예제 #1
0
파일: author.go 프로젝트: decred/dcrwallet
// NewUnsignedTransaction creates an unsigned transaction paying to one or more
// non-change outputs.  An appropriate transaction fee is included based on the
// transaction size.
//
// Transaction inputs are chosen from repeated calls to fetchInputs with
// increasing targets amounts.
//
// If any remaining output value can be returned to the wallet via a change
// output without violating mempool dust rules, a P2PKH change output is
// appended to the transaction outputs.  Since the change output may not be
// necessary, fetchChange is called zero or one times to generate this script.
// This function must return a P2PKH script or smaller, otherwise fee estimation
// will be incorrect.
//
// If successful, the transaction, total input value spent, and all previous
// output scripts are returned.  If the input source was unable to provide
// enough input value to pay for every output any any necessary fees, an
// InputSourceError is returned.
//
// BUGS: Fee estimation may be off when redeeming non-compressed P2PKH outputs.
func NewUnsignedTransaction(outputs []*wire.TxOut, relayFeePerKb dcrutil.Amount,
	fetchInputs InputSource, fetchChange ChangeSource) (*AuthoredTx, error) {

	targetAmount := h.SumOutputValues(outputs)
	estimatedSize := txsizes.EstimateSerializeSize(1, outputs, true)
	targetFee := txrules.FeeForSerializeSize(relayFeePerKb, estimatedSize)

	for {
		inputAmount, inputs, scripts, err := fetchInputs(targetAmount + targetFee)
		if err != nil {
			return nil, err
		}
		if inputAmount < targetAmount+targetFee {
			return nil, InsufficientFundsError{}
		}

		maxSignedSize := txsizes.EstimateSerializeSize(len(inputs), outputs, true)
		maxRequiredFee := txrules.FeeForSerializeSize(relayFeePerKb, maxSignedSize)
		remainingAmount := inputAmount - targetAmount
		if remainingAmount < maxRequiredFee {
			targetFee = maxRequiredFee
			continue
		}

		unsignedTransaction := &wire.MsgTx{
			Version:  wire.DefaultMsgTxVersion(),
			TxIn:     inputs,
			TxOut:    outputs,
			LockTime: 0,
			Expiry:   0,
		}
		changeIndex := -1
		changeAmount := inputAmount - targetAmount - maxRequiredFee
		if changeAmount != 0 && !txrules.IsDustAmount(changeAmount,
			txsizes.P2PKHPkScriptSize, relayFeePerKb) {
			changeScript, err := fetchChange()
			if err != nil {
				return nil, err
			}
			if len(changeScript) > txsizes.P2PKHPkScriptSize {
				return nil, errors.New("fee estimation requires change " +
					"scripts no larger than P2PKH output scripts")
			}
			change := wire.NewTxOut(int64(changeAmount), changeScript)
			l := len(outputs)
			unsignedTransaction.TxOut = append(outputs[:l:l], change)
			changeIndex = l
		}

		return &AuthoredTx{
			Tx:          unsignedTransaction,
			PrevScripts: scripts,
			TotalInput:  inputAmount,
			ChangeIndex: changeIndex,
		}, nil
	}
}
예제 #2
0
func TestNewUnsignedTransaction(t *testing.T) {
	tests := []struct {
		UnspentOutputs   []*wire.TxOut
		Outputs          []*wire.TxOut
		RelayFee         dcrutil.Amount
		ChangeAmount     dcrutil.Amount
		InputSourceError bool
		InputCount       int
	}{
		0: {
			UnspentOutputs:   p2pkhOutputs(1e8),
			Outputs:          p2pkhOutputs(1e8),
			RelayFee:         1e3,
			InputSourceError: true,
		},
		1: {
			UnspentOutputs: p2pkhOutputs(1e8),
			Outputs:        p2pkhOutputs(1e6),
			RelayFee:       1e3,
			ChangeAmount: 1e8 - 1e6 - txrules.FeeForSerializeSize(1e3,
				txsizes.EstimateSerializeSize(1, p2pkhOutputs(1e6), true)),
			InputCount: 1,
		},
		2: {
			UnspentOutputs: p2pkhOutputs(1e8),
			Outputs:        p2pkhOutputs(1e6),
			RelayFee:       1e4,
			ChangeAmount: 1e8 - 1e6 - txrules.FeeForSerializeSize(1e4,
				txsizes.EstimateSerializeSize(1, p2pkhOutputs(1e6), true)),
			InputCount: 1,
		},
		3: {
			UnspentOutputs: p2pkhOutputs(1e8),
			Outputs:        p2pkhOutputs(1e6, 1e6, 1e6),
			RelayFee:       1e4,
			ChangeAmount: 1e8 - 3e6 - txrules.FeeForSerializeSize(1e4,
				txsizes.EstimateSerializeSize(1, p2pkhOutputs(1e6, 1e6, 1e6), true)),
			InputCount: 1,
		},
		4: {
			UnspentOutputs: p2pkhOutputs(1e8),
			Outputs:        p2pkhOutputs(1e6, 1e6, 1e6),
			RelayFee:       2.55e3,
			ChangeAmount: 1e8 - 3e6 - txrules.FeeForSerializeSize(2.55e3,
				txsizes.EstimateSerializeSize(1, p2pkhOutputs(1e6, 1e6, 1e6), true)),
			InputCount: 1,
		},

