Example #1
0
// TestHasCanonicalPush ensures the canonicalPush function works as expected.
func TestHasCanonicalPush(t *testing.T) {
	t.Parallel()

	for i := 0; i < 65535; i++ {
		builder := txscript.NewScriptBuilder()
		builder.AddInt64(int64(i))
		script, err := builder.Script()
		if err != nil {
			t.Errorf("Script: test #%d unexpected error: %v\n", i,
				err)
			continue
		}
		if result := txscript.IsPushOnlyScript(script); !result {
			t.Errorf("IsPushOnlyScript: test #%d failed: %x\n", i,
				script)
			continue
		}
		pops, err := txscript.TstParseScript(script)
		if err != nil {
			t.Errorf("TstParseScript: #%d failed: %v", i, err)
			continue
		}
		for _, pop := range pops {
			if result := txscript.TstHasCanonicalPushes(pop); !result {
				t.Errorf("TstHasCanonicalPushes: test #%d "+
					"failed: %x\n", i, script)
				break
			}
		}
	}
	for i := 0; i <= txscript.MaxScriptElementSize; i++ {
		builder := txscript.NewScriptBuilder()
		builder.AddData(bytes.Repeat([]byte{0x49}, i))
		script, err := builder.Script()
		if err != nil {
			t.Errorf("StandardPushesTests test #%d unexpected error: %v\n", i, err)
			continue
		}
		if result := txscript.IsPushOnlyScript(script); !result {
			t.Errorf("StandardPushesTests IsPushOnlyScript test #%d failed: %x\n", i, script)
			continue
		}
		pops, err := txscript.TstParseScript(script)
		if err != nil {
			t.Errorf("StandardPushesTests #%d failed to TstParseScript: %v", i, err)
			continue
		}
		for _, pop := range pops {
			if result := txscript.TstHasCanonicalPushes(pop); !result {
				t.Errorf("StandardPushesTests TstHasCanonicalPushes test #%d failed: %x\n", i, script)
				break
			}
		}
	}
}
Example #2
0
// TestIsPushOnlyScript ensures the IsPushOnlyScript function returns the
// expected results.
func TestIsPushOnlyScript(t *testing.T) {
	t.Parallel()

	test := struct {
		name     string
		script   []byte
		expected bool
	}{
		name: "does not parse",
		script: mustParseShortForm("0x046708afdb0fe5548271967f1a67130" +
			"b7105cd6a828e03909a67962e0ea1f61d"),
		expected: false,
	}

	if txscript.IsPushOnlyScript(test.script) != test.expected {
		t.Errorf("IsPushOnlyScript (%s) wrong result\ngot: %v\nwant: "+
			"%v", test.name, true, test.expected)
	}
}
Example #3
0
// checkTransactionStandard performs a series of checks on a transaction to
// ensure it is a "standard" transaction.  A standard transaction is one that
// conforms to several additional limiting cases over what is considered a
// "sane" transaction such as having a version in the supported range, being
// finalized, conforming to more stringent size constraints, having scripts
// of recognized forms, and not containing "dust" outputs (those that are
// so small it costs more to process them than they are worth).
func checkTransactionStandard(tx *coinutil.Tx, height int32, timeSource blockchain.MedianTimeSource, minRelayTxFee coinutil.Amount) error {
	// The transaction must be a currently supported version.
	msgTx := tx.MsgTx()
	if msgTx.Version > wire.TxVersion || msgTx.Version < 1 {
		str := fmt.Sprintf("transaction version %d is not in the "+
			"valid range of %d-%d", msgTx.Version, 1,
			wire.TxVersion)
		return txRuleError(wire.RejectNonstandard, str)
	}

	// The transaction must be finalized to be standard and therefore
	// considered for inclusion in a block.
	adjustedTime := timeSource.AdjustedTime()
	if !blockchain.IsFinalizedTransaction(tx, height, adjustedTime) {
		return txRuleError(wire.RejectNonstandard,
			"transaction is not finalized")
	}

	// Since extremely large transactions with a lot of inputs can cost
	// almost as much to process as the sender fees, limit the maximum
	// size of a transaction.  This also helps mitigate CPU exhaustion
	// attacks.
	serializedLen := msgTx.SerializeSize()
	if serializedLen > maxStandardTxSize {
		str := fmt.Sprintf("transaction size of %v is larger than max "+
			"allowed size of %v", serializedLen, maxStandardTxSize)
		return txRuleError(wire.RejectNonstandard, str)
	}

	for i, txIn := range msgTx.TxIn {
		// Each transaction input signature script must not exceed the
		// maximum size allowed for a standard transaction.  See
		// the comment on maxStandardSigScriptSize for more details.
		sigScriptLen := len(txIn.SignatureScript)
		if sigScriptLen > maxStandardSigScriptSize {
			str := fmt.Sprintf("transaction input %d: signature "+
				"script size of %d bytes is large than max "+
				"allowed size of %d bytes", i, sigScriptLen,
				maxStandardSigScriptSize)
			return txRuleError(wire.RejectNonstandard, str)
		}

		// Each transaction input signature script must only contain
		// opcodes which push data onto the stack.
		if !txscript.IsPushOnlyScript(txIn.SignatureScript) {
			str := fmt.Sprintf("transaction input %d: signature "+
				"script is not push only", i)
			return txRuleError(wire.RejectNonstandard, str)
		}
	}

	// None of the output public key scripts can be a non-standard script or
	// be "dust" (except when the script is a null data script).
	numNullDataOutputs := 0
	for i, txOut := range msgTx.TxOut {
		scriptClass := txscript.GetScriptClass(txOut.PkScript)
		err := checkPkScriptStandard(txOut.PkScript, scriptClass)
		if err != nil {
			// Attempt to extract a reject code from the error so
			// it can be retained.  When not possible, fall back to
			// a non standard error.
			rejectCode := wire.RejectNonstandard
			if rejCode, found := extractRejectCode(err); found {
				rejectCode = rejCode
			}
			str := fmt.Sprintf("transaction output %d: %v", i, err)
			return txRuleError(rejectCode, str)
		}

		// Accumulate the number of outputs which only carry data.  For
		// all other script types, ensure the output value is not
		// "dust".
		if scriptClass == txscript.NullDataTy {
			numNullDataOutputs++
		} else if isDust(txOut, minRelayTxFee) {
			str := fmt.Sprintf("transaction output %d: payment "+
				"of %d is dust", i, txOut.Value)
			return txRuleError(wire.RejectDust, str)
		}
	}

	// A standard transaction must not have more than one output script that
	// only carries data.
	if numNullDataOutputs > 1 {
		str := "more than one transaction output in a nulldata script"
		return txRuleError(wire.RejectNonstandard, str)
	}

	return nil
}