// HandleSignRequest is a handler for incoming sign-requests. It's registered as
// a handler in the sda.Node.
func (p *Protocol) HandleSignRequest(msg structMessage) error {
p.Message = msg.Msg
p.verifySignature = msg.VerifySignature
signature, err := crypto.SignSchnorr(network.Suite, p.Private(), p.Message)
if err != nil {
return err
}
// fill our own signature
p.signature = &SignatureReply{
Sig: signature,
Index: p.TreeNode().ServerIdentityIdx}
if !p.IsLeaf() {
for _, c := range p.Children() {
err := p.SendTo(c, &msg.Message)
if err != nil {
return err
}
}
} else {
err := p.SendTo(p.Parent(), &SignatureBundle{ChildSig: p.signature})
p.Done()
return err
}
return nil
}
// computeBlockSignature compute the signature out of the block.
func (nt *Ntree) computeBlockSignature() {
// wait the end of verification of the block
ok := <-nt.verifyBlockChan
//marshal the blck
marshalled, err := json.Marshal(nt.block)
if err != nil {
log.Error(err)
return
}
// if stg is wrong, we put exceptions
if !ok {
nt.tempBlockSig.Exceptions = append(nt.tempBlockSig.Exceptions, Exception{nt.TreeNode().ID})
} else { // we put signature
schnorr, _ := crypto.SignSchnorr(nt.Suite(), nt.Private(), marshalled)
nt.tempBlockSig.Sigs = append(nt.tempBlockSig.Sigs, schnorr)
}
log.Lvl3(nt.Name(), "Block Signature Computed")
}
// computeSignatureResponse will compute the response out of the signature
// request. It's the final signature.
func (nt *Ntree) computeSignatureResponse() {
// wait for the verification to be done
ok := <-nt.verifySignatureRequestChan
if !ok {
nt.tempSignatureResponse.Exceptions = append(nt.tempSignatureResponse.Exceptions, Exception{nt.TreeNode().ID})
} else {
// compute the message out of the previous signature
// marshal only the header here (so signature between the two phases are
// garanteed to be different)
marshalled, err := json.Marshal(nt.block.Header)
if err != nil {
log.Error(err)
return
}
sig, err := crypto.SignSchnorr(nt.Suite(), nt.Private(), marshalled)
if err != nil {
return
}
nt.tempSignatureResponse.Sigs = append(nt.tempSignatureResponse.Sigs, sig)
}
}