// createCoinbaseTx returns a coinbase transaction paying an appropriate subsidy
// based on the passed block height to the provided address. When the address
// is nil, the coinbase transaction will instead be redeemable by anyone.
//
// See the comment for NewBlockTemplate for more information about why the nil
// address handling is useful.
func createCoinbaseTx(coinbaseScript []byte, nextBlockHeight int64, addr btcutil.Address) (*btcutil.Tx, error) {
// Create the script to pay to the provided payment address if one was
// specified. Otherwise create a script that allows the coinbase to be
// redeemable by anyone.
var pkScript []byte
if addr != nil {
var err error
pkScript, err = txscript.PayToAddrScript(addr)
if err != nil {
return nil, err
}
} else {
var err error
scriptBuilder := txscript.NewScriptBuilder()
pkScript, err = scriptBuilder.AddOp(txscript.OP_TRUE).Script()
if err != nil {
return nil, err
}
}
tx := btcwire.NewMsgTx()
tx.AddTxIn(&btcwire.TxIn{
// Coinbase transactions have no inputs, so previous outpoint is
// zero hash and max index.
PreviousOutPoint: *btcwire.NewOutPoint(&btcwire.ShaHash{},
btcwire.MaxPrevOutIndex),
SignatureScript: coinbaseScript,
Sequence: btcwire.MaxTxInSequenceNum,
})
tx.AddTxOut(&btcwire.TxOut{
Value: blockchain.CalcBlockSubsidy(nextBlockHeight,
activeNetParams.Params),
PkScript: pkScript,
})
return btcutil.NewTx(tx), nil
}
// TestCheckSerializedHeight tests the checkSerializedHeight function with
// various serialized heights and also does negative tests to ensure errors
// and handled properly.
func TestCheckSerializedHeight(t *testing.T) {
// Create an empty coinbase template to be used in the tests below.
coinbaseOutpoint := btcwire.NewOutPoint(&btcwire.ShaHash{}, math.MaxUint32)
coinbaseTx := btcwire.NewMsgTx()
coinbaseTx.Version = 2
coinbaseTx.AddTxIn(btcwire.NewTxIn(coinbaseOutpoint, nil))
// Expected rule errors.
missingHeightError := blockchain.RuleError{
ErrorCode: blockchain.ErrMissingCoinbaseHeight,
}
badHeightError := blockchain.RuleError{
ErrorCode: blockchain.ErrBadCoinbaseHeight,
}
tests := []struct {
sigScript []byte // Serialized data
wantHeight int64 // Expected height
err error // Expected error type
}{
// No serialized height length.
{[]byte{}, 0, missingHeightError},
// Serialized height length with no height bytes.
{[]byte{0x02}, 0, missingHeightError},
// Serialized height length with too few height bytes.
{[]byte{0x02, 0x4a}, 0, missingHeightError},
// Serialized height that needs 2 bytes to encode.
{[]byte{0x02, 0x4a, 0x52}, 21066, nil},
// Serialized height that needs 2 bytes to encode, but backwards
// endianness.
{[]byte{0x02, 0x4a, 0x52}, 19026, badHeightError},
// Serialized height that needs 3 bytes to encode.
{[]byte{0x03, 0x40, 0x0d, 0x03}, 200000, nil},
// Serialized height that needs 3 bytes to encode, but backwards
// endianness.
{[]byte{0x03, 0x40, 0x0d, 0x03}, 1074594560, badHeightError},
}
t.Logf("Running %d tests", len(tests))
for i, test := range tests {
msgTx := coinbaseTx.Copy()
msgTx.TxIn[0].SignatureScript = test.sigScript
tx := btcutil.NewTx(msgTx)
err := blockchain.TstCheckSerializedHeight(tx, test.wantHeight)
if reflect.TypeOf(err) != reflect.TypeOf(test.err) {
t.Errorf("checkSerializedHeight #%d wrong error type "+
"got: %v <%T>, want: %T", i, err, err, test.err)
continue
}
if rerr, ok := err.(blockchain.RuleError); ok {
trerr := test.err.(blockchain.RuleError)
if rerr.ErrorCode != trerr.ErrorCode {
t.Errorf("checkSerializedHeight #%d wrong "+
"error code got: %v, want: %v", i,
rerr.ErrorCode, trerr.ErrorCode)
continue
}
}
}
}
