cloudprovider/gce: use golang.org/x/oauth2

code.google.com/p/goauth2 is deprecated.
use golang.org/x/oauth2 instead.

hooks/prepare-commit-msg ignore Godeps
for sh's boilerplate check.

Godeps/_workspace/src/golang.org/x/oauth2/.travis.yml

@@ -0,0 +1,14 @@
+language: go
+
+go:
+  - 1.3
+  - 1.4
+
+install:
+  - export GOPATH="$HOME/gopath"
+  - mkdir -p "$GOPATH/src/golang.org/x"
+  - mv "$TRAVIS_BUILD_DIR" "$GOPATH/src/golang.org/x/oauth2"
+  - go get -v -t -d -tags='appengine appenginevm' golang.org/x/oauth2/...
+
+script:
+  - go test -v -tags='appengine appenginevm' golang.org/x/oauth2/...

Godeps/_workspace/src/golang.org/x/oauth2/AUTHORS

@@ -0,0 +1,3 @@
+# This source code refers to The Go Authors for copyright purposes.
+# The master list of authors is in the main Go distribution,
+# visible at http://tip.golang.org/AUTHORS.

Godeps/_workspace/src/golang.org/x/oauth2/CONTRIBUTING.md

@@ -0,0 +1,25 @@
+# Contributing
+
+We don't use GitHub pull requests but use Gerrit for code reviews,
+similar to the Go project.
+
+1. Sign one of the contributor license agreements below.
+2. `go get golang.org/x/review/git-codereview` to install the code reviewing tool.
+3. Get the package by running `go get -d golang.org/x/oauth2`.
+Make changes and create a change by running `git codereview change <name>`, provide a command message, and use `git codereview mail` to create a Gerrit CL.
+Keep amending to the change and mail as your recieve feedback.
+
+For more information about the workflow, see Go's [Contribution Guidelines](https://golang.org/doc/contribute.html).
+
+Before we can accept any pull requests
+we have to jump through a couple of legal hurdles,
+primarily a Contributor License Agreement (CLA):
+
+- **If you are an individual writing original source code**
+  and you're sure you own the intellectual property,
+  then you'll need to sign an [individual CLA](http://code.google.com/legal/individual-cla-v1.0.html).
+- **If you work for a company that wants to allow you to contribute your work**,
+  then you'll need to sign a [corporate CLA](http://code.google.com/legal/corporate-cla-v1.0.html).
+
+You can sign these electronically (just scroll to the bottom).
+After that, we'll be able to accept your pull requests.

Godeps/_workspace/src/golang.org/x/oauth2/CONTRIBUTORS

@@ -0,0 +1,3 @@
+# This source code was written by the Go contributors.
+# The master list of contributors is in the main Go distribution,
+# visible at http://tip.golang.org/CONTRIBUTORS.

Godeps/_workspace/src/golang.org/x/oauth2/LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2009 The oauth2 Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Godeps/_workspace/src/golang.org/x/oauth2/README.md

@@ -0,0 +1,18 @@
+# OAuth2 for Go
+
+[![Build Status](https://travis-ci.org/golang/oauth2.svg?branch=master)](https://travis-ci.org/golang/oauth2)
+
+oauth2 package contains a client implementation for OAuth 2.0 spec.
+
+## Installation
+
+~~~~
+go get golang.org/x/oauth2
+~~~~
+
+See godoc for further documentation and examples.
+
+* [godoc.org/golang.org/x/oauth2](http://godoc.org/golang.org/x/oauth2)
+* [godoc.org/golang.org/x/oauth2/google](http://godoc.org/golang.org/x/oauth2/google)
+
+

Godeps/_workspace/src/golang.org/x/oauth2/client_appengine.go

@@ -0,0 +1,39 @@
+// Copyright 2014 The oauth2 Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build appengine,!appenginevm
+
+// App Engine hooks.
+
+package oauth2
+
+import (
+	"log"
+	"net/http"
+	"sync"
+
+	"appengine"
+	"appengine/urlfetch"
+)
+
+var warnOnce sync.Once
+
+func init() {
+	registerContextClientFunc(contextClientAppEngine)
+}
+
+func contextClientAppEngine(ctx Context) (*http.Client, error) {
+	if actx, ok := ctx.(appengine.Context); ok {
+		return urlfetch.Client(actx), nil
+	}
+	// The user did it wrong. We'll log once (and hope they see it
+	// in dev_appserver), but stil return (nil, nil) in case some
+	// other contextClientFunc hook finds a way to proceed.
+	warnOnce.Do(gaeDoingItWrongHelp)
+	return nil, nil
+}
+
+func gaeDoingItWrongHelp() {
+	log.Printf("WARNING: you attempted to use the oauth2 package without passing a valid appengine.Context or *http.Request as the oauth2.Context. App Engine requires that all service RPCs (including urlfetch) be associated with an *http.Request/appengine.Context.")
+}

Godeps/_workspace/src/golang.org/x/oauth2/example_test.go

@@ -0,0 +1,50 @@
+// Copyright 2014 The oauth2 Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package oauth2_test
+
+import (
+	"fmt"
+	"log"
+	"testing"
+
+	"golang.org/x/oauth2"
+)
+
+// TODO(jbd): Remove after Go 1.4.
+// Related to https://codereview.appspot.com/107320046
+func TestA(t *testing.T) {}
+
+func ExampleConfig() {
+	conf := &oauth2.Config{
+		ClientID:     "YOUR_CLIENT_ID",
+		ClientSecret: "YOUR_CLIENT_SECRET",
+		Scopes:       []string{"SCOPE1", "SCOPE2"},
+		Endpoint: oauth2.Endpoint{
+			AuthURL:  "https://provider.com/o/oauth2/auth",
+			TokenURL: "https://provider.com/o/oauth2/token",
+		},
+	}
+
+	// Redirect user to consent page to ask for permission
+	// for the scopes specified above.
+	url := conf.AuthCodeURL("state", oauth2.AccessTypeOffline)
+	fmt.Printf("Visit the URL for the auth dialog: %v", url)
+
+	// Use the authorization code that is pushed to the redirect URL.
+	// NewTransportWithCode will do the handshake to retrieve
+	// an access token and initiate a Transport that is
+	// authorized and authenticated by the retrieved token.
+	var code string
+	if _, err := fmt.Scan(&code); err != nil {
+		log.Fatal(err)
+	}
+	tok, err := conf.Exchange(oauth2.NoContext, code)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	client := conf.Client(oauth2.NoContext, tok)
+	client.Get("...")
+}

Godeps/_workspace/src/golang.org/x/oauth2/github/github.go

@@ -0,0 +1,16 @@
+// Copyright 2014 The oauth2 Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package github provides constants for using OAuth2 to access Github.
+package github
+
+import (
+	"golang.org/x/oauth2"
+)
+
+// Endpoint is Github's OAuth 2.0 endpoint.
+var Endpoint = oauth2.Endpoint{
+	AuthURL:  "https://github.com/login/oauth/authorize",
+	TokenURL: "https://github.com/login/oauth/access_token",
+}

Godeps/_workspace/src/golang.org/x/oauth2/google/appengine.go

@@ -0,0 +1,37 @@
+// Copyright 2014 The oauth2 Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build appengine,!appenginevm
+
+package google
+
+import (
+	"time"
+
+	"appengine"
+
+	"golang.org/x/oauth2"
+)
+
+// AppEngineTokenSource returns a token source that fetches tokens
+// issued to the current App Engine application's service account.
+// If you are implementing a 3-legged OAuth 2.0 flow on App Engine
+// that involves user accounts, see oauth2.Config instead.
+//
+// You are required to provide a valid appengine.Context as context.
+func AppEngineTokenSource(ctx appengine.Context, scope ...string) oauth2.TokenSource {
+	return &appEngineTokenSource{
+		ctx:         ctx,
+		scopes:      scope,
+		fetcherFunc: aeFetcherFunc,
+	}
+}
+
+var aeFetcherFunc = func(ctx oauth2.Context, scope ...string) (string, time.Time, error) {
+	c, ok := ctx.(appengine.Context)
+	if !ok {
+		return "", time.Time{}, errInvalidContext
+	}
+	return appengine.AccessToken(c, scope...)
+}

Godeps/_workspace/src/golang.org/x/oauth2/google/appenginevm.go

@@ -0,0 +1,36 @@
+// Copyright 2014 The oauth2 Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build appenginevm !appengine
+
+package google
+
+import (
+	"time"
+
+	"golang.org/x/oauth2"
+	"google.golang.org/appengine"
+)
+
+// AppEngineTokenSource returns a token source that fetches tokens
+// issued to the current App Engine application's service account.
+// If you are implementing a 3-legged OAuth 2.0 flow on App Engine
+// that involves user accounts, see oauth2.Config instead.
+//
+// You are required to provide a valid appengine.Context as context.
+func AppEngineTokenSource(ctx appengine.Context, scope ...string) oauth2.TokenSource {
+	return &appEngineTokenSource{
+		ctx:         ctx,
+		scopes:      scope,
+		fetcherFunc: aeVMFetcherFunc,
+	}
+}
+
+var aeVMFetcherFunc = func(ctx oauth2.Context, scope ...string) (string, time.Time, error) {
+	c, ok := ctx.(appengine.Context)
+	if !ok {
+		return "", time.Time{}, errInvalidContext
+	}
+	return appengine.AccessToken(c, scope...)
+}

