(bigFromBase10("2"))
+	a37 := new(G1).ScalarBaseMult(bigFromBase10("37"))
+	an1 := new(G1).ScalarBaseMult(bigFromBase10("21888242871839275222246405745257275088548364400416034343698204186575808495616"))
+
+	b0 := new(G2).ScalarBaseMult(bigFromBase10("0"))
+	b1 := new(G2).ScalarBaseMult(bigFromBase10("1"))
+	b2 := new(G2).ScalarBaseMult(bigFromBase10("2"))
+	b27 := new(G2).ScalarBaseMult(bigFromBase10("27"))
+	b999 := new(G2).ScalarBaseMult(bigFromBase10("999"))
+	bn1 := new(G2).ScalarBaseMult(bigFromBase10("21888242871839275222246405745257275088548364400416034343698204186575808495616"))
+
+	p1 := Pair(a1, b1)
+	pn1 := Pair(a1, bn1)
+	np1 := Pair(an1, b1)
+	if pn1.String() != np1.String() {
+		t.Error("Pairing mismatch: e(a, -b) != e(-a, b)")
+	}
+	if !PairingCheck([]*G1{a1, an1}, []*G2{b1, b1}) {
+		t.Error("MultiAte check gave false negative!")
+	}
+	p0 := new(GT).Add(p1, pn1)
+	p0_2 := Pair(a1, b0)
+	if p0.String() != p0_2.String() {
+		t.Error("Pairing mismatch: e(a, b) * e(a, -b) != 1")
+	}
+	p0_3 := new(GT).ScalarMult(p1, bigFromBase10("21888242871839275222246405745257275088548364400416034343698204186575808495617"))
+	if p0.String() != p0_3.String() {
+		t.Error("Pairing mismatch: e(a, b) has wrong order")
+	}
+	p2 := Pair(a2, b1)
+	p2_2 := Pair(a1, b2)
+	p2_3 := new(GT).ScalarMult(p1, bigFromBase10("2"))
+	if p2.String() != p2_2.String() {
+		t.Error("Pairing mismatch: e(a, b * 2) != e(a * 2, b)")
+	}
+	if p2.String() != p2_3.String() {
+		t.Error("Pairing mismatch: e(a, b * 2) != e(a, b) ** 2")
+	}
+	if p2.String() == p1.String() {
+		t.Error("Pairing is degenerate!")
+	}
+	if PairingCheck([]*G1{a1, a1}, []*G2{b1, b1}) {
+		t.Error("MultiAte check gave false positive!")
+	}
+	p999 := Pair(a37, b27)
+	p999_2 := Pair(a1, b999)
+	if p999.String() != p999_2.String() {
+		t.Error("Pairing mismatch: e(a * 37, b * 27) != e(a, b * 999)")
+	}
+}