// getRedeemScript returns the redeem script for the given P2SH address. It must
// be called with the manager unlocked.
func getRedeemScript(mgr *waddrmgr.Manager, addr *btcutil.AddressScriptHash) ([]byte, error) {
address, err := mgr.Address(addr)
if err != nil {
return nil, err
}
return address.(waddrmgr.ManagedScriptAddress).Script()
}
// signMsgTx sets the SignatureScript for every item in msgtx.TxIn.
// It must be called every time a msgtx is changed.
// Only P2PKH outputs are supported at this point.
func signMsgTx(msgtx *wire.MsgTx, prevOutputs []wtxmgr.Credit, mgr *waddrmgr.Manager, chainParams *chaincfg.Params) error {
if len(prevOutputs) != len(msgtx.TxIn) {
return fmt.Errorf(
"Number of prevOutputs (%d) does not match number of tx inputs (%d)",
len(prevOutputs), len(msgtx.TxIn))
}
for i, output := range prevOutputs {
// Errors don't matter here, as we only consider the
// case where len(addrs) == 1.
_, addrs, _, _ := txscript.ExtractPkScriptAddrs(output.PkScript,
chainParams)
if len(addrs) != 1 {
continue
}
apkh, ok := addrs[0].(*btcutil.AddressPubKeyHash)
if !ok {
return ErrUnsupportedTransactionType
}
ai, err := mgr.Address(apkh)
if err != nil {
return fmt.Errorf("cannot get address info: %v", err)
}
pka := ai.(waddrmgr.ManagedPubKeyAddress)
privkey, err := pka.PrivKey()
if err != nil {
return fmt.Errorf("cannot get private key: %v", err)
}
sigscript, err := txscript.SignatureScript(msgtx, i,
output.PkScript, txscript.SigHashAll, privkey,
ai.Compressed())
if err != nil {
return fmt.Errorf("cannot create sigscript: %s", err)
}
msgtx.TxIn[i].SignatureScript = sigscript
}
return nil
}