Exemplo n.º 1
0
// TestApplySiacoinOutputs probes the applySiacoinOutput method of the
// consensus set.
func TestApplySiacoinOutputs(t *testing.T) {
	if testing.Short() {
		t.SkipNow()
	}
	cst, err := createConsensusSetTester("TestApplySiacoinOutputs")
	if err != nil {
		t.Fatal(err)
	}

	// Create a block node to use with application.
	bn := new(blockNode)

	// Apply a transaction with a single siacoin output.
	txn := types.Transaction{
		SiacoinOutputs: []types.SiacoinOutput{{}},
	}
	cst.cs.applySiacoinOutputs(bn, txn)
	scoid := txn.SiacoinOutputID(0)
	_, exists := cst.cs.siacoinOutputs[scoid]
	if !exists {
		t.Error("Failed to create siacoin output")
	}
	if len(cst.cs.siacoinOutputs) != 3 { // 3 because createConsensusSetTester has 2 initially.
		t.Error("siacoin outputs not correctly updated")
	}
	if len(bn.siacoinOutputDiffs) != 1 {
		t.Error("block node was not updated for single element transaction")
	}
	if bn.siacoinOutputDiffs[0].Direction != modules.DiffApply {
		t.Error("wrong diff direction applied when creating a siacoin output")
	}
	if bn.siacoinOutputDiffs[0].ID != scoid {
		t.Error("wrong id used when creating a siacoin output")
	}

	// Apply a transaction with 2 siacoin outputs.
	txn = types.Transaction{
		SiacoinOutputs: []types.SiacoinOutput{
			{Value: types.NewCurrency64(1)},
			{Value: types.NewCurrency64(2)},
		},
	}
	cst.cs.applySiacoinOutputs(bn, txn)
	scoid0 := txn.SiacoinOutputID(0)
	scoid1 := txn.SiacoinOutputID(1)
	_, exists = cst.cs.siacoinOutputs[scoid0]
	if !exists {
		t.Error("Failed to create siacoin output")
	}
	_, exists = cst.cs.siacoinOutputs[scoid1]
	if !exists {
		t.Error("Failed to create siacoin output")
	}
	if len(cst.cs.siacoinOutputs) != 5 { // 5 because createConsensusSetTester has 2 initially.
		t.Error("siacoin outputs not correctly updated")
	}
	if len(bn.siacoinOutputDiffs) != 3 {
		t.Error("block node was not updated correctly")
	}
}
Exemplo n.º 2
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// applyFileContracts iterates through all of the file contracts in a
// transaction and applies them to the state, updating the diffs in the block
// node.
func (cs *State) applyFileContracts(bn *blockNode, t types.Transaction) {
	for i, fc := range t.FileContracts {
		// Sanity check - the file contract should not exists within the state.
		fcid := t.FileContractID(i)
		if build.DEBUG {
			_, exists := cs.fileContracts[fcid]
			if exists {
				panic(ErrMisuseApplyFileContracts)
			}
		}

		fcd := modules.FileContractDiff{
			Direction:    modules.DiffApply,
			ID:           fcid,
			FileContract: fc,
		}
		bn.fileContractDiffs = append(bn.fileContractDiffs, fcd)
		cs.commitFileContractDiff(fcd, modules.DiffApply)

		// Get the portion of the contract that goes into the siafund pool and
		// add it to the siafund pool.
		sfpd := modules.SiafundPoolDiff{
			Previous: cs.siafundPool,
			Adjusted: cs.siafundPool.Add(fc.Tax()),
		}
		bn.siafundPoolDiffs = append(bn.siafundPoolDiffs, sfpd)
		cs.commitSiafundPoolDiff(sfpd, modules.DiffApply)
	}
	return
}
Exemplo n.º 3
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// validTransaction checks that all fields are valid within the current
// consensus state. If not an error is returned.
func validTransaction(tx *bolt.Tx, t types.Transaction) error {
	// StandaloneValid will check things like signatures and properties that
	// should be inherent to the transaction. (storage proof rules, etc.)
	err := t.StandaloneValid(blockHeight(tx))
	if err != nil {
		return err
	}

	// Check that each portion of the transaction is legal given the current
	// consensus set.
	err = validSiacoins(tx, t)
	if err != nil {
		return err
	}
	err = validStorageProofs(tx, t)
	if err != nil {
		return err
	}
	err = validFileContractRevisions(tx, t)
	if err != nil {
		return err
	}
	err = validSiafunds(tx, t)
	if err != nil {
		return err
	}
	return nil
}
Exemplo n.º 4
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Arquivo: valid.go Projeto: mm3/Sia
// validUnconfirmedTransaction checks that the transaction would be valid in a
// block that contained all of the other unconfirmed transactions.
func (tp *TransactionPool) validUnconfirmedTransaction(t types.Transaction) (err error) {
	// Check that the transaction follows 'Standard.md' guidelines.
	err = tp.IsStandardTransaction(t)
	if err != nil {
		return
	}

	// StandaloneValid will check things like signatures and properties that
	// should be inherent to the transaction. (storage proof rules, etc.)
	err = t.StandaloneValid(tp.consensusSetHeight)
	if err != nil {
		return
	}

	// Check the validity of the componenets in the context of the confirmed
	// and unconfirmed set.
	err = tp.validUnconfirmedSiacoins(t)
	if err != nil {
		return
	}
	err = tp.validUnconfirmedStorageProofs(t)
	if err != nil {
		return
	}
	err = tp.validUnconfirmedFileContractRevisions(t)
	if err != nil {
		return
	}
	err = tp.validUnconfirmedSiafunds(t)
	if err != nil {
		return
	}

	return
}
Exemplo n.º 5
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// validSiacoins checks that the siacoin inputs and outputs are valid in the
// context of the current consensus set.
func validSiacoins(tx *bolt.Tx, t types.Transaction) error {
	scoBucket := tx.Bucket(SiacoinOutputs)
	var inputSum types.Currency
	for _, sci := range t.SiacoinInputs {
		// Check that the input spends an existing output.
		scoBytes := scoBucket.Get(sci.ParentID[:])
		if scoBytes == nil {
			return errMissingSiacoinOutput
		}