Godeps/_workspace/src/golang.org/x/oauth2/google/example_test.go

@@ -0,0 +1,133 @@
+// Copyright 2014 The oauth2 Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build appenginevm !appengine
+
+package google_test
+
+import (
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"testing"
+
+	"golang.org/x/oauth2"
+	"golang.org/x/oauth2/google"
+	"golang.org/x/oauth2/jwt"
+	"google.golang.org/appengine"
+	"google.golang.org/appengine/urlfetch"
+)
+
+// Remove after Go 1.4.
+// Related to https://codereview.appspot.com/107320046
+func TestA(t *testing.T) {}
+
+func Example_webServer() {
+	// Your credentials should be obtained from the Google
+	// Developer Console (https://console.developers.google.com).
+	conf := &oauth2.Config{
+		ClientID:     "YOUR_CLIENT_ID",
+		ClientSecret: "YOUR_CLIENT_SECRET",
+		RedirectURL:  "YOUR_REDIRECT_URL",
+		Scopes: []string{
+			"https://www.googleapis.com/auth/bigquery",
+			"https://www.googleapis.com/auth/blogger",
+		},
+		Endpoint: google.Endpoint,
+	}
+	// Redirect user to Google's consent page to ask for permission
+	// for the scopes specified above.
+	url := conf.AuthCodeURL("state")
+	fmt.Printf("Visit the URL for the auth dialog: %v", url)
+
+	// Handle the exchange code to initiate a transport.
+	tok, err := conf.Exchange(oauth2.NoContext, "authorization-code")
+	if err != nil {
+		log.Fatal(err)
+	}
+	client := conf.Client(oauth2.NoContext, tok)
+	client.Get("...")
+}
+
+func ExampleJWTConfigFromJSON() {
+	// Your credentials should be obtained from the Google
+	// Developer Console (https://console.developers.google.com).
+	// Navigate to your project, then see the "Credentials" page
+	// under "APIs & Auth".
+	// To create a service account client, click "Create new Client ID",
+	// select "Service Account", and click "Create Client ID". A JSON
+	// key file will then be downloaded to your computer.
+	data, err := ioutil.ReadFile("/path/to/your-project-key.json")
+	if err != nil {
+		log.Fatal(err)
+	}
+	conf, err := google.JWTConfigFromJSON(data, "https://www.googleapis.com/auth/bigquery")
+	if err != nil {
+		log.Fatal(err)
+	}
+	// Initiate an http.Client. The following GET request will be
+	// authorized and authenticated on the behalf of
+	// your service account.
+	client := conf.Client(oauth2.NoContext)
+	client.Get("...")
+}
+
+func Example_serviceAccount() {
+	// Your credentials should be obtained from the Google
+	// Developer Console (https://console.developers.google.com).
+	conf := &jwt.Config{
+		Email: "xxx@developer.gserviceaccount.com",
+		// The contents of your RSA private key or your PEM file
+		// that contains a private key.
+		// If you have a p12 file instead, you
+		// can use `openssl` to export the private key into a pem file.
+		//
+		//    $ openssl pkcs12 -in key.p12 -passin pass:notasecret -out key.pem -nodes
+		//
+		// The field only supports PEM containers with no passphrase.
+		// The openssl command will convert p12 keys to passphrase-less PEM containers.
+		PrivateKey: []byte("-----BEGIN RSA PRIVATE KEY-----..."),
+		Scopes: []string{
+			"https://www.googleapis.com/auth/bigquery",
+			"https://www.googleapis.com/auth/blogger",
+		},
+		TokenURL: google.JWTTokenURL,
+		// If you would like to impersonate a user, you can
+		// create a transport with a subject. The following GET
+		// request will be made on the behalf of user@example.com.
+		// Optional.
+		Subject: "user@example.com",
+	}
+	// Initiate an http.Client, the following GET request will be
+	// authorized and authenticated on the behalf of user@example.com.
+	client := conf.Client(oauth2.NoContext)
+	client.Get("...")
+}
+
+func ExampleAppEngineTokenSource() {
+	var req *http.Request // from the ServeHTTP handler
+	ctx := appengine.NewContext(req)
+	client := &http.Client{
+		Transport: &oauth2.Transport{
+			Source: google.AppEngineTokenSource(ctx, "https://www.googleapis.com/auth/bigquery"),
+			Base: &urlfetch.Transport{
+				Context: ctx,
+			},
+		},
+	}
+	client.Get("...")
+}
+
+func ExampleComputeTokenSource() {
+	client := &http.Client{
+		Transport: &oauth2.Transport{
+			// Fetch from Google Compute Engine's metadata server to retrieve
+			// an access token for the provided account.
+			// If no account is specified, "default" is used.
+			Source: google.ComputeTokenSource(""),
+		},
+	}
+	client.Get("...")
+}

Godeps/_workspace/src/golang.org/x/oauth2/google/google.go

@@ -0,0 +1,103 @@
+// Copyright 2014 The oauth2 Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package google provides support for making
+// OAuth2 authorized and authenticated HTTP requests
+// to Google APIs. It supports Web server, client-side,
+// service accounts, Google Compute Engine service accounts,
+// and Google App Engine service accounts authorization
+// and authentications flows:
+//
+// For more information, please read
+// https://developers.google.com/accounts/docs/OAuth2.
+package google
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"strings"
+	"time"
+
+	"golang.org/x/oauth2"
+	"golang.org/x/oauth2/jwt"
+	"google.golang.org/cloud/compute/metadata"
+)
+
+// TODO(bradfitz,jbd): import "google.golang.org/cloud/compute/metadata" instead of
+// the metaClient and metadata.google.internal stuff below.
+
+// Endpoint is Google's OAuth 2.0 endpoint.
+var Endpoint = oauth2.Endpoint{
+	AuthURL:  "https://accounts.google.com/o/oauth2/auth",
+	TokenURL: "https://accounts.google.com/o/oauth2/token",
+}
+
+// JWTTokenURL is Google's OAuth 2.0 token URL to use with the JWT flow.
+const JWTTokenURL = "https://accounts.google.com/o/oauth2/token"
+
+// JWTConfigFromJSON uses a Google Developers service account JSON key file to read
+// the credentials that authorize and authenticate the requests.
+// Create a service account on "Credentials" page under "APIs & Auth" for your
+// project at https://console.developers.google.com to download a JSON key file.
+func JWTConfigFromJSON(jsonKey []byte, scope ...string) (*jwt.Config, error) {
+	var key struct {
+		Email      string `json:"client_email"`
+		PrivateKey string `json:"private_key"`
+	}
+	if err := json.Unmarshal(jsonKey, &key); err != nil {
+		return nil, err
+	}
+	return &jwt.Config{
+		Email:      key.Email,
+		PrivateKey: []byte(key.PrivateKey),
+		Scopes:     scope,
+		TokenURL:   JWTTokenURL,
+	}, nil
+}
+
+// ComputeTokenSource returns a token source that fetches access tokens
+// from Google Compute Engine (GCE)'s metadata server. It's only valid to use
+// this token source if your program is running on a GCE instance.
+// If no account is specified, "default" is used.
+// Further information about retrieving access tokens from the GCE metadata
+// server can be found at https://cloud.google.com/compute/docs/authentication.
+func ComputeTokenSource(account string) oauth2.TokenSource {
+	return oauth2.ReuseTokenSource(nil, computeSource{account: account})
+}
+
+type computeSource struct {
+	account string
+}
+
+func (cs computeSource) Token() (*oauth2.Token, error) {
+	if !metadata.OnGCE() {
+		return nil, errors.New("oauth2/google: can't get a token from the metadata service; not running on GCE")
+	}
+	acct := cs.account
+	if acct == "" {
+		acct = "default"
+	}
+	tokenJSON, err := metadata.Get("instance/service-accounts/" + acct + "/token")
+	if err != nil {
+		return nil, err
+	}
+	var res struct {
+		AccessToken  string `json:"access_token"`
+		ExpiresInSec int    `json:"expires_in"`
+		TokenType    string `json:"token_type"`
+	}
+	err = json.NewDecoder(strings.NewReader(tokenJSON)).Decode(&res)
+	if err != nil {
+		return nil, fmt.Errorf("oauth2/google: invalid token JSON from metadata: %v", err)
+	}
+	if res.ExpiresInSec == 0 || res.AccessToken == "" {
+		return nil, fmt.Errorf("oauth2/google: incomplete token received from metadata")
+	}
+	return &oauth2.Token{
+		AccessToken: res.AccessToken,
+		TokenType:   res.TokenType,
+		Expiry:      time.Now().Add(time.Duration(res.ExpiresInSec) * time.Second),
+	}, nil
+}

