Пример #1
0
// 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 := chainec.Secp256k1.PrivKeyFromBytes(privKeyBytes)
	pubKeyHash := dcrutil.Hash160(pubKey.SerializeCompressed())
	addr, err := dcrutil.NewAddressPubKeyHash(pubKeyHash,
		&chaincfg.MainNetParams, chainec.ECTypeSecp256k1)
	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 DCR.
	originTx := wire.NewMsgTx()
	prevOut := wire.NewOutPoint(&chainhash.Hash{}, ^uint32(0), dcrutil.TxTreeRegular)
	txIn := wire.NewTxIn(prevOut, []byte{txscript.OP_0, txscript.OP_0})
	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.TxSha()

	// Create the transaction to redeem the fake transaction.
	redeemTx := wire.NewMsgTx()

	// 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, dcrutil.TxTreeRegular)
	txIn = wire.NewTxIn(prevOut, 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 dcrutil.Address) (chainec.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, secp)
	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.ScriptDiscourageUpgradableNops
	vm, err := txscript.NewEngine(originTx.TxOut[0].PkScript, redeemTx, 0,
		flags, 0)
	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
}
Пример #2
0
// SignVRTransaction signs a vote (SSGen) or revocation (SSRtx)
// transaction. isSSGen indicates if it is an SSGen; if it's not,
// it's an SSRtx.
func (s *StakeStore) SignVRTransaction(waddrmgrNs walletdb.ReadBucket, msgTx *wire.MsgTx,
	sstx *dcrutil.Tx, isSSGen bool) error {

	if s.isClosed {
		str := "stake store is closed"
		return stakeStoreError(ErrStoreClosed, str, nil)
	}

	txInNumToSign := 0
	hashType := txscript.SigHashAll

	if isSSGen {
		// For an SSGen tx, skip the first input as it is a stake base
		// and doesn't need to be signed.
		msgTx.TxIn[0].SignatureScript = s.Params.StakeBaseSigScript
		txInNumToSign = 1
	}

	// Get the script for the OP_SSTX tagged output that we need
	// to sign.
	sstxOutScript := sstx.MsgTx().TxOut[0].PkScript

	// Set up our callbacks that we pass to dcrscript so it can
	// look up the appropriate keys and scripts by address.
	getKey := txscript.KeyClosure(func(addr dcrutil.Address) (
		chainec.PrivateKey, bool, error) {
		address, err := s.Manager.Address(waddrmgrNs, addr)
		if err != nil {
			return nil, false, err
		}

		pka, ok := address.(waddrmgr.ManagedPubKeyAddress)
		if !ok {
			return nil, false, fmt.Errorf("address is not " +
				"a pubkey address")
		}

		key, err := pka.PrivKey()
		if err != nil {
			return nil, false, err
		}

		return key, pka.Compressed(), nil
	})

	getScript := txscript.ScriptClosure(func(
		addr dcrutil.Address) ([]byte, error) {
		address, err := s.Manager.Address(waddrmgrNs, addr)
		if err != nil {
			return nil, err
		}
		sa, ok := address.(waddrmgr.ManagedScriptAddress)
		if !ok {
			return nil, fmt.Errorf("address is not a script" +
				" address")
		}

		return sa.Script()
	})

	// Attempt to generate the signed txin.
	signedScript, err := txscript.SignTxOutput(s.Params,
		msgTx,
		txInNumToSign,
		sstxOutScript,
		hashType,
		getKey,
		getScript,
		msgTx.TxIn[txInNumToSign].SignatureScript,
		chainec.ECTypeSecp256k1)
	if err != nil {
		return fmt.Errorf("failed to sign ssgen or "+
			"ssrtx, error: %v", err.Error())
	}

	msgTx.TxIn[txInNumToSign].SignatureScript = signedScript

	// Either it was already signed or we just signed it.
	// Find out if it is completely satisfied or still needs more.
	// Decred: Needed??
	flags := txscript.ScriptBip16
	engine, err := txscript.NewEngine(sstxOutScript,
		msgTx,
		txInNumToSign,
		flags,
		txscript.DefaultScriptVersion,
		nil)
	if err != nil {
		return fmt.Errorf("failed to generate signature script engine for "+
			"ssgen or ssrtx, error: %v", err.Error())
	}
	err = engine.Execute()
	if err != nil {
		return fmt.Errorf("failed to generate correct signature script for "+
			"ssgen or ssrtx: %v", err.Error())
	}

	return nil
}