Merge branch 'api-response-content-type' into 'master'

API safeties

Increase security and sanity checks to allow for new features.

- ability to exchange signed information with gitlab-rails via a shared secret
- content-type checks to prevent leaking internal API data

Signed messages are implemented using JWT. To make this possible we vendor the jwt-go library.

Companion MR in gitlab-rails: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/5907

See merge request !60

Godeps/Godeps.json

+{
+	"ImportPath": "gitlab.com/gitlab-org/gitlab-workhorse",
+	"GoVersion": "go1.7",
+	"GodepVersion": "v74",
+	"Packages": [
+		"./..."
+	],
+	"Deps": [
+		{
+			"ImportPath": "github.com/dgrijalva/jwt-go",
+			"Comment": "v3.0.0",
+			"Rev": "d2709f9f1f31ebcda9651b03077758c1f3a0018c"
+		}
+	]
+}

Godeps/Readme

+This directory tree is generated automatically by godep.
+
+Please do not edit.
+
+See https://github.com/tools/godep for more information.

Makefile

@@ -2,6 +2,7 @@ PREFIX=/usr/local
 VERSION=$(shell git describe)-$(shell date -u +%Y%m%d.%H%M%S)
 BUILD_DIR = $(shell pwd)
 export GOPATH=${BUILD_DIR}/_build
+export GO15VENDOREXPERIMENT=1
 GOBUILD=go build -ldflags "-X main.Version=${VERSION}"
 PKG=gitlab.com/gitlab-org/gitlab-workhorse
 

README.md

@@ -26,11 +26,13 @@ Options:
   -listenNetwork string
     	Listen 'network' (tcp, tcp4, tcp6, unix) (default "tcp")
   -listenUmask int
-    	Umask for Unix socket (default 0)
+    	Umask for Unix socket
   -pprofListenAddr string
     	pprof listening address, e.g. 'localhost:6060'
   -proxyHeadersTimeout duration
-    	How long to wait for response headers when proxying the request (default 1m0s)
+    	How long to wait for response headers when proxying the request (default 5m0s)
+  -secretPath string
+    	File with secret key to authenticate with authBackend (default "./.gitlab_workhorse_secret")
   -version
     	Print version and exit
 ```

authorization_test.go

@@ -11,6 +11,8 @@ import (
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/badgateway"
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/helper"
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/testhelper"
+
+	"github.com/dgrijalva/jwt-go"
 )
 
 func okHandler(w http.ResponseWriter, _ *http.Request, _ *api.Response) {
@@ -18,10 +20,11 @@ func okHandler(w http.ResponseWriter, _ *http.Request, _ *api.Response) {
 	fmt.Fprint(w, "{\"status\":\"ok\"}")
 }
 
-func runPreAuthorizeHandler(t *testing.T, suffix string, url *regexp.Regexp, apiResponse interface{}, returnCode, expectedCode int) *httptest.ResponseRecorder {
-	// Prepare test server and backend
-	ts := testAuthServer(url, returnCode, apiResponse)
-	defer ts.Close()
+func runPreAuthorizeHandler(t *testing.T, ts *httptest.Server, suffix string, url *regexp.Regexp, apiResponse interface{}, returnCode, expectedCode int) *httptest.ResponseRecorder {
+	if ts == nil {
+		ts = testAuthServer(url, returnCode, apiResponse)
+		defer ts.Close()
+	}
 
 	// Create http request
 	httpRequest, err := http.NewRequest("GET", "/address", nil)
@@ -29,7 +32,7 @@ func runPreAuthorizeHandler(t *testing.T, suffix string, url *regexp.Regexp, api
 		t.Fatal(err)
 	}
 	parsedURL := helper.URLMustParse(ts.URL)
-	a := api.NewAPI(parsedURL, "123", badgateway.TestRoundTripper(parsedURL))
+	a := api.NewAPI(parsedURL, "123", testhelper.SecretPath(), badgateway.TestRoundTripper(parsedURL))
 
 	response := httptest.NewRecorder()
 	a.PreAuthorizeHandler(okHandler, suffix).ServeHTTP(response, httpRequest)
@@ -39,7 +42,7 @@ func runPreAuthorizeHandler(t *testing.T, suffix string, url *regexp.Regexp, api
 
 func TestPreAuthorizeHappyPath(t *testing.T) {
 	runPreAuthorizeHandler(
-		t, "/authorize",
+		t, nil, "/authorize",
 		regexp.MustCompile(`/authorize\z`),
 		&api.Response{},
 		200, 201)
@@ -47,7 +50,7 @@ func TestPreAuthorizeHappyPath(t *testing.T) {
 
 func TestPreAuthorizeSuffix(t *testing.T) {
 	runPreAuthorizeHandler(
-		t, "/different-authorize",
+		t, nil, "/different-authorize",
 		regexp.MustCompile(`/authorize\z`),
 		&api.Response{},
 		200, 404)
@@ -55,8 +58,68 @@ func TestPreAuthorizeSuffix(t *testing.T) {
 
 func TestPreAuthorizeJsonFailure(t *testing.T) {
 	runPreAuthorizeHandler(
-		t, "/authorize",
+		t, nil, "/authorize",
 		regexp.MustCompile(`/authorize\z`),
 		"not-json",
 		200, 500)
 }
+
+func TestPreAuthorizeContentTypeFailure(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if _, err := w.Write([]byte(`{"hello":"world"}`)); err != nil {
+			t.Fatalf("write auth response: %v", err)
+		}
+	}))
+	defer ts.Close()
+
+	runPreAuthorizeHandler(
+		t, ts, "/authorize",
+		regexp.MustCompile(`/authorize\z`),
+		"",
+		200, 500)
+}
+
+func TestPreAuthorizeJWT(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		token, err := jwt.Parse(r.Header.Get(api.RequestHeader), func(token *jwt.Token) (interface{}, error) {
+			// Don't forget to validate the alg is what you expect:
+			if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
+				return nil, fmt.Errorf("Unexpected signing method: %v", token.Header["alg"])
+			}
+			secretBytes, err := (&api.Secret{Path: testhelper.SecretPath()}).Bytes()
+			if err != nil {
+				return nil, fmt.Errorf("read secret from file: %v", err)
+			}
+
+			return secretBytes, nil
+		})
+		if err != nil {
+			t.Fatalf("decode token: %v", err)
+		}
+
+		claims, ok := token.Claims.(jwt.MapClaims)
+		if !ok {
+			t.Fatal("claims cast failed")
+		}
+
+		if !token.Valid {
+			t.Fatal("JWT token invalid")
+		}
+
+		if claims["iss"] != "gitlab-workhorse" {
+			t.Fatalf("execpted issuer gitlab-workhorse, got %q", claims["iss"])
+		}
+
+		w.Header().Set("Content-Type", api.ResponseContentType)
+		if _, err := w.Write([]byte(`{"hello":"world"}`)); err != nil {
+			t.Fatalf("write auth response: %v", err)
+		}
+	}))
+	defer ts.Close()
+
+	runPreAuthorizeHandler(
+		t, ts, "/authorize",
+		regexp.MustCompile(`/authorize\z`),
+		"",
+		200, 201)
+}

internal/api/api.go

@@ -11,19 +11,28 @@ import (
 
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/badgateway"
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/helper"
+
+	"github.com/dgrijalva/jwt-go"
 )
 
+// Custom content type for API responses, to catch routing / programming mistakes
+const ResponseContentType = "application/vnd.gitlab-workhorse+json"
+
+const RequestHeader = "Gitlab-Workhorse-Api-Request"
+
 type API struct {
 	Client  *http.Client
 	URL     *url.URL
 	Version string
+	Secret  *Secret
 }
 
-func NewAPI(myURL *url.URL, version string, roundTripper *badgateway.RoundTripper) *API {
+func NewAPI(myURL *url.URL, version, secretPath string, roundTripper *badgateway.RoundTripper) *API {
 	return &API{
 		Client:  &http.Client{Transport: roundTripper},
 		URL:     myURL,
 		Version: version,
+		Secret:  &Secret{Path: secretPath},
 	}
 }
 
@@ -119,6 +128,18 @@ func (api *API) newRequest(r *http.Request, body io.Reader, suffix string) (*htt
 	// configurations (Passenger) to solve auth request routing problems.
