Make compatible for old parties with no facProof

ecdsa/keygen/local_party.go

@@ -137,6 +137,8 @@ func (p *LocalParty) StoreMessage(msg tss.ParsedMessage) (bool, *tss.Error) {
 		p.temp.kgRound1Messages[fromPIdx] = msg
 	case *KGRound2Message1:
 		p.temp.kgRound2Message1s[fromPIdx] = msg
+	case *KGRound2Message1NoProof:
+		p.temp.kgRound2Message1s[fromPIdx] = msg
 	case *KGRound2Message2:
 		p.temp.kgRound2Message2s[fromPIdx] = msg
 	case *KGRound3Message:

ecdsa/keygen/messages.go

@@ -26,6 +26,7 @@ var (
 	_ = []tss.MessageContent{
 		(*KGRound1Message)(nil),
 		(*KGRound2Message1)(nil),
+		(*KGRound2Message1NoProof)(nil),
 		(*KGRound2Message2)(nil),
 		(*KGRound3Message)(nil),
 	}
@@ -140,6 +141,31 @@ func (m *KGRound2Message1) UnmarshalFacProof() (*facproof.ProofFac, error) {
 	return facproof.NewProofFromBytes(m.GetFacProof())
 }
 
+func NewKGRound2Message1NoProof(
+	to, from *tss.PartyID,
+	share *vss.Share,
+) tss.ParsedMessage {
+	meta := tss.MessageRouting{
+		From:        from,
+		To:          []*tss.PartyID{to},
+		IsBroadcast: false,
+	}
+	content := &KGRound2Message1NoProof{
+		Share: share.Share.Bytes(),
+	}
+	msg := tss.NewMessageWrapper(meta, content)
+	return tss.NewMessage(meta, content, msg)
+}
+
+func (m *KGRound2Message1NoProof) ValidateBasic() bool {
+	return m != nil &&
+		common.NonEmptyBytes(m.GetShare())
+}
+
+func (m *KGRound2Message1NoProof) UnmarshalShare() *big.Int {
+	return new(big.Int).SetBytes(m.Share)
+}
+
 // ----- //
 
 func NewKGRound2Message2(

ecdsa/keygen/round_3.go

@@ -82,28 +82,45 @@ func (round *round3) Start() *tss.Error {
 				ch <- vssOut{err, nil}
 				return
 			}
-			r2msg1 := round.temp.kgRound2Message1s[j].Content().(*KGRound2Message1)
-			PjShare := vss.Share{
-				Threshold: round.Threshold(),
-				ID:        round.PartyID().KeyInt(),
-				Share:     r2msg1.UnmarshalShare(),
-			}
-			if ok = PjShare.Verify(round.Params().EC(), round.Threshold(), PjVs); !ok {
-				ch <- vssOut{errors.New("vss verify failed"), nil}
-				return
-			}
-			facProof, err := r2msg1.UnmarshalFacProof()
-			if err != nil {
-				ch <- vssOut{errors.New("facProof verify failed"), nil}
-				return
-			}
-			if ok = facProof.Verify(round.EC(), round.save.PaillierPKs[j].N, round.save.NTildei,
-				round.save.H1i, round.save.H2i); !ok {
-				ch <- vssOut{errors.New("facProof verify failed"), nil}
-				return
+			switch round.temp.kgRound2Message1s[j].Content().(type) {
+			case *KGRound2Message1NoProof:
+				r2msg1 := round.temp.kgRound2Message1s[j].Content().(*KGRound2Message1)
+				PjShare := vss.Share{
+					Threshold: round.Threshold(),
+					ID:        round.PartyID().KeyInt(),
+					Share:     r2msg1.UnmarshalShare(),
+				}
+				if ok = PjShare.Verify(round.Params().EC(), round.Threshold(), PjVs); !ok {
+					ch <- vssOut{errors.New("vss verify failed"), nil}
+					return
+				}
+				common.Logger.Fatalf("facProof not exist: %s", Ps[j])
+				// (9) handled above
+				ch <- vssOut{nil, PjVs}
+			case *KGRound2Message1:
+				r2msg1 := round.temp.kgRound2Message1s[j].Content().(*KGRound2Message1)
+				PjShare := vss.Share{
+					Threshold: round.Threshold(),
+					ID:        round.PartyID().KeyInt(),
+					Share:     r2msg1.UnmarshalShare(),
+				}
+				if ok = PjShare.Verify(round.Params().EC(), round.Threshold(), PjVs); !ok {
+					ch <- vssOut{errors.New("vss verify failed"), nil}
+					return
+				}
+				facProof, err := r2msg1.UnmarshalFacProof()
+				if err != nil {
+					ch <- vssOut{errors.New("facProof verify failed"), nil}
+					return
+				}
+				if ok = facProof.Verify(round.EC(), round.save.PaillierPKs[j].N, round.save.NTildei,
+					round.save.H1i, round.save.H2i); !ok {
+					ch <- vssOut{errors.New("facProof verify failed"), nil}
+					return
+				}
+				// (9) handled above
+				ch <- vssOut{nil, PjVs}
 			}
-			// (9) handled above
-			ch <- vssOut{nil, PjVs}
 		}(j, chs[j])
 	}
 

protob/ecdsa-keygen.proto

@@ -29,6 +29,10 @@ message KGRound2Message1 {
     repeated bytes facProof = 2;
 }
 
+message KGRound2Message1NoProof {
+    bytes share = 1;
+}
+
 /*
  * Represents a BROADCAST message sent to each party during Round 2 of the ECDSA TSS keygen protocol.
  */