github.com/annchain/OG@v0.0.9/poc/dkg/dkg.go (about)

     1  // Copyright © 2019 Annchain Authors <EMAIL ADDRESS>
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  package dkg
    15  
    16  import (
    17  	"errors"
    18  	"fmt"
    19  	"github.com/annchain/kyber/v3"
    20  	"github.com/annchain/kyber/v3/pairing/bn256"
    21  	"github.com/annchain/kyber/v3/share"
    22  	"github.com/annchain/kyber/v3/share/dkg/pedersen"
    23  	"github.com/annchain/kyber/v3/sign/bls"
    24  	"github.com/annchain/kyber/v3/sign/tbls"
    25  )
    26  
    27  type Partner struct {
    28  	ID                    int
    29  	PartPubs              []kyber.Point
    30  	MyPartSec             kyber.Scalar
    31  	SecretKeyContribution []kyber.Scalar
    32  	Suite                 *bn256.Suite
    33  	Dkger                 *dkg.DistKeyGenerator
    34  	Resps                 []*dkg.Response
    35  	Threshold             int
    36  	NbParticipants        int
    37  	SigShares             [][]byte
    38  }
    39  
    40  func (p *Partner) GenerateDKGer() *dkg.DistKeyGenerator {
    41  	// use all partPubs and my partSec to generate a dkg
    42  	dkger, err := dkg.NewDistKeyGenerator(p.Suite, p.MyPartSec, p.PartPubs, p.Threshold)
    43  	if err != nil {
    44  		panic(err)
    45  	}
    46  	p.Dkger = dkger
    47  	return dkger
    48  }
    49  
    50  func (p *Partner) VerifyByPubPoly(msg []byte, sig []byte) (err error) {
    51  	dks, err := p.Dkger.DistKeyShare()
    52  	if err != nil {
    53  		return
    54  	}
    55  	pubPoly := share.NewPubPoly(p.Suite, p.Suite.Point().Base(), dks.Commitments())
    56  	if pubPoly.Commit() != dks.Public() {
    57  		err = errors.New("PubPoly not aligned to dksPublic")
    58  		return
    59  	}
    60  
    61  	err = bls.Verify(p.Suite, pubPoly.Commit(), msg, sig)
    62  	fmt.Printf("ID [%d] pubPolyCommit [%s] dksPublic [%s] dksCommitments [%s]\n",
    63  		p.ID, pubPoly.Commit(), dks.Public(), dks.Commitments())
    64  	return
    65  }
    66  
    67  func (p *Partner) VerifyByDksPublic(msg []byte, sig []byte) (err error) {
    68  	dks, err := p.Dkger.DistKeyShare()
    69  	if err != nil {
    70  		return
    71  	}
    72  	err = bls.Verify(p.Suite, dks.Public(), msg, sig)
    73  	return
    74  }
    75  
    76  func (p *Partner) RecoverSig(msg []byte) (jointSig []byte, err error) {
    77  	dks, err := p.Dkger.DistKeyShare()
    78  	pubPoly := share.NewPubPoly(p.Suite, p.Suite.Point().Base(), dks.Commitments())
    79  	jointSig, err = tbls.Recover(p.Suite, pubPoly, msg, p.SigShares, p.Threshold, p.NbParticipants)
    80  	return
    81  }
    82  
    83  func (p *Partner) RecoverPub() (jointPubKey kyber.Point, err error) {
    84  	dks, err := p.Dkger.DistKeyShare()
    85  	if err != nil {
    86  		return
    87  	}
    88  	pubPoly := share.NewPubPoly(p.Suite, p.Suite.Point().Base(), dks.Commitments())
    89  	jointPubKey = pubPoly.Commit()
    90  	return
    91  }
    92  
    93  func (p *Partner) Sig(msg []byte) (partSig []byte, err error) {
    94  	dks, err := p.Dkger.DistKeyShare()
    95  	if err != nil {
    96  		return
    97  	}
    98  	partSig, err = tbls.Sign(p.Suite, dks.PriShare(), msg)
    99  	return
   100  }