// 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
import (
"encoding/json"
"errors"
"fmt"
"io"
"io/ioutil"
"mime"
"net/http"
"net/url"
"strconv"
"strings"
"time"
"golang.org/x/net/context"
"golang.org/x/net/context/ctxhttp"
)
// Token represents the credentials 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://id.twitch.tv/",
"https://app.box.com/",
"https://api.box.com/",
"https://connect.stripe.com/",
"https://login.mailchimp.com/",
"https://login.microsoftonline.com/",
"https://login.salesforce.com/",
"https://login.windows.net",
"https://login.live.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",
"https://api.medium.com/v1/tokens",
"https://log.finalsurge.com/oauth/token",
"https://multisport.todaysplan.com.au/rest/oauth/access_token",
"https://whats.todaysplan.com.au/rest/oauth/access_token",
"https://stackoverflow.com/oauth/access_token",
"https://account.health.nokia.com",
}
// brokenAuthHeaderDomains lists broken providers that issue dynamic endpoints.
var brokenAuthHeaderDomains = []string{
".auth0.com",
".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) {
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(url.QueryEscape(clientID), url.QueryEscape(clientSecret))
}
r, err := ctxhttp.Do(ctx, ContextClient(ctx), 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, &RetrieveError{
Response: r,
Body: 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")
}
if token.AccessToken == "" {
return token, errors.New("oauth2: server response missing access_token")
}
return token, nil
}
type RetrieveError struct {
Response *http.Response
Body []byte
}
func (r *RetrieveError) Error() string {
return fmt.Sprintf("oauth2: cannot fetch token: %v\nResponse: %s", r.Response.Status, r.Body)
}
