1 files changed, 92 insertions, 0 deletions
diff --git a/vendor/github.com/tangerine-network/tangerine-consensus/core/crypto/dkg/utils.go b/vendor/github.com/tangerine-network/tangerine-consensus/core/crypto/dkg/utils.go
new file mode 100644
index 000000000..295658291
--- /dev/null
+++ b/vendor/github.com/tangerine-network/tangerine-consensus/core/crypto/dkg/utils.go
@@ -0,0 +1,92 @@
+// Copyright 2018 The dexon-consensus Authors
+// This file is part of the dexon-consensus library.
+//
+// The dexon-consensus 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 dexon-consensus 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 dexon-consensus library. If not, see
+// <http://www.gnu.org/licenses/>.
+
+package dkg
+
+import (
+	"encoding/binary"
+	"fmt"
+	"math/rand"
+
+	"github.com/tangerine-network/bls/ffi/go/bls"
+
+	"github.com/tangerine-network/tangerine-consensus/core/crypto"
+)
+
+// PartialSignature is a partial signature in DKG+TSIG protocol.
+type PartialSignature crypto.Signature
+
+var (
+	// ErrEmptySignature is reported if the signature is empty.
+	ErrEmptySignature = fmt.Errorf("invalid empty signature")
+)
+
+// RecoverSignature recovers TSIG signature.
+func RecoverSignature(sigs []PartialSignature, signerIDs IDs) (
+	crypto.Signature, error) {
+	blsSigs := make([]bls.Sign, len(sigs))
+	for i, sig := range sigs {
+		if len(sig.Signature) == 0 {
+			return crypto.Signature{}, ErrEmptySignature
+		}
+		if err := blsSigs[i].Deserialize([]byte(sig.Signature)); err != nil {
+			return crypto.Signature{}, err
+		}
+	}
+	var recoverSig bls.Sign
+	if err := recoverSig.Recover(blsSigs, []bls.ID(signerIDs)); err != nil {
+		return crypto.Signature{}, err
+	}
+	return crypto.Signature{
+		Type:      cryptoType,
+		Signature: recoverSig.Serialize()}, nil
+}
+
+// RecoverGroupPublicKey recovers group public key.
+func RecoverGroupPublicKey(pubShares []*PublicKeyShares) *PublicKey {
+	var pub *PublicKey
+	for _, pubShare := range pubShares {
+		pk0 := pubShare.masterPublicKey[0]
+		if pub == nil {
+			pub = &PublicKey{
+				publicKey: pk0,
+			}
+		} else {
+			pub.publicKey.Add(&pk0)
+		}
+	}
+	return pub
+}
+
+// NewRandomPrivateKeyShares constructs a private key shares randomly.
+func NewRandomPrivateKeyShares() *PrivateKeyShares {
+	// Generate IDs.
+	rndIDs := make(IDs, 0, 10)
+	for i := range rndIDs {
+		id := make([]byte, 8)
+		binary.LittleEndian.PutUint64(id, rand.Uint64())
+		rndIDs[i] = NewID(id)
+	}
+	prvShares := NewEmptyPrivateKeyShares()
+	prvShares.SetParticipants(rndIDs)
+	for _, id := range rndIDs {
+		if err := prvShares.AddShare(id, NewPrivateKey()); err != nil {
+			panic(err)
+		}
+	}
+	return prvShares
+}