oauth2/internal/token.go
voutasaurus 5432cc9688 internal: add broken auth header provider
Azure AD applications use login.microsoft.net for token URLs for OAuth
and OpenID Connect. This service expects the OAuth client ID and client
secret in the body of the OAuth exchange request.

Fixes #238

Change-Id: I9cfd46787ebfb27cf2775dd3357eb26e089322a3
Reviewed-on: https://go-review.googlesource.com/47097
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-06-29 03:27:40 +00:00

251 lines
7.3 KiB
Go

// 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 internal contains support packages for oauth2 package.
package internal
import (
"encoding/json"
"fmt"
"io"
"io/ioutil"
"mime"
"net/http"
"net/url"
"strconv"
"strings"
"time"
"golang.org/x/net/context"
)
// Token represents the crendentials used to authorize
// the requests to access protected resources on the OAuth 2.0
// provider's backend.
//
// This type is a mirror of oauth2.Token and exists to break
// an otherwise-circular dependency. Other internal packages
// should convert this Token into an oauth2.Token before use.
type Token struct {
// AccessToken is the token that authorizes and authenticates
// the requests.
AccessToken string
// TokenType is the type of token.
// The Type method returns either this or "Bearer", the default.
TokenType string
// 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
// 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
// Raw optionally contains extra metadata from the server
// when updating a token.
Raw interface{}
}
// 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 expirationTime `json:"expires_in"` // at least PayPal returns string, while most return number
Expires expirationTime `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
}
type expirationTime int32
func (e *expirationTime) UnmarshalJSON(b []byte) error {
var n json.Number
err := json.Unmarshal(b, &n)
if err != nil {
return err
}
i, err := n.Int64()
if err != nil {
return err
}
*e = expirationTime(i)
return nil
}
var brokenAuthHeaderProviders = []string{
"https://accounts.google.com/",
"https://api.codeswholesale.com/oauth/token",
"https://api.dropbox.com/",
"https://api.dropboxapi.com/",
"https://api.instagram.com/",
"https://api.netatmo.net/",
"https://api.odnoklassniki.ru/",
"https://api.pushbullet.com/",
"https://api.soundcloud.com/",
"https://api.twitch.tv/",
"https://app.box.com/",
"https://connect.stripe.com/",
"https://graph.facebook.com", // see https://github.com/golang/oauth2/issues/214
"https://login.microsoft.net",
"https://login.microsoftonline.com/",
"https://login.salesforce.com/",
"https://oauth.sandbox.trainingpeaks.com/",
"https://oauth.trainingpeaks.com/",
"https://oauth.vk.com/",
"https://openapi.baidu.com/",
"https://slack.com/",
"https://test-sandbox.auth.corp.google.com",
"https://test.salesforce.com/",
"https://user.gini.net/",
"https://www.douban.com/",
"https://www.googleapis.com/",
"https://www.linkedin.com/",
"https://www.strava.com/oauth/",
"https://www.wunderlist.com/oauth/",
"https://api.patreon.com/",
"https://sandbox.codeswholesale.com/oauth/token",
"https://api.sipgate.com/v1/authorization/oauth",
}
// brokenAuthHeaderDomains lists broken providers that issue dynamic endpoints.
var brokenAuthHeaderDomains = []string{
".force.com",
".myshopify.com",
".okta.com",
".oktapreview.com",
}
func RegisterBrokenAuthHeaderProvider(tokenURL string) {
brokenAuthHeaderProviders = append(brokenAuthHeaderProviders, tokenURL)
}
// 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
// - Stripe only accepts client secret in Auth header with Bearer method, not Basic
func providerAuthHeaderWorks(tokenURL string) bool {
for _, s := range brokenAuthHeaderProviders {
if strings.HasPrefix(tokenURL, s) {
// Some sites fail to implement the OAuth2 spec fully.
return false
}
}
if u, err := url.Parse(tokenURL); err == nil {
for _, s := range brokenAuthHeaderDomains {
if strings.HasSuffix(u.Host, s) {
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
}
func RetrieveToken(ctx context.Context, clientID, clientSecret, tokenURL string, v url.Values) (*Token, error) {
hc, err := ContextClient(ctx)
if err != nil {
return nil, err
}
bustedAuth := !providerAuthHeaderWorks(tokenURL)
if bustedAuth {
if clientID != "" {
v.Set("client_id", clientID)
}
if clientSecret != "" {
v.Set("client_secret", clientSecret)
}
}
req, err := http.NewRequest("POST", tokenURL, strings.NewReader(v.Encode()))
if err != nil {
return nil, err
}
req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
if !bustedAuth {
req.SetBasicAuth(clientID, 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
}