// Check if Tx is standard.
func (t *Tx) IsStandard(blockHeight uint32, blockTime uint32) error {
if t.Version > numbers.TxCurrentVersion || t.Version < 1 {
return errBadVersion
}
if !t.IsFinal(blockHeight, blockTime) {
return errNotFinal
}
// Uses ">=" to follow the Satoshi client
if t.ByteSize() >= numbers.MaxStandardTxSize {
return errStdSizeLimit
}
for _, txin := range t.TxIns {
s := script.Script(txin.SigScript)
if len(s) > numbers.MaxSigScriptSize {
return errSigScriptSizeLimit
}
if !s.IsPushOnly() {
return errSigScriptNotPushOnly
}
if !s.PushesCanonical() {
return errNonCanonicalPush
}
}
dataOut := 0
for _, txout := range t.TxOuts {
sType := script.Script(txout.PKScript).PKScriptType()
if sType == script.PKS_NonStandard {
return errNonStandardPKScript
} else if sType == script.PKS_NullData {
dataOut++
} else if txout.IsDust() {
return errDustTxOut
}
}
if dataOut > 1 {
return errMoreThanOneReturn
}
return nil
}
// Check inputs and the "script" of pay-to-script-hash
func (t *Tx) InputsStandard(utxos UTXOs) bool {
if t.IsCoinBase() {
return true
}
for _, txi := range t.TxIns {
txo := utxos.GetTxOut(&txi.PreviousOutput)
pkScript := script.Script(txo.PKScript)
ttype := pkScript.PKScriptType()
ok, argCount := pkScript.SigArgsExpected(ttype)
if !ok {
return false
}
err, result := script.RunSigScript(txi.SigScript)
if err != nil {
return false
}
if ttype == script.PKS_ScriptHash {
if len(result) == 0 {
return false
}
pkScript := script.Script(result[len(result)-1])
ttype := pkScript.PKScriptType()
if ttype == script.PKS_ScriptHash {
return false // Recursive P2SH
}
ok, count := pkScript.SigArgsExpected(ttype)
if !ok {
return false
}
argCount += count
}
if len(result) != argCount {
return false
}
}
return true
}
func encodeTxo(txo *catma.TxOut) ([]byte, error) {
s := script.Script(txo.PKScript)
if s.IsTypePubKeyHash() {
ret := make([]byte, 20+1+8)
ret[0] = byte(script.PKS_PubKeyHash)
binary.LittleEndian.PutUint64(ret[1:], uint64(txo.Value))
copy(ret[9:], txo.PKScript[3:23])
return ret, nil
} else if s.IsTypeScriptHash() {
ret := make([]byte, 20+1+8)
ret[0] = byte(script.PKS_ScriptHash)
binary.LittleEndian.PutUint64(ret[1:], uint64(txo.Value))
copy(ret[9:], txo.PKScript[2:22])
return ret, nil
} else {
ret := make([]byte, len(txo.PKScript)+1+8)
ret[0] = 0
binary.LittleEndian.PutUint64(ret[len(txo.PKScript)+1:], uint64(txo.Value))
copy(ret[9:], txo.PKScript)
return ret, nil
}
}