func (h *BlockHeader) Hash() []byte {
if h.hash == nil {
var b bytes.Buffer
h.Serialize(&b)
h.hash = utils.DoubleHash(b.Bytes())
}
return h.hash
}
func TestPayments(t *testing.T) {
seed := "xprv9z29aRLQo4Gkn2z7XczXBDup2Nig8EvDCXV7wub6FnSe36UkakkEfTN4TZH9obaPj" +
"7yn4Zh5P1JSRvnfXAi6riG9g8WqrZjzenkU9MHxy6g"
account, err := NewAccount(seed)
if err != nil {
t.Fatalf("Failed to set up account", err)
}
mock := NewMockInventory()
account.SetTxInventory(mock)
pay := account.NewPayment()
decoded, _, _ := base58.BitcoinCheckDecode("1QAsw4fsfq3MJdgiEGod3MxY9BY2EnTWEU")
pay.AddOutput(decoded, 50000)
err = pay.AddInputsAndFee(10000)
if err != nil {
t.Fatalf("Failed to add inputs to payment: %v", err)
}
err = pay.Sign()
if err != nil {
t.Fatalf("Failed to sign payment: %v", err)
}
transactions := pay.Transactions()
if len(transactions) != 1 {
t.Errorf("Bad number of transactions, got %d expected 1.",
len(transactions))
}
tx := transactions[0]
for index, input := range tx.Inputs {
stack := script.Stack{}
err = stack.Execute(input.Signature, nil)
if err != nil {
t.Fatalf("Failed to push signature: %v", err)
}
prev := input.PreviousOutput
inputTx, found := mock.inv[string(prev.Hash)]
if !found {
t.Fatalf("Input tx %x not found in map.", prev.Hash)
}
subscript := inputTx.Outputs[prev.Index].Script
data := &script.Data{
Hasher: func(c uint32) []byte {
return utils.DoubleHash(tx.SignSerialize(
index, subscript, c))
}}
err = stack.Execute(inputTx.Outputs[prev.Index].Script, data)
if err != nil {
t.Fatalf("Failed to execute script: %v", err)
}
if !stack.CheckSuccess() {
t.Errorf("Signature on input %d not valid.", index)
}
}
}
func ParseTransaction(data []byte) (*Transaction, error) {
b := bytes.NewBuffer(data)
t, err := parseTransactionFromStreamWithoutHash(b)
if err != nil {
return nil, err
}
t.data = data
t.hash = utils.DoubleHash(data)
return t, nil
}
func ParseTransactionFromStream(input io.Reader) (*Transaction, error) {
// Tee stream to save the raw data.
data := new(bytes.Buffer)
b := io.TeeReader(input, data)
t, err := parseTransactionFromStreamWithoutHash(b)
if err != nil {
return nil, err
}
t.data = data.Bytes()
t.hash = utils.DoubleHash(t.data)
return t, nil
}
func (n *MerkleNode) Process(hashes *HashStack, bits *BitStack, levels int) error {
flag := bits.Pop()
if n.level < levels-1 {
// non-txid
if !flag {
// Hash will be nil once we're out of hashes. nils will
// be replaced by copies from their sibling.
n.Hash = hashes.Pop()
return nil
}
} else {
// txid
n.Hash = hashes.Pop()
n.match = flag
return nil
}
// non-txid and flag==1: Append child and compute hash from them.
n.Left = &MerkleNode{
level: n.level + 1,
rank: n.rank * 2,
}
err := n.Left.Process(hashes, bits, levels)
if err != nil {
return err
}
n.Right = &MerkleNode{
level: n.level + 1,
rank: n.rank*2 + 1,
}
err = n.Right.Process(hashes, bits, levels)
if err != nil {
return err
}
if n.Left.Hash != nil {
var hash []byte
if n.Right.Hash != nil {
hash = append(n.Left.Hash, n.Right.Hash...)
} else {
// Take left hash twice.
hash = append(n.Left.Hash, n.Left.Hash...)
}
n.Hash = utils.DoubleHash(hash)
} else {
return fmt.Errorf("Left child (%d,%d) has nil hash.",
n.Left.level, n.Left.rank)
}
return nil
}
func ParseBlock(data []byte) (*Block, error) {
var err error
block := Block{
Hash: utils.DoubleHash(data[0:80]),
}
b := bytes.NewBuffer(data)
block.BlockHeader, err = parseBlockHeader(b)
if err != nil {
return nil, err
}
block.Transactions, err = parseTransactions(b)
if err != nil {
return nil, fmt.Errorf("Could not parse transactions: %v", err)
}
if b.Len() != 0 {
return nil, fmt.Errorf("Excess data: %x", b.Bytes())
}
return &block, nil
}
// Sign all the inputs of the payment transaction.
func (p *Payment) Sign() error {
j := 0
for _, tx := range p.transactions {
for i, input := range tx.Inputs {
// These keys were appended in the order of the
// transactions and inputs, so they should correspond
// to the addresses of the inputs.
key := p.keys[j]
hashCode := messages.SigTypeAll
// Subscript is temporarily stored in signature field.
data := utils.DoubleHash(tx.SignSerialize(
i, input.Signature, uint32(hashCode)))
r, s := key.Sign(data)
input.Signature = script.SigScriptEncode(
append(utils.DEREncode(r, s), byte(hashCode)), key.PublicKey())
j++
}
}
return nil
}
func (inv *Inventory) VerifyTransaction(tx *messages.Transaction) (bool, error) {
var inputValue, outputValue uint64
for index, input := range tx.Inputs {
stack := script.Stack{}
err := stack.Execute(input.Signature, nil)
if err != nil {
return false, fmt.Errorf("Failed to push signature: %v", err)
}
prev := input.PreviousOutput
d, found := inv.txHashes[string(prev.Hash)]
if !found {
return false, fmt.Errorf("Input tx %x not found in map.", prev.Hash)
}
inputTx := d.tx
output := inputTx.Outputs[prev.Index]
inputValue += output.Value
data := &script.Data{
Hasher: func(c uint32) []byte {
return utils.DoubleHash(tx.SignSerialize(
index, output.Script, c))
}}
err = stack.Execute(output.Script, data)
if err != nil {
return false, fmt.Errorf("Failed to execute script: %v", err)
}
if !stack.CheckSuccess() {
return false, fmt.Errorf("Signature on input %d not valid.", index)
}
}
for _, output := range tx.Outputs {
outputValue += output.Value
}
if outputValue > inputValue {
return false, fmt.Errorf("Outputs have higher value (%d) than inputs (%d).",
outputValue, inputValue)
}
return true, nil
}
func (t *Transaction) Hash() []byte {
if t.hash == nil {
t.hash = utils.DoubleHash(t.Data())
}
return t.hash
}
// Fingerprint returns a fingerprint that is unique for each tx but doen't
// include the signatures (or other things that can be changed after broadcast).
func (t *Transaction) Fingerprint() []byte {
if t.fingerprint == nil {
t.fingerprint = utils.DoubleHash(t.SerializeWithoutSignature())
}
return t.fingerprint
}