jws: add EncodeWithSigner function.

This permits controlling the mechanism for signing the token;
for instance, one can use EncodeWithSigner in an App Engine app
to use the App Identity API to perform the signing (you don't have
direct access to the private key there).

An alternate would be to replace Encode with EncodeWithSigner,
and add a little wrapper type that turns a *rsa.PrivateKey into
a Signer. That's probably what I'd do if this were being written
from scratch, but I wasn't keen on breaking existing code.

Change-Id: Id48f5dfa15c179832e613268d4a4098b96648f9a
Reviewed-on: https://go-review.googlesource.com/16711
Reviewed-by: Burcu Dogan <jbd@google.com>
Run-TryBot: David Symonds <dsymonds@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
1 file changed
tree: c0938cc97b53fc39e2836f665f0e2239a7f70b28
  1. bitbucket/
  2. clientcredentials/
  3. facebook/
  4. github/
  5. google/
  6. internal/
  7. jws/
  8. jwt/
  9. linkedin/
  10. odnoklassniki/
  11. paypal/
  12. vk/
  13. .travis.yml
  18. README.md
  19. client_appengine.go
  20. example_test.go
  21. oauth2.go
  22. oauth2_test.go
  23. token.go
  24. token_test.go
  25. transport.go
  26. transport_test.go

OAuth2 for Go

Build Status

oauth2 package contains a client implementation for OAuth 2.0 spec.


go get golang.org/x/oauth2

See godoc for further documentation and examples.

App Engine

In change 96e89be (March 2015) we removed the oauth2.Context2 type in favor of the context.Context type from the golang.org/x/net/context package

This means its no longer possible to use the “Classic App Engine” appengine.Context type with the oauth2 package. (You're using Classic App Engine if you import the package "appengine".)

To work around this, you may use the new "google.golang.org/appengine" package. This package has almost the same API as the "appengine" package, but it can be fetched with go get and used on “Managed VMs” and well as Classic App Engine.

See the new appengine package's readme for information on updating your app.

If you don't want to update your entire app to use the new App Engine packages, you may use both sets of packages in parallel, using only the new packages with the oauth2 package.

import (
	newappengine "google.golang.org/appengine"
	newurlfetch "google.golang.org/appengine/urlfetch"


func handler(w http.ResponseWriter, r *http.Request) {
	var c appengine.Context = appengine.NewContext(r)
	c.Infof("Logging a message with the old package")

	var ctx context.Context = newappengine.NewContext(r)
	client := &http.Client{
		Transport: &oauth2.Transport{
			Source: google.AppEngineTokenSource(ctx, "scope"),
			Base:   &newurlfetch.Transport{Context: ctx},