		// Check that the unlock conditions match the required unlock hash.
		var sco types.SiacoinOutput
		err := encoding.Unmarshal(scoBytes, &sco)
		if build.DEBUG && err != nil {
			panic(err)
		}
		if sci.UnlockConditions.UnlockHash() != sco.UnlockHash {
			return errWrongUnlockConditions
		}

		inputSum = inputSum.Add(sco.Value)
	}
	if inputSum.Cmp(t.SiacoinOutputSum()) != 0 {
		return errSiacoinInputOutputMismatch
	}
	return nil
}
Exemplo n.º 6
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// applySiacoinOutputs takes all of the siacoin outputs in a transaction and
// applies them to the state, updating the diffs in the processed block.
func applySiacoinOutputs(tx *bolt.Tx, pb *processedBlock, t types.Transaction) {
	// Add all siacoin outputs to the unspent siacoin outputs list.
	for i, sco := range t.SiacoinOutputs {
		scoid := t.SiacoinOutputID(uint64(i))
		scod := modules.SiacoinOutputDiff{
			Direction:     modules.DiffApply,
			ID:            scoid,
			SiacoinOutput: sco,
		}
		pb.SiacoinOutputDiffs = append(pb.SiacoinOutputDiffs, scod)
		commitSiacoinOutputDiff(tx, scod, modules.DiffApply)
	}
}
Exemplo n.º 7
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// applySiafundOutput applies a siafund output to the consensus set.
func applySiafundOutputs(tx *bolt.Tx, pb *processedBlock, t types.Transaction) {
	for i, sfo := range t.SiafundOutputs {
		sfoid := t.SiafundOutputID(uint64(i))
		sfo.ClaimStart = getSiafundPool(tx)
		sfod := modules.SiafundOutputDiff{
			Direction:     modules.DiffApply,
			ID:            sfoid,
			SiafundOutput: sfo,
		}
		pb.SiafundOutputDiffs = append(pb.SiafundOutputDiffs, sfod)
		commitSiafundOutputDiff(tx, sfod, modules.DiffApply)
	}
}
Exemplo n.º 8
0
Arquivo: update.go Projeto: mm3/Sia
// removeSiafundOutputs removes all of the siafund outputs of a transaction
// from the unconfirmed consensus set.
func (tp *TransactionPool) removeSiafundOutputs(t types.Transaction) {
	for i, _ := range t.SiafundOutputs {
		// Sanity check - the output should exist in the unconfirmed set as
		// there is no dependent transaction which could have spent the output.
		sfoid := t.SiafundOutputID(i)
		if build.DEBUG {
			_, exists := tp.siafundOutputs[sfoid]
			if !exists {
				panic("trying to remove nonexisting siafund output from unconfirmed set")
			}
		}

		delete(tp.siafundOutputs, sfoid)
	}
}
Exemplo n.º 9
0
Arquivo: update.go Projeto: mm3/Sia
// removeSiacoinOutputs removes all of the siacoin outputs of a transaction
// from the unconfirmed consensus set.
func (tp *TransactionPool) removeSiacoinOutputs(t types.Transaction) {
	for i, _ := range t.SiacoinOutputs {
		scoid := t.SiacoinOutputID(i)
		// Sanity check - the output should exist in the unconfirmed set as
		// there should be no transaction dependents who have spent the output.
		if build.DEBUG {
			_, exists := tp.siacoinOutputs[scoid]
			if !exists {
				panic("trying to delete missing siacoin output")
			}
		}

		delete(tp.siacoinOutputs, scoid)
	}
}
Exemplo n.º 10
0
Arquivo: update.go Projeto: mm3/Sia
// removeFileContracts removes all of the file contracts of a transaction from
// the unconfirmed consensus set.
func (tp *TransactionPool) removeFileContracts(t types.Transaction) {
	for i, _ := range t.FileContracts {
		fcid := t.FileContractID(i)
		// Sanity check - file contract should be in the unconfirmed set as
		// there should be no dependent transactions who have terminated the
		// contract.
		if build.DEBUG {
			_, exists := tp.fileContracts[fcid]
			if !exists {
				panic("trying to remove missing file contract")
			}
		}

		delete(tp.fileContracts, fcid)
	}
}
Exemplo n.º 11
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// applySiafundOutput applies a siafund output to the consensus set.
func (cs *ConsensusSet) applySiafundOutputs(tx *bolt.Tx, pb *processedBlock, t types.Transaction) error {
	for i, sfo := range t.SiafundOutputs {
		sfoid := t.SiafundOutputID(i)
		sfo.ClaimStart = getSiafundPool(tx)
		sfod := modules.SiafundOutputDiff{
			Direction:     modules.DiffApply,
			ID:            sfoid,
			SiafundOutput: sfo,
		}
		pb.SiafundOutputDiffs = append(pb.SiafundOutputDiffs, sfod)
		err := cs.commitTxSiafundOutputDiff(tx, sfod, modules.DiffApply)
		if err != nil {
			return err
		}
	}
	return nil
}
Exemplo n.º 12
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// applySiacoinOutputs takes all of the siacoin outputs in a transaction and
// applies them to the state, updating the diffs in the processed block.
func (cs *ConsensusSet) applySiacoinOutputs(tx *bolt.Tx, pb *processedBlock, t types.Transaction) error {
	// Add all siacoin outputs to the unspent siacoin outputs list.
	scoBucket := tx.Bucket(SiacoinOutputs)
	for i, sco := range t.SiacoinOutputs {
		scoid := t.SiacoinOutputID(i)
		scod := modules.SiacoinOutputDiff{
			Direction:     modules.DiffApply,
			ID:            scoid,
			SiacoinOutput: sco,
		}
		pb.SiacoinOutputDiffs = append(pb.SiacoinOutputDiffs, scod)
		err := cs.commitBucketSiacoinOutputDiff(scoBucket, scod, modules.DiffApply)
		if err != nil {
			return err
		}
	}
	return nil
}
Exemplo n.º 13
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// reviseObligation takes a file contract revision + transaction and applies it
// to an existing obligation.
func (h *Host) reviseObligation(revisionTransaction types.Transaction) {
	// Sanity checks - there should be exactly one revision in the transaction,
	// and that revision should correspond to a known obligation.
	fcrlen := len(revisionTransaction.FileContractRevisions)
	if fcrlen != 1 {
		h.log.Critical("reviseObligation: revisionTransaction has the wrong number of revisions:", fcrlen)
		return
	}
	obligation, exists := h.obligationsByID[revisionTransaction.FileContractRevisions[0].ParentID]
	if !exists {
		h.log.Critical("reviseObligation: revisionTransaction has no corresponding obligation")
		return
	}
	// Expensive Sanity check - obligation being added should have a valid tranasction.
	if build.DEBUG {
		err := revisionTransaction.StandaloneValid(h.blockHeight)
		if err != nil {
			h.log.Critical("invalid transaction is being added in an obligation")
		}
	}

