feat: BBS+ signer

cmd/aries-agent-mobile/go.mod

@@ -17,5 +17,5 @@ require (
 replace (
 	github.com/hyperledger/aries-framework-go => ../../
 	github.com/kilic/bls12-381 => github.com/trustbloc/bls12-381 v0.0.0-20201008080608-ba2e87ef05ef
-	github.com/phoreproject/bls => github.com/trustbloc/bls v0.0.0-20201008085849-81064514c3cc
+	github.com/phoreproject/bls => github.com/trustbloc/bls v0.0.0-20201023141329-a1e218beb89e
 )

cmd/aries-agent-mobile/go.sum

@@ -263,6 +263,8 @@ github.com/teserakt-io/golang-ed25519 v0.0.0-20200315192543-8255be791ce4 h1:Sq/6
 github.com/teserakt-io/golang-ed25519 v0.0.0-20200315192543-8255be791ce4/go.mod h1:9PdLyPiZIiW3UopXyRnPYyjUXSpiQNHRLu8fOsR3o8M=
 github.com/trustbloc/bls v0.0.0-20201008085849-81064514c3cc h1:312UsgPy3LxPl3dM+OrjQ6M2ymLcVTXIp+6wdDWkSY8=
 github.com/trustbloc/bls v0.0.0-20201008085849-81064514c3cc/go.mod h1:xHJKf2TLXUA39Dhv8k5QmQOxLsbrb1KeTS/3ERfLeqc=
+github.com/trustbloc/bls v0.0.0-20201023141329-a1e218beb89e h1:IuSryDFXv17anJ2sux9qSEmIyaqKSWXnfVMv5CFCmDc=
+github.com/trustbloc/bls v0.0.0-20201023141329-a1e218beb89e/go.mod h1:xHJKf2TLXUA39Dhv8k5QmQOxLsbrb1KeTS/3ERfLeqc=
 github.com/trustbloc/bls12-381 v0.0.0-20201008080608-ba2e87ef05ef h1:nZF/RNtWszq+WD8+p7blxWsWJjiTgdGQ1rv2IEffLj8=
 github.com/trustbloc/bls12-381 v0.0.0-20201008080608-ba2e87ef05ef/go.mod h1:XXfR6YFCRSrkEXbNlIyDsgXVNJWVUV30m/ebkVy9n6s=
 github.com/urfave/cli v1.20.0/go.mod h1:70zkFmudgCuE/ngEzBv17Jvp/497gISqfk5gWijbERA=

cmd/aries-agent-rest/go.mod

@@ -8,7 +8,7 @@ replace (
 	github.com/hyperledger/aries-framework-go => ../..
 	github.com/hyperledger/aries-framework-go/component/storage/leveldb => ../../component/storage/leveldb
 	github.com/kilic/bls12-381 => github.com/trustbloc/bls12-381 v0.0.0-20201008080608-ba2e87ef05ef
-	github.com/phoreproject/bls => github.com/trustbloc/bls v0.0.0-20201008085849-81064514c3cc
+	github.com/phoreproject/bls => github.com/trustbloc/bls v0.0.0-20201023141329-a1e218beb89e
 )
 
 require (

cmd/aries-agent-rest/go.sum

@@ -341,6 +341,8 @@ github.com/teserakt-io/golang-ed25519 v0.0.0-20200315192543-8255be791ce4/go.mod
 github.com/tmc/grpc-websocket-proxy v0.0.0-20190109142713-0ad062ec5ee5/go.mod h1:ncp9v5uamzpCO7NfCPTXjqaC+bZgJeR0sMTm6dMHP7U=
 github.com/trustbloc/bls v0.0.0-20201008085849-81064514c3cc h1:312UsgPy3LxPl3dM+OrjQ6M2ymLcVTXIp+6wdDWkSY8=
 github.com/trustbloc/bls v0.0.0-20201008085849-81064514c3cc/go.mod h1:xHJKf2TLXUA39Dhv8k5QmQOxLsbrb1KeTS/3ERfLeqc=
+github.com/trustbloc/bls v0.0.0-20201023141329-a1e218beb89e h1:IuSryDFXv17anJ2sux9qSEmIyaqKSWXnfVMv5CFCmDc=
+github.com/trustbloc/bls v0.0.0-20201023141329-a1e218beb89e/go.mod h1:xHJKf2TLXUA39Dhv8k5QmQOxLsbrb1KeTS/3ERfLeqc=
 github.com/trustbloc/bls12-381 v0.0.0-20201008080608-ba2e87ef05ef h1:nZF/RNtWszq+WD8+p7blxWsWJjiTgdGQ1rv2IEffLj8=
 github.com/trustbloc/bls12-381 v0.0.0-20201008080608-ba2e87ef05ef/go.mod h1:XXfR6YFCRSrkEXbNlIyDsgXVNJWVUV30m/ebkVy9n6s=
 github.com/ugorji/go v1.1.4/go.mod h1:uQMGLiO92mf5W77hV/PUCpI3pbzQx3CRekS0kk+RGrc=

