// Verify a signature
func (client *GenericBlindingClient) Verify(csi genericblinding.ClearSignature, cmi genericblinding.ClearMessage) (bool, error) {
_, err := genericblinding.MatchMessage(csi, SchemeName, genericblinding.TypeClearSignature, client.PubKey)
if err != nil {
return false, err
}
cs, ok := csi.(ClearSignature)
if !ok {
return false, genericblinding.ErrBadType
}
_, err = genericblinding.MatchMessage(cmi, SchemeName, genericblinding.TypeClearMessage, client.PubKey)
if err != nil {
return false, err
}
cm, ok := cmi.(ClearMessage)
if !ok {
return false, genericblinding.ErrBadType
}
bc := NewBlindingClient(client.curve, client.PubKey)
signature := new(SignatureInt)
signature.PointR = &cs.PointR
signature.ScalarR = cs.ScalarR
signature.ScalarS = cs.ScalarS
return bc.Verify(cm.UniqueID(), signature), nil
}
// Unblind a signature
func (client *GenericBlindingClient) Unblind(bfi genericblinding.BlindingFactors, cmi genericblinding.ClearMessage, bsi genericblinding.BlindSignature) (genericblinding.ClearSignature, genericblinding.ClearMessage, error) {
_, err := genericblinding.MatchMessage(bfi, SchemeName, genericblinding.TypeBlindingFactors, client.PubKey)
if err != nil {
return nil, nil, err
}
bf, ok := bfi.(BlindingFactors)
if !ok {
return nil, nil, genericblinding.ErrBadType
}
_, err = genericblinding.MatchMessage(cmi, SchemeName, genericblinding.TypeClearMessage, client.PubKey)
if err != nil {
return nil, nil, err
}
cm, ok := cmi.(ClearMessage)
if !ok {
return nil, nil, genericblinding.ErrBadType
}
_, err = genericblinding.MatchMessage(bsi, SchemeName, genericblinding.TypeBlindSignature, client.PubKey)
if err != nil {
return nil, nil, err
}
bs, ok := bsi.(BlindSignature)
if !ok {
return nil, nil, genericblinding.ErrBadType
}
bc := NewBlindingClient(client.curve, client.PubKey)
blindSignature := new(BlindSignatureInt)
blindSignature.ScalarS1, blindSignature.ScalarS2 = bs.ScalarS1, bs.ScalarS2
blindingParams := new(BlindingParamsPrivateInt)
blindingParams.ScalarW, blindingParams.ScalarZ = bf.ScalarW, bf.ScalarZ
blindingParams.ScalarE, blindingParams.ScalarD = bf.ScalarE, bf.ScalarD
blindingParams.ScalarA, blindingParams.ScalarB = bf.ScalarA, bf.ScalarB
blindingParams.PointR1, blindingParams.PointR2 = &bf.PointR1, &bf.PointR2
blindingParams.ScalarR1, blindingParams.ScalarR2 = bf.ScalarR1, bf.ScalarR2
blindingParams.ScalarRs1, blindingParams.ScalarRs2 = bf.ScalarRs1, bf.ScalarRs2
signature, err := bc.Unblind(blindSignature, blindingParams)
if err != nil {
return nil, nil, err
}
sig := NewClearSignature(client.PubKey)
sig.PointR = *signature.PointR
sig.ScalarS = signature.ScalarS
sig.ScalarR = signature.ScalarR
return sig, cm, nil
}
// Blind a message
func (client *GenericBlindingClient) Blind(bpci genericblinding.BlindingParamClient, cmi genericblinding.ClearMessage) (genericblinding.BlindingFactors, genericblinding.BlindMessage, error) {
_, err := genericblinding.MatchMessage(bpci, SchemeName, genericblinding.TypeBlindingParamClient, client.PubKey)
if err != nil {
return nil, nil, err
}
bpc, ok := bpci.(BlindingParamClient)
if !ok {
return nil, nil, genericblinding.ErrBadType
}
_, err = genericblinding.MatchMessage(cmi, SchemeName, genericblinding.TypeClearMessage, client.PubKey)
if err != nil {
return nil, nil, err
}
cm, ok := cmi.(ClearMessage)
if !ok {
return nil, nil, genericblinding.ErrBadType
}
bc := NewBlindingClient(client.curve, client.PubKey)
serverParams := new(SignRequestPublicInt)
serverParams.PointRs1, serverParams.PointRs2 = &bpc.PointRs1, &bpc.PointRs2
serverParams.ScalarLs1, serverParams.ScalarLs2 = bpc.ScalarLs1, bpc.ScalarLs2
privateParams, err := bc.CalculateBlindingParams(serverParams)
if err != nil {
return nil, nil, err
}
blindmessage, err := bc.Blind(cm.UniqueID(), serverParams, privateParams)
if err != nil {
return nil, nil, err
}
bf := NewBlindingFactors(client.PubKey)
bf.ScalarW, bf.ScalarZ = privateParams.ScalarW, privateParams.ScalarZ
bf.ScalarE, bf.ScalarD = privateParams.ScalarE, privateParams.ScalarD
bf.ScalarA, bf.ScalarB = privateParams.ScalarA, privateParams.ScalarB
bf.PointR1, bf.PointR2 = *privateParams.PointR1, *privateParams.PointR2
bf.ScalarR1, bf.ScalarR2 = privateParams.ScalarR1, privateParams.ScalarR2
bf.ScalarRs1, bf.ScalarRs2 = privateParams.ScalarRs1, privateParams.ScalarRs2
bf.IsUsed = false
bm := NewBlindMessage(client.PubKey)
bm.M1, bm.M2 = blindmessage.M1, blindmessage.M2
return bf, bm, nil
}
// Sign a blind message
func (server *GenericBlindingServer) Sign(bpsi genericblinding.BlindingParamServer, bmi genericblinding.BlindMessage) (genericblinding.BlindSignature, error) {
_, err := genericblinding.MatchMessage(bpsi, SchemeName, genericblinding.TypeBlindingParamServer, server.pubkey)
if err != nil {
return nil, err
}
bps, ok := bpsi.(BlindingParamServer)
if !ok {
return nil, genericblinding.ErrBadType
}
_, err = genericblinding.MatchMessage(bmi, SchemeName, genericblinding.TypeBlindMessage, server.pubkey)
if err != nil {
return nil, err
}
bm, ok := bmi.(BlindMessage)
if !ok {
fmt.Println("Message")
return nil, genericblinding.ErrBadType
}
bs := NewSigner(server.privkey, server.pubkey, server.curve)
blindmessage := new(BlindMessageInt)
blindmessage.M1, blindmessage.M2 = bm.M1, bm.M2
privateParams := new(SignRequestPrivateInt)
privateParams.ScalarKs1, privateParams.ScalarKs2 = bps.ScalarKs1, bps.ScalarKs2
privateParams.PointRs1, privateParams.PointRs2 = &bps.PointRs1, &bps.PointRs2
privateParams.ScalarLs1, privateParams.ScalarLs2 = bps.ScalarLs1, bps.ScalarLs2
privateParams.ScalarRs1, privateParams.ScalarRs2 = bps.ScalarRs1, bps.ScalarRs2
signature, err := bs.Sign(blindmessage, privateParams)
if err != nil {
return nil, err
}
blindsig := NewBlindSignature(server.pubkey)
blindsig.ScalarS1, blindsig.ScalarS2 = signature.ScalarS1, signature.ScalarS2
return blindsig, nil
}