	// Update the host's statistics.
	h.spaceRemaining += int64(obligation.fileSize())
	h.spaceRemaining -= int64(revisionTransaction.FileContractRevisions[0].NewFileSize)
	h.anticipatedRevenue = h.anticipatedRevenue.Sub(obligation.value())
	h.anticipatedRevenue = h.anticipatedRevenue.Add(revisionTransaction.FileContractRevisions[0].NewValidProofOutputs[1].Value)

	// The host needs to verify that the revision transaction made it into the
	// blockchain.
	h.addActionItem(h.blockHeight+resubmissionTimeout, obligation)

	// Add the revision to the obligation
	obligation.RevisionTransaction = revisionTransaction
	obligation.RevisionConfirmed = false

	err := obligation.isSane()
	if err != nil {
		h.log.Critical("reviseObligation: obligation is not sane: " + err.Error())
	}
	err = h.save()
	if err != nil {
		h.log.Println("WARN: failed to save host:", err)
	}
}
Exemplo n.º 14
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// TestDuplicateStorageProof applies a storage proof which has already been
// applied.
func TestDuplicateStorageProof(t *testing.T) {
	if testing.Short() {
		t.SkipNow()
	}
	cst, err := createConsensusSetTester("TestDuplicateStorageProof")
	if err != nil {
		t.Fatal(err)
	}

	// Create a block node.
	bn := new(blockNode)
	bn.height = cst.cs.height()

	// Create a file contract for the storage proof to prove.
	txn0 := types.Transaction{
		FileContracts: []types.FileContract{
			{
				Payout: types.NewCurrency64(300e3),
				ValidProofOutputs: []types.SiacoinOutput{
					{Value: types.NewCurrency64(290e3)},
				},
			},
		},
	}
	cst.cs.applyFileContracts(bn, txn0)
	fcid := txn0.FileContractID(0)

	// Apply a single storage proof.
	txn1 := types.Transaction{
		StorageProofs: []types.StorageProof{{ParentID: fcid}},
	}
	cst.cs.applyStorageProofs(bn, txn1)

	// Trigger a panic by applying the storage proof again.
	defer func() {
		r := recover()
		if r != ErrDuplicateValidProofOutput {
			t.Error("failed to trigger ErrDuplicateValidProofOutput:", r)
		}
	}()
	cst.cs.applyFileContracts(bn, txn0) // File contract was consumed by the first proof.
	cst.cs.applyStorageProofs(bn, txn1)
}
Exemplo n.º 15
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// addSignatures will sign a transaction using a spendable key, with support
// for multisig spendable keys. Because of the restricted input, the function
// is compatible with both siacoin inputs and siafund inputs.
func addSignatures(txn *types.Transaction, cf types.CoveredFields, uc types.UnlockConditions, parentID crypto.Hash, spendKey spendableKey) (newSigIndices []int, err error) {
	// Try to find the matching secret key for each public key - some public
	// keys may not have a match. Some secret keys may be used multiple times,
	// which is why public keys are used as the outer loop.
	totalSignatures := uint64(0)
	for i, siaPubKey := range uc.PublicKeys {
		// Search for the matching secret key to the public key.
		for j := range spendKey.SecretKeys {
			pubKey := spendKey.SecretKeys[j].PublicKey()
			if bytes.Compare(siaPubKey.Key, pubKey[:]) != 0 {
				continue
			}

			// Found the right secret key, add a signature.
			sig := types.TransactionSignature{
				ParentID:       parentID,
				CoveredFields:  cf,
				PublicKeyIndex: uint64(i),
			}
			newSigIndices = append(newSigIndices, len(txn.TransactionSignatures))
			txn.TransactionSignatures = append(txn.TransactionSignatures, sig)
			sigIndex := len(txn.TransactionSignatures) - 1
			sigHash := txn.SigHash(sigIndex)
			encodedSig, err := crypto.SignHash(sigHash, spendKey.SecretKeys[j])
			if err != nil {
				return nil, err
			}
			txn.TransactionSignatures[sigIndex].Signature = encodedSig[:]

			// Count that the signature has been added, and break out of the
			// secret key loop.
			totalSignatures++
			break
		}

		// If there are enough signatures to satisfy the unlock conditions,
		// break out of the outer loop.
		if totalSignatures == uc.SignaturesRequired {
			break
		}
	}
	return newSigIndices, nil
}
Exemplo n.º 16
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// applySiacoinOutputs takes all of the siacoin outputs in a transaction and
// applies them to the state, updating the diffs in the block node.
func (cs *State) applySiacoinOutputs(bn *blockNode, t types.Transaction) {
	// Add all siacoin outputs to the unspent siacoin outputs list.
	for i, sco := range t.SiacoinOutputs {
		// Sanity check - the output should not exist within the state.
		scoid := t.SiacoinOutputID(i)
		if build.DEBUG {
			_, exists := cs.siacoinOutputs[scoid]
			if exists {
				panic(ErrMisuseApplySiacoinOutput)
			}
		}

		scod := modules.SiacoinOutputDiff{
			Direction:     modules.DiffApply,
			ID:            scoid,
			SiacoinOutput: sco,
		}
		bn.siacoinOutputDiffs = append(bn.siacoinOutputDiffs, scod)
		cs.commitSiacoinOutputDiff(scod, modules.DiffApply)
	}
}
Exemplo n.º 17
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// VerifyFileContractRevisionTransactionSignatures checks that the signatures
// on a file contract revision are valid and cover the right fields.
func VerifyFileContractRevisionTransactionSignatures(fcr types.FileContractRevision, tsigs []types.TransactionSignature, height types.BlockHeight) error {
	if len(tsigs) != 2 {
		return ErrRevisionSigCount
	}
	for _, tsig := range tsigs {
		// The transaction needs to be malleable so that miner fees can be
		// added. If the whole transaction is covered, it is doomed to have no
		// fees.
		if tsig.CoveredFields.WholeTransaction {
			return ErrRevisionCoveredFields
		}
	}
	txn := types.Transaction{
		FileContractRevisions: []types.FileContractRevision{fcr},
		TransactionSignatures: tsigs,
	}
	// Check that the signatures verify. This will also check that the covered
	// fields object is not over-aggressive, because if the object is pointing
	// to elements that haven't been added to the transaction, verification
	// will fail.
	return txn.StandaloneValid(height)
}
Exemplo n.º 18
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// addSignatures will sign a transaction using a spendable key, with support
// for multisig spendable keys. Because of the restricted input, the function
// is compatible with both siacoin inputs and siafund inputs.
func addSignatures(txn *types.Transaction, cf types.CoveredFields, uc types.UnlockConditions, parentID crypto.Hash, key spendableKey) error {
	usedIndices := make(map[int]struct{})
	for i := range key.secretKeys {
		found := false
		keyIndex := 0
		pubKey := key.secretKeys[i].PublicKey()
		for i, siaPublicKey := range uc.PublicKeys {
			_, exists := usedIndices[i]
			if !exists && bytes.Compare(pubKey[:], siaPublicKey.Key) == 0 {
				found = true
				keyIndex = i
				break
			}
		}
		if !found && build.DEBUG {
			panic("transaction builder cannot sign an input that it added")
		}
		usedIndices[keyIndex] = struct{}{}

