Exemplo n.º 1
0
// managedFinalizeContract will take a file contract, add the host's
// collateral, and then try submitting the file contract to the transaction
// pool. If there is no error, the completed transaction set will be returned
// to the caller.
func (h *Host) managedFinalizeContract(builder modules.TransactionBuilder, renterPK crypto.PublicKey, renterSignatures []types.TransactionSignature, renterRevisionSignature types.TransactionSignature, initialSectorRoots []crypto.Hash, hostCollateral, hostInitialRevenue, hostInitialRisk types.Currency) ([]types.TransactionSignature, types.TransactionSignature, types.FileContractID, error) {
	for _, sig := range renterSignatures {
		builder.AddTransactionSignature(sig)
	}
	fullTxnSet, err := builder.Sign(true)
	if err != nil {
		builder.Drop()
		return nil, types.TransactionSignature{}, types.FileContractID{}, err
	}

	// Verify that the signature for the revision from the renter is correct.
	h.mu.RLock()
	blockHeight := h.blockHeight
	hostSPK := h.publicKey
	hostSK := h.secretKey
	h.mu.RUnlock()
	contractTxn := fullTxnSet[len(fullTxnSet)-1]
	fc := contractTxn.FileContracts[0]
	noOpRevision := types.FileContractRevision{
		ParentID: contractTxn.FileContractID(0),
		UnlockConditions: types.UnlockConditions{
			PublicKeys: []types.SiaPublicKey{
				{
					Algorithm: types.SignatureEd25519,
					Key:       renterPK[:],
				},
				hostSPK,
			},
			SignaturesRequired: 2,
		},
		NewRevisionNumber: fc.RevisionNumber + 1,

		NewFileSize:           fc.FileSize,
		NewFileMerkleRoot:     fc.FileMerkleRoot,
		NewWindowStart:        fc.WindowStart,
		NewWindowEnd:          fc.WindowEnd,
		NewValidProofOutputs:  fc.ValidProofOutputs,
		NewMissedProofOutputs: fc.MissedProofOutputs,
		NewUnlockHash:         fc.UnlockHash,
	}
	// createRevisionSignature will also perform validation on the result,
	// returning an error if the renter provided an incorrect signature.
	revisionTransaction, err := createRevisionSignature(noOpRevision, renterRevisionSignature, hostSK, blockHeight)
	if err != nil {
		return nil, types.TransactionSignature{}, types.FileContractID{}, err
	}

	// Create and add the storage obligation for this file contract.
	fullTxn, _ := builder.View()
	so := storageObligation{
		SectorRoots: initialSectorRoots,

		ContractCost:            h.settings.MinContractPrice,
		LockedCollateral:        hostCollateral,
		PotentialStorageRevenue: hostInitialRevenue,
		RiskedCollateral:        hostInitialRisk,

		OriginTransactionSet:   fullTxnSet,
		RevisionTransactionSet: []types.Transaction{revisionTransaction},
	}

	// Get a lock on the storage obligation.
	lockErr := h.managedTryLockStorageObligation(so.id())
	if lockErr != nil {
		build.Critical("failed to get a lock on a brand new storage obligation")
		return nil, types.TransactionSignature{}, types.FileContractID{}, lockErr
	}
	defer func() {
		if err != nil {
			h.managedUnlockStorageObligation(so.id())
		}
	}()

	// addStorageObligation will submit the transaction to the transaction
	// pool, and will only do so if there was not some error in creating the
	// storage obligation. If the transaction pool returns a consensus
	// conflict, wait 30 seconds and try again.
	err = func() error {
		// Try adding the storage obligation. If there's an error, wait a few
		// seconds and try again. Eventually time out. It should be noted that
		// the storage obligation locking is both crappy and incomplete, and
		// that I'm not sure how this timeout plays with the overall host
		// timeouts.
		//
		// The storage obligation locks should occur at the highest level, not
		// just when the actual modification is happening.
		i := 0
		for {
			h.mu.Lock()
			err = h.addStorageObligation(so)
			h.mu.Unlock()
			if err == nil {
				return nil
			}
			if err != nil && i > 4 {
				h.log.Println(err)
				builder.Drop()
				return err
			}

			i++
			if build.Release == "standard" {
				time.Sleep(time.Second * 15)
			}
		}
	}()
	if err != nil {
		return nil, types.TransactionSignature{}, types.FileContractID{}, err
	}

	// Get the host's transaction signatures from the builder.
	var hostTxnSignatures []types.TransactionSignature
	_, _, _, txnSigIndices := builder.ViewAdded()
	for _, sigIndex := range txnSigIndices {
		hostTxnSignatures = append(hostTxnSignatures, fullTxn.TransactionSignatures[sigIndex])
	}
	return hostTxnSignatures, revisionTransaction.TransactionSignatures[1], so.id(), nil
}
Exemplo n.º 2
0
// negotiateContract establishes a connection to a host and negotiates an
// initial file contract according to the terms of the host.
func negotiateContract(conn net.Conn, addr modules.NetAddress, fc types.FileContract, txnBuilder modules.TransactionBuilder, tpool modules.TransactionPool) (hostContract, error) {
	// allow 30 seconds for negotiation
	conn.SetDeadline(time.Now().Add(30 * time.Second))