Godeps/_workspace/src/golang.org/x/oauth2/google/source_appengine.go

@@ -0,0 +1,71 @@
+// Copyright 2014 The oauth2 Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package google
+
+import (
+	"errors"
+	"sort"
+	"strings"
+	"sync"
+	"time"
+
+	"golang.org/x/oauth2"
+)
+
+var (
+	aeTokensMu sync.Mutex // guards aeTokens and appEngineTokenSource.key
+
+	// aeTokens helps the fetched tokens to be reused until their expiration.
+	aeTokens = make(map[string]*tokenLock) // key is '\0'-separated scopes
+)
+
+var errInvalidContext = errors.New("oauth2: a valid appengine.Context is required")
+
+type tokenLock struct {
+	mu sync.Mutex // guards t; held while updating t
+	t  *oauth2.Token
+}
+
+type appEngineTokenSource struct {
+	ctx oauth2.Context
+
+	// fetcherFunc makes the actual RPC to fetch a new access
+	// token with an expiry time.  Provider of this function is
+	// responsible to assert that the given context is valid.
+	fetcherFunc func(ctx oauth2.Context, scope ...string) (accessToken string, expiry time.Time, err error)
+
+	// scopes and key are guarded by the package-level mutex aeTokensMu
+	scopes []string
+	key    string
+}
+
+func (ts *appEngineTokenSource) Token() (*oauth2.Token, error) {
+	aeTokensMu.Lock()
+	if ts.key == "" {
+		sort.Sort(sort.StringSlice(ts.scopes))
+		ts.key = strings.Join(ts.scopes, string(0))
+	}
+	tok, ok := aeTokens[ts.key]
+	if !ok {
+		tok = &tokenLock{}
+		aeTokens[ts.key] = tok
+	}
+	aeTokensMu.Unlock()
+
+	tok.mu.Lock()
+	defer tok.mu.Unlock()
+	if tok.t.Valid() {
+		return tok.t, nil
+	}
+	access, exp, err := ts.fetcherFunc(ts.ctx, ts.scopes...)
+	if err != nil {
+		return nil, err
+	}
+	tok.t = &oauth2.Token{
+		AccessToken: access,
+		Expiry:      exp,
+	}
+	return tok.t, nil
+}

Godeps/_workspace/src/golang.org/x/oauth2/internal/oauth2.go

@@ -0,0 +1,37 @@
+// Copyright 2014 The oauth2 Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package internal contains support packages for oauth2 package.
+package internal
+
+import (
+	"crypto/rsa"
+	"crypto/x509"
+	"encoding/pem"
+	"errors"
+)
+
+// ParseKey converts the binary contents of a private key file
+// to an *rsa.PrivateKey. It detects whether the private key is in a
+// PEM container or not. If so, it extracts the the private key
+// from PEM container before conversion. It only supports PEM
+// containers with no passphrase.
+func ParseKey(key []byte) (*rsa.PrivateKey, error) {
+	block, _ := pem.Decode(key)
+	if block != nil {
+		key = block.Bytes
+	}
+	parsedKey, err := x509.ParsePKCS8PrivateKey(key)
+	if err != nil {
+		parsedKey, err = x509.ParsePKCS1PrivateKey(key)
+		if err != nil {
+			return nil, err
+		}
+	}
+	parsed, ok := parsedKey.(*rsa.PrivateKey)
+	if !ok {
+		return nil, errors.New("oauth2: private key is invalid")
+	}
+	return parsed, nil
+}

Godeps/_workspace/src/golang.org/x/oauth2/jws/jws.go

@@ -0,0 +1,160 @@
+// Copyright 2014 The oauth2 Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package jws provides encoding and decoding utilities for
+// signed JWS messages.
+package jws
+
+import (
+	"bytes"
+	"crypto"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"strings"
+	"time"
+)
+
+// ClaimSet contains information about the JWT signature including the
+// permissions being requested (scopes), the target of the token, the issuer,
+// the time the token was issued, and the lifetime of the token.
+type ClaimSet struct {
+	Iss   string `json:"iss"`             // email address of the client_id of the application making the access token request
+	Scope string `json:"scope,omitempty"` // space-delimited list of the permissions the application requests
+	Aud   string `json:"aud"`             // descriptor of the intended target of the assertion (Optional).
+	Exp   int64  `json:"exp"`             // the expiration time of the assertion
+	Iat   int64  `json:"iat"`             // the time the assertion was issued.
+	Typ   string `json:"typ,omitempty"`   // token type (Optional).
+
+	// Email for which the application is requesting delegated access (Optional).
+	Sub string `json:"sub,omitempty"`
+
+	// The old name of Sub. Client keeps setting Prn to be
+	// complaint with legacy OAuth 2.0 providers. (Optional)
+	Prn string `json:"prn,omitempty"`
+
+	// See http://tools.ietf.org/html/draft-jones-json-web-token-10#section-4.3
+	// This array is marshalled using custom code (see (c *ClaimSet) encode()).
+	PrivateClaims map[string]interface{} `json:"-"`
+
+	exp time.Time
+	iat time.Time
+}
+
+func (c *ClaimSet) encode() (string, error) {
+	if c.exp.IsZero() || c.iat.IsZero() {
+		// Reverting time back for machines whose time is not perfectly in sync.
+		// If client machine's time is in the future according
+		// to Google servers, an access token will not be issued.
+		now := time.Now().Add(-10 * time.Second)
+		c.iat = now
+		c.exp = now.Add(time.Hour)
+	}
+
+	c.Exp = c.exp.Unix()
+	c.Iat = c.iat.Unix()
+
+	b, err := json.Marshal(c)
+	if err != nil {
+		return "", err
+	}
+
+	if len(c.PrivateClaims) == 0 {
+		return base64Encode(b), nil
+	}
+
+	// Marshal private claim set and then append it to b.
+	prv, err := json.Marshal(c.PrivateClaims)
+	if err != nil {
+		return "", fmt.Errorf("jws: invalid map of private claims %v", c.PrivateClaims)
+	}
+
+	// Concatenate public and private claim JSON objects.
+	if !bytes.HasSuffix(b, []byte{'}'}) {
+		return "", fmt.Errorf("jws: invalid JSON %s", b)
+	}
+	if !bytes.HasPrefix(prv, []byte{'{'}) {
+		return "", fmt.Errorf("jws: invalid JSON %s", prv)
+	}
+	b[len(b)-1] = ','         // Replace closing curly brace with a comma.
+	b = append(b, prv[1:]...) // Append private claims.
+	return base64Encode(b), nil
+}
+
+// Header represents the header for the signed JWS payloads.
+type Header struct {
+	// The algorithm used for signature.
+	Algorithm string `json:"alg"`
+
+	// Represents the token type.
+	Typ string `json:"typ"`
+}
+
+func (h *Header) encode() (string, error) {
+	b, err := json.Marshal(h)
+	if err != nil {
+		return "", err
+	}
+	return base64Encode(b), nil
+}
+
+// Decode decodes a claim set from a JWS payload.
+func Decode(payload string) (*ClaimSet, error) {
+	// decode returned id token to get expiry
+	s := strings.Split(payload, ".")
+	if len(s) < 2 {
+		// TODO(jbd): Provide more context about the error.
+		return nil, errors.New("jws: invalid token received")
+	}
+	decoded, err := base64Decode(s[1])
+	if err != nil {
+		return nil, err
+	}
+	c := &ClaimSet{}
+	err = json.NewDecoder(bytes.NewBuffer(decoded)).Decode(c)
+	return c, err
+}
+
+// Encode encodes a signed JWS with provided header and claim set.
+func Encode(header *Header, c *ClaimSet, signature *rsa.PrivateKey) (string, error) {
+	head, err := header.encode()
+	if err != nil {
+		return "", err
+	}
+	cs, err := c.encode()
+	if err != nil {
+		return "", err
+	}
+	ss := fmt.Sprintf("%s.%s", head, cs)
+	h := sha256.New()
+	h.Write([]byte(ss))
+	b, err := rsa.SignPKCS1v15(rand.Reader, signature, crypto.SHA256, h.Sum(nil))
+	if err != nil {
+		return "", err
+	}
+	sig := base64Encode(b)
+	return fmt.Sprintf("%s.%s", ss, sig), nil
+}
+
+// base64Encode returns and Base64url encoded version of the input string with any
+// trailing "=" stripped.
+func base64Encode(b []byte) string {
+	return strings.TrimRight(base64.URLEncoding.EncodeToString(b), "=")
+}
+
+// base64Decode decodes the Base64url encoded string
+func base64Decode(s string) ([]byte, error) {
+	// add back missing padding
+	switch len(s) % 4 {
+	case 2:
+		s += "=="
+	case 3:
+		s += "="
+	}
+	return base64.URLEncoding.DecodeString(s)
+}