		// Create the unsigned transaction signature.
		sig := types.TransactionSignature{
			ParentID:       parentID,
			CoveredFields:  cf,
			PublicKeyIndex: uint64(keyIndex),
		}
		txn.TransactionSignatures = append(txn.TransactionSignatures, sig)

		// Get the signature.
		sigIndex := len(txn.TransactionSignatures) - 1
		sigHash := txn.SigHash(sigIndex)
		encodedSig, err := crypto.SignHash(sigHash, key.secretKeys[i])
		if err != nil {
			return err
		}
		txn.TransactionSignatures[sigIndex].Signature = encodedSig[:]
	}
	return nil
}
Exemplo n.º 19
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// negotiateRevision sends the revision and new piece data to the host.
func negotiateRevision(conn net.Conn, rev types.FileContractRevision, piece []byte, secretKey crypto.SecretKey) (types.Transaction, error) {
	conn.SetDeadline(time.Now().Add(5 * time.Minute)) // sufficient to transfer 4 MB over 100 kbps
	defer conn.SetDeadline(time.Time{})               // reset timeout after each revision

	// create transaction containing the revision
	signedTxn := types.Transaction{
		FileContractRevisions: []types.FileContractRevision{rev},
		TransactionSignatures: []types.TransactionSignature{{
			ParentID:       crypto.Hash(rev.ParentID),
			CoveredFields:  types.CoveredFields{FileContractRevisions: []uint64{0}},
			PublicKeyIndex: 0, // renter key is always first -- see negotiateContract
		}},
	}
	// sign the transaction
	encodedSig, _ := crypto.SignHash(signedTxn.SigHash(0), secretKey) // no error possible
	signedTxn.TransactionSignatures[0].Signature = encodedSig[:]

	// send the transaction
	if err := encoding.WriteObject(conn, signedTxn); err != nil {
		return types.Transaction{}, errors.New("couldn't send revision transaction: " + err.Error())
	}

	// host sends acceptance
	var response string
	if err := encoding.ReadObject(conn, &response, 128); err != nil {
		return types.Transaction{}, errors.New("couldn't read host acceptance: " + err.Error())
	}
	if response != modules.AcceptResponse {
		return types.Transaction{}, errors.New("host rejected revision: " + response)
	}

	// transfer piece
	if _, err := conn.Write(piece); err != nil {
		return types.Transaction{}, errors.New("couldn't transfer piece: " + err.Error())
	}

	// read txn signed by host
	var signedHostTxn types.Transaction
	if err := encoding.ReadObject(conn, &signedHostTxn, types.BlockSizeLimit); err != nil {
		return types.Transaction{}, errors.New("couldn't read signed revision transaction: " + err.Error())
	}

	if signedHostTxn.ID() != signedTxn.ID() {
		return types.Transaction{}, errors.New("host sent bad signed transaction")
	}

	return signedHostTxn, nil
}
Exemplo n.º 20
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// applyFileContracts iterates through all of the file contracts in a
// transaction and applies them to the state, updating the diffs in the proccesed
// block.
func applyFileContracts(tx *bolt.Tx, pb *processedBlock, t types.Transaction) {
	for i, fc := range t.FileContracts {
		fcid := t.FileContractID(uint64(i))
		fcd := modules.FileContractDiff{
			Direction:    modules.DiffApply,
			ID:           fcid,
			FileContract: fc,
		}
		pb.FileContractDiffs = append(pb.FileContractDiffs, fcd)
		commitFileContractDiff(tx, fcd, modules.DiffApply)

		// Get the portion of the contract that goes into the siafund pool and
		// add it to the siafund pool.
		sfp := getSiafundPool(tx)
		sfpd := modules.SiafundPoolDiff{
			Direction: modules.DiffApply,
			Previous:  sfp,
			Adjusted:  sfp.Add(types.Tax(blockHeight(tx), fc.Payout)),
		}
		pb.SiafundPoolDiffs = append(pb.SiafundPoolDiffs, sfpd)
		commitSiafundPoolDiff(tx, sfpd, modules.DiffApply)
	}
}
Exemplo n.º 21
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// applyFileContracts iterates through all of the file contracts in a
// transaction and applies them to the state, updating the diffs in the proccesed
// block.
func (cs *ConsensusSet) applyFileContracts(tx *bolt.Tx, pb *processedBlock, t types.Transaction) error {
	for i, fc := range t.FileContracts {
		fcid := t.FileContractID(i)
		fcd := modules.FileContractDiff{
			Direction:    modules.DiffApply,
			ID:           fcid,
			FileContract: fc,
		}
		pb.FileContractDiffs = append(pb.FileContractDiffs, fcd)
		cs.commitTxFileContractDiff(tx, fcd, modules.DiffApply)

		// Get the portion of the contract that goes into the siafund pool and
		// add it to the siafund pool.
		sfp := getSiafundPool(tx)
		sfpd := modules.SiafundPoolDiff{
			Direction: modules.DiffApply,
			Previous:  sfp,
			Adjusted:  sfp.Add(fc.Tax()),
		}
		pb.SiafundPoolDiffs = append(pb.SiafundPoolDiffs, sfpd)
		cs.commitTxSiafundPoolDiff(tx, sfpd, modules.DiffApply)
	}
	return nil
}
Exemplo n.º 22
0
Arquivo: valid.go Projeto: mm3/Sia
// validUnconfirmedSiacoins checks that all siacoin inputs and outputs are
// valid in the context of the unconfirmed consensus set.
func (tp *TransactionPool) validUnconfirmedSiacoins(t types.Transaction) (err error) {
	var inputSum types.Currency
	for _, sci := range t.SiacoinInputs {
		// All inputs must have corresponding outputs in the unconfirmed set.
		sco, exists := tp.siacoinOutputs[sci.ParentID]
		if !exists {
			return ErrUnrecognizedSiacoinInput
		}

