// // Copyright Coinbase, Inc. All Rights Reserved. // // SPDX-License-Identifier: Apache-2.0 // package main import ( "crypto/ecdsa" crand "crypto/rand" "crypto/sha512" "flag" "fmt" "math/big" "github.com/btcsuite/btcd/btcec" "source.quilibrium.com/quilibrium/monorepo/nekryptology/pkg/core/curves" dkg "source.quilibrium.com/quilibrium/monorepo/nekryptology/pkg/dkg/frost" "source.quilibrium.com/quilibrium/monorepo/nekryptology/pkg/sharing" ) const LIMIT = 4 const THRESHOLD = 2 const Ctx = "string to prevent replay attack" func main() { var threshold int var limit int var help bool flag.IntVar(&threshold, "t", THRESHOLD, "the minimum number of participants to sign") flag.IntVar(&threshold, "threshold", THRESHOLD, "the minimum number of participants to sign") flag.IntVar(&limit, "n", LIMIT, "the total number of participants") flag.IntVar(&limit, "limit", LIMIT, "the total number of participants") flag.BoolVar(&help, "h", false, "Print this menu") flag.BoolVar(&help, "help", false, "Print this menu") flag.Parse() if help { printHelp() return } fmt.Printf("Threshold is %d\n", threshold) fmt.Printf("Total participants is %d\n", limit) // DEMO doing FROST DKG and that signers can compute a signature participants := createDkgParticipants(threshold, limit) // DKG Round 1 rnd1Bcast, rnd1P2p := round1(participants) // DKG Round 2 verificationKey, signingShares := round2(participants, rnd1Bcast, rnd1P2p) // Signing common setup for all participants curve := curves.K256() msg := []byte("All my bitcoin is stored here") scheme, _ := sharing.NewShamir(uint32(threshold), uint32(limit), curve) shares := make([]*sharing.ShamirShare, 0, threshold) cnt := 0 for _, share := range signingShares { if cnt == threshold { break } cnt++ shares = append(shares, share) } sk, err := scheme.Combine(shares...) if err != nil { panic(err) } pk := curve.ScalarBaseMult(sk) if !pk.Equal(verificationKey) { panic("verification keys are not equal") } privKey, pubKey := btcec.PrivKeyFromBytes(btcec.S256(), sk.Bytes()) hBytes := sha512.Sum384(msg) hMsg := new(big.Int).SetBytes(hBytes[:]) hMsg.Mod(hMsg, btcec.S256().N) r, s, err := ecdsa.Sign(crand.Reader, privKey.ToECDSA(), hMsg.Bytes()) if err != nil { panic(err) } ok := ecdsa.Verify(pubKey.ToECDSA(), hMsg.Bytes(), r, s) fmt.Printf("Signature verification - %v\n", ok) } func round1(participants map[uint32]*dkg.DkgParticipant) (map[uint32]*dkg.Round1Bcast, map[uint32]dkg.Round1P2PSend) { // DKG Round 1 rnd1Bcast := make(map[uint32]*dkg.Round1Bcast, len(participants)) rnd1P2p := make(map[uint32]dkg.Round1P2PSend, len(participants)) for id, p := range participants { fmt.Printf("Computing DKG Round 1 for participant %d\n", id) bcast, p2psend, err := p.Round1(nil) if err != nil { panic(err) } rnd1Bcast[id] = bcast rnd1P2p[id] = p2psend } return rnd1Bcast, rnd1P2p } func round2(participants map[uint32]*dkg.DkgParticipant, rnd1Bcast map[uint32]*dkg.Round1Bcast, rnd1P2p map[uint32]dkg.Round1P2PSend, ) (curves.Point, map[uint32]*sharing.ShamirShare) { signingShares := make(map[uint32]*sharing.ShamirShare, len(participants)) var verificationKey curves.Point for id := range rnd1Bcast { fmt.Printf("Computing DKG Round 2 for participant %d\n", id) rnd1P2pForP := make(map[uint32]*sharing.ShamirShare) for jid := range rnd1P2p { if jid == id { continue } rnd1P2pForP[jid] = rnd1P2p[jid][id] } rnd2Out, err := participants[id].Round2(rnd1Bcast, rnd1P2pForP) if err != nil { panic(err) } verificationKey = rnd2Out.VerificationKey share := &sharing.ShamirShare{ Id: id, Value: participants[id].SkShare.Bytes(), } signingShares[id] = share } return verificationKey, signingShares } func createDkgParticipants(thresh, limit int) map[uint32]*dkg.DkgParticipant { curve := curves.K256() participants := make(map[uint32]*dkg.DkgParticipant, limit) for i := 1; i <= limit; i++ { otherIds := make([]uint32, limit-1) idx := 0 for j := 1; j <= limit; j++ { if i == j { continue } otherIds[idx] = uint32(j) idx++ } p, err := dkg.NewDkgParticipant(uint32(i), uint32(thresh), Ctx, curve, otherIds...) if err != nil { panic(err) } participants[uint32(i)] = p } return participants } func printHelp() { fmt.Printf(` bls INPUT Simulate a DKG using K256 keys FLAGS: -h, --help Show this help message and exit -n, --limit The total number of participants -t, --treshold The minimum number of participants needed to sign `) }