func (p *Protocol) verifySignatureReply(sig *SignatureReply) string {
if sig.Index >= len(p.Roster().List) {
log.Error("Index in signature reply out of range")
return "FAIL"
}
entity := p.Roster().List[sig.Index]
var s string
if err := crypto.VerifySchnorr(p.Suite(), entity.Public, p.Message, sig.Sig); err != nil {
s = "FAIL"
} else {
s = "SUCCESS"
}
return s
}
func verifySchnorr(suite abstract.Suite, key abstract.Point, m interface{}) error {
// Make a copy of the signature
x := reflect.ValueOf(m).Elem().FieldByName("Sig")
sig := reflect.New(x.Type()).Elem()
sig.Set(x)
// Reset signature field
reflect.ValueOf(m).Elem().FieldByName("Sig").Set(reflect.ValueOf(crypto.SchnorrSig{})) // XXX: hack
// Marshal message
mb, err := network.MarshalRegisteredType(m)
if err != nil {
return err
}
// Copy back original signature
reflect.ValueOf(m).Elem().FieldByName("Sig").Set(sig) // XXX: hack
return crypto.VerifySchnorr(suite, key, mb, sig.Interface().(crypto.SchnorrSig))
}
// Go routine that will do the verification of the signature request in
// parrallele
func (nt *Ntree) verifySignatureRequest(msg *RoundSignatureRequest) {
// verification if we have too much exceptions
threshold := int(math.Ceil(float64(len(nt.Tree().List())) / 3.0))
if len(msg.Exceptions) > threshold {
nt.verifySignatureRequestChan <- false
}
// verification of all the signatures
var goodSig int
marshalled, _ := json.Marshal(nt.block)
for _, sig := range msg.Sigs {
if err := crypto.VerifySchnorr(nt.Suite(), nt.Public(), marshalled, sig); err == nil {
goodSig++
}
}
log.Lvl3(nt.Name(), "Verification of signatures =>", goodSig, "/", len(msg.Sigs), ")")
// enough good signatures ?
if goodSig <= 2*threshold {
nt.verifySignatureRequestChan <- false
}
nt.verifySignatureRequestChan <- true
}
// ProposeVote takes int account a vote for the proposed config. It also verifies
// that the voter is in the latest config.
// An empty signature signifies that the vote has been rejected.
func (s *Service) ProposeVote(v *ProposeVote) (network.Body, onet.ClientError) {
log.Lvl2(s, "Voting on proposal")
// First verify if the signature is legitimate
sid := s.getIdentityStorage(v.ID)
if sid == nil {
return nil, onet.NewClientErrorCode(ErrorBlockMissing, "Didn't find identity")
}
// Putting this in a function because of the lock which needs to be held
// over all calls that might return an error.
cerr := func() onet.ClientError {
sid.Lock()
defer sid.Unlock()
log.Lvl3("Voting on", sid.Proposed.Device)
owner, ok := sid.Latest.Device[v.Signer]
if !ok {
return onet.NewClientErrorCode(ErrorAccountMissing, "Didn't find signer")
}
if sid.Proposed == nil {
return onet.NewClientErrorCode(ErrorConfigMissing, "No proposed block")
}
hash, err := sid.Proposed.Hash()
if err != nil {
return onet.NewClientErrorCode(ErrorOnet, "Couldn't get hash")
}
if _, exists := sid.Votes[v.Signer]; exists {
return onet.NewClientErrorCode(ErrorVoteDouble, "Already voted for that block")
}
log.Lvl3(v.Signer, "voted", v.Signature)
if v.Signature != nil {
err = crypto.VerifySchnorr(network.Suite, owner.Point, hash, *v.Signature)
if err != nil {
return onet.NewClientErrorCode(ErrorVoteSignature, "Wrong signature: "+err.Error())
}
}
return nil
}()
if cerr != nil {
return nil, cerr
}
// Propagate the vote
_, err := s.propagateConfig(sid.Root.Roster, v, propagateTimeout)
if err != nil {
return nil, onet.NewClientErrorCode(ErrorOnet, cerr.Error())
}
if len(sid.Votes) >= sid.Latest.Threshold ||
len(sid.Votes) == len(sid.Latest.Device) {
// If we have enough signatures, make a new data-skipblock and
// propagate it
log.Lvl3("Having majority or all votes")
// Making a new data-skipblock
log.Lvl3("Sending data-block with", sid.Proposed.Device)
reply, cerr := s.skipchain.ProposeData(sid.Root, sid.Data, sid.Proposed)
if cerr != nil {
return nil, cerr
}
_, msg, _ := network.UnmarshalRegistered(reply.Latest.Data)
log.Lvl3("SB signed is", msg.(*Config).Device)
usb := &UpdateSkipBlock{
ID: v.ID,
Latest: reply.Latest,
}
_, err = s.propagateSkipBlock(sid.Root.Roster, usb, propagateTimeout)
if err != nil {
return nil, onet.NewClientErrorCode(ErrorOnet, cerr.Error())
}
s.save()
return &ProposeVoteReply{sid.Data}, nil
}
return nil, nil
}