		// The unlock conditions provided must match the unlock hash of the
		// corresponding output.
		if sci.UnlockConditions.UnlockHash() != sco.UnlockHash {
			return ErrBadUnlockConditions
		}

		inputSum = inputSum.Add(sco.Value)
	}

	// The sum of all inputs must equal the sum of all outputs.
	if inputSum.Cmp(t.SiacoinOutputSum()) != 0 {
		return ErrSiacoinOverspend
	}
	return
}
Exemplo n.º 23
0
// applySiafundOutputs takes all of the siafund outputs in a transaction and
// applies them to the state, updating the diffs in the block node.
func (cs *State) applySiafundOutputs(bn *blockNode, t types.Transaction) {
	for i, sfo := range t.SiafundOutputs {
		// Sanity check - the output should not exist within the blockchain.
		sfoid := t.SiafundOutputID(i)
		if build.DEBUG {
			_, exists := cs.siafundOutputs[sfoid]
			if exists {
				panic(ErrMisuseApplySiafundOutput)
			}
		}

		// Set the claim start.
		sfo.ClaimStart = cs.siafundPool

		// Create and apply the diff.
		sfod := modules.SiafundOutputDiff{
			Direction:     modules.DiffApply,
			ID:            sfoid,
			SiafundOutput: sfo,
		}
		bn.siafundOutputDiffs = append(bn.siafundOutputDiffs, sfod)
		cs.commitSiafundOutputDiff(sfod, modules.DiffApply)
	}
}
Exemplo n.º 24
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// createRevisionSignature creates a signature for a file contract revision
// that signs on the file contract revision. The renter should have already
// provided the signature. createRevisionSignature will check to make sure that
// the renter's signature is valid.
func createRevisionSignature(fcr types.FileContractRevision, renterSig types.TransactionSignature, secretKey crypto.SecretKey, blockHeight types.BlockHeight) (types.Transaction, error) {
	hostSig := types.TransactionSignature{
		ParentID:       crypto.Hash(fcr.ParentID),
		PublicKeyIndex: 1,
		CoveredFields: types.CoveredFields{
			FileContractRevisions: []uint64{0},
		},
	}
	txn := types.Transaction{
		FileContractRevisions: []types.FileContractRevision{fcr},
		TransactionSignatures: []types.TransactionSignature{renterSig, hostSig},
	}
	sigHash := txn.SigHash(1)
	encodedSig, err := crypto.SignHash(sigHash, secretKey)
	if err != nil {
		return types.Transaction{}, err
	}
	txn.TransactionSignatures[1].Signature = encodedSig[:]
	err = modules.VerifyFileContractRevisionTransactionSignatures(fcr, txn.TransactionSignatures, blockHeight)
	if err != nil {
		return types.Transaction{}, err
	}
	return txn, nil
}
Exemplo n.º 25
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// verifyKeysSiag_1_0 is a copy-pasted version of the verifyKeys method
// from siag 1.0.
func verifyKeysSiag_1_0(uc types.UnlockConditions, folder string, keyname string) error {
	keysRequired := uc.SignaturesRequired
	totalKeys := uint64(len(uc.PublicKeys))
	loadedKeys := make([]KeyPairSiag_1_0, totalKeys)
	for i := 0; i < len(loadedKeys); i++ {
		err := encoding.ReadFile(filepath.Join(folder, keyname+"_Key"+strconv.Itoa(i)+".siakey"), &loadedKeys[i])
		if err != nil {
			return err
		}
	}
	for _, loadedKey := range loadedKeys {
		if loadedKey.UnlockConditions.UnlockHash() != uc.UnlockHash() {
			return errors.New("ErrCorruptedKey")
		}
	}
	txn := types.Transaction{
		SiafundInputs: []types.SiafundInput{
			types.SiafundInput{
				UnlockConditions: loadedKeys[0].UnlockConditions,
			},
		},
	}
	var i uint64
	for i != totalKeys {
		if i+keysRequired > totalKeys {
			i = totalKeys - keysRequired
		}
		var j uint64
		for j < keysRequired {
			txn.TransactionSignatures = append(txn.TransactionSignatures, types.TransactionSignature{
				PublicKeyIndex: i,
				CoveredFields:  types.CoveredFields{WholeTransaction: true},
			})
			sigHash := txn.SigHash(int(j))
			sig, err := crypto.SignHash(sigHash, loadedKeys[i].SecretKey)
			if err != nil {
				return err
			}
			txn.TransactionSignatures[j].Signature = sig[:]
			i++
			j++
		}
		err := txn.StandaloneValid(0)
		if err != nil {
			return err
		}
		txn.TransactionSignatures = nil
	}
	return nil
}
Exemplo n.º 26
0
// negotiateRevision sends a revision and actions to the host for approval,
// completing one iteration of the revision loop.
func negotiateRevision(conn net.Conn, rev types.FileContractRevision, secretKey crypto.SecretKey) (types.Transaction, error) {
	// create transaction containing the revision
	signedTxn := types.Transaction{
		FileContractRevisions: []types.FileContractRevision{rev},
		TransactionSignatures: []types.TransactionSignature{{
			ParentID:       crypto.Hash(rev.ParentID),
			CoveredFields:  types.CoveredFields{FileContractRevisions: []uint64{0}},
			PublicKeyIndex: 0, // renter key is always first -- see formContract
		}},
	}
	// sign the transaction
	encodedSig, _ := crypto.SignHash(signedTxn.SigHash(0), secretKey) // no error possible
	signedTxn.TransactionSignatures[0].Signature = encodedSig[:]

	// send the revision
	if err := encoding.WriteObject(conn, rev); err != nil {
		return types.Transaction{}, errors.New("couldn't send revision: " + err.Error())
	}
	// read acceptance
	if err := modules.ReadNegotiationAcceptance(conn); err != nil {
		return types.Transaction{}, errors.New("host did not accept revision: " + err.Error())
	}

	// send the new transaction signature
	if err := encoding.WriteObject(conn, signedTxn.TransactionSignatures[0]); err != nil {
		return types.Transaction{}, errors.New("couldn't send transaction signature: " + err.Error())
	}
	// read the host's acceptance and transaction signature
	// NOTE: if the host sends ErrStopResponse, we should continue processing
	// the revision, but return the error anyway.
	responseErr := modules.ReadNegotiationAcceptance(conn)
	if responseErr != nil && responseErr != modules.ErrStopResponse {
		return types.Transaction{}, errors.New("host did not accept transaction signature: " + responseErr.Error())
	}
	var hostSig types.TransactionSignature
	if err := encoding.ReadObject(conn, &hostSig, 16e3); err != nil {
		return types.Transaction{}, errors.New("couldn't read host's signature: " + err.Error())
	}