cmd/aries-js-worker/go.mod

@@ -18,6 +18,6 @@ replace (
 	github.com/hyperledger/aries-framework-go => ../../
 	github.com/hyperledger/aries-framework-go/component/storage/jsindexeddb => ../../component/storage/jsindexeddb
 	github.com/kilic/bls12-381 => github.com/trustbloc/bls12-381 v0.0.0-20201008080608-ba2e87ef05ef
-	github.com/phoreproject/bls => github.com/trustbloc/bls v0.0.0-20201008085849-81064514c3cc
+	github.com/phoreproject/bls => github.com/trustbloc/bls v0.0.0-20201023141329-a1e218beb89e
 	github.com/piprate/json-gold => github.com/trustbloc/json-gold v0.3.1-0.20200414173446-30d742ee949e
 )

cmd/aries-js-worker/go.sum

@@ -259,8 +259,8 @@ github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/teserakt-io/golang-ed25519 v0.0.0-20200315192543-8255be791ce4 h1:Sq/68UWgBzKT+pLTUTkSf0jS2IUwwXLFlZmeh+nAzQM=
 github.com/teserakt-io/golang-ed25519 v0.0.0-20200315192543-8255be791ce4/go.mod h1:9PdLyPiZIiW3UopXyRnPYyjUXSpiQNHRLu8fOsR3o8M=
-github.com/trustbloc/bls v0.0.0-20201008085849-81064514c3cc h1:312UsgPy3LxPl3dM+OrjQ6M2ymLcVTXIp+6wdDWkSY8=
-github.com/trustbloc/bls v0.0.0-20201008085849-81064514c3cc/go.mod h1:xHJKf2TLXUA39Dhv8k5QmQOxLsbrb1KeTS/3ERfLeqc=
+github.com/trustbloc/bls v0.0.0-20201023141329-a1e218beb89e h1:IuSryDFXv17anJ2sux9qSEmIyaqKSWXnfVMv5CFCmDc=
+github.com/trustbloc/bls v0.0.0-20201023141329-a1e218beb89e/go.mod h1:xHJKf2TLXUA39Dhv8k5QmQOxLsbrb1KeTS/3ERfLeqc=
 github.com/trustbloc/bls12-381 v0.0.0-20201008080608-ba2e87ef05ef h1:nZF/RNtWszq+WD8+p7blxWsWJjiTgdGQ1rv2IEffLj8=
 github.com/trustbloc/bls12-381 v0.0.0-20201008080608-ba2e87ef05ef/go.mod h1:XXfR6YFCRSrkEXbNlIyDsgXVNJWVUV30m/ebkVy9n6s=
 github.com/trustbloc/json-gold v0.3.1-0.20200414173446-30d742ee949e h1:i+hGa8C1MKGO71j3jIV7e2aKX72/DTrzLjq9R8kc6xk=

go.mod

@@ -38,7 +38,7 @@ require (
 
 replace (
 	github.com/kilic/bls12-381 => github.com/trustbloc/bls12-381 v0.0.0-20201008080608-ba2e87ef05ef
-	github.com/phoreproject/bls => github.com/trustbloc/bls v0.0.0-20201008085849-81064514c3cc
+	github.com/phoreproject/bls => github.com/trustbloc/bls v0.0.0-20201023141329-a1e218beb89e
 	github.com/piprate/json-gold => github.com/trustbloc/json-gold v0.3.1-0.20200414173446-30d742ee949e
 	golang.org/x/sys => golang.org/x/sys v0.0.0-20200826173525-f9321e4c35a6
 )

