lbcd/txscript/example_test.go

183 lines
5.9 KiB
Go
Raw Normal View History

// Copyright (c) 2014-2016 The btcsuite developers
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package txscript_test
import (
2014-07-08 21:59:57 +02:00
"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"
)
// This example demonstrates creating a script which pays to a bitcoin address.
// It also prints the created script hex and uses the DisasmString function to
// display the disassembled script.
func ExamplePayToAddrScript() {
// Parse the address to send the coins to into a btcutil.Address
// which is useful to ensure the accuracy of the address and determine
// the address type. It is also required for the upcoming call to
// PayToAddrScript.
addressStr := "12gpXQVcCL2qhTNQgyLVdCFG2Qs2px98nV"
address, err := btcutil.DecodeAddress(addressStr, &chaincfg.MainNetParams)
if err != nil {
fmt.Println(err)
return
}
// Create a public key script that pays to the address.
script, err := txscript.PayToAddrScript(address)
if err != nil {
fmt.Println(err)
return
}
fmt.Printf("Script Hex: %x\n", script)
disasm, err := txscript.DisasmString(script)
if err != nil {
fmt.Println(err)
return
}
fmt.Println("Script Disassembly:", disasm)
// Output:
// Script Hex: 76a914128004ff2fcaf13b2b91eb654b1dc2b674f7ec6188ac
// Script Disassembly: OP_DUP OP_HASH160 128004ff2fcaf13b2b91eb654b1dc2b674f7ec61 OP_EQUALVERIFY OP_CHECKSIG
}
2014-07-08 21:59:57 +02:00
// This example demonstrates extracting information from a standard public key
// script.
func ExampleExtractPkScriptAddrs() {
// Start with a standard pay-to-pubkey-hash script.
scriptHex := "76a914128004ff2fcaf13b2b91eb654b1dc2b674f7ec6188ac"
script, err := hex.DecodeString(scriptHex)
if err != nil {
fmt.Println(err)
return
}
// Extract and print details from the script.
scriptClass, addresses, reqSigs, err := txscript.ExtractPkScriptAddrs(
script, &chaincfg.MainNetParams)
2014-07-08 21:59:57 +02:00
if err != nil {
fmt.Println(err)
return
}
fmt.Println("Script Class:", scriptClass)
fmt.Println("Addresses:", addresses)
fmt.Println("Required Signatures:", reqSigs)
// Output:
// Script Class: pubkeyhash
// Addresses: [12gpXQVcCL2qhTNQgyLVdCFG2Qs2px98nV]
// Required Signatures: 1
}
// This example demonstrates manually creating and signing a redeem transaction.
func ExampleSignTxOutput() {
// Ordinarily the private key would come from whatever storage mechanism
// is being used, but for this example just hard code it.
privKeyBytes, err := hex.DecodeString("22a47fa09a223f2aa079edf85a7c2" +
"d4f8720ee63e502ee2869afab7de234b80c")
if err != nil {
fmt.Println(err)
return
}
privKey, pubKey := btcec.PrivKeyFromBytes(btcec.S256(), privKeyBytes)
pubKeyHash := btcutil.Hash160(pubKey.SerializeCompressed())
addr, err := btcutil.NewAddressPubKeyHash(pubKeyHash,
&chaincfg.MainNetParams)
if err != nil {
fmt.Println(err)
return
}
// For this example, create a fake transaction that represents what
// would ordinarily be the real transaction that is being spent. It
// contains a single output that pays to address in the amount of 1 BTC.
originTx := wire.NewMsgTx(wire.TxVersion)
prevOut := wire.NewOutPoint(&chainhash.Hash{}, ^uint32(0))
txIn := wire.NewTxIn(prevOut, []byte{txscript.OP_0, txscript.OP_0}, nil)
originTx.AddTxIn(txIn)
pkScript, err := txscript.PayToAddrScript(addr)
if err != nil {
fmt.Println(err)
return
}
txOut := wire.NewTxOut(100000000, pkScript)
originTx.AddTxOut(txOut)
originTxHash := originTx.TxHash()
// Create the transaction to redeem the fake transaction.
redeemTx := wire.NewMsgTx(wire.TxVersion)
// Add the input(s) the redeeming transaction will spend. There is no
// signature script at this point since it hasn't been created or signed
// yet, hence nil is provided for it.
prevOut = wire.NewOutPoint(&originTxHash, 0)
txIn = wire.NewTxIn(prevOut, nil, nil)
redeemTx.AddTxIn(txIn)
// Ordinarily this would contain that actual destination of the funds,
// but for this example don't bother.
txOut = wire.NewTxOut(0, nil)
redeemTx.AddTxOut(txOut)
// Sign the redeeming transaction.
lookupKey := func(a btcutil.Address) (*btcec.PrivateKey, bool, error) {
// Ordinarily this function would involve looking up the private
// key for the provided address, but since the only thing being
// signed in this example uses the address associated with the
// private key from above, simply return it with the compressed
// flag set since the address is using the associated compressed
// public key.
//
// NOTE: If you want to prove the code is actually signing the
// transaction properly, uncomment the following line which
// intentionally returns an invalid key to sign with, which in
// turn will result in a failure during the script execution
// when verifying the signature.
//
// privKey.D.SetInt64(12345)
//
return privKey, true, nil
}
// Notice that the script database parameter is nil here since it isn't
// used. It must be specified when pay-to-script-hash transactions are
// being signed.
sigScript, err := txscript.SignTxOutput(&chaincfg.MainNetParams,
redeemTx, 0, originTx.TxOut[0].PkScript, txscript.SigHashAll,
txscript.KeyClosure(lookupKey), nil, nil)
if err != nil {
fmt.Println(err)
return
}
redeemTx.TxIn[0].SignatureScript = sigScript
// Prove that the transaction has been validly signed by executing the
// script pair.
flags := txscript.ScriptBip16 | txscript.ScriptVerifyDERSignatures |
txscript.ScriptStrictMultiSig |
txscript.ScriptDiscourageUpgradableNops
vm, err := txscript.NewEngine(originTx.TxOut[0].PkScript, redeemTx, 0,
flags, nil, nil, -1)
if err != nil {
fmt.Println(err)
return
}
if err := vm.Execute(); err != nil {
fmt.Println(err)
return
}
fmt.Println("Transaction successfully signed")
// Output:
// Transaction successfully signed
}