func write_tx_file(tx *btc.Tx) {
signedrawtx := tx.Serialize()
tx.Hash = btc.NewSha2Hash(signedrawtx)
hs := tx.Hash.String()
fmt.Println("TxID", hs)
f, _ := os.Create(hs[:8] + ".txt")
if f != nil {
f.Write([]byte(hex.EncodeToString(signedrawtx)))
f.Close()
fmt.Println("Transaction data stored in", hs[:8]+".txt")
}
}
// prepare a signed transaction
func make_signed_tx() {
// Make an empty transaction
tx := new(btc.Tx)
tx.Version = 1
tx.Lock_time = 0
// Select as many inputs as we need to pay the full amount (with the fee)
var btcsofar uint64
var inpcnt uint
for inpcnt = 0; inpcnt < uint(len(unspentOuts)); inpcnt++ {
uo := UO(unspentOuts[inpcnt])
// add the input to our transaction:
tin := new(btc.TxIn)
tin.Input = *unspentOuts[inpcnt]
tin.Sequence = 0xffffffff
tx.TxIn = append(tx.TxIn, tin)
btcsofar += uo.Value
if btcsofar >= spendBtc+feeBtc {
break
}
}
changeBtc = btcsofar - (spendBtc + feeBtc)
fmt.Printf("Spending %d out of %d outputs...\n", inpcnt+1, len(unspentOuts))
// Build transaction outputs:
tx.TxOut = make([]*btc.TxOut, len(sendTo))
for o := range sendTo {
tx.TxOut[o] = &btc.TxOut{Value: sendTo[o].amount, Pk_script: sendTo[o].addr.OutScript()}
}
if changeBtc > 0 {
// Add one more output (with the change)
tx.TxOut = append(tx.TxOut, &btc.TxOut{Value: changeBtc, Pk_script: get_change_addr().OutScript()})
}
//fmt.Println("Unsigned:", hex.EncodeToString(tx.Serialize()))
for in := range tx.TxIn {
uo := UO(unspentOuts[in])
var found bool
for j := range publ_addrs {
if publ_addrs[j].Owns(uo.Pk_script) {
pub_key, e := btc.NewPublicKey(publ_addrs[j].Pubkey)
if e != nil {
println("NewPublicKey:", e.Error(), "\007")
os.Exit(1)
}
// Load the key (private and public)
var key ecdsa.PrivateKey
key.D = new(big.Int).SetBytes(priv_keys[j][:])
key.PublicKey = pub_key.PublicKey
//Calculate proper transaction hash
h := tx.SignatureHash(uo.Pk_script, in, btc.SIGHASH_ALL)
//fmt.Println("SignatureHash:", btc.NewUint256(h).String())
// Sign
r, s, err := ecdsa.Sign(rand.Reader, &key, h)
if err != nil {
println("Sign:", err.Error(), "\007")
os.Exit(1)
}
rb := r.Bytes()
sb := s.Bytes()
if rb[0] >= 0x80 { // I thinnk this is needed, thought I am not quite sure... :P
rb = append([]byte{0x00}, rb...)
}
if sb[0] >= 0x80 { // I thinnk this is needed, thought I am not quite sure... :P
sb = append([]byte{0x00}, sb...)
}
// Output the signing result into a buffer, in format expected by bitcoin protocol
busig := new(bytes.Buffer)
busig.WriteByte(0x30)
busig.WriteByte(byte(4 + len(rb) + len(sb)))
busig.WriteByte(0x02)
busig.WriteByte(byte(len(rb)))
busig.Write(rb)
busig.WriteByte(0x02)
busig.WriteByte(byte(len(sb)))
busig.Write(sb)
busig.WriteByte(0x01) // hash type
// Output the signature and the public key into tx.ScriptSig
buscr := new(bytes.Buffer)
buscr.WriteByte(byte(busig.Len()))
buscr.Write(busig.Bytes())
buscr.WriteByte(byte(len(publ_addrs[j].Pubkey)))
buscr.Write(publ_addrs[j].Pubkey)
// assign:
tx.TxIn[in].ScriptSig = buscr.Bytes()
found = true
break
}
}
if !found {
fmt.Println("You do not have private key for input number", hex.EncodeToString(uo.Pk_script), "\007")
os.Exit(1)
}
}
rawtx := tx.Serialize()
tx.Hash = btc.NewSha2Hash(rawtx)
hs := tx.Hash.String()
fmt.Println(hs)
f, _ := os.Create(hs[:8] + ".txt")
if f != nil {
f.Write([]byte(hex.EncodeToString(rawtx)))
f.Close()
fmt.Println("Transaction data stored in", hs[:8]+".txt")
}
f, _ = os.Create("balance/unspent.txt")
if f != nil {
for j := uint(0); j < uint(len(unspentOuts)); j++ {
if j > inpcnt {
fmt.Fprintln(f, unspentOuts[j], unspentOutsLabel[j])
}
}
fmt.Println(inpcnt, "spent output(s) removed from 'balance/unspent.txt'")
var addback int
for out := range tx.TxOut {
for j := range publ_addrs {
if publ_addrs[j].Owns(tx.TxOut[out].Pk_script) {
fmt.Fprintf(f, "%s-%03d # %.8f / %s\n", tx.Hash.String(), out,
float64(tx.TxOut[out].Value)/1e8, publ_addrs[j].String())
addback++
}
}
}
f.Close()
if addback > 0 {
f, _ = os.Create("balance/" + hs + ".tx")
if f != nil {
f.Write(rawtx)
f.Close()
}
fmt.Println(addback, "new output(s) appended to 'balance/unspent.txt'")
}
}
}