 	authReq.Header.Set("Gitlab-Workhorse", api.Version)
 
+	secretBytes, err := api.Secret.Bytes()
+	if err != nil {
+		return nil, fmt.Errorf("newRequest: %v", err)
+	}
+
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, jwt.StandardClaims{Issuer: "gitlab-workhorse"})
+	tokenString, err := token.SignedString(secretBytes)
+	if err != nil {
+		return nil, fmt.Errorf("newRequest: sign JWT: %v", err)
+	}
+	authReq.Header.Set(RequestHeader, tokenString)
+
 	return authReq, nil
 }
 
@@ -138,11 +159,6 @@ func (api *API) PreAuthorizeHandler(h HandleFunc, suffix string) http.Handler {
 		defer authResponse.Body.Close()
 
 		if authResponse.StatusCode != 200 {
-			// The Git request is not allowed by the backend. Maybe the
-			// client needs to send HTTP Basic credentials.  Forward the
-			// response from the auth backend to our client. This includes
-			// the 'WWW-Authenticate' header that acts as a hint that
-			// Basic auth credentials are needed.
 			for k, v := range authResponse.Header {
 				// Accomodate broken clients that do case-sensitive header lookup
 				if k == "Www-Authenticate" {
@@ -156,6 +172,11 @@ func (api *API) PreAuthorizeHandler(h HandleFunc, suffix string) http.Handler {
 			return
 		}
 
+		if contentType := authResponse.Header.Get("Content-Type"); contentType != ResponseContentType {
+			helper.Fail500(w, fmt.Errorf("preAuthorizeHandler: API responded with wrong content type: %v", contentType))
+			return
+		}
+
 		a := &Response{}
 		// The auth backend validated the client request and told us additional
 		// request metadata. We must extract this information from the auth

internal/api/block.go

+package api
+
+import (
+	"fmt"
+	"net/http"
+
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/helper"
+)
+
+// Prevent internal API responses intended for gitlab-workhorse from
+// leaking to the end user
+func Block(h http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		rw := &blocker{rw: w}
+		defer rw.Flush()
+		h.ServeHTTP(rw, r)
+	})
+}
+
+type blocker struct {
+	rw       http.ResponseWriter
+	hijacked bool
+	status   int
+}
+
+func (b *blocker) Header() http.Header {
+	return b.rw.Header()
+}
+
+func (b *blocker) Write(data []byte) (int, error) {
+	if b.status == 0 {
+		b.WriteHeader(http.StatusOK)
+	}
+	if b.hijacked {
+		return 0, nil
+	}
+
+	return b.rw.Write(data)
+}
+
+func (b *blocker) WriteHeader(status int) {
+	if b.status != 0 {
+		return
+	}
+
+	if b.Header().Get("Content-Type") == ResponseContentType {
+		b.status = 500
+		b.Header().Del("Content-Length")
+		b.hijacked = true
+		helper.Fail500(b.rw, fmt.Errorf("api.blocker: forbidden content-type: %q", ResponseContentType))
+		return
+	}
+
+	b.status = status
+	b.rw.WriteHeader(b.status)
+}
+
+func (b *blocker) Flush() {
+	b.WriteHeader(http.StatusOK)
+}

internal/api/secret.go

+package api
+
+import (
+	"encoding/base64"
+	"fmt"
+	"io/ioutil"
+	"sync"
+)
+
+const numSecretBytes = 32
+
+type Secret struct {
+	Path  string
+	bytes []byte
+	sync.RWMutex
+}
+
+// Lazy access to the HMAC secret key. We must be lazy because if the key
+// is not already there, it will be generated by gitlab-rails, and
+// gitlab-rails is slow.
+func (s *Secret) Bytes() ([]byte, error) {
+	if bytes := s.getBytes(); bytes != nil {
+		return bytes, nil
+	}
+
+	return s.setBytes()
+}
+
+func (s *Secret) getBytes() []byte {
+	s.RLock()
+	defer s.RUnlock()
+	return s.bytes
+}
+
+func (s *Secret) setBytes() ([]byte, error) {
+	s.Lock()
+	defer s.Unlock()
+
+	if s.bytes != nil {
+		return s.bytes, nil
+	}
+
+	base64Bytes, err := ioutil.ReadFile(s.Path)
+	if err != nil {
+		return nil, fmt.Errorf("read Secret.Path: %v", err)
+	}
+
+	secretBytes := make([]byte, base64.StdEncoding.DecodedLen(len(base64Bytes)))
+	n, err := base64.StdEncoding.Decode(secretBytes, base64Bytes)
+	if err != nil {
+		return nil, fmt.Errorf("decode secret: %v", err)
+	}
+
+	if n != numSecretBytes {
+		return nil, fmt.Errorf("expected %d secretBytes in %s, found %d", numSecretBytes, s.Path, n)
+	}
+
+	s.bytes = secretBytes
+	return s.bytes, nil
+}

internal/artifacts/artifacts_upload_test.go

@@ -29,7 +29,7 @@ func testArtifactsUploadServer(t *testing.T, tempPath string) *httptest.Server {
 			t.Fatal("Expected POST request")
 		}
 
-		w.Header().Set("Content-Type", "application/json")
+		w.Header().Set("Content-Type", api.ResponseContentType)
 
 		data, err := json.Marshal(&api.Response{
 			TempPath: tempPath,
@@ -93,7 +93,7 @@ func testUploadArtifacts(contentType string, body io.Reader, t *testing.T, ts *h
 	response := httptest.NewRecorder()
 	parsedURL := helper.URLMustParse(ts.URL)
 	roundTripper := badgateway.TestRoundTripper(parsedURL)
-	apiClient := api.NewAPI(parsedURL, "123", roundTripper)
+	apiClient := api.NewAPI(parsedURL, "123", testhelper.SecretPath(), roundTripper)
 	proxyClient := proxy.NewProxy(parsedURL, "123", roundTripper)
 	UploadArtifacts(apiClient, proxyClient).ServeHTTP(response, httpRequest)
 	return response

internal/testhelper/testhelper.go

@@ -15,6 +15,10 @@ import (
 	"testing"
 )
 
+func SecretPath() string {
+	return path.Join(RootDir(), "testdata/test-secret")
+}
+
 func AssertResponseCode(t *testing.T, response *httptest.ResponseRecorder, expectedCode int) {
 	if response.Code != expectedCode {
 		t.Fatalf("for HTTP request expected to get %d, got %d instead", expectedCode, response.Code)
@@ -52,11 +56,7 @@ func TestServerWithHandler(url *regexp.Regexp, handler http.HandlerFunc) *httpte
 }
 
 func BuildExecutables() (func(), error) {
-	_, currentFile, _, ok := runtime.Caller(0)
-	if !ok {
-		return nil, errors.New("BuildExecutables: calling runtime.Caller failed")
-	}
-	rootDir := path.Join(path.Dir(currentFile), "../..")
+	rootDir := RootDir()
 
 	// This method will be invoked more than once due to Go test
 	// parallelization. We must use a unique temp directory for each
@@ -85,3 +85,11 @@ func BuildExecutables() (func(), error) {
 		os.RemoveAll(testDir)
 	}, nil
 }
+
+func RootDir() string {
+	_, currentFile, _, ok := runtime.Caller(0)
+	if !ok {
+		panic(errors.New("RootDir: calling runtime.Caller failed"))
+	}
+	return path.Join(path.Dir(currentFile), "../..")
