blob: 90657915fbcf0ea51e8d97858432d793060de436 [file] [log] [blame]
// Copyright 2014 The Go 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 (
// 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
// RoundTrip authorizes and authenticates the request with an
// access token from Transport's Source.
func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) {
reqBodyClosed := false
if req.Body != nil {
defer func() {
if !reqBodyClosed {
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
// req.Body is assumed to be closed by the base RoundTripper.
reqBodyClosed = true
return t.base().RoundTrip(req2)
var cancelOnce sync.Once
// CancelRequest does nothing. It used to be a legacy cancellation mechanism
// but now only it only logs on first use to warn that it's deprecated.
// Deprecated: use contexts for cancellation instead.
func (t *Transport) CancelRequest(req *http.Request) {
cancelOnce.Do(func() {
log.Printf("deprecated: Transport.CancelRequest no longer does anything; use contexts")
func (t *Transport) base() http.RoundTripper {
if t.Base != nil {
return t.Base
return http.DefaultTransport
// 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