Example #1
0
// Manages the complete lifecycle of a buy.
// When a bool can be read from interrupt, the buy is aborted.
func (a *BuyActivity) PerformBuy(log bitwrk.Logger, interrupt <-chan bool, workFile cafs.File) (cafs.File, error) {
	a.workFile = workFile.Duplicate()

	file, err := a.doPerformBuy(log, interrupt)
	if err != nil {
		a.execSync(func() { a.lastError = err })
	}
	return file, err
}
Example #2
0
func (a *SellActivity) dispatchWorkAndSaveEncryptedResult(log bitwrk.Logger, workFile cafs.File) error {
	// Watch transaction state and close connection to worker when transaction expires
	connChan := make(chan io.Closer)
	exitChan := make(chan bool)
	go a.watchdog(log, exitChan, connChan, func() bool { return a.tx.State == bitwrk.StateActive })
	defer func() {
		exitChan <- true
	}()

	st := NewScopedTransport()
	connChan <- st
	defer st.Close()

	reader := workFile.Open()
	defer reader.Close()
	result, err := a.worker.DoWork(reader, NewClient(&st.Transport))
	if err != nil {
		return err
	}
	defer result.Close()

	temp := a.manager.storage.Create(fmt.Sprintf("Sell #%v: encrypted result", a.GetKey()))
	defer temp.Dispose()

	// Use AES-256 to encrypt the result
	block, err := aes.NewCipher(a.encResultKey[:])
	if err != nil {
		return err
	}

	// Create OFB stream with null initialization vector (ok for one-time key)
	var iv [aes.BlockSize]byte
	stream := cipher.NewOFB(block, iv[:])

	writer := &cipher.StreamWriter{S: stream, W: temp}
	_, err = io.Copy(writer, result)
	if err != nil {
		return err
	}

	if err := temp.Close(); err != nil {
		return err
	}

	if err := result.Close(); err != nil {
		return err
	}

	a.execSync(func() { a.encResultFile = temp.File() })

	return nil
}
Example #3
0
func (a *SellActivity) HandleWork(log bitwrk.Logger, workFile cafs.File, buyerSecret bitwrk.Thash) (io.ReadCloser, error) {
	// Wait for buyer to establish
	active := true
	var workHash, workSecretHash *bitwrk.Thash
	log.Printf("Watching transaction state...")
	a.waitWhile(func() bool {
		active = a.tx.State == bitwrk.StateActive
		workHash, workSecretHash = a.tx.WorkHash, a.tx.WorkSecretHash
		log.Printf("  state: %v    phase: %v", a.tx.State, a.tx.Phase)
		return active && a.tx.Phase != bitwrk.PhaseTransmitting
	})

	if !active {
		return nil, fmt.Errorf("Transaction timed out waiting for buyer to establish")
	}

	// Verify work hash
	if *workHash != bitwrk.Thash(workFile.Key()) {
		return nil, fmt.Errorf("WorkHash and received data do not match")
	}

	if err := verifyBuyerSecret(workHash, workSecretHash, &buyerSecret); err != nil {
		return nil, err
	}

	log.Println("Got valid work data. Publishing buyer's secret.")
	if err := SendTxMessagePublishBuyerSecret(a.txId, a.identity, &buyerSecret); err != nil {
		return nil, fmt.Errorf("Error publishing buyer's secret: %v", err)
	}

	log.Println("Starting to work...")
	r, err := a.dispatchWork(log, workFile)
	if err != nil {
		log.Printf("Rejecting work because of error '%v'", err)
		if err := SendTxMessageRejectWork(a.txId, a.identity); err != nil {
			log.Printf("Rejecting work failed: %v", err)
		}
	}
	return r, err
}
Example #4
0
func (a *SellActivity) dispatchWork(log bitwrk.Logger, workFile cafs.File) (io.ReadCloser, error) {
	// Watch transaction state and close connection to worker when transaction expires
	connChan := make(chan io.Closer)
	exitChan := make(chan bool)
	go a.watchdog(log, exitChan, connChan, func() bool { return a.tx.State == bitwrk.StateActive })
	defer func() {
		exitChan <- true
	}()

	reader := workFile.Open()
	defer reader.Close()

	st := NewScopedTransport()
	connChan <- st
	defer st.Close()
	r, err := a.worker.DoWork(reader, NewClient(&st.Transport))
	if err == nil {
		// Defuse connection closing mechanism
		st.DisownConnections()
	}
	return r, err
}
Example #5
0
func handleBuy(w http.ResponseWriter, r *http.Request) {
	article := r.URL.Path[5:]

	log.Printf("Handling buy for %#v from %v", article, r.RemoteAddr)

	if r.Method != "POST" {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	var buy *client.BuyActivity
	if _buy, err := client.GetActivityManager().NewBuy(bitwrk.ArticleId(article)); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		log.Printf("Error creating buy activity: %v", err)
		return
	} else {
		buy = _buy
	}
	defer buy.Dispose()

	log := bitwrk.Root().Newf("Buy #%v", buy.GetKey())

	var reader io.Reader
	if multipart, err := r.MultipartReader(); err != nil {
		// read directly from body
		reader = r.Body
	} else {
		// Iterate through parts of multipart body, find the one called "data"
		for {
			if part, err := multipart.NextPart(); err != nil {
				http.Error(w, err.Error(), http.StatusInternalServerError)
				log.Printf("Error iterating through multipart content: %v", err)
				return
			} else {
				if part.FormName() == "data" {
					reader = part
					break
				} else {
					log.Printf("Skipping form part %v", part)
				}
			}
		}
	}

	workTemp := client.GetActivityManager().GetStorage().Create(fmt.Sprintf("buy #%v: work", buy.GetKey()))
	defer workTemp.Dispose()
	if _, err := io.Copy(workTemp, reader); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		log.Printf("Error receiving work data from client: %v", err)
		return
	} else {
		if err := workTemp.Close(); err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			log.Printf("Error writing work data to storage: %v", err)
			return
		}
	}

	// Listen for close notfications
	interrupt := w.(http.CloseNotifier).CloseNotify()

	workFile := workTemp.File()
	defer workFile.Dispose()
	var result cafs.File
	if res, err := buy.PerformBuy(log, interrupt, workFile); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		log.Printf("Error receiving result from BitWrk network: %v", err)
		return
	} else {
		result = res
	}

	http.Redirect(w, r, "/file/"+result.Key().String(), http.StatusSeeOther)
}