+}

internal/upstream/routes.go

@@ -37,15 +37,18 @@ func (u *Upstream) configureRoutes() {
 	api := apipkg.NewAPI(
 		u.Backend,
 		u.Version,
+		u.SecretPath,
 		u.RoundTripper,
 	)
 	static := &staticpages.Static{u.DocumentRoot}
 	proxy := senddata.SendData(
-		sendfile.SendFile(proxypkg.NewProxy(
-			u.Backend,
-			u.Version,
-			u.RoundTripper,
-		)),
+		sendfile.SendFile(
+			apipkg.Block(
+				proxypkg.NewProxy(
+					u.Backend,
+					u.Version,
+					u.RoundTripper,
+				))),
 		git.SendArchive,
 		git.SendBlob,
 		git.SendDiff,

internal/upstream/upstream.go

@@ -23,6 +23,7 @@ var DefaultBackend = helper.URLMustParse("http://localhost:8080")
 type Upstream struct {
 	Backend         *url.URL
 	Version         string
+	SecretPath      string
 	DocumentRoot    string
 	DevelopmentMode bool
 
@@ -31,10 +32,11 @@ type Upstream struct {
 	RoundTripper *badgateway.RoundTripper
 }
 
-func NewUpstream(backend *url.URL, socket string, version string, documentRoot string, developmentMode bool, proxyHeadersTimeout time.Duration) *Upstream {
+func NewUpstream(backend *url.URL, socket, version, secretFile, documentRoot string, developmentMode bool, proxyHeadersTimeout time.Duration) *Upstream {
 	up := Upstream{
 		Backend:         backend,
 		Version:         version,
+		SecretPath:      secretFile,
 		DocumentRoot:    documentRoot,
 		DevelopmentMode: developmentMode,
 	}

main.go

@@ -40,6 +40,7 @@ var pprofListenAddr = flag.String("pprofListenAddr", "", "pprof listening addres
 var documentRoot = flag.String("documentRoot", "public", "Path to static files content")
 var proxyHeadersTimeout = flag.Duration("proxyHeadersTimeout", 5*time.Minute, "How long to wait for response headers when proxying the request")
 var developmentMode = flag.Bool("developmentMode", false, "Allow to serve assets from Rails app")
+var secretPath = flag.String("secretPath", "./.gitlab_workhorse_secret", "File with secret key to authenticate with authBackend")
 
 func main() {
 	flag.Usage = func() {
@@ -92,6 +93,7 @@ func main() {
 		backendURL,
 		*authSocket,
 		Version,
+		*secretPath,
 		*documentRoot,
 		*developmentMode,
 		*proxyHeadersTimeout,

main_test.go

@@ -330,8 +330,14 @@ func TestDownloadCacheCreate(t *testing.T) {
 
 func TestRegularProjectsAPI(t *testing.T) {
 	apiResponse := "API RESPONSE"
-	ts := testAuthServer(nil, 200, apiResponse)
+
+	ts := testhelper.TestServerWithHandler(regexp.MustCompile(`.`), func(w http.ResponseWriter, _ *http.Request) {
+		if _, err := w.Write([]byte(apiResponse)); err != nil {
+			t.Fatalf("write upstream response: %v", err)
+		}
+	})
 	defer ts.Close()
+
 	ws := startWorkhorseServer(ts.URL)
 	defer ws.Close()
 
@@ -537,6 +543,7 @@ func TestArtifactsUpload(t *testing.T) {
 
 	ts := testhelper.TestServerWithHandler(regexp.MustCompile(`.`), func(w http.ResponseWriter, r *http.Request) {
 		if strings.HasSuffix(r.URL.Path, "/authorize") {
+			w.Header().Set("Content-Type", api.ResponseContentType)
 			if _, err := fmt.Fprintf(w, `{"TempPath":"%s"}`, scratchDir); err != nil {
 				t.Fatal(err)
 			}
@@ -736,6 +743,39 @@ func TestGetGitPatch(t *testing.T) {
 	}
 }
 
+func TestApiContentTypeBlock(t *testing.T) {
+	wrongResponse := `{"hello":"world"}`
+	ts := testhelper.TestServerWithHandler(regexp.MustCompile(`.`), func(w http.ResponseWriter, _ *http.Request) {
+		w.Header().Set("Content-Type", api.ResponseContentType)
+		if _, err := w.Write([]byte(wrongResponse)); err != nil {
+			t.Fatalf("write upstream response: %v", err)
+		}
+	})
+	defer ts.Close()
+
+	ws := startWorkhorseServer(ts.URL)
+	defer ws.Close()
+
+	resourcePath := "/something"
+	resp, err := http.Get(ws.URL + resourcePath)
+	if err != nil {
+		t.Error(err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 500 {
+		t.Errorf("GET %q: expected 500, got %d", resourcePath, resp.StatusCode)
+	}
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if strings.Contains(string(body), "world") {
+		t.Errorf("unexpected response body: %q", body)
+	}
+}
+
 func setupStaticFile(fpath, content string) error {
 	cwd, err := os.Getwd()
 	if err != nil {
@@ -775,6 +815,8 @@ func newBranch() string {
 
 func testAuthServer(url *regexp.Regexp, code int, body interface{}) *httptest.Server {
 	return testhelper.TestServerWithHandler(url, func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", api.ResponseContentType)
+
 		// Write pure string
 		if data, ok := body.(string); ok {
 			log.Println("UPSTREAM", r.Method, r.URL, code)
@@ -826,6 +868,7 @@ func startWorkhorseServer(authBackend string) *httptest.Server {
 		helper.URLMustParse(authBackend),
 		"",
 		"123",
+		testhelper.SecretPath(),
 		testDocumentRoot,
 		false,
 		0,

testdata/test-secret

++M8OJgJxoxdDRgOR0UT8sDbAgp/63y/XUNE3d8+tawA=

vendor/github.com/dgrijalva/jwt-go/.gitignore

+.DS_Store
+bin
+
+

vendor/github.com/dgrijalva/jwt-go/.travis.yml

+language: go
+
+go:
+  - 1.3
+  - 1.4
+  - 1.5
+  - 1.6
+  - tip

vendor/github.com/dgrijalva/jwt-go/LICENSE

+Copyright (c) 2012 Dave Grijalva
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+

vendor/github.com/dgrijalva/jwt-go/MIGRATION_GUIDE.md

+## Migration Guide from v2 -> v3
+
+Version 3 adds several new, frequently requested features.  To do so, it introduces a few breaking changes.  We've worked to keep these as minimal as possible.  This guide explains the breaking changes and how you can quickly update your code.
+
+### `Token.Claims` is now an interface type
+
+The most requested feature from the 2.0 verison of this library was the ability to provide a custom type to the JSON parser for claims. This was implemented by introducing a new interface, `Claims`, to replace `map[string]interface{}`.  We also included two concrete implementations of `Claims`: `MapClaims` and `StandardClaims`.
+
+`MapClaims` is an alias for `map[string]interface{}` with built in validation behavior.  It is the default claims type when using `Parse`.  The usage is unchanged except you must type cast the claims property.
+
+The old example for parsing a token looked like this..
+
+```go
+	if token, err := jwt.Parse(tokenString, keyLookupFunc); err == nil {
+		fmt.Printf("Token for user %v expires %v", token.Claims["user"], token.Claims["exp"])
+	}
+```
+
+is now directly mapped to...
+
+```go
+	if token, err := jwt.Parse(tokenString, keyLookupFunc); err == nil {
+		claims := token.Claims.(jwt.MapClaims)
+		fmt.Printf("Token for user %v expires %v", claims["user"], claims["exp"])
+	}
+```
+
+`StandardClaims` is designed to be embedded in your custom type.  You can supply a custom claims type with the new `ParseWithClaims` function.  Here's an example of using a custom claims type.
+
+```go
+	type MyCustomClaims struct {
+		User string
+		*StandardClaims
+	}
+	
+	if token, err := jwt.ParseWithClaims(tokenString, &MyCustomClaims{}, keyLookupFunc); err == nil {
+		claims := token.Claims.(*MyCustomClaims)
+		fmt.Printf("Token for user %v expires %v", claims.User, claims.StandardClaims.ExpiresAt)
+	}
+```
+
+### `ParseFromRequest` has been moved
+
+To keep this library focused on the tokens without becoming overburdened with complex request processing logic, `ParseFromRequest` and its new companion `ParseFromRequestWithClaims` have been moved to a subpackage, `request`.  The method signatues have also been augmented to receive a new argument: `Extractor`.
+
+`Extractors` do the work of picking the token string out of a request.  The interface is simple and composable.
+
+This simple parsing example:
+
+```go
+	if token, err := jwt.ParseFromRequest(tokenString, req, keyLookupFunc); err == nil {
+		fmt.Printf("Token for user %v expires %v", token.Claims["user"], token.Claims["exp"])
+	}
+```
+
+is directly mapped to:
+
+```go
+	if token, err := request.ParseFromRequest(tokenString, request.OAuth2Extractor, req, keyLookupFunc); err == nil {
+		fmt.Printf("Token for user %v expires %v", token.Claims["user"], token.Claims["exp"])
+	}
+```
+
+There are several concrete `Extractor` types provided for your convenience:
+
+* `HeaderExtractor` will search a list of headers until one contains content.
+* `ArgumentExtractor` will search a list of keys in request query and form arguments until one contains content.
+* `MultiExtractor` will try a list of `Extractors` in order until one returns content.
+* `AuthorizationHeaderExtractor` will look in the `Authorization` header for a `Bearer` token.
+* `OAuth2Extractor` searches the places an OAuth2 token would be specified (per the spec): `Authorization` header and `access_token` argument
+* `PostExtractionFilter` wraps an `Extractor`, allowing you to process the content before it's parsed.  A simple example is stripping the `Bearer ` text from a header
+
+
+### RSA signing methods no longer accept `[]byte` keys
+
+Due to a [critical vulnerability](https://auth0.com/blog/2015/03/31/critical-vulnerabilities-in-json-web-token-libraries/), we've decided the convenience of accepting `[]byte` instead of `rsa.PublicKey` or `rsa.PrivateKey` isn't worth the risk of misuse.
