TUN-1099: Bring back changes in 2018.10.1

cmd/cloudflared/transfer/transfer.go

@@ -0,0 +1,171 @@
+package transfer
+
+import (
+	"bytes"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/cloudflare/cloudflared/cmd/cloudflared/encrypter"
+	"github.com/cloudflare/cloudflared/cmd/cloudflared/shell"
+	"github.com/cloudflare/cloudflared/log"
+	cli "gopkg.in/urfave/cli.v2"
+)
+
+const (
+	baseStoreURL  = "https://login.cloudflarewarp.com/"
+	clientTimeout = time.Second * 60
+)
+
+var logger = log.CreateLogger()
+
+// Run does the transfer "dance" with the end result downloading the supported resource.
+// The expanded description is run is encapsulation of shared business logic needed
+// to request a resource (token/cert/etc) from the transfer service (loginhelper).
+// The "dance" we refer to is building a HTTP request, opening that in a browser waiting for
+// the user to complete an action, while it long polls in the background waiting for an
+// action to be completed to download the resource.
+func Run(c *cli.Context, transferURL *url.URL, resourceName, key, value, path string, shouldEncrypt bool) ([]byte, error) {
+	encrypterClient, err := encrypter.New("cloudflared_priv.pem", "cloudflared_pub.pem")
+	if err != nil {
+		return nil, err
+	}
+	requestURL, err := buildRequestURL(transferURL, key, value+encrypterClient.PublicKey(), shouldEncrypt)
+	if err != nil {
+		return nil, err
+	}
+
+	err = shell.OpenBrowser(requestURL)
+	if err != nil {
+		fmt.Fprintf(os.Stdout, "Please open the following URL and log in with your Cloudflare account:\n\n%s\n\nLeave cloudflared running to download the %s automatically.\n", resourceName, requestURL)
+	} else {
+		fmt.Fprintf(os.Stdout, "A browser window should have opened at the following URL:\n\n%s\n\nIf the browser failed to open, open it yourself and visit the URL above.\n", requestURL)
+	}
+
+	// for local debugging
+	baseURL := baseStoreURL
+	if c.IsSet("url") {
+		baseURL = c.String("url")
+	}
+
+	var resourceData []byte
+
+	if shouldEncrypt {
+		buf, key, err := transferRequest(baseURL + filepath.Join("transfer", encrypterClient.PublicKey()))
+		if err != nil {
+			return nil, err
+		}
+
+		decodedBuf, err := base64.StdEncoding.DecodeString(string(buf))
+		if err != nil {
+			return nil, err
+		}
+		decrypted, err := encrypterClient.Decrypt(decodedBuf, key)
+		if err != nil {
+			return nil, err
+		}
+
+		resourceData = decrypted
+	} else {
+		buf, _, err := transferRequest(baseURL + filepath.Join(encrypterClient.PublicKey()))
+		if err != nil {
+			return nil, err
+		}
+		resourceData = buf
+	}
+
+	if err := ioutil.WriteFile(path, resourceData, 0600); err != nil {
+		return nil, err
+	}
+
+	return resourceData, nil
+}
+
+// BuildRequestURL creates a request suitable for a resource transfer.
+// it will return a constructed url based off the base url and query key/value provided.
+// follow will follow redirects.
+func buildRequestURL(baseURL *url.URL, key, value string, follow bool) (string, error) {
+	q := baseURL.Query()
+	q.Set(key, value)
+	baseURL.RawQuery = q.Encode()
+	if !follow {
+		return baseURL.String(), nil
+	}
+
+	response, err := http.Get(baseURL.String())
+	if err != nil {
+		return "", err
+	}
+	return response.Request.URL.String(), nil
+
+}
+
+// transferRequest downloads the requested resource from the request URL
+func transferRequest(requestURL string) ([]byte, string, error) {
+	client := &http.Client{Timeout: clientTimeout}
+	const pollAttempts = 10
+	// we do "long polling" on the endpoint to get the resource.
+	for i := 0; i < pollAttempts; i++ {
+		buf, key, err := poll(client, requestURL)
+		if err != nil {
+			return nil, "", err
+		} else if len(buf) > 0 {
+			if err := putSuccess(client, requestURL); err != nil {
+				logger.WithError(err).Error("Failed to update resource success")
+			}
+			return buf, key, nil
+		}
+	}
+	return nil, "", errors.New("Failed to fetch resource")
+}
+
+// poll the endpoint for the request resource, waiting for the user interaction
+func poll(client *http.Client, requestURL string) ([]byte, string, error) {
+	resp, err := client.Get(requestURL)
+	if err != nil {
+		return nil, "", err
+	}
+	defer resp.Body.Close()
+
+	// ignore everything other than server errors as the resource
+	// may not exist until the user does the interaction
+	if resp.StatusCode >= 500 {
+		return nil, "", fmt.Errorf("error on request %d", resp.StatusCode)
+	}
+	if resp.StatusCode != 200 {
+		logger.Info("Waiting for login...")
+		return nil, "", nil
+	}
+
+	buf := new(bytes.Buffer)
+	if _, err := io.Copy(buf, resp.Body); err != nil {
+		return nil, "", err
+	}
+	return buf.Bytes(), resp.Header.Get("service-public-key"), nil
+}
+
+// putSuccess tells the server we successfully downloaded the resource
+func putSuccess(client *http.Client, requestURL string) error {
+	req, err := http.NewRequest("PUT", requestURL+"/ok", nil)
+	if err != nil {
+		return err
+	}
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return err
+	}
+
+	resp.Body.Close()
+	if resp.StatusCode != 200 {
+		return fmt.Errorf("HTTP Response Status Code: %d", resp.StatusCode)
+	}
+	return nil
+}