		// Test dust thresholds (603 for a 1e3 relay fee).
		5: {
			UnspentOutputs: p2pkhOutputs(1e8),
			Outputs: p2pkhOutputs(1e8 - 602 - txrules.FeeForSerializeSize(1e3,
				txsizes.EstimateSerializeSize(1, p2pkhOutputs(0), true))),
			RelayFee:     1e3,
			ChangeAmount: 0,
			InputCount:   1,
		},
		6: {
			UnspentOutputs: p2pkhOutputs(1e8),
			Outputs: p2pkhOutputs(1e8 - 603 - txrules.FeeForSerializeSize(1e3,
				txsizes.EstimateSerializeSize(1, p2pkhOutputs(0), true))),
			RelayFee:     1e3,
			ChangeAmount: 603,
			InputCount:   1,
		},

		// Test dust thresholds (1537.65 for a 2.55e3 relay fee).
		7: {
			UnspentOutputs: p2pkhOutputs(1e8),
			Outputs: p2pkhOutputs(1e8 - 1537 - txrules.FeeForSerializeSize(2.55e3,
				txsizes.EstimateSerializeSize(1, p2pkhOutputs(0), true))),
			RelayFee:     2.55e3,
			ChangeAmount: 0,
			InputCount:   1,
		},
		8: {
			UnspentOutputs: p2pkhOutputs(1e8),
			Outputs: p2pkhOutputs(1e8 - 1538 - txrules.FeeForSerializeSize(2.55e3,
				txsizes.EstimateSerializeSize(1, p2pkhOutputs(0), true))),
			RelayFee:     2.55e3,
			ChangeAmount: 1538,
			InputCount:   1,
		},

		// Test two unspent outputs available but only one needed
		// (tested fee only includes one input rather than using a
		// serialize size for each).
		9: {
			UnspentOutputs: p2pkhOutputs(1e8, 1e8),
			Outputs: p2pkhOutputs(1e8 - 603 - txrules.FeeForSerializeSize(1e3,
				txsizes.EstimateSerializeSize(1, p2pkhOutputs(0), true))),
			RelayFee:     1e3,
			ChangeAmount: 603,
			InputCount:   1,
		},

		// Test that second output is not included to make the change
		// output not dust and be included in the transaction.
		//
		// It's debatable whether or not this is a good idea, but it's
		// how the function was written, so test it anyways.
		10: {
			UnspentOutputs: p2pkhOutputs(1e8, 1e8),
			Outputs: p2pkhOutputs(1e8 - 545 - txrules.FeeForSerializeSize(1e3,
				txsizes.EstimateSerializeSize(1, p2pkhOutputs(0), true))),
			RelayFee:     1e3,
			ChangeAmount: 0,
			InputCount:   1,
		},

		// Test two unspent outputs available where both are needed.
		11: {
			UnspentOutputs: p2pkhOutputs(1e8, 1e8),
			Outputs:        p2pkhOutputs(1e8),
			RelayFee:       1e3,
			ChangeAmount: 1e8 - txrules.FeeForSerializeSize(1e3,
				txsizes.EstimateSerializeSize(2, p2pkhOutputs(1e8), true)),
			InputCount: 2,
		},

		// Test that zero change outputs are not included
		// (ChangeAmount=0 means don't include any change output).
		12: {
			UnspentOutputs: p2pkhOutputs(1e8),
			Outputs:        p2pkhOutputs(1e8),
			RelayFee:       0,
			ChangeAmount:   0,
			InputCount:     1,
		},
	}

	changeSource := func() ([]byte, error) {
		// Only length matters for these tests.
		return make([]byte, txsizes.P2PKHPkScriptSize), nil
	}