+
+To replace this behavior, we've added two helper methods: `ParseRSAPrivateKeyFromPEM(key []byte) (*rsa.PrivateKey, error)` and `ParseRSAPublicKeyFromPEM(key []byte) (*rsa.PublicKey, error)`.  These are just simple helpers for unpacking PEM encoded PKCS1 and PKCS8 keys. If your keys are encoded any other way, all you need to do is convert them to the `crypto/rsa` package's types.
+
+```go 
+	func keyLookupFunc(*Token) (interface{}, error) {
+		// Don't forget to validate the alg is what you expect:
+		if _, ok := token.Method.(*jwt.SigningMethodRSA); !ok {
+			return nil, fmt.Errorf("Unexpected signing method: %v", token.Header["alg"])
+		}
+		
+		// Look up key 
+		key, err := lookupPublicKey(token.Header["kid"])
+		if err != nil {
+			return nil, err
+		}
+		
+		// Unpack key from PEM encoded PKCS8
+		return jwt.ParseRSAPublicKeyFromPEM(key)
+	}
+```

vendor/github.com/dgrijalva/jwt-go/README.md

+A [go](http://www.golang.org) (or 'golang' for search engine friendliness) implementation of [JSON Web Tokens](http://self-issued.info/docs/draft-ietf-oauth-json-web-token.html)
+
+[![Build Status](https://travis-ci.org/dgrijalva/jwt-go.svg?branch=master)](https://travis-ci.org/dgrijalva/jwt-go)
+
+**BREAKING CHANGES:*** Version 3.0.0 is here. It includes _a lot_ of changes including a few that break the API.  We've tried to break as few things as possible, so there should just be a few type signature changes.  A full list of breaking changes is available in `VERSION_HISTORY.md`.  See `MIGRATION_GUIDE.md` for more information on updating your code.
+
+**NOTICE:** A vulnerability in JWT was [recently published](https://auth0.com/blog/2015/03/31/critical-vulnerabilities-in-json-web-token-libraries/).  As this library doesn't force users to validate the `alg` is what they expected, it's possible your usage is effected.  There will be an update soon to remedy this, and it will likey require backwards-incompatible changes to the API.  In the short term, please make sure your implementation verifies the `alg` is what you expect.
+
+
+## What the heck is a JWT?
+
+JWT.io has [a great introduction](https://jwt.io/introduction) to JSON Web Tokens.
+
+In short, it's a signed JSON object that does something useful (for example, authentication).  It's commonly used for `Bearer` tokens in Oauth 2.  A token is made of three parts, separated by `.`'s.  The first two parts are JSON objects, that have been [base64url](http://tools.ietf.org/html/rfc4648) encoded.  The last part is the signature, encoded the same way.
+
+The first part is called the header.  It contains the necessary information for verifying the last part, the signature.  For example, which encryption method was used for signing and what key was used.
+
+The part in the middle is the interesting bit.  It's called the Claims and contains the actual stuff you care about.  Refer to [the RFC](http://self-issued.info/docs/draft-jones-json-web-token.html) for information about reserved keys and the proper way to add your own.
+
+## What's in the box?
+
+This library supports the parsing and verification as well as the generation and signing of JWTs.  Current supported signing algorithms are HMAC SHA, RSA, RSA-PSS, and ECDSA, though hooks are present for adding your own.
+
+## Examples
+
+See [the project documentation](https://godoc.org/github.com/dgrijalva/jwt-go) for examples of usage:
+
+* [Simple example of parsing and validating a token](https://godoc.org/github.com/dgrijalva/jwt-go#example_Parse_hmac)
+* [Simple example of building and signing a token](https://godoc.org/github.com/dgrijalva/jwt-go#example_New_hmac)
+* [Directory of Examples](https://godoc.org/github.com/dgrijalva/jwt-go#pkg-examples)
+
+## Extensions
+
+This library publishes all the necessary components for adding your own signing methods.  Simply implement the `SigningMethod` interface and register a factory method using `RegisterSigningMethod`.  
+
+Here's an example of an extension that integrates with the Google App Engine signing tools: https://github.com/someone1/gcp-jwt-go
+
+## Compliance
+
+This library was last reviewed to comply with [RTF 7519](http://www.rfc-editor.org/info/rfc7519) dated May 2015 with a few notable differences: 
+
+* In order to protect against accidental use of [Unsecured JWTs](http://self-issued.info/docs/draft-ietf-oauth-json-web-token.html#UnsecuredJWT), tokens using `alg=none` will only be accepted if the constant `jwt.UnsafeAllowNoneSignatureType` is provided as the key.
+
+## Project Status & Versioning
+
+This library is considered production ready.  Feedback and feature requests are appreciated.  The API should be considered stable.  There should be very few backwards-incompatible changes outside of major version updates (and only with good reason).
+
+This project uses [Semantic Versioning 2.0.0](http://semver.org).  Accepted pull requests will land on `master`.  Periodically, versions will be tagged from `master`.  You can find all the releases on [the project releases page](https://github.com/dgrijalva/jwt-go/releases).
+
+While we try to make it obvious when we make breaking changes, there isn't a great mechanism for pushing announcements out to users.  You may want to use this alternative package include: `gopkg.in/dgrijalva/jwt-go.v2`.  It will do the right thing WRT semantic versioning.
+
+## Usage Tips
+
+### Signing vs Encryption
+
+A token is simply a JSON object that is signed by its author. this tells you exactly two things about the data:
+
+* The author of the token was in the possession of the signing secret
+* The data has not been modified since it was signed
+
+It's important to know that JWT does not provide encryption, which means anyone who has access to the token can read its contents. If you need to protect (encrypt) the data, there is a companion spec, `JWE`, that provides this functionality. JWE is currently outside the scope of this library.
+
+### Choosing a Signing Method
+
+There are several signing methods available, and you should probably take the time to learn about the various options before choosing one.  The principal design decision is most likely going to be symmetric vs asymmetric.
+
+Symmetric signing methods, such as HSA, use only a single secret. This is probably the simplest signing method to use since any `[]byte` can be used as a valid secret. They are also slightly computationally faster to use, though this rarely is enough to matter. Symmetric signing methods work the best when both producers and consumers of tokens are trusted, or even the same system. Since the same secret is used to both sign and validate tokens, you can't easily distribute the key for validation.
+
+Asymmetric signing methods, such as RSA, use different keys for signing and verifying tokens. This makes it possible to produce tokens with a private key, and allow any consumer to access the public key for verification.
+
+### JWT and OAuth
+
+It's worth mentioning that OAuth and JWT are not the same thing. A JWT token is simply a signed JSON object. It can be used anywhere such a thing is useful. There is some confusion, though, as JWT is the most common type of bearer token used in OAuth2 authentication.
+
+Without going too far down the rabbit hole, here's a description of the interaction of these technologies:
+
+* OAuth is a protocol for allowing an identity provider to be separate from the service a user is logging in to.  For example, whenever you use Facebook to log into a different service (Yelp, Spotify, etc), you are using OAuth.
+* OAuth defines several options for passing around authentication data. One popular method is called a "bearer token". A bearer token is simply a string that _should_ only be held by an authenticated user. Thus, simply presenting this token proves your identity. You can probably derive from here why a JWT might make a good bearer token.
+* Because bearer tokens are used for authentication, it's important they're kept secret. This is why transactions that use bearer tokens typically happen over SSL.
+ 
+## More
+
+Documentation can be found [on godoc.org](http://godoc.org/github.com/dgrijalva/jwt-go).
+
+The command line utility included in this project (cmd/jwt) provides a straightforward example of token creation and parsing as well as a useful tool for debugging your own integration.  You'll also find several implementation examples in to documentation.

vendor/github.com/dgrijalva/jwt-go/VERSION_HISTORY.md

+## `jwt-go` Version History
+
+#### 3.0.0
+
+* **Compatibility Breaking Changes**: See MIGRATION_GUIDE.md for tips on updating your code
+	* Dropped support for `[]byte` keys when using RSA signing methods.  This convenience feature could contribute to security vulnerabilities involving mismatched key types with signing methods.
+	* `ParseFromRequest` has been moved to `request` subpackage and usage has changed
+	* The `Claims` property on `Token` is now type `Claims` instead of `map[string]interface{}`.  The default value is type `MapClaims`, which is an alias to `map[string]interface{}`.  This makes it possible to use a custom type when decoding claims.
