Golang Transaction.StandaloneValid方法代碼示例

// 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
}

// 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
}

// 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
}

// 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
}

// 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)
	}
}

// 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)
}

//.........這裏部分代碼省略.........
		t.Fatal(err)
	}

	// generate keys
	sk, pk, err := crypto.GenerateKeyPair()
	if err != nil {
		t.Fatal(err)
	}
	renterPubKey := types.SiaPublicKey{
		Algorithm: types.SignatureEd25519,
		Key:       pk[:],
	}

	uc := types.UnlockConditions{
		PublicKeys:         []types.SiaPublicKey{renterPubKey, renterPubKey},
		SignaturesRequired: 1,
	}

	// create file contract
	payout := types.NewCurrency64(1e16)

	fc := types.FileContract{
		FileSize:       0,
		FileMerkleRoot: crypto.Hash{}, // no proof possible without data
		WindowStart:    100,
		WindowEnd:      1000,
		Payout:         payout,
		UnlockHash:     uc.UnlockHash(),
		RevisionNumber: 0,
	}
	// outputs need account for tax
	fc.ValidProofOutputs = []types.SiacoinOutput{
		{Value: types.PostTax(ct.contractor.blockHeight, payout), UnlockHash: ourAddr.UnlockHash()},
		{Value: types.ZeroCurrency, UnlockHash: types.UnlockHash{}}, // no collateral
	}
	fc.MissedProofOutputs = []types.SiacoinOutput{
		// same as above
		fc.ValidProofOutputs[0],
		// goes to the void, not the hostdb
		{Value: types.ZeroCurrency, UnlockHash: types.UnlockHash{}},
	}

	txnBuilder := ct.wallet.StartTransaction()
	err = txnBuilder.FundSiacoins(fc.Payout)
	if err != nil {
		t.Fatal(err)
	}
	txnBuilder.AddFileContract(fc)
	signedTxnSet, err := txnBuilder.Sign(true)
	if err != nil {
		t.Fatal(err)
	}

	// submit contract
	err = ct.tpool.AcceptTransactionSet(signedTxnSet)
	if err != nil {
		t.Fatal(err)
	}

	// create revision
	fcid := signedTxnSet[len(signedTxnSet)-1].FileContractID(0)
	rev := types.FileContractRevision{
		ParentID:              fcid,
		UnlockConditions:      uc,
		NewFileSize:           10,
		NewWindowStart:        100,
		NewWindowEnd:          1000,
		NewRevisionNumber:     1,
		NewValidProofOutputs:  fc.ValidProofOutputs,
		NewMissedProofOutputs: fc.MissedProofOutputs,
	}

	// create transaction containing the revision
	signedTxn := types.Transaction{
		FileContractRevisions: []types.FileContractRevision{rev},
		TransactionSignatures: []types.TransactionSignature{{
			ParentID:       crypto.Hash(fcid),
			CoveredFields:  types.CoveredFields{FileContractRevisions: []uint64{0}},
			PublicKeyIndex: 0, // hostdb key is always first -- see negotiateContract
		}},
	}

	// sign the transaction
	encodedSig, err := crypto.SignHash(signedTxn.SigHash(0), sk)
	if err != nil {
		t.Fatal(err)
	}
	signedTxn.TransactionSignatures[0].Signature = encodedSig[:]

	err = signedTxn.StandaloneValid(ct.contractor.blockHeight)
	if err != nil {
		t.Fatal(err)
	}

	// submit revision
	err = ct.tpool.AcceptTransactionSet([]types.Transaction{signedTxn})
	if err != nil {
		t.Fatal(err)
	}
}

// revise revises fc to cover piece and uploads both the revision and the
// piece data to the host.
func (hu *hostUploader) revise(fc types.FileContract, piece []byte, height types.BlockHeight) error {
	hu.conn.SetDeadline(time.Now().Add(5 * time.Minute)) // sufficient to transfer 4 MB over 100 kbps
	defer hu.conn.SetDeadline(time.Time{})               // reset timeout after each revision

	// calculate new merkle root
	err := hu.tree.ReadSegments(bytes.NewReader(piece))
	if err != nil {
		return err
	}

	// create revision
	rev := types.FileContractRevision{
		ParentID:          hu.contract.ID,
		UnlockConditions:  hu.unlockConditions,
		NewRevisionNumber: fc.RevisionNumber + 1,