	// add the signature to the transaction and verify it
	// NOTE: we can fake the blockheight here because it doesn't affect
	// verification; it just needs to be above the fork height and below the
	// contract expiration (which was checked earlier).
	verificationHeight := rev.NewWindowStart - 1
	signedTxn.TransactionSignatures = append(signedTxn.TransactionSignatures, hostSig)
	if err := signedTxn.StandaloneValid(verificationHeight); err != nil {
		return types.Transaction{}, err
	}

	// if the host sent ErrStopResponse, return it
	return signedTxn, responseErr
}
Exemplo n.º 27
0
// TestPartialConfirmationWeave checks that the transaction pool correctly
// accepts a transaction set which has parents that have been accepted by the
// consensus set but not the whole set has been accepted by the consensus set,
// this time weaving the dependencies, such that the first transaction is not
// in the consensus set, the second is, and the third has both as dependencies.
func TestPartialConfirmationWeave(t *testing.T) {
	if testing.Short() {
		t.SkipNow()
	}
	tpt, err := createTpoolTester("TestPartialConfirmation")
	if err != nil {
		t.Fatal(err)
	}
	defer tpt.Close()

	// Step 1: create an output to the empty address in a tx.
	// Step 2: create a second output to the empty address in another tx.
	// Step 3: create a transaction using both those outputs.
	// Step 4: mine the txn set in step 2
	// Step 5: Submit the complete set.

	// Create a transaction with a single output to a fully controlled address.
	emptyUH := types.UnlockConditions{}.UnlockHash()
	builder1 := tpt.wallet.StartTransaction()
	funding1 := types.NewCurrency64(1e9)
	err = builder1.FundSiacoins(funding1)
	if err != nil {
		t.Fatal(err)
	}
	scOutput1 := types.SiacoinOutput{
		Value:      funding1,
		UnlockHash: emptyUH,
	}
	i1 := builder1.AddSiacoinOutput(scOutput1)
	tSet1, err := builder1.Sign(true)
	if err != nil {
		t.Fatal(err)
	}
	// Submit to the transaction pool and mine the block, to minimize
	// complexity.
	err = tpt.tpool.AcceptTransactionSet(tSet1)
	if err != nil {
		t.Fatal(err)
	}
	_, err = tpt.miner.AddBlock()
	if err != nil {
		t.Fatal(err)
	}

	// Create a second output to the fully controlled address, to fund the
	// second transaction in the weave.
	builder2 := tpt.wallet.StartTransaction()
	funding2 := types.NewCurrency64(2e9)
	err = builder2.FundSiacoins(funding2)
	if err != nil {
		t.Fatal(err)
	}
	scOutput2 := types.SiacoinOutput{
		Value:      funding2,
		UnlockHash: emptyUH,
	}
	i2 := builder2.AddSiacoinOutput(scOutput2)
	tSet2, err := builder2.Sign(true)
	if err != nil {
		t.Fatal(err)
	}
	// Submit to the transaction pool and mine the block, to minimize
	// complexity.
	err = tpt.tpool.AcceptTransactionSet(tSet2)
	if err != nil {
		t.Fatal(err)
	}
	_, err = tpt.miner.AddBlock()
	if err != nil {
		t.Fatal(err)
	}

	// Create a passthrough transaction for output1 and output2, so that they
	// can be used as unconfirmed dependencies.
	txn1 := types.Transaction{
		SiacoinInputs: []types.SiacoinInput{{
			ParentID: tSet1[len(tSet1)-1].SiacoinOutputID(i1),
		}},
		SiacoinOutputs: []types.SiacoinOutput{{
			Value:      funding1,
			UnlockHash: emptyUH,
		}},
	}
	txn2 := types.Transaction{
		SiacoinInputs: []types.SiacoinInput{{
			ParentID: tSet2[len(tSet2)-1].SiacoinOutputID(i2),
		}},
		SiacoinOutputs: []types.SiacoinOutput{{
			Value:      funding2,
			UnlockHash: emptyUH,
		}},
	}

	// Create a child transaction that depends on inputs from both txn1 and
	// txn2.
	child := types.Transaction{
		SiacoinInputs: []types.SiacoinInput{
			{
				ParentID: txn1.SiacoinOutputID(0),
			},
			{
				ParentID: txn2.SiacoinOutputID(0),
			},
		},
		SiacoinOutputs: []types.SiacoinOutput{{
			Value: funding1.Add(funding2),
		}},
	}

	// Get txn2 accepted into the consensus set.
	err = tpt.tpool.AcceptTransactionSet([]types.Transaction{txn2})
	if err != nil {
		t.Fatal(err)
	}
	_, err = tpt.miner.AddBlock()
	if err != nil {
		t.Fatal(err)
	}

	// Try to get the set of txn1, txn2, and child accepted into the
	// transaction pool.
	err = tpt.tpool.AcceptTransactionSet([]types.Transaction{txn1, txn2, child})
	if err != nil {
		t.Fatal(err)
	}
}
Exemplo n.º 28
0
// FundSiafunds will add a siafund input of exaclty 'amount' to the
// transaction. A parent transaction may be needed to achieve an input with the
// correct value. The siafund input will not be signed until 'Sign' is called
// on the transaction builder.
func (tb *transactionBuilder) FundSiafunds(amount types.Currency) error {
	tb.wallet.mu.Lock()
	defer tb.wallet.mu.Unlock()

	// Create and fund a parent transaction that will add the correct amount of
	// siafunds to the transaction.
	var fund types.Currency
	var potentialFund types.Currency
	parentTxn := types.Transaction{}
	var spentSfoids []types.SiafundOutputID
	for sfoid, sfo := range tb.wallet.siafundOutputs {
		// Check that this output has not recently been spent by the wallet.
		spendHeight := tb.wallet.spentOutputs[types.OutputID(sfoid)]
		// Prevent an underflow error.
		allowedHeight := tb.wallet.consensusSetHeight - RespendTimeout
		if tb.wallet.consensusSetHeight < RespendTimeout {
			allowedHeight = 0
		}
		if spendHeight > allowedHeight {
			potentialFund = potentialFund.Add(sfo.Value)
			continue
		}
		outputUnlockConditions := tb.wallet.keys[sfo.UnlockHash].UnlockConditions
		if tb.wallet.consensusSetHeight < outputUnlockConditions.Timelock {
			continue
		}

		// Add a siafund input for this output.
		parentClaimUnlockConditions, err := tb.wallet.nextPrimarySeedAddress()
		if err != nil {
			return err
		}
		sfi := types.SiafundInput{
			ParentID:         sfoid,
			UnlockConditions: outputUnlockConditions,
			ClaimUnlockHash:  parentClaimUnlockConditions.UnlockHash(),
		}
		parentTxn.SiafundInputs = append(parentTxn.SiafundInputs, sfi)
		spentSfoids = append(spentSfoids, sfoid)