Godeps/_workspace/src/golang.org/x/oauth2/jwt/example_test.go

@@ -0,0 +1,31 @@
+// Copyright 2014 The oauth2 Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package jwt_test
+
+import (
+	"golang.org/x/oauth2"
+	"golang.org/x/oauth2/jwt"
+)
+
+func ExampleJWTConfig() {
+	conf := &jwt.Config{
+		Email: "xxx@developer.com",
+		// The contents of your RSA private key or your PEM file
+		// that contains a private key.
+		// If you have a p12 file instead, you
+		// can use `openssl` to export the private key into a pem file.
+		//
+		//    $ openssl pkcs12 -in key.p12 -out key.pem -nodes
+		//
+		// It only supports PEM containers with no passphrase.
+		PrivateKey: []byte("-----BEGIN RSA PRIVATE KEY-----..."),
+		Subject:    "user@example.com",
+		TokenURL:   "https://provider.com/o/oauth2/token",
+	}
+	// Initiate an http.Client, the following GET request will be
+	// authorized and authenticated on the behalf of user@example.com.
+	client := conf.Client(oauth2.NoContext)
+	client.Get("...")
+}

Godeps/_workspace/src/golang.org/x/oauth2/jwt/jwt.go

@@ -0,0 +1,146 @@
+// Copyright 2014 The oauth2 Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package jwt implements the OAuth 2.0 JSON Web Token flow, commonly
+// known as "two-legged OAuth 2.0".
+//
+// See: https://tools.ietf.org/html/draft-ietf-oauth-jwt-bearer-12
+package jwt
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+
+	"golang.org/x/oauth2"
+	"golang.org/x/oauth2/internal"
+	"golang.org/x/oauth2/jws"
+)
+
+var (
+	defaultGrantType = "urn:ietf:params:oauth:grant-type:jwt-bearer"
+	defaultHeader    = &jws.Header{Algorithm: "RS256", Typ: "JWT"}
+)
+
+// Config is the configuration for using JWT to fetch tokens,
+// commonly known as "two-legged OAuth 2.0".
+type Config struct {
+	// Email is the OAuth client identifier used when communicating with
+	// the configured OAuth provider.
+	Email string
+
+	// PrivateKey contains the contents of an RSA private key or the
+	// contents of a PEM file that contains a private key. The provided
+	// private key is used to sign JWT payloads.
+	// PEM containers with a passphrase are not supported.
+	// Use the following command to convert a PKCS 12 file into a PEM.
+	//
+	//    $ openssl pkcs12 -in key.p12 -out key.pem -nodes
+	//
+	PrivateKey []byte
+
+	// Subject is the optional user to impersonate.
+	Subject string
+
+	// Scopes optionally specifies a list of requested permission scopes.
+	Scopes []string
+
+	// TokenURL is the endpoint required to complete the 2-legged JWT flow.
+	TokenURL string
+}
+
+// TokenSource returns a JWT TokenSource using the configuration
+// in c and the HTTP client from the provided context.
+func (c *Config) TokenSource(ctx oauth2.Context) oauth2.TokenSource {
+	return oauth2.ReuseTokenSource(nil, jwtSource{ctx, c})
+}
+
+// Client returns an HTTP client wrapping the context's
+// HTTP transport and adding Authorization headers with tokens
+// obtained from c.
+//
+// The returned client and its Transport should not be modified.
+func (c *Config) Client(ctx oauth2.Context) *http.Client {
+	return oauth2.NewClient(ctx, c.TokenSource(ctx))
+}
+
+// jwtSource is a source that always does a signed JWT request for a token.
+// It should typically be wrapped with a reuseTokenSource.
+type jwtSource struct {
+	ctx  oauth2.Context
+	conf *Config
+}
+
+func (js jwtSource) Token() (*oauth2.Token, error) {
+	pk, err := internal.ParseKey(js.conf.PrivateKey)
+	if err != nil {
+		return nil, err
+	}
+	hc := oauth2.NewClient(js.ctx, nil)
+	claimSet := &jws.ClaimSet{
+		Iss:   js.conf.Email,
+		Scope: strings.Join(js.conf.Scopes, " "),
+		Aud:   js.conf.TokenURL,
+	}
+	if subject := js.conf.Subject; subject != "" {
+		claimSet.Sub = subject
+		// prn is the old name of sub. Keep setting it
+		// to be compatible with legacy OAuth 2.0 providers.
+		claimSet.Prn = subject
+	}
+	payload, err := jws.Encode(defaultHeader, claimSet, pk)
+	if err != nil {
+		return nil, err
+	}
+	v := url.Values{}
+	v.Set("grant_type", defaultGrantType)
+	v.Set("assertion", payload)
+	resp, err := hc.PostForm(js.conf.TokenURL, v)
+	if err != nil {
+		return nil, fmt.Errorf("oauth2: cannot fetch token: %v", err)
+	}
+	defer resp.Body.Close()
+	body, err := ioutil.ReadAll(io.LimitReader(resp.Body, 1<<20))
+	if err != nil {
+		return nil, fmt.Errorf("oauth2: cannot fetch token: %v", err)
+	}
+	if c := resp.StatusCode; c < 200 || c > 299 {
+		return nil, fmt.Errorf("oauth2: cannot fetch token: %v\nResponse: %s", resp.Status, body)
+	}
+	// tokenRes is the JSON response body.
+	var tokenRes struct {
+		AccessToken string `json:"access_token"`
+		TokenType   string `json:"token_type"`
+		IDToken     string `json:"id_token"`
+		ExpiresIn   int64  `json:"expires_in"` // relative seconds from now
+	}
+	if err := json.Unmarshal(body, &tokenRes); err != nil {
+		return nil, fmt.Errorf("oauth2: cannot fetch token: %v", err)
+	}
+	token := &oauth2.Token{
+		AccessToken: tokenRes.AccessToken,
+		TokenType:   tokenRes.TokenType,
+	}
+	raw := make(map[string]interface{})
+	json.Unmarshal(body, &raw) // no error checks for optional fields
+	token = token.WithExtra(raw)
+
+	if secs := tokenRes.ExpiresIn; secs > 0 {
+		token.Expiry = time.Now().Add(time.Duration(secs) * time.Second)
+	}
+	if v := tokenRes.IDToken; v != "" {
+		// decode returned id token to get expiry
+		claimSet, err := jws.Decode(v)
+		if err != nil {
+			return nil, fmt.Errorf("oauth2: error decoding JWT token: %v", err)
+		}
+		token.Expiry = time.Unix(claimSet.Exp, 0)
+	}
+	return token, nil
+}

Godeps/_workspace/src/golang.org/x/oauth2/jwt/jwt_test.go

@@ -0,0 +1,134 @@
+// Copyright 2014 The oauth2 Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package jwt
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"golang.org/x/oauth2"
+)
+
+var dummyPrivateKey = []byte(`-----BEGIN RSA PRIVATE KEY-----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+-----END RSA PRIVATE KEY-----`)
+
+func TestJWTFetch_JSONResponse(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.Write([]byte(`{
+			"access_token": "90d64460d14870c08c81352a05dedd3465940a7c",
+			"scope": "user",
+			"token_type": "bearer",
+			"expires_in": 3600
+		}`))
+	}))
+	defer ts.Close()
+
+	conf := &Config{
+		Email:      "aaa@xxx.com",
+		PrivateKey: dummyPrivateKey,
+		TokenURL:   ts.URL,
+	}
+	tok, err := conf.TokenSource(oauth2.NoContext).Token()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !tok.Valid() {
+		t.Errorf("Token invalid")
+	}
+	if tok.AccessToken != "90d64460d14870c08c81352a05dedd3465940a7c" {
+		t.Errorf("Unexpected access token, %#v", tok.AccessToken)
+	}
+	if tok.TokenType != "bearer" {
+		t.Errorf("Unexpected token type, %#v", tok.TokenType)
+	}
+	if tok.Expiry.IsZero() {
+		t.Errorf("Unexpected token expiry, %#v", tok.Expiry)
+	}
+	scope := tok.Extra("scope")
+	if scope != "user" {
+		t.Errorf("Unexpected value for scope: %v", scope)
+	}
+}
+
+func TestJWTFetch_BadResponse(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.Write([]byte(`{"scope": "user", "token_type": "bearer"}`))
+	}))
+	defer ts.Close()
+
+	conf := &Config{
+		Email:      "aaa@xxx.com",
+		PrivateKey: dummyPrivateKey,
+		TokenURL:   ts.URL,
+	}
+	tok, err := conf.TokenSource(oauth2.NoContext).Token()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if tok == nil {
+		t.Fatalf("token is nil")
+	}
+	if tok.Valid() {
+		t.Errorf("token is valid. want invalid.")
+	}
+	if tok.AccessToken != "" {
+		t.Errorf("Unexpected non-empty access token %q.", tok.AccessToken)
+	}
+	if want := "bearer"; tok.TokenType != want {
+		t.Errorf("TokenType = %q; want %q", tok.TokenType, want)
+	}
+	scope := tok.Extra("scope")
+	if want := "user"; scope != want {
+		t.Errorf("token scope = %q; want %q", scope, want)
+	}
+}
+
+func TestJWTFetch_BadResponseType(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.Write([]byte(`{"access_token":123, "scope": "user", "token_type": "bearer"}`))
+	}))
+	defer ts.Close()
+	conf := &Config{
+		Email:      "aaa@xxx.com",
+		PrivateKey: dummyPrivateKey,
+		TokenURL:   ts.URL,
+	}
+	tok, err := conf.TokenSource(oauth2.NoContext).Token()
+	if err == nil {
+		t.Error("got a token; expected error")
+		if tok.AccessToken != "" {
+			t.Errorf("Unexpected access token, %#v.", tok.AccessToken)
+		}
+	}
+}