		NewFileSize:           fc.FileSize + uint64(len(piece)),
		NewFileMerkleRoot:     hu.tree.Root(),
		NewWindowStart:        fc.WindowStart,
		NewWindowEnd:          fc.WindowEnd,
		NewValidProofOutputs:  fc.ValidProofOutputs,
		NewMissedProofOutputs: fc.MissedProofOutputs,
		NewUnlockHash:         fc.UnlockHash,
	}
	// transfer value of piece from renter to host
	safeDuration := uint64(fc.WindowStart - height + 20) // buffer in case host is behind
	piecePrice := types.NewCurrency64(uint64(len(piece))).Mul(types.NewCurrency64(safeDuration)).Mul(hu.settings.Price)
	// prevent a negative currency panic
	if piecePrice.Cmp(fc.ValidProofOutputs[0].Value) > 0 {
		// probably not enough money, but the host might accept it anyway
		piecePrice = fc.ValidProofOutputs[0].Value
	}
	rev.NewValidProofOutputs[0].Value = rev.NewValidProofOutputs[0].Value.Sub(piecePrice)   // less returned to renter
	rev.NewValidProofOutputs[1].Value = rev.NewValidProofOutputs[1].Value.Add(piecePrice)   // more given to host
	rev.NewMissedProofOutputs[0].Value = rev.NewMissedProofOutputs[0].Value.Sub(piecePrice) // less returned to renter
	rev.NewMissedProofOutputs[1].Value = rev.NewMissedProofOutputs[1].Value.Add(piecePrice) // more given to void

	// create transaction containing the revision
	signedTxn := types.Transaction{
		FileContractRevisions: []types.FileContractRevision{rev},
		TransactionSignatures: []types.TransactionSignature{{
			ParentID:       crypto.Hash(hu.contract.ID),
			CoveredFields:  types.CoveredFields{FileContractRevisions: []uint64{0}},
			PublicKeyIndex: 0, // renter key is always first -- see negotiateContract
		}},
	}

	// sign the transaction
	encodedSig, err := crypto.SignHash(signedTxn.SigHash(0), hu.secretKey)
	if err != nil {
		return err
	}
	signedTxn.TransactionSignatures[0].Signature = encodedSig[:]

	// send the transaction
	if err := encoding.WriteObject(hu.conn, signedTxn); err != nil {
		return err
	}

	// host sends acceptance
	var response string
	if err := encoding.ReadObject(hu.conn, &response, 128); err != nil {
		return err
	}
	if response != modules.AcceptResponse {
		return errors.New("host rejected revision: " + response)
	}

	// transfer piece
	if _, err := hu.conn.Write(piece); err != nil {
		return err
	}

	// read txn signed by host
	var signedHostTxn types.Transaction
	if err := encoding.ReadObject(hu.conn, &signedHostTxn, types.BlockSizeLimit); err != nil {
		return err
	}

	if signedHostTxn.ID() != signedTxn.ID() {
		return errors.New("host sent bad signed transaction")
	} else if err = signedHostTxn.StandaloneValid(height); err != nil {
		return err
	}

	hu.lastTxn = signedHostTxn

	return nil
}

// verifyKeys checks a set of keys on disk to see that they can spend funds
// sent to their address.
func verifyKeys(uc types.UnlockConditions, folder string, keyname string) error {
	keysRequired := uc.SignaturesRequired
	totalKeys := uint64(len(uc.PublicKeys))

	// Load the keys from disk back into memory, then verify that the keys on
	// disk are able to sign outputs in transactions.
	loadedKeys := make([]KeyPair, totalKeys)
	for i := 0; i < len(loadedKeys); i++ {
		err := encoding.ReadFile(filepath.Join(folder, keyname+"_Key"+strconv.Itoa(i)+FileExtension), &loadedKeys[i])
		if err != nil {
			return err
		}
		if loadedKeys[i].Header != FileHeader {
			return ErrUnknownHeader
		}
		if loadedKeys[i].Version != FileVersion {
			return ErrUnknownVersion
		}
	}

	// Check that the keys can be used to spend transactions.
	for _, loadedKey := range loadedKeys {
		if loadedKey.UnlockConditions.UnlockHash() != uc.UnlockHash() {
			return ErrCorruptedKey
		}
	}
	// Create a transaction for the keys to sign.
	txn := types.Transaction{
		SiafundInputs: []types.SiafundInput{
			types.SiafundInput{
				UnlockConditions: loadedKeys[0].UnlockConditions,
			},
		},
	}
	// Loop through and sign the transaction multiple times. All keys will be
	// used at least once by the time the loop terminates.
	var i uint64
	for i != totalKeys {
		// i tracks which key is next to be used. If i + RequiredKeys results
		// in going out-of-bounds, reduce i so that the last key will be used
		// for the final signature.
		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++
		}
		// Check that the signature is valid.
		err := txn.StandaloneValid(0)
		if err != nil {
			return err
		}
		// Delete all of the signatures for the next iteration.
		txn.TransactionSignatures = nil
	}
	return nil
}