go.sum

@@ -279,8 +279,8 @@ github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/teserakt-io/golang-ed25519 v0.0.0-20200315192543-8255be791ce4 h1:Sq/68UWgBzKT+pLTUTkSf0jS2IUwwXLFlZmeh+nAzQM=
 github.com/teserakt-io/golang-ed25519 v0.0.0-20200315192543-8255be791ce4/go.mod h1:9PdLyPiZIiW3UopXyRnPYyjUXSpiQNHRLu8fOsR3o8M=
-github.com/trustbloc/bls v0.0.0-20201008085849-81064514c3cc h1:312UsgPy3LxPl3dM+OrjQ6M2ymLcVTXIp+6wdDWkSY8=
-github.com/trustbloc/bls v0.0.0-20201008085849-81064514c3cc/go.mod h1:xHJKf2TLXUA39Dhv8k5QmQOxLsbrb1KeTS/3ERfLeqc=
+github.com/trustbloc/bls v0.0.0-20201023141329-a1e218beb89e h1:IuSryDFXv17anJ2sux9qSEmIyaqKSWXnfVMv5CFCmDc=
+github.com/trustbloc/bls v0.0.0-20201023141329-a1e218beb89e/go.mod h1:xHJKf2TLXUA39Dhv8k5QmQOxLsbrb1KeTS/3ERfLeqc=
 github.com/trustbloc/bls12-381 v0.0.0-20201008080608-ba2e87ef05ef h1:nZF/RNtWszq+WD8+p7blxWsWJjiTgdGQ1rv2IEffLj8=
 github.com/trustbloc/bls12-381 v0.0.0-20201008080608-ba2e87ef05ef/go.mod h1:XXfR6YFCRSrkEXbNlIyDsgXVNJWVUV30m/ebkVy9n6s=
 github.com/trustbloc/json-gold v0.3.1-0.20200414173446-30d742ee949e h1:i+hGa8C1MKGO71j3jIV7e2aKX72/DTrzLjq9R8kc6xk=

pkg/doc/bbs/api.go

@@ -9,8 +9,15 @@ package bbs
 // BBS defines BBS+ signature scheme (https://eprint.iacr.org/2016/663.pdf, section 4.3).
 type BBS interface {
 
-	// Verify will verify each signature against a public key
+	// Verify will verify an aggregated signature of one or more messages against a public key
 	// returns:
 	// 		error in case of errors or nil if signature verification was successful
 	Verify(messages [][]byte, signature, pubKey []byte) error
+
+	// Sign will sign create signature of each message and aggregate it into a single signature using
+	// provided private key in binary form.
+	// returns:
+	// 		signature in []byte
+	//		error in case of errors
+	Sign(messages [][]byte, privKey []byte) ([]byte, error)
 }

pkg/doc/bbs/bbs12381g2pub/bbs.go

@@ -7,13 +7,15 @@ SPDX-License-Identifier: Apache-2.0
 package bbs12381g2pub
 
 import (
+	"crypto/rand"
 	"encoding/binary"
 	"errors"
 	"fmt"
 	"hash"
 
 	bls12381 "github.com/kilic/bls12-381"
 	"github.com/phoreproject/bls"
+	"github.com/phoreproject/bls/g2pubs"
 	"golang.org/x/crypto/blake2b"
 )
 
@@ -44,16 +46,19 @@ const (
 
 	// Number of bytes in scalar compressed form.
 	frCompressedSize = 32
+
+	// Number of bytes in scalar uncompressed form.
+	frUncompressedSize = 48
 )
 
 // Verify makes BLS BBS12-381 signature verification.
-func (b BBSG2Pub) Verify(messages [][]byte, sigBytes, pubKeyBytes []byte) error {
+func (bbs *BBSG2Pub) Verify(messages [][]byte, sigBytes, pubKeyBytes []byte) error {
 	signature, err := ParseSignature(sigBytes)
 	if err != nil {
 		return fmt.Errorf("parse signature: %w", err)
 	}
 