	for i, test := range tests {
		inputSource := makeInputSource(test.UnspentOutputs)
		tx, err := NewUnsignedTransaction(test.Outputs, test.RelayFee, inputSource, changeSource)
		switch e := err.(type) {
		case nil:
		case InputSourceError:
			if !test.InputSourceError {
				t.Errorf("Test %d: Returned InputSourceError but expected "+
					"change output with amount %v", i, test.ChangeAmount)
			}
			continue
		default:
			t.Errorf("Test %d: Unexpected error: %v", i, e)
			continue
		}
		if tx.ChangeIndex < 0 {
			if test.ChangeAmount != 0 {
				t.Errorf("Test %d: No change output added but expected output with amount %v",
					i, test.ChangeAmount)
				continue
			}
		} else {
			changeAmount := dcrutil.Amount(tx.Tx.TxOut[tx.ChangeIndex].Value)
			if test.ChangeAmount == 0 {
				t.Errorf("Test %d: Included change output with value %v but expected no change",
					i, changeAmount)
				continue
			}
			if changeAmount != test.ChangeAmount {
				t.Errorf("Test %d: Got change amount %v, Expected %v",
					i, changeAmount, test.ChangeAmount)
				continue
			}
		}
		if len(tx.Tx.TxIn) != test.InputCount {
			t.Errorf("Test %d: Used %d outputs from input source, Expected %d",
				i, len(tx.Tx.TxIn), test.InputCount)
		}
	}
}
예제 #3
0
파일: stake.go 프로젝트: decred/dcrwallet
// GenerateRevocation generates a revocation (SSRtx), signs it, and
// submits it by SendRawTransaction. It also stores a record of it
// in the local database.
func (s *StakeStore) generateRevocation(ns walletdb.ReadWriteBucket, waddrmgrNs walletdb.ReadBucket, blockHash *chainhash.Hash, height int64, sstxHash *chainhash.Hash,
	allowHighFees bool) (*StakeNotification, error) {

	// 1. Fetch the SStx, then calculate all the values we'll need later for
	// the generation of the SSRtx tx outputs.
	sstxRecord, err := s.getSStx(ns, sstxHash)
	if err != nil {
		return nil, err
	}
	sstx := sstxRecord.tx

	// Store the sstx pubkeyhashes and amounts as found in the transaction
	// outputs.
	// TODO Get information on the allowable fee range for the revocation
	// and check to make sure we don't overflow that.
	sstxPayTypes, sstxPkhs, sstxAmts, _, _, _ :=
		stake.TxSStxStakeOutputInfo(sstx.MsgTx())
	ssrtxCalcAmts := stake.CalculateRewards(sstxAmts, sstx.MsgTx().TxOut[0].Value,
		int64(0))

	// Calculate the fee to use for this revocation based on the fee
	// per KB that is standard for mainnet.
	revocationSizeEst := estimateSSRtxTxSize(1, len(sstxPkhs))
	revocationFee := txrules.FeeForSerializeSize(revocationFeePerKB,
		revocationSizeEst)

	// 2. Add the only input.
	msgTx := wire.NewMsgTx()

	// SStx tagged output as an OutPoint; reference this as
	// the only input.
	prevOut := wire.NewOutPoint(sstxHash,
		0, // Index 0
		1) // Tree stake
	txIn := wire.NewTxIn(prevOut, []byte{})
	msgTx.AddTxIn(txIn)

	// 3. Add all the OP_SSRTX tagged outputs.

	// Add all the SSRtx-tagged transaction outputs to the transaction after
	// performing some validity checks.
	feeAdded := false
	for i, sstxPkh := range sstxPkhs {
		// Create a new script which pays to the provided address specified in
		// the original ticket tx.
		var ssrtxOutScript []byte
		switch sstxPayTypes[i] {
		case false: // P2PKH
			ssrtxOutScript, err = txscript.PayToSSRtxPKHDirect(sstxPkh)
			if err != nil {
				return nil, err
			}
		case true: // P2SH
			ssrtxOutScript, err = txscript.PayToSSRtxSHDirect(sstxPkh)
			if err != nil {
				return nil, err
			}
		}

		// Add a fee from an output that has enough.
		amt := ssrtxCalcAmts[i]
		if !feeAdded && ssrtxCalcAmts[i] >= int64(revocationFee) {
			amt -= int64(revocationFee)
			feeAdded = true
		}

		// Add the txout to our SSRtx tx.
		txOut := wire.NewTxOut(amt, ssrtxOutScript)
		msgTx.AddTxOut(txOut)
	}

	// Check to make sure our SSRtx was created correctly.
	_, err = stake.IsSSRtx(msgTx)
	if err != nil {
		return nil, err
	}

	// Sign the transaction.
	err = s.SignVRTransaction(waddrmgrNs, msgTx, sstx, false)
	if err != nil {
		return nil, err
	}

	// Store the information about the SSRtx.
	hash := msgTx.TxSha()
	err = s.insertSSRtx(ns,
		blockHash,
		height,
		&hash,
		sstx.Sha())
	if err != nil {
		return nil, err
	}

	// Send the transaction.
	ssrtxSha, err := s.chainSvr.SendRawTransaction(msgTx, allowHighFees)
	if err != nil {
		return nil, err
	}

	log.Debugf("Generated SSRtx %v. The ticket used to "+
		"generate the SSRtx was %v.", ssrtxSha, sstx.Sha())

	// Generate a notification to return.
	ntfn := &StakeNotification{
		TxType:    int8(stake.TxTypeSSRtx),
		TxHash:    *ssrtxSha,
		BlockHash: chainhash.Hash{},
		Height:    0,
		Amount:    0,
		SStxIn:    *sstx.Sha(),
		VoteBits:  0,
	}

	return ntfn, nil
}