Skip to content
Permalink
Branch: master
Find file Copy path
Find file Copy path
295 lines (268 sloc) 8.58 KB
// 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 (
"context"
"encoding/json"
"errors"
"fmt"
"io"
"io/ioutil"
"math"
"mime"
"net/http"
"net/url"
"strconv"
"strings"
"sync"
"time"
"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
}
func (e *tokenJSON) expiry() (t time.Time) {
if v := e.ExpiresIn; v != 0 {
return time.Now().Add(time.Duration(v) * time.Second)
}
return
}
type expirationTime int32
func (e *expirationTime) UnmarshalJSON(b []byte) error {
if len(b) == 0 || string(b) == "null" {
return nil
}
var n json.Number
err := json.Unmarshal(b, &n)
if err != nil {
return err
}
i, err := n.Int64()
if err != nil {
return err
}
if i > math.MaxInt32 {
i = math.MaxInt32
}
*e = expirationTime(i)
return nil
}
// RegisterBrokenAuthHeaderProvider previously did something. It is now a no-op.
//
// Deprecated: this function no longer does anything. Caller code that
// wants to avoid potential extra HTTP requests made during
// auto-probing of the provider's auth style should set
// Endpoint.AuthStyle.
func RegisterBrokenAuthHeaderProvider(tokenURL string) {}
// AuthStyle is a copy of the golang.org/x/oauth2 package's AuthStyle type.
type AuthStyle int
const (
AuthStyleUnknown AuthStyle = 0
AuthStyleInParams AuthStyle = 1
AuthStyleInHeader AuthStyle = 2
)
// authStyleCache is the set of tokenURLs we've successfully used via
// RetrieveToken and which style auth we ended up using.
// It's called a cache, but it doesn't (yet?) shrink. It's expected that
// the set of OAuth2 servers a program contacts over time is fixed and
// small.
var authStyleCache struct {
sync.Mutex
m map[string]AuthStyle // keyed by tokenURL
}
// ResetAuthCache resets the global authentication style cache used
// for AuthStyleUnknown token requests.
func ResetAuthCache() {
authStyleCache.Lock()
defer authStyleCache.Unlock()
authStyleCache.m = nil
}
// lookupAuthStyle reports which auth style we last used with tokenURL
// when calling RetrieveToken and whether we have ever done so.
func lookupAuthStyle(tokenURL string) (style AuthStyle, ok bool) {
authStyleCache.Lock()
defer authStyleCache.Unlock()
style, ok = authStyleCache.m[tokenURL]
return
}
// setAuthStyle adds an entry to authStyleCache, documented above.
func setAuthStyle(tokenURL string, v AuthStyle) {
authStyleCache.Lock()
defer authStyleCache.Unlock()
if authStyleCache.m == nil {
authStyleCache.m = make(map[string]AuthStyle)
}
authStyleCache.m[tokenURL] = v
}
// newTokenRequest returns a new *http.Request to retrieve a new token
// from tokenURL using the provided clientID, clientSecret, and POST
// body parameters.
//
// inParams is whether the clientID & clientSecret should be encoded
// as the POST body. An 'inParams' value of true means to send it in
// the POST body (along with any values in v); false means to send it
// in the Authorization header.
func newTokenRequest(tokenURL, clientID, clientSecret string, v url.Values, authStyle AuthStyle) (*http.Request, error) {
if authStyle == AuthStyleInParams {
v = cloneURLValues(v)
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 authStyle == AuthStyleInHeader {
req.SetBasicAuth(url.QueryEscape(clientID), url.QueryEscape(clientSecret))
}
return req, nil
}
func cloneURLValues(v url.Values) url.Values {
v2 := make(url.Values, len(v))
for k, vv := range v {
v2[k] = append([]string(nil), vv...)
}
return v2
}
func RetrieveToken(ctx context.Context, clientID, clientSecret, tokenURL string, v url.Values, authStyle AuthStyle) (*Token, error) {
needsAuthStyleProbe := authStyle == 0
if needsAuthStyleProbe {
if style, ok := lookupAuthStyle(tokenURL); ok {
authStyle = style
needsAuthStyleProbe = false
} else {
authStyle = AuthStyleInHeader // the first way we'll try
}
}
req, err := newTokenRequest(tokenURL, clientID, clientSecret, v, authStyle)
if err != nil {
return nil, err
}
token, err := doTokenRoundTrip(ctx, req)
if err != nil && needsAuthStyleProbe {
// If we get an error, assume the server wants the
// clientID & clientSecret in a different form.
// 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
//
// We used to maintain a big table in this code of all the sites and which way
// they went, but maintaining it didn't scale & got annoying.
// So just try both ways.
authStyle = AuthStyleInParams // the second way we'll try
req, _ = newTokenRequest(tokenURL, clientID, clientSecret, v, authStyle)
token, err = doTokenRoundTrip(ctx, req)
}
if needsAuthStyleProbe && err == nil {
setAuthStyle(tokenURL, authStyle)
}
// Don't overwrite `RefreshToken` with an empty value
// if this was a token refreshing request.
if token != nil && token.RefreshToken == "" {
token.RefreshToken = v.Get("refresh_token")
}
return token, err
}
func doTokenRoundTrip(ctx context.Context, req *http.Request) (*Token, error) {
r, err := ctxhttp.Do(ctx, ContextClient(ctx), req)
if err != nil {
return nil, err
}
body, err := ioutil.ReadAll(io.LimitReader(r.Body, 1<<20))
r.Body.Close()
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")
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
}
if token.AccessToken == "" {
return nil, 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)
}
You can’t perform that action at this time.