	// read host key
	var hostPublicKey types.SiaPublicKey
	if err := encoding.ReadObject(conn, &hostPublicKey, 256); err != nil {
		return hostContract{}, errors.New("couldn't read host's public key: " + err.Error())
	}

	// create our key
	ourSK, ourPK, err := crypto.GenerateKeyPair()
	if err != nil {
		return hostContract{}, errors.New("failed to generate keypair: " + err.Error())
	}
	ourPublicKey := types.SiaPublicKey{
		Algorithm: types.SignatureEd25519,
		Key:       ourPK[:],
	}

	// send our public key
	if err := encoding.WriteObject(conn, ourPublicKey); err != nil {
		return hostContract{}, errors.New("couldn't send our public key: " + err.Error())
	}

	// create unlock conditions
	uc := types.UnlockConditions{
		PublicKeys:         []types.SiaPublicKey{ourPublicKey, hostPublicKey},
		SignaturesRequired: 2,
	}

	// add UnlockHash to file contract
	fc.UnlockHash = uc.UnlockHash()

	// build transaction containing fc
	err = txnBuilder.FundSiacoins(fc.Payout)
	if err != nil {
		return hostContract{}, err
	}
	txnBuilder.AddFileContract(fc)
	txn, parents := txnBuilder.View()
	txnSet := append(parents, txn)

	// calculate contract ID
	fcid := txn.FileContractID(0) // TODO: is it actually 0?

	// send txn
	if err := encoding.WriteObject(conn, txnSet); err != nil {
		return hostContract{}, errors.New("couldn't send our proposed contract: " + err.Error())
	}

	// read back acceptance
	var response string
	if err := encoding.ReadObject(conn, &response, 128); err != nil {
		return hostContract{}, errors.New("couldn't read the host's response to our proposed contract: " + err.Error())
	}
	if response != modules.AcceptResponse {
		return hostContract{}, errors.New("host rejected proposed contract: " + response)
	}

	// read back txn with host collateral.
	var hostTxnSet []types.Transaction
	if err := encoding.ReadObject(conn, &hostTxnSet, types.BlockSizeLimit); err != nil {
		return hostContract{}, errors.New("couldn't read the host's updated contract: " + err.Error())
	}

	// check that txn is okay. For now, no collateral will be added, so the
	// transaction sets should be identical.
	if len(hostTxnSet) != len(txnSet) {
		return hostContract{}, errors.New("host sent bad collateral transaction")
	}
	for i := range hostTxnSet {
		if hostTxnSet[i].ID() != txnSet[i].ID() {
			return hostContract{}, errors.New("host sent bad collateral transaction")
		}
	}

	// sign the txn and resend
	// NOTE: for now, we are assuming that the transaction has not changed
	// since we sent it. Otherwise, the txnBuilder would have to be updated
	// with whatever fields were added by the host.
	signedTxnSet, err := txnBuilder.Sign(true)
	if err != nil {
		return hostContract{}, err
	}
	if err := encoding.WriteObject(conn, signedTxnSet); err != nil {
		return hostContract{}, errors.New("couldn't send the contract signed by us: " + err.Error())
	}

	// read signed txn from host
	var signedHostTxnSet []types.Transaction
	if err := encoding.ReadObject(conn, &signedHostTxnSet, types.BlockSizeLimit); err != nil {
		return hostContract{}, errors.New("couldn't read the contract signed by the host: " + err.Error())
	}

	// submit to blockchain
	err = tpool.AcceptTransactionSet(signedHostTxnSet)
	if err == modules.ErrDuplicateTransactionSet {
		// this can happen if the renter is uploading to itself
		err = nil
	}
	if err != nil {
		return hostContract{}, err
	}

	// create host contract
	hc := hostContract{
		IP:           addr,
		ID:           fcid,
		FileContract: fc,
		LastRevision: types.FileContractRevision{
			ParentID:              fcid,
			UnlockConditions:      uc,
			NewRevisionNumber:     fc.RevisionNumber,
			NewFileSize:           fc.FileSize,
			NewFileMerkleRoot:     fc.FileMerkleRoot,
			NewWindowStart:        fc.WindowStart,
			NewWindowEnd:          fc.WindowEnd,
			NewValidProofOutputs:  []types.SiacoinOutput{fc.ValidProofOutputs[0], fc.ValidProofOutputs[1]},
			NewMissedProofOutputs: []types.SiacoinOutput{fc.MissedProofOutputs[0], fc.MissedProofOutputs[1]},
			NewUnlockHash:         fc.UnlockHash,
		},
		LastRevisionTxn: types.Transaction{},
		SecretKey:       ourSK,
	}

	return hc, nil
}