		// Add the output to the total fund
		fund = fund.Add(sfo.Value)
		potentialFund = potentialFund.Add(sfo.Value)
		if fund.Cmp(amount) >= 0 {
			break
		}
	}
	if potentialFund.Cmp(amount) >= 0 && fund.Cmp(amount) < 0 {
		return modules.ErrPotentialDoubleSpend
	}
	if fund.Cmp(amount) < 0 {
		return modules.ErrLowBalance
	}

	// Create and add the output that will be used to fund the standard
	// transaction.
	parentUnlockConditions, err := tb.wallet.nextPrimarySeedAddress()
	if err != nil {
		return err
	}
	exactOutput := types.SiafundOutput{
		Value:      amount,
		UnlockHash: parentUnlockConditions.UnlockHash(),
	}
	parentTxn.SiafundOutputs = append(parentTxn.SiafundOutputs, exactOutput)

	// Create a refund output if needed.
	if amount.Cmp(fund) != 0 {
		refundUnlockConditions, err := tb.wallet.nextPrimarySeedAddress()
		if err != nil {
			return err
		}
		refundOutput := types.SiafundOutput{
			Value:      fund.Sub(amount),
			UnlockHash: refundUnlockConditions.UnlockHash(),
		}
		parentTxn.SiafundOutputs = append(parentTxn.SiafundOutputs, refundOutput)
	}

	// Sign all of the inputs to the parent trancstion.
	for _, sfi := range parentTxn.SiafundInputs {
		_, err := addSignatures(&parentTxn, types.FullCoveredFields, sfi.UnlockConditions, crypto.Hash(sfi.ParentID), tb.wallet.keys[sfi.UnlockConditions.UnlockHash()])
		if err != nil {
			return err
		}
	}

	// Add the exact output.
	claimUnlockConditions, err := tb.wallet.nextPrimarySeedAddress()
	if err != nil {
		return err
	}
	newInput := types.SiafundInput{
		ParentID:         parentTxn.SiafundOutputID(0),
		UnlockConditions: parentUnlockConditions,
		ClaimUnlockHash:  claimUnlockConditions.UnlockHash(),
	}
	tb.newParents = append(tb.newParents, len(tb.parents))
	tb.parents = append(tb.parents, parentTxn)
	tb.siafundInputs = append(tb.siafundInputs, len(tb.transaction.SiafundInputs))
	tb.transaction.SiafundInputs = append(tb.transaction.SiafundInputs, newInput)

	// Mark all outputs that were spent as spent.
	for _, sfoid := range spentSfoids {
		tb.wallet.spentOutputs[types.OutputID(sfoid)] = tb.wallet.consensusSetHeight
	}
	return nil
}
Exemplo n.º 29
0
// managedRPCRevise is an RPC that allows a renter to revise a file contract. It will
// read new revisions in a loop until the renter sends a termination signal.
func (h *Host) managedRPCRevise(conn net.Conn) error {
	// read ID of contract to be revised
	var fcid types.FileContractID
	if err := encoding.ReadObject(conn, &fcid, crypto.HashSize); err != nil {
		return errors.New("couldn't read contract ID: " + err.Error())
	}

	// remove conn deadline while we wait for lock and rebuild the Merkle tree.
	err := conn.SetDeadline(time.Now().Add(15 * time.Minute))
	if err != nil {
		return err
	}

	h.mu.RLock()
	obligation, exists := h.obligationsByID[fcid]
	h.mu.RUnlock()
	if !exists {
		return errors.New("no record of that contract")
	}
	// need to protect against two simultaneous revisions to the same
	// contract; this can cause inconsistency and data loss, making storage
	// proofs impossible
	//
	// TODO: DOS vector - the host has locked the obligation even though the
	// renter has not proven themselves to be the owner of the file contract.
	obligation.mu.Lock()
	defer obligation.mu.Unlock()

	// open the file in append mode
	file, err := os.OpenFile(obligation.Path, os.O_CREATE|os.O_RDWR|os.O_APPEND, 0660)
	if err != nil {
		return err
	}

	// rebuild current Merkle tree
	tree := crypto.NewTree()
	err = tree.ReadSegments(file)
	if err != nil {
		// Error does not need to be checked when closing the file, already
		// there have been issues related to the filesystem.
		_ = file.Close()
		return err
	}

	// accept new revisions in a loop. The final good transaction will be
	// submitted to the blockchain.
	revisionErr := func() error {
		for {
			// allow 5 minutes between revisions
			err := conn.SetDeadline(time.Now().Add(5 * time.Minute))
			if err != nil {
				return err
			}

			// read proposed revision
			var revTxn types.Transaction
			if err = encoding.ReadObject(conn, &revTxn, types.BlockSizeLimit); err != nil {
				return errors.New("couldn't read revision: " + err.Error())
			}
			// an empty transaction indicates completion
			if revTxn.ID() == (types.Transaction{}).ID() {
				return nil
			}

			// allow 5 minutes for each revision
			err = conn.SetDeadline(time.Now().Add(5 * time.Minute))
			if err != nil {
				return err
			}

			// check revision against original file contract
			h.mu.RLock()
			err = h.considerRevision(revTxn, obligation)
			h.mu.RUnlock()
			if err != nil {
				// There is nothing that can be done if there is an error while
				// writing to a connection.
				_ = encoding.WriteObject(conn, err.Error())
				return err
			}

			// indicate acceptance
			if err := encoding.WriteObject(conn, modules.AcceptResponse); err != nil {
				return errors.New("couldn't write acceptance: " + err.Error())
			}

			// read piece
			// TODO: simultaneously read into tree and file
			rev := revTxn.FileContractRevisions[0]
			piece := make([]byte, rev.NewFileSize-obligation.fileSize())
			_, err = io.ReadFull(conn, piece)
			if err != nil {
				return errors.New("couldn't read piece data: " + err.Error())
			}

			// verify Merkle root
			err = tree.ReadSegments(bytes.NewReader(piece))
			if err != nil {
				return errors.New("couldn't verify Merkle root: " + err.Error())
			}
			if tree.Root() != rev.NewFileMerkleRoot {
				return errors.New("revision has bad Merkle root")
			}

