add dpos consensus

[bytom/vapor.git] / blockchain / txbuilder / signature_witness.go

diff --git a/blockchain/txbuilder/signature_witness.go b/blockchain/txbuilder/signature_witness.go
index ff6674a..576d095 100644 (file)
--- a/blockchain/txbuilder/signature_witness.go
+++ b/blockchain/txbuilder/signature_witness.go
@@ -99,7 +99,56 @@ func (sw *SignatureWitness) sign(ctx context.Context, tpl *Template, index uint3
        return nil
 }
 
-func (sw SignatureWitness) materialize(args *[][]byte) error {
+func (sw *SignatureWitness) Sign(tpl *Template, index uint32, xprv chainkd.XPrv) error {
+       // Compute the predicate to sign. This is either a
+       // txsighash program if tpl.AllowAdditional is false (i.e., the tx is complete
+       // and no further changes are allowed) or a program enforcing
+       // constraints derived from the existing outputs and current input.
+       if len(sw.Program) == 0 {
+               var err error
+               sw.Program, err = buildSigProgram(tpl, tpl.SigningInstructions[index].Position)
+               if err != nil {
+                       return err
+               }
+               if len(sw.Program) == 0 {
+                       return ErrEmptyProgram
+               }
+       }
+       if len(sw.Sigs) < len(sw.Keys) {
+               // Each key in sw.Keys may produce a signature in sw.Sigs. Make
+               // sure there are enough slots in sw.Sigs and that we preserve any
+               // sigs already present.
+               newSigs := make([]chainjson.HexBytes, len(sw.Keys))
+               copy(newSigs, sw.Sigs)
+               sw.Sigs = newSigs
+       }
+       var h [32]byte
+       sha3pool.Sum256(h[:], sw.Program)
+       for i, keyID := range sw.Keys {
+               if len(sw.Sigs[i]) > 0 {
+                       // Already have a signature for this key
+                       continue
+               }
+               path := make([][]byte, len(keyID.DerivationPath))
+               for i, p := range keyID.DerivationPath {
+                       path[i] = p
+               }
+               if keyID.XPub.String() != xprv.XPub().String() {
+                       continue
+               }
+
+               sigBytes := xprv.Sign(h[:])
+
+               // This break is ordered to avoid signing transaction successfully only once for a multiple-sign account
+               // that consist of different keys by the same password. Exit immediately when the signature is success,
+               // it means that only one signature will be successful in the loop for this multiple-sign account.
+               sw.Sigs[i] = sigBytes
+               break
+       }
+       return nil
+}
+
+func (sw SignatureWitness) Materialize(args *[][]byte) error {
        // This is the value of N for the CHECKPREDICATE call. The code
        // assumes that everything already in the arg list before this call
        // to Materialize is input to the signature program, so N is