+* Other Additions and Changes
+	* Added `Claims` interface type to allow users to decode the claims into a custom type
+	* Added `ParseWithClaims`, which takes a third argument of type `Claims`.  Use this function instead of `Parse` if you have a custom type you'd like to decode into.
+	* Dramatically improved the functionality and flexibility of `ParseFromRequest`, which is now in the `request` subpackage
+	* Added `ParseFromRequestWithClaims` which is the `FromRequest` equivalent of `ParseWithClaims`
+	* Added new interface type `Extractor`, which is used for extracting JWT strings from http requests.  Used with `ParseFromRequest` and `ParseFromRequestWithClaims`.
+	* Added several new, more specific, validation errors to error type bitmask
+	* Moved examples from README to executable example files
+	* Signing method registry is now thread safe
+	* Added new property to `ValidationError`, which contains the raw error returned by calls made by parse/verify (such as those returned by keyfunc or json parser)
+
+#### 2.7.0
+
+This will likely be the last backwards compatible release before 3.0.0, excluding essential bug fixes.
+
+* Added new option `-show` to the `jwt` command that will just output the decoded token without verifying
+* Error text for expired tokens includes how long it's been expired
+* Fixed incorrect error returned from `ParseRSAPublicKeyFromPEM`
+* Documentation updates
+
+#### 2.6.0
+
+* Exposed inner error within ValidationError
+* Fixed validation errors when using UseJSONNumber flag
+* Added several unit tests
+
+#### 2.5.0
+
+* Added support for signing method none.  You shouldn't use this.  The API tries to make this clear.
+* Updated/fixed some documentation
+* Added more helpful error message when trying to parse tokens that begin with `BEARER `
+
+#### 2.4.0
+
+* Added new type, Parser, to allow for configuration of various parsing parameters
+	* You can now specify a list of valid signing methods.  Anything outside this set will be rejected.
+	* You can now opt to use the `json.Number` type instead of `float64` when parsing token JSON
+* Added support for [Travis CI](https://travis-ci.org/dgrijalva/jwt-go)
+* Fixed some bugs with ECDSA parsing
+
+#### 2.3.0
+
+* Added support for ECDSA signing methods
+* Added support for RSA PSS signing methods (requires go v1.4)
+
+#### 2.2.0
+
+* Gracefully handle a `nil` `Keyfunc` being passed to `Parse`.  Result will now be the parsed token and an error, instead of a panic.
+
+#### 2.1.0
+
+Backwards compatible API change that was missed in 2.0.0.
+
+* The `SignedString` method on `Token` now takes `interface{}` instead of `[]byte`
+
+#### 2.0.0
+
+There were two major reasons for breaking backwards compatibility with this update.  The first was a refactor required to expand the width of the RSA and HMAC-SHA signing implementations.  There will likely be no required code changes to support this change.
+
+The second update, while unfortunately requiring a small change in integration, is required to open up this library to other signing methods.  Not all keys used for all signing methods have a single standard on-disk representation.  Requiring `[]byte` as the type for all keys proved too limiting.  Additionally, this implementation allows for pre-parsed tokens to be reused, which might matter in an application that parses a high volume of tokens with a small set of keys.  Backwards compatibilty has been maintained for passing `[]byte` to the RSA signing methods, but they will also accept `*rsa.PublicKey` and `*rsa.PrivateKey`.
+
+It is likely the only integration change required here will be to change `func(t *jwt.Token) ([]byte, error)` to `func(t *jwt.Token) (interface{}, error)` when calling `Parse`.
+
+* **Compatibility Breaking Changes**
+	* `SigningMethodHS256` is now `*SigningMethodHMAC` instead of `type struct`
+	* `SigningMethodRS256` is now `*SigningMethodRSA` instead of `type struct`
+	* `KeyFunc` now returns `interface{}` instead of `[]byte`
+	* `SigningMethod.Sign` now takes `interface{}` instead of `[]byte` for the key
+	* `SigningMethod.Verify` now takes `interface{}` instead of `[]byte` for the key
+* Renamed type `SigningMethodHS256` to `SigningMethodHMAC`.  Specific sizes are now just instances of this type.
+    * Added public package global `SigningMethodHS256`
+    * Added public package global `SigningMethodHS384`
+    * Added public package global `SigningMethodHS512`
+* Renamed type `SigningMethodRS256` to `SigningMethodRSA`.  Specific sizes are now just instances of this type.
+    * Added public package global `SigningMethodRS256`
+    * Added public package global `SigningMethodRS384`
+    * Added public package global `SigningMethodRS512`
+* Moved sample private key for HMAC tests from an inline value to a file on disk.  Value is unchanged.
+* Refactored the RSA implementation to be easier to read
+* Exposed helper methods `ParseRSAPrivateKeyFromPEM` and `ParseRSAPublicKeyFromPEM`
+
+#### 1.0.2
+
+* Fixed bug in parsing public keys from certificates
+* Added more tests around the parsing of keys for RS256
+* Code refactoring in RS256 implementation.  No functional changes
+
+#### 1.0.1
+
+* Fixed panic if RS256 signing method was passed an invalid key
+
+#### 1.0.0
+
+* First versioned release
+* API stabilized
+* Supports creating, signing, parsing, and validating JWT tokens
+* Supports RS256 and HS256 signing methods
\ No newline at end of file

vendor/github.com/dgrijalva/jwt-go/claims.go

+package jwt
+
+import (
+	"crypto/subtle"
+	"fmt"
+	"time"
+)
+
+// For a type to be a Claims object, it must just have a Valid method that determines
+// if the token is invalid for any supported reason
+type Claims interface {
+	Valid() error
+}
+
+// Structured version of Claims Section, as referenced at
+// https://tools.ietf.org/html/rfc7519#section-4.1
+// See examples for how to use this with your own claim types
+type StandardClaims struct {
+	Audience  string `json:"aud,omitempty"`
+	ExpiresAt int64  `json:"exp,omitempty"`
+	Id        string `json:"jti,omitempty"`
+	IssuedAt  int64  `json:"iat,omitempty"`
+	Issuer    string `json:"iss,omitempty"`
+	NotBefore int64  `json:"nbf,omitempty"`
+	Subject   string `json:"sub,omitempty"`
+}
+
+// Validates time based claims "exp, iat, nbf".
+// There is no accounting for clock skew.
+// As well, if any of the above claims are not in the token, it will still
+// be considered a valid claim.
+func (c StandardClaims) Valid() error {
+	vErr := new(ValidationError)
+	now := TimeFunc().Unix()
+
+	// The claims below are optional, by default, so if they are set to the
+	// default value in Go, let's not fail the verification for them.
+	if c.VerifyExpiresAt(now, false) == false {
+		delta := time.Unix(now, 0).Sub(time.Unix(c.ExpiresAt, 0))
+		vErr.Inner = fmt.Errorf("token is expired by %v", delta)
+		vErr.Errors |= ValidationErrorExpired
+	}
+
+	if c.VerifyIssuedAt(now, false) == false {
+		vErr.Inner = fmt.Errorf("Token used before issued")
+		vErr.Errors |= ValidationErrorIssuedAt
+	}
+
+	if c.VerifyNotBefore(now, false) == false {
+		vErr.Inner = fmt.Errorf("token is not valid yet")
+		vErr.Errors |= ValidationErrorNotValidYet
+	}
+
+	if vErr.valid() {
+		return nil
+	}
+
+	return vErr
+}
+
+// Compares the aud claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (c *StandardClaims) VerifyAudience(cmp string, req bool) bool {
+	return verifyAud(c.Audience, cmp, req)
+}
+
+// Compares the exp claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (c *StandardClaims) VerifyExpiresAt(cmp int64, req bool) bool {
+	return verifyExp(c.ExpiresAt, cmp, req)
+}
+
+// Compares the iat claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (c *StandardClaims) VerifyIssuedAt(cmp int64, req bool) bool {
+	return verifyIat(c.IssuedAt, cmp, req)
+}
+
+// Compares the iss claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (c *StandardClaims) VerifyIssuer(cmp string, req bool) bool {
+	return verifyIss(c.Issuer, cmp, req)
+}
+
+// Compares the nbf claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (c *StandardClaims) VerifyNotBefore(cmp int64, req bool) bool {
+	return verifyNbf(c.NotBefore, cmp, req)
+}
+
+// ----- helpers
+
+func verifyAud(aud string, cmp string, required bool) bool {
+	if aud == "" {
+		return !required
+	}
+	if subtle.ConstantTimeCompare([]byte(aud), []byte(cmp)) != 0 {
+		return true
+	} else {
+		return false
+	}
+}
+
+func verifyExp(exp int64, now int64, required bool) bool {
+	if exp == 0 {
+		return !required
+	}
+	return now <= exp
+}
+
+func verifyIat(iat int64, now int64, required bool) bool {
+	if iat == 0 {
+		return !required
+	}
+	return now >= iat
+}
+
+func verifyIss(iss string, cmp string, required bool) bool {
+	if iss == "" {
+		return !required
+	}
+	if subtle.ConstantTimeCompare([]byte(iss), []byte(cmp)) != 0 {
+		return true
+	} else {
+		return false
+	}
+}
+
+func verifyNbf(nbf int64, now int64, required bool) bool {
+	if nbf == 0 {
+		return !required
+	}
+	return now >= nbf
+}

vendor/github.com/dgrijalva/jwt-go/doc.go

+// Package jwt is a Go implementation of JSON Web Tokens: http://self-issued.info/docs/draft-jones-json-web-token.html
+//
+// See README.md for more info.