			// manually sign the transaction
			revTxn.TransactionSignatures = append(revTxn.TransactionSignatures, types.TransactionSignature{
				ParentID:       crypto.Hash(fcid),
				CoveredFields:  types.CoveredFields{FileContractRevisions: []uint64{0}},
				PublicKeyIndex: 1, // host key is always second
			})
			encodedSig, err := crypto.SignHash(revTxn.SigHash(1), h.secretKey)
			if err != nil {
				return err
			}
			revTxn.TransactionSignatures[1].Signature = encodedSig[:]

			// append piece to file
			if _, err := file.Write(piece); err != nil {
				return errors.New("couldn't write new data to file: " + err.Error())
			}

			// save updated obligation to disk
			h.mu.Lock()
			h.reviseObligation(revTxn)
			h.mu.Unlock()

			// send the signed transaction - this must be the last thing that happens.
			if err := encoding.WriteObject(conn, revTxn); err != nil {
				return errors.New("couldn't write signed revision transaction: " + err.Error())
			}
		}
	}()
	err = file.Close()
	if err != nil {
		return err
	}

	err = h.tpool.AcceptTransactionSet([]types.Transaction{obligation.RevisionTransaction})
	if err != nil {
		h.log.Println("WARN: transaction pool rejected revision transaction: " + err.Error())
	}
	return revisionErr
}
Exemplo n.º 30
0
// FundSiacoins will add a siacoin input of exaclty 'amount' to the
// transaction. A parent transaction may be needed to achieve an input with the
// correct value. The siacoin input will not be signed until 'Sign' is called
// on the transaction builder.
func (tb *transactionBuilder) FundSiacoins(amount types.Currency) error {
	tb.wallet.mu.Lock()
	defer tb.wallet.mu.Unlock()

	// Collect a value-sorted set of siacoin outputs.
	var so sortedOutputs
	for scoid, sco := range tb.wallet.siacoinOutputs {
		so.ids = append(so.ids, scoid)
		so.outputs = append(so.outputs, sco)
	}
	// Add all of the unconfirmed outputs as well.
	for _, upt := range tb.wallet.unconfirmedProcessedTransactions {
		for i, sco := range upt.Transaction.SiacoinOutputs {
			// Determine if the output belongs to the wallet.
			_, exists := tb.wallet.keys[sco.UnlockHash]
			if !exists {
				continue
			}
			so.ids = append(so.ids, upt.Transaction.SiacoinOutputID(uint64(i)))
			so.outputs = append(so.outputs, sco)
		}
	}
	sort.Sort(sort.Reverse(so))

	// Create and fund a parent transaction that will add the correct amount of
	// siacoins to the transaction.
	var fund types.Currency
	// potentialFund tracks the balance of the wallet including outputs that
	// have been spent in other unconfirmed transactions recently. This is to
	// provide the user with a more useful error message in the event that they
	// are overspending.
	var potentialFund types.Currency
	parentTxn := types.Transaction{}
	var spentScoids []types.SiacoinOutputID
	for i := range so.ids {
		scoid := so.ids[i]
		sco := so.outputs[i]
		// Check that this output has not recently been spent by the wallet.
		spendHeight := tb.wallet.spentOutputs[types.OutputID(scoid)]
		// Prevent an underflow error.
		allowedHeight := tb.wallet.consensusSetHeight - RespendTimeout
		if tb.wallet.consensusSetHeight < RespendTimeout {
			allowedHeight = 0
		}
		if spendHeight > allowedHeight {
			potentialFund = potentialFund.Add(sco.Value)
			continue
		}
		outputUnlockConditions := tb.wallet.keys[sco.UnlockHash].UnlockConditions
		if tb.wallet.consensusSetHeight < outputUnlockConditions.Timelock {
			continue
		}

		// Add a siacoin input for this output.
		sci := types.SiacoinInput{
			ParentID:         scoid,
			UnlockConditions: outputUnlockConditions,
		}
		parentTxn.SiacoinInputs = append(parentTxn.SiacoinInputs, sci)
		spentScoids = append(spentScoids, scoid)

		// Add the output to the total fund
		fund = fund.Add(sco.Value)
		potentialFund = potentialFund.Add(sco.Value)
		if fund.Cmp(amount) >= 0 {
			break
		}
	}
	if potentialFund.Cmp(amount) >= 0 && fund.Cmp(amount) < 0 {
		return modules.ErrPotentialDoubleSpend
	}
	if fund.Cmp(amount) < 0 {
		return modules.ErrLowBalance
	}

	// Create and add the output that will be used to fund the standard
	// transaction.
	parentUnlockConditions, err := tb.wallet.nextPrimarySeedAddress()
	if err != nil {
		return err
	}
	exactOutput := types.SiacoinOutput{
		Value:      amount,
		UnlockHash: parentUnlockConditions.UnlockHash(),
	}
	parentTxn.SiacoinOutputs = append(parentTxn.SiacoinOutputs, exactOutput)

	// Create a refund output if needed.
	if amount.Cmp(fund) != 0 {
		refundUnlockConditions, err := tb.wallet.nextPrimarySeedAddress()
		if err != nil {
			return err
		}
		refundOutput := types.SiacoinOutput{
			Value:      fund.Sub(amount),
			UnlockHash: refundUnlockConditions.UnlockHash(),
		}
		parentTxn.SiacoinOutputs = append(parentTxn.SiacoinOutputs, refundOutput)
	}

	// Sign all of the inputs to the parent trancstion.
	for _, sci := range parentTxn.SiacoinInputs {
		_, err := addSignatures(&parentTxn, types.FullCoveredFields, sci.UnlockConditions, crypto.Hash(sci.ParentID), tb.wallet.keys[sci.UnlockConditions.UnlockHash()])
		if err != nil {
			return err
		}
	}
	// Mark the parent output as spent. Must be done after the transaction is
	// finished because otherwise the txid and output id will change.
	tb.wallet.spentOutputs[types.OutputID(parentTxn.SiacoinOutputID(0))] = tb.wallet.consensusSetHeight

	// Add the exact output.
	newInput := types.SiacoinInput{
		ParentID:         parentTxn.SiacoinOutputID(0),
		UnlockConditions: parentUnlockConditions,
	}
	tb.newParents = append(tb.newParents, len(tb.parents))
	tb.parents = append(tb.parents, parentTxn)
	tb.siacoinInputs = append(tb.siacoinInputs, len(tb.transaction.SiacoinInputs))
	tb.transaction.SiacoinInputs = append(tb.transaction.SiacoinInputs, newInput)

	// Mark all outputs that were spent as spent.
	for _, scoid := range spentScoids {
		tb.wallet.spentOutputs[types.OutputID(scoid)] = tb.wallet.consensusSetHeight
	}
	return nil
}