Godeps/_workspace/src/golang.org/x/oauth2/oauth2.go

@@ -0,0 +1,462 @@
+// Copyright 2014 The oauth2 Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package oauth2 provides support for making
+// OAuth2 authorized and authenticated HTTP requests.
+// It can additionally grant authorization with Bearer JWT.
+package oauth2
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"mime"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"golang.org/x/net/context"
+)
+
+// Context can be an golang.org/x/net.Context, or an App Engine Context.
+// If you don't care and aren't running on App Engine, you may use NoContext.
+type Context interface{}
+
+// NoContext is the default context. If you're not running this code
+// on App Engine or not using golang.org/x/net.Context to provide a custom
+// HTTP client, you should use NoContext.
+var NoContext Context = nil
+
+// Config describes a typical 3-legged OAuth2 flow, with both the
+// client application information and the server's endpoint URLs.
+type Config struct {
+	// ClientID is the application's ID.
+	ClientID string
+
+	// ClientSecret is the application's secret.
+	ClientSecret string
+
+	// Endpoint contains the resource server's token endpoint
+	// URLs. These are constants specific to each server and are
+	// often available via site-specific packages, such as
+	// google.Endpoint or github.Endpoint.
+	Endpoint Endpoint
+
+	// RedirectURL is the URL to redirect users going through
+	// the OAuth flow, after the resource owner's URLs.
+	RedirectURL string
+
+	// Scope specifies optional requested permissions.
+	Scopes []string
+}
+
+// A TokenSource is anything that can return a token.
+type TokenSource interface {
+	// Token returns a token or an error.
+	// Token must be safe for concurrent use by multiple goroutines.
+	// The returned Token must not be modified.
+	Token() (*Token, error)
+}
+
+// Endpoint contains the OAuth 2.0 provider's authorization and token
+// endpoint URLs.
+type Endpoint struct {
+	AuthURL  string
+	TokenURL string
+}
+
+var (
+	// AccessTypeOnline and AccessTypeOffline are options passed
+	// to the Options.AuthCodeURL method. They modify the
+	// "access_type" field that gets sent in the URL returned by
+	// AuthCodeURL.
+	//
+	// Online (the default if neither is specified) is the default.
+	// If your application needs to refresh access tokens when the
+	// user is not present at the browser, then use offline. This
+	// will result in your application obtaining a refresh token
+	// the first time your application exchanges an authorization
+	// code for a user.
+	AccessTypeOnline  AuthCodeOption = setParam{"access_type", "online"}
+	AccessTypeOffline AuthCodeOption = setParam{"access_type", "offline"}
+
+	// ApprovalForce forces the users to view the consent dialog
+	// and confirm the permissions request at the URL returned
+	// from AuthCodeURL, even if they've already done so.
+	ApprovalForce AuthCodeOption = setParam{"approval_prompt", "force"}
+)
+
+type setParam struct{ k, v string }
+
+func (p setParam) setValue(m url.Values) { m.Set(p.k, p.v) }
+
+// An AuthCodeOption is passed to Config.AuthCodeURL.
+type AuthCodeOption interface {
+	setValue(url.Values)
+}
+
+// AuthCodeURL returns a URL to OAuth 2.0 provider's consent page
+// that asks for permissions for the required scopes explicitly.
+//
+// State is a token to protect the user from CSRF attacks. You must
+// always provide a non-zero string and validate that it matches the
+// the state query parameter on your redirect callback.
+// See http://tools.ietf.org/html/rfc6749#section-10.12 for more info.
+//
+// Opts may include AccessTypeOnline or AccessTypeOffline, as well
+// as ApprovalForce.
+func (c *Config) AuthCodeURL(state string, opts ...AuthCodeOption) string {
+	var buf bytes.Buffer
+	buf.WriteString(c.Endpoint.AuthURL)
+	v := url.Values{
+		"response_type": {"code"},
+		"client_id":     {c.ClientID},
+		"redirect_uri":  condVal(c.RedirectURL),
+		"scope":         condVal(strings.Join(c.Scopes, " ")),
+		"state":         condVal(state),
+	}
+	for _, opt := range opts {
+		opt.setValue(v)
+	}
+	if strings.Contains(c.Endpoint.AuthURL, "?") {
+		buf.WriteByte('&')
+	} else {
+		buf.WriteByte('?')
+	}
+	buf.WriteString(v.Encode())
+	return buf.String()
+}
+
+// Exchange converts an authorization code into a token.
+//
+// It is used after a resource provider redirects the user back
+// to the Redirect URI (the URL obtained from AuthCodeURL).
+//
+// The HTTP client to use is derived from the context. If nil,
+// http.DefaultClient is used. See the Context type's documentation.
+//
+// The code will be in the *http.Request.FormValue("code"). Before
+// calling Exchange, be sure to validate FormValue("state").
+func (c *Config) Exchange(ctx Context, code string) (*Token, error) {
+	return retrieveToken(ctx, c, url.Values{
+		"grant_type":   {"authorization_code"},
+		"code":         {code},
+		"redirect_uri": condVal(c.RedirectURL),
+		"scope":        condVal(strings.Join(c.Scopes, " ")),
+	})
+}
+
+// contextClientFunc is a func which tries to return an *http.Client
+// given a Context value. If it returns an error, the search stops
+// with that error.  If it returns (nil, nil), the search continues
+// down the list of registered funcs.
+type contextClientFunc func(Context) (*http.Client, error)
+
+var contextClientFuncs []contextClientFunc
+
+func registerContextClientFunc(fn contextClientFunc) {
+	contextClientFuncs = append(contextClientFuncs, fn)
+}
+
+func contextClient(ctx Context) (*http.Client, error) {
+	for _, fn := range contextClientFuncs {
+		c, err := fn(ctx)
+		if err != nil {
+			return nil, err
+		}
+		if c != nil {
+			return c, nil
+		}
+	}
+	if xc, ok := ctx.(context.Context); ok {
+		if hc, ok := xc.Value(HTTPClient).(*http.Client); ok {
+			return hc, nil
+		}
+	}
+	return http.DefaultClient, nil
+}
+
+func contextTransport(ctx Context) http.RoundTripper {
+	hc, err := contextClient(ctx)
+	if err != nil {
+		// This is a rare error case (somebody using nil on App Engine),
+		// so I'd rather not everybody do an error check on this Client
+		// method. They can get the error that they're doing it wrong
+		// later, at client.Get/PostForm time.
+		return errorTransport{err}
+	}
+	return hc.Transport
+}
+
+// Client returns an HTTP client using the provided token.
+// The token will auto-refresh as necessary. The underlying
+// HTTP transport will be obtained using the provided context.
+// The returned client and its Transport should not be modified.
+func (c *Config) Client(ctx Context, t *Token) *http.Client {
+	return NewClient(ctx, c.TokenSource(ctx, t))
+}
+
+// TokenSource returns a TokenSource that returns t until t expires,
+// automatically refreshing it as necessary using the provided context.
+// See the the Context documentation.
+//
+// Most users will use Config.Client instead.
+func (c *Config) TokenSource(ctx Context, t *Token) TokenSource {
+	nwn := &reuseTokenSource{t: t}
+	nwn.new = tokenRefresher{
+		ctx:      ctx,
+		conf:     c,
+		oldToken: &nwn.t,
+	}
+	return nwn
+}
+
+// tokenRefresher is a TokenSource that makes "grant_type"=="refresh_token"
+// HTTP requests to renew a token using a RefreshToken.
+type tokenRefresher struct {
+	ctx      Context // used to get HTTP requests
+	conf     *Config
+	oldToken **Token // pointer to old *Token w/ RefreshToken
+}
+
+func (tf tokenRefresher) Token() (*Token, error) {
+	t := *tf.oldToken
+	if t == nil {
+		return nil, errors.New("oauth2: attempted use of nil Token")
