create and send transaction on testnet

.gitignore

@@ -3,3 +3,4 @@ main
 .idea/misc.xml
 .idea/modules.xml
 .idea/workspace.xml
+vcs.xml

go.mod

@@ -0,0 +1,9 @@
+module github.com/hlongvu/golang_ecdsa
+
+require (
+	github.com/btcsuite/btcd v0.0.0-20181013004428-67e573d211ac
+	github.com/btcsuite/btclog v0.0.0-20170628155309-84c8d2346e9f // indirect
+	github.com/btcsuite/btcutil v0.0.0-20180706230648-ab6388e0c60a
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	golang.org/x/crypto v0.0.0-20181112202954-3d3f9f413869
+)

transaction.go

@@ -0,0 +1,151 @@
+package main
+
+import (
+	"bytes"
+	"encoding/hex"
+	"fmt"
+	"github.com/btcsuite/btcd/btcec"
+	"github.com/btcsuite/btcd/chaincfg"
+	"github.com/btcsuite/btcd/chaincfg/chainhash"
+	"github.com/btcsuite/btcd/txscript"
+	"github.com/btcsuite/btcd/wire"
+	"github.com/btcsuite/btcutil"
+	"log"
+)
+
+const test3_privKey = "291ad7996fa06e26379ce3640ca8752ae9ed7b87e27d2143f44ec1510ede3d74"
+const my_address = "myeZPsW8yv8u9yy4gEG2ADuiczpf2257Vt"
+const receiver_address = "mv4rnyY3Su5gjcDNzbMLKBQkBicCtHUtFB"
+
+// https://tchain.btc.com/myeZPsW8yv8u9yy4gEG2ADuiczpf2257Vt
+
+type utxo struct {
+	Address     string
+	TxID        string
+	OutputIndex uint32
+	Script      []byte
+	Satoshis    int64
+}
+
+func main() {
+
+	// 1. Get address from your private key
+	myPrivateKey, fromAddress := GetKeyAddressFromPrivateKey(test3_privKey)
+	fmt.Printf("TestNet3 Address: %s\n", fromAddress)
+	if fromAddress != my_address{
+		log.Fatal("Wrong private key and address pair. Please recheck!")
+	}
+
+	// 2. Get some test-net-3 btc at https://coinfaucet.eu/en/btc-testnet/
+	// 3. Create transaction
+	// 	  We will send back the bitcoin to faucet address: mv4rnyY3Su5gjcDNzbMLKBQkBicCtHUtFB
+	// 	  My balance is 0.00340000 BTC, we will send an amount less than that and leave some fee for the miners
+	//
+
+	unspentTx := utxo{
+		Address:     my_address,
+		TxID:        "b8d84fbcce0914ddc6688db53ef0dc6509833bf292189eb245a791a8415f9a58",
+		OutputIndex: 0,
+		Script:      GetPayToAddrScript(my_address),
+		Satoshis:    200000,
+	}
+
+	// create new empty transaction
+
+	redemTx := wire.NewMsgTx(wire.TxVersion)
+
+	hash, err := chainhash.NewHashFromStr(unspentTx.TxID)
+	if err != nil {
+		log.Fatalf("could not get hash from transaction ID: %v", err)
+	}
+
+	// create TxIn
+
+	outPoint := wire.NewOutPoint(hash, unspentTx.OutputIndex)
+	txIn := wire.NewTxIn(outPoint, nil, nil)
+	redemTx.AddTxIn(txIn)
+
+	// create TxOut
+	rcv_script := GetPayToAddrScript(receiver_address)
+	outCoin := unspentTx.Satoshis
+
+	txOut := wire.NewTxOut(outCoin, rcv_script)
+	redemTx.AddTxOut(txOut)
+
+	// sign transaction
+
+	sig, err := txscript.SignatureScript(
+		redemTx,                  // The tx to be signed.
+		0,                   // The index of the txin the signature is for.
+		unspentTx.Script,        // The other half of the script from the PubKeyHash.
+		txscript.SigHashAll, // The signature flags that indicate what the sig covers.
+		myPrivateKey,          // The key to generate the signature with.
+		false)                // The compress sig flag. This saves space on the blockchain.
+
+
+	if err != nil {
+		log.Fatalf("could not generate signature: %v", err)
+	}
+
+	redemTx.TxIn[0].SignatureScript = sig
+
+	//Validate signature
+	flags := txscript.StandardVerifyFlags
+	vm, err := txscript.NewEngine(unspentTx.Script, redemTx, 0, flags, nil, nil, outCoin)
+	if err != nil {
+		fmt.Printf("err != nil: %v\n",err)
+	}
+	if err := vm.Execute(); err != nil {
+		fmt.Printf("vm.Execute > err != nil: %v\n",err)
+	}
+
+	fmt.Printf("redeemTx: %v\n", txToHex(redemTx))
+}
+
+
+func txToHex(tx *wire.MsgTx) string {
+	buf := bytes.NewBuffer(make([]byte, 0, tx.SerializeSize()))
+	tx.Serialize(buf)
+	return hex.EncodeToString(buf.Bytes())
+}
+
+func GetPayToAddrScript(address string) []byte{
+	rcvAddress, _ := btcutil.DecodeAddress(address, &chaincfg.TestNet3Params)
+	rcvScript, _ := txscript.PayToAddrScript(rcvAddress)
+	return rcvScript
+}
+
+func GenerateKeyAddress() ([]byte, string){
+	key, err := btcec.NewPrivateKey(btcec.S256())
+	if err != nil {
+		fmt.Printf("failed to make privKey for %s: %v" , err)
+	}
+
+	pk := (*btcec.PublicKey)(&key.PublicKey).
+		SerializeUncompressed()
+	address, err := btcutil.NewAddressPubKeyHash(
+		btcutil.Hash160(pk), &chaincfg.TestNet3Params)
+	keyBytes := key.Serialize()
+	//keyHex := hex.EncodeToString(keyBytes)
+
+	fmt.Printf("PrivateKey: %x \n", keyBytes)
+	fmt.Printf("Address: %q\n", address.EncodeAddress())
+
+	return keyBytes, address.EncodeAddress()
+}
+
+func GetKeyAddressFromPrivateKey(privKey string) (*btcec.PrivateKey, string){
+	privByte, err := hex.DecodeString(privKey)
+
+	if err!=nil{
+		log.Panic(err)
+	}
+
+	priv, pubKey := btcec.PrivKeyFromBytes( btcec.S256(), privByte) //secp256k1
+
+	address, err := btcutil.NewAddressPubKeyHash(
+		btcutil.Hash160(pubKey.SerializeUncompressed()), &chaincfg.TestNet3Params)
+
+	return priv, address.EncodeAddress()
+}
+