+package jwt

vendor/github.com/dgrijalva/jwt-go/ecdsa.go

+package jwt
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/rand"
+	"errors"
+	"math/big"
+)
+
+var (
+	// Sadly this is missing from crypto/ecdsa compared to crypto/rsa
+	ErrECDSAVerification = errors.New("crypto/ecdsa: verification error")
+)
+
+// Implements the ECDSA family of signing methods signing methods
+type SigningMethodECDSA struct {
+	Name      string
+	Hash      crypto.Hash
+	KeySize   int
+	CurveBits int
+}
+
+// Specific instances for EC256 and company
+var (
+	SigningMethodES256 *SigningMethodECDSA
+	SigningMethodES384 *SigningMethodECDSA
+	SigningMethodES512 *SigningMethodECDSA
+)
+
+func init() {
+	// ES256
+	SigningMethodES256 = &SigningMethodECDSA{"ES256", crypto.SHA256, 32, 256}
+	RegisterSigningMethod(SigningMethodES256.Alg(), func() SigningMethod {
+		return SigningMethodES256
+	})
+
+	// ES384
+	SigningMethodES384 = &SigningMethodECDSA{"ES384", crypto.SHA384, 48, 384}
+	RegisterSigningMethod(SigningMethodES384.Alg(), func() SigningMethod {
+		return SigningMethodES384
+	})
+
+	// ES512
+	SigningMethodES512 = &SigningMethodECDSA{"ES512", crypto.SHA512, 66, 521}
+	RegisterSigningMethod(SigningMethodES512.Alg(), func() SigningMethod {
+		return SigningMethodES512
+	})
+}
+
+func (m *SigningMethodECDSA) Alg() string {
+	return m.Name
+}
+
+// Implements the Verify method from SigningMethod
+// For this verify method, key must be an ecdsa.PublicKey struct
+func (m *SigningMethodECDSA) Verify(signingString, signature string, key interface{}) error {
+	var err error
+
+	// Decode the signature
+	var sig []byte
+	if sig, err = DecodeSegment(signature); err != nil {
+		return err
+	}
+
+	// Get the key
+	var ecdsaKey *ecdsa.PublicKey
+	switch k := key.(type) {
+	case *ecdsa.PublicKey:
+		ecdsaKey = k
+	default:
+		return ErrInvalidKeyType
+	}
+
+	if len(sig) != 2*m.KeySize {
+		return ErrECDSAVerification
+	}
+
+	r := big.NewInt(0).SetBytes(sig[:m.KeySize])
+	s := big.NewInt(0).SetBytes(sig[m.KeySize:])
+
+	// Create hasher
+	if !m.Hash.Available() {
+		return ErrHashUnavailable
+	}
+	hasher := m.Hash.New()
+	hasher.Write([]byte(signingString))
+
+	// Verify the signature
+	if verifystatus := ecdsa.Verify(ecdsaKey, hasher.Sum(nil), r, s); verifystatus == true {
+		return nil
+	} else {
+		return ErrECDSAVerification
+	}
+}
+
+// Implements the Sign method from SigningMethod
+// For this signing method, key must be an ecdsa.PrivateKey struct
+func (m *SigningMethodECDSA) Sign(signingString string, key interface{}) (string, error) {
+	// Get the key
+	var ecdsaKey *ecdsa.PrivateKey
+	switch k := key.(type) {
+	case *ecdsa.PrivateKey:
+		ecdsaKey = k
+	default:
+		return "", ErrInvalidKeyType
+	}
+
+	// Create the hasher
+	if !m.Hash.Available() {
+		return "", ErrHashUnavailable
+	}
+
+	hasher := m.Hash.New()
+	hasher.Write([]byte(signingString))
+
+	// Sign the string and return r, s
+	if r, s, err := ecdsa.Sign(rand.Reader, ecdsaKey, hasher.Sum(nil)); err == nil {
+		curveBits := ecdsaKey.Curve.Params().BitSize
+
+		if m.CurveBits != curveBits {
+			return "", ErrInvalidKey
+		}
+
+		keyBytes := curveBits / 8
+		if curveBits%8 > 0 {
+			keyBytes += 1
+		}
+
+		// We serialize the outpus (r and s) into big-endian byte arrays and pad
+		// them with zeros on the left to make sure the sizes work out. Both arrays
+		// must be keyBytes long, and the output must be 2*keyBytes long.
+		rBytes := r.Bytes()
+		rBytesPadded := make([]byte, keyBytes)
+		copy(rBytesPadded[keyBytes-len(rBytes):], rBytes)
+
+		sBytes := s.Bytes()
+		sBytesPadded := make([]byte, keyBytes)
+		copy(sBytesPadded[keyBytes-len(sBytes):], sBytes)
+
+		out := append(rBytesPadded, sBytesPadded...)
+
+		return EncodeSegment(out), nil
+	} else {
+		return "", err
+	}
+}

vendor/github.com/dgrijalva/jwt-go/ecdsa_utils.go

+package jwt
+
+import (
+	"crypto/ecdsa"
+	"crypto/x509"
+	"encoding/pem"
+	"errors"
+)
+
+var (
+	ErrNotECPublicKey  = errors.New("Key is not a valid ECDSA public key")
+	ErrNotECPrivateKey = errors.New("Key is not a valid ECDSA private key")
+)
+
+// Parse PEM encoded Elliptic Curve Private Key Structure
+func ParseECPrivateKeyFromPEM(key []byte) (*ecdsa.PrivateKey, error) {
+	var err error
+
+	// Parse PEM block
+	var block *pem.Block
+	if block, _ = pem.Decode(key); block == nil {
+		return nil, ErrKeyMustBePEMEncoded
+	}
+
+	// Parse the key
+	var parsedKey interface{}
+	if parsedKey, err = x509.ParseECPrivateKey(block.Bytes); err != nil {
+		return nil, err
+	}
+
+	var pkey *ecdsa.PrivateKey
+	var ok bool
+	if pkey, ok = parsedKey.(*ecdsa.PrivateKey); !ok {
+		return nil, ErrNotECPrivateKey
+	}
+
+	return pkey, nil
+}
+
+// Parse PEM encoded PKCS1 or PKCS8 public key
+func ParseECPublicKeyFromPEM(key []byte) (*ecdsa.PublicKey, error) {
+	var err error
+
+	// Parse PEM block
+	var block *pem.Block
+	if block, _ = pem.Decode(key); block == nil {
+		return nil, ErrKeyMustBePEMEncoded
+	}
+
+	// Parse the key
+	var parsedKey interface{}
+	if parsedKey, err = x509.ParsePKIXPublicKey(block.Bytes); err != nil {
+		if cert, err := x509.ParseCertificate(block.Bytes); err == nil {
+			parsedKey = cert.PublicKey
+		} else {
+			return nil, err
+		}
+	}
+
+	var pkey *ecdsa.PublicKey
+	var ok bool
+	if pkey, ok = parsedKey.(*ecdsa.PublicKey); !ok {
+		return nil, ErrNotECPublicKey
+	}
+
+	return pkey, nil
+}

vendor/github.com/dgrijalva/jwt-go/errors.go

+package jwt
+
+import (
+	"errors"
+)
+
+// Error constants
+var (
+	ErrInvalidKey      = errors.New("key is invalid")
+	ErrInvalidKeyType  = errors.New("key is of invalid type")
+	ErrHashUnavailable = errors.New("the requested hash function is unavailable")
+)
+
+// The errors that might occur when parsing and validating a token
+const (
+	ValidationErrorMalformed        uint32 = 1 << iota // Token is malformed
+	ValidationErrorUnverifiable                        // Token could not be verified because of signing problems
+	ValidationErrorSignatureInvalid                    // Signature validation failed
+
+	// Standard Claim validation errors
+	ValidationErrorAudience      // AUD validation failed
+	ValidationErrorExpired       // EXP validation failed
+	ValidationErrorIssuedAt      // IAT validation failed
+	ValidationErrorIssuer        // ISS validation failed
+	ValidationErrorNotValidYet   // NBF validation failed
+	ValidationErrorId            // JTI validation failed
+	ValidationErrorClaimsInvalid // Generic claims validation error
+)
+
+// Helper for constructing a ValidationError with a string error message
+func NewValidationError(errorText string, errorFlags uint32) *ValidationError {
+	return &ValidationError{
+		text:   errorText,
+		Errors: errorFlags,
+	}
+}
+
+// The error from Parse if token is not valid
+type ValidationError struct {
+	Inner  error  // stores the error returned by external dependencies, i.e.: KeyFunc
+	Errors uint32 // bitfield.  see ValidationError... constants