+	}
+	if t.RefreshToken == "" {
+		return nil, errors.New("oauth2: token expired and refresh token is not set")
+	}
+	return retrieveToken(tf.ctx, tf.conf, url.Values{
+		"grant_type":    {"refresh_token"},
+		"refresh_token": {t.RefreshToken},
+	})
+}
+
+// reuseTokenSource is a TokenSource that holds a single token in memory
+// and validates its expiry before each call to retrieve it with
+// Token. If it's expired, it will be auto-refreshed using the
+// new TokenSource.
+//
+// The first call to TokenRefresher must be SetToken.
+type reuseTokenSource struct {
+	new TokenSource // called when t is expired.
+
+	mu sync.Mutex // guards t
+	t  *Token
+}
+
+// Token returns the current token if it's still valid, else will
+// refresh the current token (using r.Context for HTTP client
+// information) and return the new one.
+func (s *reuseTokenSource) Token() (*Token, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if s.t.Valid() {
+		return s.t, nil
+	}
+	t, err := s.new.Token()
+	if err != nil {
+		return nil, err
+	}
+	s.t = t
+	return t, nil
+}
+
+func retrieveToken(ctx Context, c *Config, v url.Values) (*Token, error) {
+	hc, err := contextClient(ctx)
+	if err != nil {
+		return nil, err
+	}
+	v.Set("client_id", c.ClientID)
+	bustedAuth := !providerAuthHeaderWorks(c.Endpoint.TokenURL)
+	if bustedAuth && c.ClientSecret != "" {
+		v.Set("client_secret", c.ClientSecret)
+	}
+	req, err := http.NewRequest("POST", c.Endpoint.TokenURL, strings.NewReader(v.Encode()))
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	if !bustedAuth && c.ClientSecret != "" {
+		req.SetBasicAuth(c.ClientID, c.ClientSecret)
+	}
+	r, err := hc.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer r.Body.Close()
+	body, err := ioutil.ReadAll(io.LimitReader(r.Body, 1<<20))
+	if err != nil {
+		return nil, fmt.Errorf("oauth2: cannot fetch token: %v", err)
+	}
+	if code := r.StatusCode; code < 200 || code > 299 {
+		return nil, fmt.Errorf("oauth2: cannot fetch token: %v\nResponse: %s", r.Status, body)
+	}
+
+	var token *Token
+	content, _, _ := mime.ParseMediaType(r.Header.Get("Content-Type"))
+	switch content {
+	case "application/x-www-form-urlencoded", "text/plain":
+		vals, err := url.ParseQuery(string(body))
+		if err != nil {
+			return nil, err
+		}
+		token = &Token{
+			AccessToken:  vals.Get("access_token"),
+			TokenType:    vals.Get("token_type"),
+			RefreshToken: vals.Get("refresh_token"),
+			raw:          vals,
+		}
+		e := vals.Get("expires_in")
+		if e == "" {
+			// TODO(jbd): Facebook's OAuth2 implementation is broken and
+			// returns expires_in field in expires. Remove the fallback to expires,
+			// when Facebook fixes their implementation.
+			e = vals.Get("expires")
+		}
+		expires, _ := strconv.Atoi(e)
+		if expires != 0 {
+			token.Expiry = time.Now().Add(time.Duration(expires) * time.Second)
+		}
+	default:
+		var tj tokenJSON
+		if err = json.Unmarshal(body, &tj); err != nil {
+			return nil, err
+		}
+		token = &Token{
+			AccessToken:  tj.AccessToken,
+			TokenType:    tj.TokenType,
+			RefreshToken: tj.RefreshToken,
+			Expiry:       tj.expiry(),
+			raw:          make(map[string]interface{}),
+		}
+		json.Unmarshal(body, &token.raw) // no error checks for optional fields
+	}
+	// Don't overwrite `RefreshToken` with an empty value
+	// if this was a token refreshing request.
+	if token.RefreshToken == "" {
+		token.RefreshToken = v.Get("refresh_token")
+	}
+	return token, nil
+}
+
+// tokenJSON is the struct representing the HTTP response from OAuth2
+// providers returning a token in JSON form.
+type tokenJSON struct {
+	AccessToken  string `json:"access_token"`
+	TokenType    string `json:"token_type"`
+	RefreshToken string `json:"refresh_token"`
+	ExpiresIn    int32  `json:"expires_in"`
+	Expires      int32  `json:"expires"` // broken Facebook spelling of expires_in
+}
+
+func (e *tokenJSON) expiry() (t time.Time) {
+	if v := e.ExpiresIn; v != 0 {
+		return time.Now().Add(time.Duration(v) * time.Second)
+	}
+	if v := e.Expires; v != 0 {
+		return time.Now().Add(time.Duration(v) * time.Second)
+	}
+	return
+}
+
+func condVal(v string) []string {
+	if v == "" {
+		return nil
+	}
+	return []string{v}
+}
+
+// providerAuthHeaderWorks reports whether the OAuth2 server identified by the tokenURL
+// implements the OAuth2 spec correctly
+// See https://code.google.com/p/goauth2/issues/detail?id=31 for background.
+// In summary:
+// - Reddit only accepts client secret in the Authorization header
+// - Dropbox accepts either it in URL param or Auth header, but not both.
+// - Google only accepts URL param (not spec compliant?), not Auth header
+func providerAuthHeaderWorks(tokenURL string) bool {
+	if strings.HasPrefix(tokenURL, "https://accounts.google.com/") ||
+		strings.HasPrefix(tokenURL, "https://github.com/") ||
+		strings.HasPrefix(tokenURL, "https://api.instagram.com/") ||
+		strings.HasPrefix(tokenURL, "https://www.douban.com/") ||
+		strings.HasPrefix(tokenURL, "https://api.dropbox.com/") ||
+		strings.HasPrefix(tokenURL, "https://api.soundcloud.com/") ||
+		strings.HasPrefix(tokenURL, "https://www.linkedin.com/") {
+		// Some sites fail to implement the OAuth2 spec fully.
+		return false
+	}
+
+	// Assume the provider implements the spec properly
+	// otherwise. We can add more exceptions as they're
+	// discovered. We will _not_ be adding configurable hooks
+	// to this package to let users select server bugs.
+	return true
+}
+
+// HTTPClient is the context key to use with golang.org/x/net/context's
+// WithValue function to associate an *http.Client value with a context.
+var HTTPClient contextKey
+
+// contextKey is just an empty struct. It exists so HTTPClient can be
+// an immutable public variable with a unique type. It's immutable
+// because nobody else can create a contextKey, being unexported.
+type contextKey struct{}
+
+// NewClient creates an *http.Client from a Context and TokenSource.
+// The returned client is not valid beyond the lifetime of the context.
+//
+// As a special case, if src is nil, a non-OAuth2 client is returned
+// using the provided context. This exists to support related OAuth2
+// packages.
+func NewClient(ctx Context, src TokenSource) *http.Client {
+	if src == nil {
+		c, err := contextClient(ctx)
+		if err != nil {
+			return &http.Client{Transport: errorTransport{err}}
+		}
+		return c
+	}
+	return &http.Client{
+		Transport: &Transport{
+			Base:   contextTransport(ctx),
+			Source: ReuseTokenSource(nil, src),
+		},
+	}
+}
+
+// ReuseTokenSource returns a TokenSource which repeatedly returns the
+// same token as long as it's valid, starting with t.
+// When its cached token is invalid, a new token is obtained from src.
+//
+// ReuseTokenSource is typically used to reuse tokens from a cache
+// (such as a file on disk) between runs of a program, rather than
+// obtaining new tokens unnecessarily.
+//
+// The initial token t may be nil, in which case the TokenSource is
+// wrapped in a caching version if it isn't one already. This also
+// means it's always safe to wrap ReuseTokenSource around any other
+// TokenSource without adverse effects.
+func ReuseTokenSource(t *Token, src TokenSource) TokenSource {
+	// Don't wrap a reuseTokenSource in itself. That would work,
+	// but cause an unnecessary number of mutex operations.
+	// Just build the equivalent one.
+	if rt, ok := src.(*reuseTokenSource); ok {
+		if t == nil {
+			// Just use it directly.
+			return rt
+		}
+		src = rt.new
+	}
+	return &reuseTokenSource{
+		t:   t,
+		new: src,
+	}
+}