-	publicKey, err := ParsePublicKey(pubKeyBytes)
+	publicKey, err := UnmarshalPublicKey(pubKeyBytes)
 	if err != nil {
 		return fmt.Errorf("parse public key: %w", err)
 	}
@@ -62,7 +67,7 @@ func (b BBSG2Pub) Verify(messages [][]byte, sigBytes, pubKeyBytes []byte) error
 	for i := range messages {
 		messagesFr[i], err = ParseSignatureMessage(messages[i])
 		if err != nil {
-			return fmt.Errorf("parse signature message: %w", err)
+			return fmt.Errorf("parse signature message %d: %w", i+1, err)
 		}
 	}
 
@@ -83,7 +88,63 @@ func (b BBSG2Pub) Verify(messages [][]byte, sigBytes, pubKeyBytes []byte) error
 	return errors.New("BLS12-381: invalid signature")
 }
 
-func getB(s *bls.FR, messages []*SignatureMessage, key *PublicKey) (*bls.G1Affine, error) {
+// Sign signs the one or more messages using private key in compressed form.
+func (bbs *BBSG2Pub) Sign(messages [][]byte, privKeyBytes []byte) ([]byte, error) {
+	privKey, err := UnmarshalPrivateKey(privKeyBytes)
+	if err != nil {
+		return nil, fmt.Errorf("unmarshal private key: %w", err)
+	}
+
+	if len(messages) == 0 {
+		return nil, errors.New("messages are not defined")
+	}
+
+	return bbs.SignWithKey(messages, privKey)
+}
+
+// SignWithKey signs the one or more messages using BBS+ key pair.
+func (bbs *BBSG2Pub) SignWithKey(messages [][]byte, privKey *PrivateKey) ([]byte, error) {
+	var err error
+
+	pubKey := privKey.PublicKey()
+
+	messagesFr := make([]*SignatureMessage, len(messages))
+	for i := range messages {
+		messagesFr[i], err = ParseSignatureMessage(messages[i])
+		if err != nil {
+			return nil, fmt.Errorf("parse signature message %d: %w", i+1, err)
+		}
+	}
+
+	e, err := bls.RandFR(rand.Reader)
+	if err != nil {
+		return nil, fmt.Errorf("create signature.E: %w", err)
+	}
+
+	s, err := bls.RandFR(rand.Reader)
+	if err != nil {
+		return nil, fmt.Errorf("create signature.S: %w", err)
+	}
+
+	b, err := computeB(s, messagesFr, pubKey)
+	if err != nil {
+		return nil, fmt.Errorf("compute B point: %w", err)
+	}
+
+	exp := privKey.GetFRElement().Copy()
+	exp.AddAssign(e)
+	sig := b.MulFR(exp.Inverse().ToRepr())
+
+	signature := &Signature{
+		Signature: g2pubs.NewSignatureFromG1(sig.ToAffine()),
+		E:         e,
+		S:         s,
+	}
+
+	return signature.ToBytes()
+}
+
+func computeB(s *bls.FR, messages []*SignatureMessage, key *PublicKey) (*bls.G1Projective, error) {
 	const basesOffset = 2
 
 	messagesCount := len(messages)
@@ -139,9 +200,18 @@ func getB(s *bls.FR, messages []*SignatureMessage, key *PublicKey) (*bls.G1Affin
 		res = res.Add(g)
 	}
 
-	res.NegAssign()
+	return res, nil
+}
+
+func getB(s *bls.FR, messages []*SignatureMessage, key *PublicKey) (*bls.G1Affine, error) {
+	b, err := computeB(s, messages, key)
+	if err != nil {
+		return nil, err
+	}
+
+	b.NegAssign()
 
-	return res.ToAffine(), nil
+	return b.ToAffine(), nil
 }
 
 func calcData(key *PublicKey, messagesCount int) []byte {
@@ -215,16 +285,3 @@ func compareTwoPairings(p1 *bls.G1Projective, q1 *bls.G2Projective, p2 *bls.G1Pr
 
 	return engine.Check()
 }
-
-func parseFr(data []byte) (*bls.FR, error) {
-	var arr [32]byte
-
-	copy(arr[:], data)
-
-	fr := bls.FRReprToFR(bls.FRReprFromBytes(arr))
-	if fr == nil {
-		return nil, errors.New("invalid FR")
-	}
-
-	return fr, nil
-}