+	text   string // errors that do not have a valid error just have text
+}
+
+// Validation error is an error type
+func (e ValidationError) Error() string {
+	if e.Inner != nil {
+		return e.Inner.Error()
+	} else if e.text != "" {
+		return e.text
+	} else {
+		return "token is invalid"
+	}
+	return e.Inner.Error()
+}
+
+// No errors
+func (e *ValidationError) valid() bool {
+	if e.Errors > 0 {
+		return false
+	}
+	return true
+}

vendor/github.com/dgrijalva/jwt-go/hmac.go

+package jwt
+
+import (
+	"crypto"
+	"crypto/hmac"
+	"errors"
+)
+
+// Implements the HMAC-SHA family of signing methods signing methods
+type SigningMethodHMAC struct {
+	Name string
+	Hash crypto.Hash
+}
+
+// Specific instances for HS256 and company
+var (
+	SigningMethodHS256  *SigningMethodHMAC
+	SigningMethodHS384  *SigningMethodHMAC
+	SigningMethodHS512  *SigningMethodHMAC
+	ErrSignatureInvalid = errors.New("signature is invalid")
+)
+
+func init() {
+	// HS256
+	SigningMethodHS256 = &SigningMethodHMAC{"HS256", crypto.SHA256}
+	RegisterSigningMethod(SigningMethodHS256.Alg(), func() SigningMethod {
+		return SigningMethodHS256
+	})
+
+	// HS384
+	SigningMethodHS384 = &SigningMethodHMAC{"HS384", crypto.SHA384}
+	RegisterSigningMethod(SigningMethodHS384.Alg(), func() SigningMethod {
+		return SigningMethodHS384
+	})
+
+	// HS512
+	SigningMethodHS512 = &SigningMethodHMAC{"HS512", crypto.SHA512}
+	RegisterSigningMethod(SigningMethodHS512.Alg(), func() SigningMethod {
+		return SigningMethodHS512
+	})
+}
+
+func (m *SigningMethodHMAC) Alg() string {
+	return m.Name
+}
+
+// Verify the signature of HSXXX tokens.  Returns nil if the signature is valid.
+func (m *SigningMethodHMAC) Verify(signingString, signature string, key interface{}) error {
+	// Verify the key is the right type
+	keyBytes, ok := key.([]byte)
+	if !ok {
+		return ErrInvalidKeyType
+	}
+
+	// Decode signature, for comparison
+	sig, err := DecodeSegment(signature)
+	if err != nil {
+		return err
+	}
+
+	// Can we use the specified hashing method?
+	if !m.Hash.Available() {
+		return ErrHashUnavailable
+	}
+
+	// This signing method is symmetric, so we validate the signature
+	// by reproducing the signature from the signing string and key, then
+	// comparing that against the provided signature.
+	hasher := hmac.New(m.Hash.New, keyBytes)
+	hasher.Write([]byte(signingString))
+	if !hmac.Equal(sig, hasher.Sum(nil)) {
+		return ErrSignatureInvalid
+	}
+
+	// No validation errors.  Signature is good.
+	return nil
+}
+
+// Implements the Sign method from SigningMethod for this signing method.
+// Key must be []byte
+func (m *SigningMethodHMAC) Sign(signingString string, key interface{}) (string, error) {
+	if keyBytes, ok := key.([]byte); ok {
+		if !m.Hash.Available() {
+			return "", ErrHashUnavailable
+		}
+
+		hasher := hmac.New(m.Hash.New, keyBytes)
+		hasher.Write([]byte(signingString))
+
+		return EncodeSegment(hasher.Sum(nil)), nil
+	}
+
+	return "", ErrInvalidKey
+}

vendor/github.com/dgrijalva/jwt-go/map_claims.go

+package jwt
+
+import (
+	"encoding/json"
+	"errors"
+	// "fmt"
+)
+
+// Claims type that uses the map[string]interface{} for JSON decoding
+// This is the default claims type if you don't supply one
+type MapClaims map[string]interface{}
+
+// Compares the aud claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (m MapClaims) VerifyAudience(cmp string, req bool) bool {
+	aud, _ := m["aud"].(string)
+	return verifyAud(aud, cmp, req)
+}
+
+// Compares the exp claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (m MapClaims) VerifyExpiresAt(cmp int64, req bool) bool {
+	switch exp := m["exp"].(type) {
+	case float64:
+		return verifyExp(int64(exp), cmp, req)
+	case json.Number:
+		v, _ := exp.Int64()
+		return verifyExp(v, cmp, req)
+	}
+	return req == false
+}
+
+// Compares the iat claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (m MapClaims) VerifyIssuedAt(cmp int64, req bool) bool {
+	switch iat := m["iat"].(type) {
+	case float64:
+		return verifyIat(int64(iat), cmp, req)
+	case json.Number:
+		v, _ := iat.Int64()
+		return verifyIat(v, cmp, req)
+	}
+	return req == false
+}
+
+// Compares the iss claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (m MapClaims) VerifyIssuer(cmp string, req bool) bool {
+	iss, _ := m["iss"].(string)
+	return verifyIss(iss, cmp, req)
+}
+
+// Compares the nbf claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (m MapClaims) VerifyNotBefore(cmp int64, req bool) bool {
+	switch nbf := m["nbf"].(type) {
+	case float64:
+		return verifyNbf(int64(nbf), cmp, req)
+	case json.Number:
+		v, _ := nbf.Int64()
+		return verifyNbf(v, cmp, req)
+	}
+	return req == false
+}
+
+// Validates time based claims "exp, iat, nbf".
+// There is no accounting for clock skew.
+// As well, if any of the above claims are not in the token, it will still
+// be considered a valid claim.
+func (m MapClaims) Valid() error {
+	vErr := new(ValidationError)
+	now := TimeFunc().Unix()
+
+	if m.VerifyExpiresAt(now, false) == false {
+		vErr.Inner = errors.New("Token is expired")
+		vErr.Errors |= ValidationErrorExpired
+	}
+
+	if m.VerifyIssuedAt(now, false) == false {
+		vErr.Inner = errors.New("Token used before issued")
+		vErr.Errors |= ValidationErrorIssuedAt
+	}
+
+	if m.VerifyNotBefore(now, false) == false {
+		vErr.Inner = errors.New("Token is not valid yet")
+		vErr.Errors |= ValidationErrorNotValidYet
+	}
+
+	if vErr.valid() {
+		return nil
+	}
+
+	return vErr
+}

vendor/github.com/dgrijalva/jwt-go/none.go

+package jwt
+
+// Implements the none signing method.  This is required by the spec
+// but you probably should never use it.
+var SigningMethodNone *signingMethodNone
+
+const UnsafeAllowNoneSignatureType unsafeNoneMagicConstant = "none signing method allowed"
+
+var NoneSignatureTypeDisallowedError error
+
+type signingMethodNone struct{}
+type unsafeNoneMagicConstant string
+
+func init() {
+	SigningMethodNone = &signingMethodNone{}
+	NoneSignatureTypeDisallowedError = NewValidationError("'none' signature type is not allowed", ValidationErrorSignatureInvalid)
+
+	RegisterSigningMethod(SigningMethodNone.Alg(), func() SigningMethod {
+		return SigningMethodNone
+	})
+}
+
+func (m *signingMethodNone) Alg() string {
+	return "none"
+}
+
+// Only allow 'none' alg type if UnsafeAllowNoneSignatureType is specified as the key
+func (m *signingMethodNone) Verify(signingString, signature string, key interface{}) (err error) {
+	// Key must be UnsafeAllowNoneSignatureType to prevent accidentally
+	// accepting 'none' signing method
+	if _, ok := key.(unsafeNoneMagicConstant); !ok {
+		return NoneSignatureTypeDisallowedError
+	}
+	// If signing method is none, signature must be an empty string
+	if signature != "" {
+		return NewValidationError(
+			"'none' signing method with non-empty signature",
+			ValidationErrorSignatureInvalid,
+		)
+	}
+
+	// Accept 'none' signing method.