Godeps/_workspace/src/golang.org/x/oauth2/oauth2_test.go

@@ -0,0 +1,260 @@
+// Copyright 2014 The oauth2 Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package oauth2
+
+import (
+	"errors"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"golang.org/x/net/context"
+)
+
+type mockTransport struct {
+	rt func(req *http.Request) (resp *http.Response, err error)
+}
+
+func (t *mockTransport) RoundTrip(req *http.Request) (resp *http.Response, err error) {
+	return t.rt(req)
+}
+
+type mockCache struct {
+	token   *Token
+	readErr error
+}
+
+func (c *mockCache) ReadToken() (*Token, error) {
+	return c.token, c.readErr
+}
+
+func (c *mockCache) WriteToken(*Token) {
+	// do nothing
+}
+
+func newConf(url string) *Config {
+	return &Config{
+		ClientID:     "CLIENT_ID",
+		ClientSecret: "CLIENT_SECRET",
+		RedirectURL:  "REDIRECT_URL",
+		Scopes:       []string{"scope1", "scope2"},
+		Endpoint: Endpoint{
+			AuthURL:  url + "/auth",
+			TokenURL: url + "/token",
+		},
+	}
+}
+
+func TestAuthCodeURL(t *testing.T) {
+	conf := newConf("server")
+	url := conf.AuthCodeURL("foo", AccessTypeOffline, ApprovalForce)
+	if url != "server/auth?access_type=offline&approval_prompt=force&client_id=CLIENT_ID&redirect_uri=REDIRECT_URL&response_type=code&scope=scope1+scope2&state=foo" {
+		t.Errorf("Auth code URL doesn't match the expected, found: %v", url)
+	}
+}
+
+func TestAuthCodeURL_Optional(t *testing.T) {
+	conf := &Config{
+		ClientID: "CLIENT_ID",
+		Endpoint: Endpoint{
+			AuthURL:  "/auth-url",
+			TokenURL: "/token-url",
+		},
+	}
+	url := conf.AuthCodeURL("")
+	if url != "/auth-url?client_id=CLIENT_ID&response_type=code" {
+		t.Fatalf("Auth code URL doesn't match the expected, found: %v", url)
+	}
+}
+
+func TestExchangeRequest(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.String() != "/token" {
+			t.Errorf("Unexpected exchange request URL, %v is found.", r.URL)
+		}
+		headerAuth := r.Header.Get("Authorization")
+		if headerAuth != "Basic Q0xJRU5UX0lEOkNMSUVOVF9TRUNSRVQ=" {
+			t.Errorf("Unexpected authorization header, %v is found.", headerAuth)
+		}
+		headerContentType := r.Header.Get("Content-Type")
+		if headerContentType != "application/x-www-form-urlencoded" {
+			t.Errorf("Unexpected Content-Type header, %v is found.", headerContentType)
+		}
+		body, err := ioutil.ReadAll(r.Body)
+		if err != nil {
+			t.Errorf("Failed reading request body: %s.", err)
+		}
+		if string(body) != "client_id=CLIENT_ID&code=exchange-code&grant_type=authorization_code&redirect_uri=REDIRECT_URL&scope=scope1+scope2" {
+			t.Errorf("Unexpected exchange payload, %v is found.", string(body))
+		}
+		w.Header().Set("Content-Type", "application/x-www-form-urlencoded")
+		w.Write([]byte("access_token=90d64460d14870c08c81352a05dedd3465940a7c&scope=user&token_type=bearer"))
+	}))
+	defer ts.Close()
+	conf := newConf(ts.URL)
+	tok, err := conf.Exchange(NoContext, "exchange-code")
+	if err != nil {
+		t.Error(err)
+	}
+	if !tok.Valid() {
+		t.Fatalf("Token invalid. Got: %#v", tok)
+	}
+	if tok.AccessToken != "90d64460d14870c08c81352a05dedd3465940a7c" {
+		t.Errorf("Unexpected access token, %#v.", tok.AccessToken)
+	}
+	if tok.TokenType != "bearer" {
+		t.Errorf("Unexpected token type, %#v.", tok.TokenType)
+	}
+	scope := tok.Extra("scope")
+	if scope != "user" {
+		t.Errorf("Unexpected value for scope: %v", scope)
+	}
+}
+
+func TestExchangeRequest_JSONResponse(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.String() != "/token" {
+			t.Errorf("Unexpected exchange request URL, %v is found.", r.URL)
+		}
+		headerAuth := r.Header.Get("Authorization")
+		if headerAuth != "Basic Q0xJRU5UX0lEOkNMSUVOVF9TRUNSRVQ=" {
+			t.Errorf("Unexpected authorization header, %v is found.", headerAuth)
+		}
+		headerContentType := r.Header.Get("Content-Type")
+		if headerContentType != "application/x-www-form-urlencoded" {
+			t.Errorf("Unexpected Content-Type header, %v is found.", headerContentType)
+		}
+		body, err := ioutil.ReadAll(r.Body)
+		if err != nil {
+			t.Errorf("Failed reading request body: %s.", err)
+		}
+		if string(body) != "client_id=CLIENT_ID&code=exchange-code&grant_type=authorization_code&redirect_uri=REDIRECT_URL&scope=scope1+scope2" {
+			t.Errorf("Unexpected exchange payload, %v is found.", string(body))
+		}
+		w.Header().Set("Content-Type", "application/json")
+		w.Write([]byte(`{"access_token": "90d64460d14870c08c81352a05dedd3465940a7c", "scope": "user", "token_type": "bearer", "expires_in": 86400}`))
+	}))
+	defer ts.Close()
+	conf := newConf(ts.URL)
+	tok, err := conf.Exchange(NoContext, "exchange-code")
+	if err != nil {
+		t.Error(err)
+	}
+	if !tok.Valid() {
+		t.Fatalf("Token invalid. Got: %#v", tok)
+	}
+	if tok.AccessToken != "90d64460d14870c08c81352a05dedd3465940a7c" {
+		t.Errorf("Unexpected access token, %#v.", tok.AccessToken)
+	}
+	if tok.TokenType != "bearer" {
+		t.Errorf("Unexpected token type, %#v.", tok.TokenType)
+	}
+	scope := tok.Extra("scope")
+	if scope != "user" {
+		t.Errorf("Unexpected value for scope: %v", scope)
+	}
+}
+
+func TestExchangeRequest_BadResponse(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.Write([]byte(`{"scope": "user", "token_type": "bearer"}`))
+	}))
+	defer ts.Close()
+	conf := newConf(ts.URL)
+	tok, err := conf.Exchange(NoContext, "code")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if tok.AccessToken != "" {
+		t.Errorf("Unexpected access token, %#v.", tok.AccessToken)
+	}
+}
+
+func TestExchangeRequest_BadResponseType(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.Write([]byte(`{"access_token":123,  "scope": "user", "token_type": "bearer"}`))
+	}))
+	defer ts.Close()
+	conf := newConf(ts.URL)
+	_, err := conf.Exchange(NoContext, "exchange-code")
+	if err == nil {
+		t.Error("expected error from invalid access_token type")
+	}
+}
+
+func TestExchangeRequest_NonBasicAuth(t *testing.T) {
+	tr := &mockTransport{
+		rt: func(r *http.Request) (w *http.Response, err error) {
+			headerAuth := r.Header.Get("Authorization")
+			if headerAuth != "" {
+				t.Errorf("Unexpected authorization header, %v is found.", headerAuth)
+			}
+			return nil, errors.New("no response")
+		},
+	}
+	c := &http.Client{Transport: tr}
+	conf := &Config{
+		ClientID: "CLIENT_ID",
+		Endpoint: Endpoint{
+			AuthURL:  "https://accounts.google.com/auth",
+			TokenURL: "https://accounts.google.com/token",
+		},
+	}
+
+	ctx := context.WithValue(context.Background(), HTTPClient, c)
+	conf.Exchange(ctx, "code")
+}
+
+func TestTokenRefreshRequest(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.String() == "/somethingelse" {
+			return
+		}
+		if r.URL.String() != "/token" {
+			t.Errorf("Unexpected token refresh request URL, %v is found.", r.URL)
+		}
+		headerContentType := r.Header.Get("Content-Type")
+		if headerContentType != "application/x-www-form-urlencoded" {
+			t.Errorf("Unexpected Content-Type header, %v is found.", headerContentType)
+		}
+		body, _ := ioutil.ReadAll(r.Body)
+		if string(body) != "client_id=CLIENT_ID&grant_type=refresh_token&refresh_token=REFRESH_TOKEN" {
+			t.Errorf("Unexpected refresh token payload, %v is found.", string(body))
+		}
+	}))
+	defer ts.Close()
+	conf := newConf(ts.URL)
+	c := conf.Client(NoContext, &Token{RefreshToken: "REFRESH_TOKEN"})
+	c.Get(ts.URL + "/somethingelse")
+}
+
+func TestFetchWithNoRefreshToken(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.String() == "/somethingelse" {
+			return
+		}
+		if r.URL.String() != "/token" {
+			t.Errorf("Unexpected token refresh request URL, %v is found.", r.URL)
+		}
+		headerContentType := r.Header.Get("Content-Type")
+		if headerContentType != "application/x-www-form-urlencoded" {
+			t.Errorf("Unexpected Content-Type header, %v is found.", headerContentType)
+		}
+		body, _ := ioutil.ReadAll(r.Body)
+		if string(body) != "client_id=CLIENT_ID&grant_type=refresh_token&refresh_token=REFRESH_TOKEN" {
+			t.Errorf("Unexpected refresh token payload, %v is found.", string(body))
+		}
+	}))
+	defer ts.Close()
+	conf := newConf(ts.URL)
+	c := conf.Client(NoContext, nil)
+	_, err := c.Get(ts.URL + "/somethingelse")
+	if err == nil {
+		t.Errorf("Fetch should return an error if no refresh token is set")
+	}
+}