pkg/doc/bbs/bbs12381g2pub/bbs_test.go

@@ -74,3 +74,56 @@ func TestBlsG2Pub_Verify(t *testing.T) {
 		require.Contains(t, err.Error(), "parse signature: deserialize G1 compressed signature")
 	})
 }
+
+func TestBBSG2Pub_SignWithKeyPair(t *testing.T) {
+	pubKey, privKey, err := generateKeyPairRandom()
+	require.NoError(t, err)
+
+	bls := bbs12381g2pub.New()
+
+	messagesBytes := [][]byte{[]byte("message1"), []byte("message2")}
+
+	signatureBytes, err := bls.SignWithKey(messagesBytes, privKey)
+	require.NoError(t, err)
+	require.NotEmpty(t, signatureBytes)
+	require.Len(t, signatureBytes, 112)
+
+	pubKeyBytes, err := pubKey.Marshal()
+	require.NoError(t, err)
+
+	require.NoError(t, bls.Verify(messagesBytes, signatureBytes, pubKeyBytes))
+}
+
+func TestBBSG2Pub_Sign(t *testing.T) {
+	pubKey, privKey, err := generateKeyPairRandom()
+	require.NoError(t, err)
+
+	bls := bbs12381g2pub.New()
+
+	messagesBytes := [][]byte{[]byte("message1"), []byte("message2")}
+
+	privKeyBytes, err := privKey.Marshal()
+	require.NoError(t, err)
+
+	signatureBytes, err := bls.Sign(messagesBytes, privKeyBytes)
+	require.NoError(t, err)
+	require.NotEmpty(t, signatureBytes)
+	require.Len(t, signatureBytes, 112)
+
+	pubKeyBytes, err := pubKey.Marshal()
+	require.NoError(t, err)
+
+	require.NoError(t, bls.Verify(messagesBytes, signatureBytes, pubKeyBytes))
+
+	// invalid private key bytes
+	signatureBytes, err = bls.Sign(messagesBytes, []byte("invalid"))
+	require.Error(t, err)
+	require.EqualError(t, err, "unmarshal private key: invalid size of private key")
+	require.Nil(t, signatureBytes)
+
+	// at least one message must be passed
+	signatureBytes, err = bls.Sign([][]byte{}, privKeyBytes)
+	require.Error(t, err)
+	require.EqualError(t, err, "messages are not defined")
+	require.Nil(t, signatureBytes)
+}

pkg/doc/bbs/bbs12381g2pub/fr.go

@@ -0,0 +1,72 @@
+/*
+Copyright SecureKey Technologies Inc. All Rights Reserved.
+
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package bbs12381g2pub
+
+import (
+	"errors"
+
+	"github.com/phoreproject/bls"
+	"golang.org/x/crypto/blake2b"
+)
+
+func frFromOKM(message []byte) (*bls.FR, error) {
+	const (
+		eightBytes = 8
+		okmMiddle  = 24
+	)
+
+	// We pass a null key so error is impossible here.
+	h, _ := blake2b.New384(nil) //nolint:errcheck
+
+	// blake2b.digest() does not return an error.
+	_, _ = h.Write(message) //nolint:errcheck
+	okm := h.Sum(nil)
+	emptyEightBytes := make([]byte, eightBytes)
+
+	elm, err := parseFr(append(emptyEightBytes, okm[:okmMiddle]...))
+	if err != nil {
+		return nil, err
+	}
+
+	elm.MulAssign(f2192())
+
+	fr, err := parseFr(append(emptyEightBytes, okm[okmMiddle:]...))
+	if err != nil {
+		return nil, err
+	}
+
+	elm.AddAssign(fr)
+
+	return elm, nil
+}
+
+func parseFr(data []byte) (*bls.FR, error) {
+	var arr [frCompressedSize]byte
+
+	copy(arr[:], data)
+
+	fr := bls.FRReprToFR(bls.FRReprFromBytes(arr))
+	if fr == nil {
+		return nil, errors.New("invalid FR")
+	}
+
+	return fr, nil
+}
+
+func frToBytes(fr *bls.FR) []byte {
+	bytes := fr.ToRepr().Bytes()
+	return bytes[:]
+}
+
+func f2192() *bls.FR {
+	return bls.NewFr(&bls.FRRepr{
+		0x59476ebc41b4528f,
+		0xc5a30cb243fcc152,
+		0x2b34e63940ccbd72,
+		0x1e179025ca247088,
+	})
+}