1 files changed, 153 insertions, 0 deletions
diff --git a/vendor/golang.org/x/oauth2/jwt/jwt.go b/vendor/golang.org/x/oauth2/jwt/jwt.go
new file mode 100644
index 0000000..2ffad21
--- /dev/null
+++ b/vendor/golang.org/x/oauth2/jwt/jwt.go
@@ -0,0 +1,153 @@
+// 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 jwt implements the OAuth 2.0 JSON Web Token flow, commonly
+// known as "two-legged OAuth 2.0".
+//
+// See: https://tools.ietf.org/html/draft-ietf-oauth-jwt-bearer-12
+package jwt
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+
+	"golang.org/x/net/context"
+	"golang.org/x/oauth2"
+	"golang.org/x/oauth2/internal"
+	"golang.org/x/oauth2/jws"
+)
+
+var (
+	defaultGrantType = "urn:ietf:params:oauth:grant-type:jwt-bearer"
+	defaultHeader    = &jws.Header{Algorithm: "RS256", Typ: "JWT"}
+)
+
+// Config is the configuration for using JWT to fetch tokens,
+// commonly known as "two-legged OAuth 2.0".
+type Config struct {
+	// Email is the OAuth client identifier used when communicating with
+	// the configured OAuth provider.
+	Email string
+
+	// PrivateKey contains the contents of an RSA private key or the
+	// contents of a PEM file that contains a private key. The provided
+	// private key is used to sign JWT payloads.
+	// PEM containers with a passphrase are not supported.
+	// Use the following command to convert a PKCS 12 file into a PEM.
+	//
+	//    $ openssl pkcs12 -in key.p12 -out key.pem -nodes
+	//
+	PrivateKey []byte
+
+	// Subject is the optional user to impersonate.
+	Subject string
+
+	// Scopes optionally specifies a list of requested permission scopes.
+	Scopes []string
+
+	// TokenURL is the endpoint required to complete the 2-legged JWT flow.
+	TokenURL string
+
+	// Expires optionally specifies how long the token is valid for.
+	Expires time.Duration
+}
+
+// TokenSource returns a JWT TokenSource using the configuration
+// in c and the HTTP client from the provided context.
+func (c *Config) TokenSource(ctx context.Context) oauth2.TokenSource {
+	return oauth2.ReuseTokenSource(nil, jwtSource{ctx, c})
+}
+
+// Client returns an HTTP client wrapping the context's
+// HTTP transport and adding Authorization headers with tokens
+// obtained from c.
+//
+// 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))
+}
+
+// jwtSource is a source that always does a signed JWT request for a token.
+// It should typically be wrapped with a reuseTokenSource.
+type jwtSource struct {
+	ctx  context.Context
+	conf *Config
+}
+
+func (js jwtSource) Token() (*oauth2.Token, error) {
+	pk, err := internal.ParseKey(js.conf.PrivateKey)
+	if err != nil {
+		return nil, err
+	}
+	hc := oauth2.NewClient(js.ctx, nil)
+	claimSet := &jws.ClaimSet{
+		Iss:   js.conf.Email,
+		Scope: strings.Join(js.conf.Scopes, " "),
+		Aud:   js.conf.TokenURL,
+	}
+	if subject := js.conf.Subject; subject != "" {
+		claimSet.Sub = subject
+		// prn is the old name of sub. Keep setting it
+		// to be compatible with legacy OAuth 2.0 providers.
+		claimSet.Prn = subject
+	}
+	if t := js.conf.Expires; t > 0 {
+		claimSet.Exp = time.Now().Add(t).Unix()
+	}
+	payload, err := jws.Encode(defaultHeader, claimSet, pk)
+	if err != nil {
+		return nil, err
+	}
+	v := url.Values{}
+	v.Set("grant_type", defaultGrantType)
+	v.Set("assertion", payload)
+	resp, err := hc.PostForm(js.conf.TokenURL, v)
+	if err != nil {
+		return nil, fmt.Errorf("oauth2: cannot fetch token: %v", err)
+	}
+	defer resp.Body.Close()
+	body, err := ioutil.ReadAll(io.LimitReader(resp.Body, 1<<20))
+	if err != nil {
+		return nil, fmt.Errorf("oauth2: cannot fetch token: %v", err)
+	}
+	if c := resp.StatusCode; c < 200 || c > 299 {
+		return nil, fmt.Errorf("oauth2: cannot fetch token: %v\nResponse: %s", resp.Status, body)
+	}
+	// tokenRes is the JSON response body.
+	var tokenRes struct {
+		AccessToken string `json:"access_token"`
+		TokenType   string `json:"token_type"`
+		IDToken     string `json:"id_token"`
+		ExpiresIn   int64  `json:"expires_in"` // relative seconds from now
+	}
+	if err := json.Unmarshal(body, &tokenRes); err != nil {
+		return nil, fmt.Errorf("oauth2: cannot fetch token: %v", err)
+	}
+	token := &oauth2.Token{
+		AccessToken: tokenRes.AccessToken,
+		TokenType:   tokenRes.TokenType,
+	}
+	raw := make(map[string]interface{})
+	json.Unmarshal(body, &raw) // no error checks for optional fields
+	token = token.WithExtra(raw)
+
+	if secs := tokenRes.ExpiresIn; secs > 0 {
+		token.Expiry = time.Now().Add(time.Duration(secs) * time.Second)
+	}
+	if v := tokenRes.IDToken; v != "" {
+		// decode returned id token to get expiry
+		claimSet, err := jws.Decode(v)
+		if err != nil {
+			return nil, fmt.Errorf("oauth2: error decoding JWT token: %v", err)
+		}
+		token.Expiry = time.Unix(claimSet.Exp, 0)
+	}
+	return token, nil
+}