Godeps/_workspace/src/golang.org/x/oauth2/token.go

@@ -0,0 +1,99 @@
+// Copyright 2014 The oauth2 Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package oauth2
+
+import (
+	"net/http"
+	"net/url"
+	"time"
+)
+
+// Token represents the crendentials used to authorize
+// the requests to access protected resources on the OAuth 2.0
+// provider's backend.
+//
+// Most users of this package should not access fields of Token
+// directly. They're exported mostly for use by related packages
+// implementing derivative OAuth2 flows.
+type Token struct {
+	// AccessToken is the token that authorizes and authenticates
+	// the requests.
+	AccessToken string `json:"access_token"`
+
+	// TokenType is the type of token.
+	// The Type method returns either this or "Bearer", the default.
+	TokenType string `json:"token_type,omitempty"`
+
+	// RefreshToken is a token that's used by the application
+	// (as opposed to the user) to refresh the access token
+	// if it expires.
+	RefreshToken string `json:"refresh_token,omitempty"`
+
+	// Expiry is the optional expiration time of the access token.
+	//
+	// If zero, TokenSource implementations will reuse the same
+	// token forever and RefreshToken or equivalent
+	// mechanisms for that TokenSource will not be used.
+	Expiry time.Time `json:"expiry,omitempty"`
+
+	// raw optionally contains extra metadata from the server
+	// when updating a token.
+	raw interface{}
+}
+
+// Type returns t.TokenType if non-empty, else "Bearer".
+func (t *Token) Type() string {
+	if t.TokenType != "" {
+		return t.TokenType
+	}
+	return "Bearer"
+}
+
+// SetAuthHeader sets the Authorization header to r using the access
+// token in t.
+//
+// This method is unnecessary when using Transport or an HTTP Client
+// returned by this package.
+func (t *Token) SetAuthHeader(r *http.Request) {
+	r.Header.Set("Authorization", t.Type()+" "+t.AccessToken)
+}
+
+// WithExtra returns a new Token that's a clone of t, but using the
+// provided raw extra map. This is only intended for use by packages
+// implementing derivative OAuth2 flows.
+func (t *Token) WithExtra(extra interface{}) *Token {
+	t2 := new(Token)
+	*t2 = *t
+	t2.raw = extra
+	return t2
+}
+
+// Extra returns an extra field.
+// Extra fields are key-value pairs returned by the server as a
+// part of the token retrieval response.
+func (t *Token) Extra(key string) interface{} {
+	if vals, ok := t.raw.(url.Values); ok {
+		// TODO(jbd): Cast numeric values to int64 or float64.
+		return vals.Get(key)
+	}
+	if raw, ok := t.raw.(map[string]interface{}); ok {
+		return raw[key]
+	}
+	return nil
+}
+
+// expired reports whether the token is expired.
+// t must be non-nil.
+func (t *Token) expired() bool {
+	if t.Expiry.IsZero() {
+		return false
+	}
+	return t.Expiry.Before(time.Now())
+}
+
+// Valid reports whether t is non-nil, has an AccessToken, and is not expired.
+func (t *Token) Valid() bool {
+	return t != nil && t.AccessToken != "" && !t.expired()
+}

Godeps/_workspace/src/golang.org/x/oauth2/token_test.go

@@ -0,0 +1,30 @@
+// Copyright 2014 The oauth2 Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package oauth2
+
+import "testing"
+
+func TestTokenExtra(t *testing.T) {
+	type testCase struct {
+		key  string
+		val  interface{}
+		want interface{}
+	}
+	const key = "extra-key"
+	cases := []testCase{
+		{key: key, val: "abc", want: "abc"},
+		{key: key, val: 123, want: 123},
+		{key: key, val: "", want: ""},
+		{key: "other-key", val: "def", want: nil},
+	}
+	for _, tc := range cases {
+		extra := make(map[string]interface{})
+		extra[tc.key] = tc.val
+		tok := &Token{raw: extra}
+		if got, want := tok.Extra(key), tc.want; got != want {
+			t.Errorf("Extra(%q) = %q; want %q", key, got, want)
+		}
+	}
+}

Godeps/_workspace/src/golang.org/x/oauth2/transport.go

@@ -0,0 +1,138 @@
+// Copyright 2014 The oauth2 Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package oauth2
+
+import (
+	"errors"
+	"io"
+	"net/http"
+	"sync"
+)
+
+// Transport is an http.RoundTripper that makes OAuth 2.0 HTTP requests,
+// wrapping a base RoundTripper and adding an Authorization header
+// with a token from the supplied Sources.
+//
+// Transport is a low-level mechanism. Most code will use the
+// higher-level Config.Client method instead.
+type Transport struct {
+	// Source supplies the token to add to outgoing requests'
+	// Authorization headers.
+	Source TokenSource
+
+	// Base is the base RoundTripper used to make HTTP requests.
+	// If nil, http.DefaultTransport is used.
+	Base http.RoundTripper
+
+	mu     sync.Mutex                      // guards modReq
+	modReq map[*http.Request]*http.Request // original -> modified
+}
+
+// RoundTrip authorizes and authenticates the request with an
+// access token. If no token exists or token is expired,
+// tries to refresh/fetch a new token.
+func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) {
+	if t.Source == nil {
+		return nil, errors.New("oauth2: Transport's Source is nil")
+	}
+	token, err := t.Source.Token()
+	if err != nil {
+		return nil, err
+	}
+
+	req2 := cloneRequest(req) // per RoundTripper contract
+	token.SetAuthHeader(req2)
+	t.setModReq(req, req2)
+	res, err := t.base().RoundTrip(req2)
+	if err != nil {
+		t.setModReq(req, nil)
+		return nil, err
+	}
+	res.Body = &onEOFReader{
+		rc: res.Body,
+		fn: func() { t.setModReq(req, nil) },
+	}
+	return res, nil
+}
+
+// CancelRequest cancels an in-flight request by closing its connection.
+func (t *Transport) CancelRequest(req *http.Request) {
+	type canceler interface {
+		CancelRequest(*http.Request)
+	}
+	if cr, ok := t.base().(canceler); ok {
+		t.mu.Lock()
+		modReq := t.modReq[req]
+		delete(t.modReq, req)
+		t.mu.Unlock()
+		cr.CancelRequest(modReq)
+	}
+}
+
+func (t *Transport) base() http.RoundTripper {
+	if t.Base != nil {
+		return t.Base
+	}
+	return http.DefaultTransport
+}
+
+func (t *Transport) setModReq(orig, mod *http.Request) {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	if t.modReq == nil {
+		t.modReq = make(map[*http.Request]*http.Request)
+	}
+	if mod == nil {
+		delete(t.modReq, orig)
+	} else {
+		t.modReq[orig] = mod
+	}
+}
+
+// cloneRequest returns a clone of the provided *http.Request.
+// The clone is a shallow copy of the struct and its Header map.
+func cloneRequest(r *http.Request) *http.Request {
+	// shallow copy of the struct
+	r2 := new(http.Request)
+	*r2 = *r
+	// deep copy of the Header
+	r2.Header = make(http.Header, len(r.Header))
+	for k, s := range r.Header {
+		r2.Header[k] = append([]string(nil), s...)
+	}
+	return r2
+}
+
+type onEOFReader struct {
+	rc io.ReadCloser
+	fn func()
+}
+
+func (r *onEOFReader) Read(p []byte) (n int, err error) {
+	n, err = r.rc.Read(p)
+	if err == io.EOF {
+		r.runFunc()
+	}
+	return
+}
+
+func (r *onEOFReader) Close() error {
+	err := r.rc.Close()
+	r.runFunc()
+	return err
+}
+
+func (r *onEOFReader) runFunc() {
+	if fn := r.fn; fn != nil {
+		fn()
+		r.fn = nil
+	}
+}
+
+type errorTransport struct{ err error }
+
+func (t errorTransport) RoundTrip(*http.Request) (*http.Response, error) {
+	return nil, t.err
+}

Godeps/_workspace/src/golang.org/x/oauth2/transport_test.go

@@ -0,0 +1,53 @@
+package oauth2
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+)
+
+type tokenSource struct{ token *Token }
+
+func (t *tokenSource) Token() (*Token, error) {
+	return t.token, nil
+}
+
+func TestTransportTokenSource(t *testing.T) {
+	ts := &tokenSource{
+		token: &Token{
+			AccessToken: "abc",
+		},
+	}
+	tr := &Transport{
+		Source: ts,
+	}
+	server := newMockServer(func(w http.ResponseWriter, r *http.Request) {
+		if r.Header.Get("Authorization") != "Bearer abc" {
+			t.Errorf("Transport doesn't set the Authorization header from the fetched token")
+		}
+	})
+	defer server.Close()
+	client := http.Client{Transport: tr}
+	client.Get(server.URL)
+}
+
+func TestTokenValidNoAccessToken(t *testing.T) {
+	token := &Token{}
+	if token.Valid() {
+		t.Errorf("Token should not be valid with no access token")
+	}
+}
+
+func TestExpiredWithExpiry(t *testing.T) {
+	token := &Token{
+		Expiry: time.Now().Add(-5 * time.Hour),
+	}
+	if token.Valid() {
+		t.Errorf("Token should not be valid if it expired in the past")
+	}
+}
+
+func newMockServer(handler func(w http.ResponseWriter, r *http.Request)) *httptest.Server {
+	return httptest.NewServer(http.HandlerFunc(handler))
+}