oauth2/clientcredentials/clientcredentials.go
Tim Cooper 0448841f0c oauth2: add error type for unsuccessful token endpoint status
Allows the HTTP response and body to be extracted without parsing
the error string, but keeps backwards compatibility for users who
are currently doing so.

Fixes golang/oauth2#173

Change-Id: Id7709da827a155299b047f0bcb74aa8f91b01e96
Reviewed-on: https://go-review.googlesource.com/84156
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-12-19 02:07:21 +00:00

108 lines
3.3 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 clientcredentials implements the OAuth2.0 "client credentials" token flow,
// also known as the "two-legged OAuth 2.0".
//
// This should be used when the client is acting on its own behalf or when the client
// is the resource owner. It may also be used when requesting access to protected
// resources based on an authorization previously arranged with the authorization
// server.
//
// See https://tools.ietf.org/html/rfc6749#section-4.4
package clientcredentials // import "golang.org/x/oauth2/clientcredentials"
import (
"fmt"
"net/http"
"net/url"
"strings"
"golang.org/x/net/context"
"golang.org/x/oauth2"
"golang.org/x/oauth2/internal"
)
// Config describes a 2-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
// TokenURL is the resource server's token endpoint
// URL. This is a constant specific to each server.
TokenURL string
// Scope specifies optional requested permissions.
Scopes []string
// EndpointParams specifies additional parameters for requests to the token endpoint.
EndpointParams url.Values
}
// Token uses client credentials to retrieve a token.
// The HTTP client to use is derived from the context.
// If nil, http.DefaultClient is used.
func (c *Config) Token(ctx context.Context) (*oauth2.Token, error) {
return c.TokenSource(ctx).Token()
}
// 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.Context) *http.Client {
return oauth2.NewClient(ctx, c.TokenSource(ctx))
}
// TokenSource returns a TokenSource that returns t until t expires,
// automatically refreshing it as necessary using the provided context and the
// client ID and client secret.
//
// Most users will use Config.Client instead.
func (c *Config) TokenSource(ctx context.Context) oauth2.TokenSource {
source := &tokenSource{
ctx: ctx,
conf: c,
}
return oauth2.ReuseTokenSource(nil, source)
}
type tokenSource struct {
ctx context.Context
conf *Config
}
// Token refreshes the token by using a new client credentials request.
// tokens received this way do not include a refresh token
func (c *tokenSource) Token() (*oauth2.Token, error) {
v := url.Values{
"grant_type": {"client_credentials"},
"scope": internal.CondVal(strings.Join(c.conf.Scopes, " ")),
}
for k, p := range c.conf.EndpointParams {
if _, ok := v[k]; ok {
return nil, fmt.Errorf("oauth2: cannot overwrite parameter %q", k)
}
v[k] = p
}
tk, err := internal.RetrieveToken(c.ctx, c.conf.ClientID, c.conf.ClientSecret, c.conf.TokenURL, v)
if err != nil {
if rErr, ok := err.(*internal.RetrieveError); ok {
return nil, (*oauth2.RetrieveError)(rErr)
}
return nil, err
}
t := &oauth2.Token{
AccessToken: tk.AccessToken,
TokenType: tk.TokenType,
RefreshToken: tk.RefreshToken,
Expiry: tk.Expiry,
}
return t.WithExtra(tk.Raw), nil
}