Adding G1, G2 and GT from bn256 as independant suites.

pairing/bn256/curve.go

@@ -1,6 +1,7 @@
 package bn256
 
 import (
+	"fmt"
 	"math/big"
 )
 
@@ -25,7 +26,7 @@ func (c *curvePoint) String() string {
 	x, y := &gfP{}, &gfP{}
 	montDecode(x, &c.x)
 	montDecode(y, &c.y)
-	return x.String() + y.String()
+	return fmt.Sprintf("(%s, %s)", x.String(), y.String())
 }
 
 func (c *curvePoint) Set(a *curvePoint) {

pairing/bn256/point.go

@@ -184,7 +184,7 @@ func (p *pointG1) ElementSize() int {
 }
 
 func (p *pointG1) String() string {
-	return p.g.String()
+	return "bn256.G1:" + p.g.String()
 }
 
 type pointG2 struct {
@@ -371,7 +371,7 @@ func (p *pointG2) ElementSize() int {
 }
 
 func (p *pointG2) String() string {
-	return p.g.String()
+	return "bn256.G2:" + p.g.String()
 }
 
 type pointGT struct {
@@ -563,7 +563,7 @@ func (p *pointGT) ElementSize() int {
 }
 
 func (p *pointGT) String() string {
-	return p.g.String()
+	return "bn256.GT:" + p.g.String()
 }
 
 func (p *pointGT) Finalize() kyber.Point {

pairing/bn256/suite.go

@@ -9,7 +9,6 @@ import (
 
 	"github.com/dedis/fixbuf"
 	"github.com/dedis/kyber"
-	"github.com/dedis/kyber/group/mod"
 	"github.com/dedis/kyber/util/random"
 	"github.com/dedis/kyber/xof/blake2xb"
 )
@@ -31,10 +30,31 @@ func NewSuite() *Suite {
 	return s
 }
 
+// NewSuiteG1 returns a G1 suite.
+func NewSuiteG1() *Suite {
+	s := NewSuite()
+	s.commonSuite.Group = &groupG1{commonSuite: &commonSuite{}}
+	return s
+}
+
+// NewSuiteG2 returns a G2 suite.
+func NewSuiteG2() *Suite {
+	s := NewSuite()
+	s.commonSuite.Group = &groupG2{commonSuite: &commonSuite{}}
+	return s
+}
+
+// NewSuiteGT returns a GT suite.
+func NewSuiteGT() *Suite {
+	s := NewSuite()
+	s.commonSuite.Group = &groupGT{commonSuite: &commonSuite{}}
+	return s
+}
+
 // NewSuiteRand generates and returns a new BN256 suite seeded by the
 // given cipher stream.
 func NewSuiteRand(rand cipher.Stream) *Suite {
-	s := &Suite{commonSuite: &commonSuite{rand}}
+	s := &Suite{commonSuite: &commonSuite{s: rand}}
 	s.g1 = &groupG1{commonSuite: s.commonSuite}
 	s.g2 = &groupG2{commonSuite: s.commonSuite}
 	s.gt = &groupGT{commonSuite: s.commonSuite}
@@ -63,26 +83,31 @@ func (s *Suite) Pair(p1 kyber.Point, p2 kyber.Point) kyber.Point {
 }
 
 // Not used other than for reflect.TypeOf()
-var aScalar mod.Int
+var aScalar kyber.Scalar
+var aPoint kyber.Point
 var aPointG1 pointG1
 var aPointG2 pointG2
 var aPointGT pointGT
 
 var tScalar = reflect.TypeOf(&aScalar).Elem()
+var tPoint = reflect.TypeOf(&aPoint).Elem()
 var tPointG1 = reflect.TypeOf(&aPointG1).Elem()
 var tPointG2 = reflect.TypeOf(&aPointG2).Elem()
 var tPointGT = reflect.TypeOf(&aPointGT).Elem()
 
 type commonSuite struct {
 	s cipher.Stream
+	// kyber.Group is only set if we have a combined Suite
+	kyber.Group
 }
 
 // New implements the kyber.Encoding interface.
 func (c *commonSuite) New(t reflect.Type) interface{} {
 	switch t {
 	case tScalar:
-		g1 := groupG1{}
-		return g1.Scalar()
+		return c.Scalar()
+	case tPoint:
+		return c.Point()
 	case tPointG1:
 		g1 := groupG1{}
 		return g1.Point()
@@ -124,3 +149,11 @@ func (c *commonSuite) RandomStream() cipher.Stream {
 	}
 	return random.New()
 }
+
+// String returns a recognizable string that this is a combined suite.
+func (c commonSuite) String() string {
+	if c.Group != nil {
+		return c.Group.String()
+	}
+	return "bn256"
+}

pairing/bn256/suite_test.go

@@ -237,3 +237,21 @@ func TestTripartiteDiffieHellman(t *testing.T) {
 	require.Equal(t, k1, k2)
 	require.Equal(t, k2, k3)
 }
+
+func TestCombined(t *testing.T) {
+	// Making sure we can do some basic arithmetic with the suites without having
+	// to extract the suite using .G1(), .G2(), .GT()
+	basicPointTest(t, NewSuiteG1())
+	basicPointTest(t, NewSuiteG2())
+	basicPointTest(t, NewSuiteGT())
+}
+
+func basicPointTest(t *testing.T, s *Suite) {
+	a := s.Scalar().Pick(random.New())
+	pa := s.Point().Mul(a, nil)
+
+	b := s.Scalar().Add(a, s.Scalar().One())
+	pb1 := s.Point().Mul(b, nil)
+	pb2 := s.Point().Add(pa, s.Point().Base())
+	require.True(t, pb1.Equal(pb2))
+}

suites/all.go

@@ -2,13 +2,8 @@ package suites
 
 import (
 	"github.com/dedis/kyber/group/edwards25519"
-	"github.com/dedis/kyber/pairing/bn256"
 )
 
 func init() {
 	register(edwards25519.NewBlakeSHA256Ed25519())
-	register(bn256.NewSuite().G1().(Suite))
-	register(bn256.NewSuite().G2().(Suite))
-	register(bn256.NewSuite().GT().(Suite))
-
 }

suites/all_vartime.go

@@ -13,7 +13,7 @@ func init() {
 	register(curve25519.NewBlakeSHA256Curve25519(true))
 	register(nist.NewBlakeSHA256P256())
 	register(nist.NewBlakeSHA256QR512())
-	register(bn256.NewSuite().G1().(Suite))
-	register(bn256.NewSuite().G2().(Suite))
-	register(bn256.NewSuite().GT().(Suite))
+	register(bn256.NewSuiteG1())
+	register(bn256.NewSuiteG2())
+	register(bn256.NewSuiteGT())
 }