initial commit

vendor/golang.org/x/oauth2/clientcredentials/clientcredentials.go

@@ -0,0 +1,112 @@
+// 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 http://tools.ietf.org/html/draft-ietf-oauth-v2-31#section-4.4
+package clientcredentials // import "golang.org/x/oauth2/clientcredentials"
+
+import (
+	"net/http"
+	"net/url"
+	"strings"
+
+	"golang.org/x/net/context"
+	"golang.org/x/oauth2"
+	"golang.org/x/oauth2/internal"
+)
+
+// tokenFromInternal maps an *internal.Token struct into
+// an *oauth2.Token struct.
+func tokenFromInternal(t *internal.Token) *oauth2.Token {
+	if t == nil {
+		return nil
+	}
+	tk := &oauth2.Token{
+		AccessToken:  t.AccessToken,
+		TokenType:    t.TokenType,
+		RefreshToken: t.RefreshToken,
+		Expiry:       t.Expiry,
+	}
+	return tk.WithExtra(t.Raw)
+}
+
+// retrieveToken takes a *Config and uses that to retrieve an *internal.Token.
+// This token is then mapped from *internal.Token into an *oauth2.Token which is
+// returned along with an error.
+func retrieveToken(ctx context.Context, c *Config, v url.Values) (*oauth2.Token, error) {
+	tk, err := internal.RetrieveToken(ctx, c.ClientID, c.ClientSecret, c.TokenURL, v)
+	if err != nil {
+		return nil, err
+	}
+	return tokenFromInternal(tk), nil
+}
+
+// Client Credentials 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
+}
+
+// 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 retrieveToken(ctx, c, url.Values{
+		"grant_type": {"client_credentials"},
+		"scope":      internal.CondVal(strings.Join(c.Scopes, " ")),
+	})
+}
+
+// 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) {
+	return retrieveToken(c.ctx, c.conf, url.Values{
+		"grant_type": {"client_credentials"},
+		"scope":      internal.CondVal(strings.Join(c.conf.Scopes, " ")),
+	})
+}