+	return nil
+}
+
+// Only allow 'none' signing if UnsafeAllowNoneSignatureType is specified as the key
+func (m *signingMethodNone) Sign(signingString string, key interface{}) (string, error) {
+	if _, ok := key.(unsafeNoneMagicConstant); ok {
+		return "", nil
+	}
+	return "", NoneSignatureTypeDisallowedError
+}

vendor/github.com/dgrijalva/jwt-go/parser.go

+package jwt
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"strings"
+)
+
+type Parser struct {
+	ValidMethods  []string // If populated, only these methods will be considered valid
+	UseJSONNumber bool     // Use JSON Number format in JSON decoder
+}
+
+// Parse, validate, and return a token.
+// keyFunc will receive the parsed token and should return the key for validating.
+// If everything is kosher, err will be nil
+func (p *Parser) Parse(tokenString string, keyFunc Keyfunc) (*Token, error) {
+	return p.ParseWithClaims(tokenString, MapClaims{}, keyFunc)
+}
+
+func (p *Parser) ParseWithClaims(tokenString string, claims Claims, keyFunc Keyfunc) (*Token, error) {
+	parts := strings.Split(tokenString, ".")
+	if len(parts) != 3 {
+		return nil, NewValidationError("token contains an invalid number of segments", ValidationErrorMalformed)
+	}
+
+	var err error
+	token := &Token{Raw: tokenString}
+
+	// parse Header
+	var headerBytes []byte
+	if headerBytes, err = DecodeSegment(parts[0]); err != nil {
+		if strings.HasPrefix(strings.ToLower(tokenString), "bearer ") {
+			return token, NewValidationError("tokenstring should not contain 'bearer '", ValidationErrorMalformed)
+		}
+		return token, &ValidationError{Inner: err, Errors: ValidationErrorMalformed}
+	}
+	if err = json.Unmarshal(headerBytes, &token.Header); err != nil {
+		return token, &ValidationError{Inner: err, Errors: ValidationErrorMalformed}
+	}
+
+	// parse Claims
+	var claimBytes []byte
+	token.Claims = claims
+
+	if claimBytes, err = DecodeSegment(parts[1]); err != nil {
+		return token, &ValidationError{Inner: err, Errors: ValidationErrorMalformed}
+	}
+	dec := json.NewDecoder(bytes.NewBuffer(claimBytes))
+	if p.UseJSONNumber {
+		dec.UseNumber()
+	}
+	// JSON Decode.  Special case for map type to avoid weird pointer behavior
+	if c, ok := token.Claims.(MapClaims); ok {
+		err = dec.Decode(&c)
+	} else {
+		err = dec.Decode(&claims)
+	}
+	// Handle decode error
+	if err != nil {
+		return token, &ValidationError{Inner: err, Errors: ValidationErrorMalformed}
+	}
+
+	// Lookup signature method
+	if method, ok := token.Header["alg"].(string); ok {
+		if token.Method = GetSigningMethod(method); token.Method == nil {
+			return token, NewValidationError("signing method (alg) is unavailable.", ValidationErrorUnverifiable)
+		}
+	} else {
+		return token, NewValidationError("signing method (alg) is unspecified.", ValidationErrorUnverifiable)
+	}
+
+	// Verify signing method is in the required set
+	if p.ValidMethods != nil {
+		var signingMethodValid = false
+		var alg = token.Method.Alg()
+		for _, m := range p.ValidMethods {
+			if m == alg {
+				signingMethodValid = true
+				break
+			}
+		}
+		if !signingMethodValid {
+			// signing method is not in the listed set
+			return token, NewValidationError(fmt.Sprintf("signing method %v is invalid", alg), ValidationErrorSignatureInvalid)
+		}
+	}
+
+	// Lookup key
+	var key interface{}
+	if keyFunc == nil {
+		// keyFunc was not provided.  short circuiting validation
+		return token, NewValidationError("no Keyfunc was provided.", ValidationErrorUnverifiable)
+	}
+	if key, err = keyFunc(token); err != nil {
+		// keyFunc returned an error
+		return token, &ValidationError{Inner: err, Errors: ValidationErrorUnverifiable}
+	}
+
+	vErr := &ValidationError{}
+
+	// Validate Claims
+	if err := token.Claims.Valid(); err != nil {
+
+		// If the Claims Valid returned an error, check if it is a validation error,
+		// If it was another error type, create a ValidationError with a generic ClaimsInvalid flag set
+		if e, ok := err.(*ValidationError); !ok {
+			vErr = &ValidationError{Inner: err, Errors: ValidationErrorClaimsInvalid}
+		} else {
+			vErr = e
+		}
+	}
+
+	// Perform validation
+	token.Signature = parts[2]
+	if err = token.Method.Verify(strings.Join(parts[0:2], "."), token.Signature, key); err != nil {
+		vErr.Inner = err
+		vErr.Errors |= ValidationErrorSignatureInvalid
+	}
+
+	if vErr.valid() {
+		token.Valid = true
+		return token, nil
+	}
+
+	return token, vErr
+}

vendor/github.com/dgrijalva/jwt-go/rsa.go

+package jwt
+
+import (
+	"crypto"
+	"crypto/rand"
+	"crypto/rsa"
+)
+
+// Implements the RSA family of signing methods signing methods
+type SigningMethodRSA struct {
+	Name string
+	Hash crypto.Hash
+}
+
+// Specific instances for RS256 and company
+var (
+	SigningMethodRS256 *SigningMethodRSA
+	SigningMethodRS384 *SigningMethodRSA
+	SigningMethodRS512 *SigningMethodRSA
+)
+
+func init() {
+	// RS256
+	SigningMethodRS256 = &SigningMethodRSA{"RS256", crypto.SHA256}
+	RegisterSigningMethod(SigningMethodRS256.Alg(), func() SigningMethod {
+		return SigningMethodRS256
+	})
+
+	// RS384
+	SigningMethodRS384 = &SigningMethodRSA{"RS384", crypto.SHA384}
+	RegisterSigningMethod(SigningMethodRS384.Alg(), func() SigningMethod {
+		return SigningMethodRS384
+	})
+
+	// RS512
+	SigningMethodRS512 = &SigningMethodRSA{"RS512", crypto.SHA512}
+	RegisterSigningMethod(SigningMethodRS512.Alg(), func() SigningMethod {
+		return SigningMethodRS512
+	})
+}
+
+func (m *SigningMethodRSA) Alg() string {
+	return m.Name
+}
+
+// Implements the Verify method from SigningMethod
+// For this signing method, must be an rsa.PublicKey structure.
+func (m *SigningMethodRSA) Verify(signingString, signature string, key interface{}) error {
+	var err error
+
+	// Decode the signature
+	var sig []byte
+	if sig, err = DecodeSegment(signature); err != nil {
+		return err
+	}
+
+	var rsaKey *rsa.PublicKey
+	var ok bool
+
+	if rsaKey, ok = key.(*rsa.PublicKey); !ok {
+		return ErrInvalidKeyType
+	}
+
+	// Create hasher
+	if !m.Hash.Available() {
+		return ErrHashUnavailable
+	}
+	hasher := m.Hash.New()
+	hasher.Write([]byte(signingString))
+
+	// Verify the signature
+	return rsa.VerifyPKCS1v15(rsaKey, m.Hash, hasher.Sum(nil), sig)
+}
+
+// Implements the Sign method from SigningMethod
+// For this signing method, must be an rsa.PrivateKey structure.
+func (m *SigningMethodRSA) Sign(signingString string, key interface{}) (string, error) {
+	var rsaKey *rsa.PrivateKey
+	var ok bool
+
+	// Validate type of key
+	if rsaKey, ok = key.(*rsa.PrivateKey); !ok {
+		return "", ErrInvalidKey
+	}
+
+	// Create the hasher
+	if !m.Hash.Available() {
+		return "", ErrHashUnavailable
+	}
+
+	hasher := m.Hash.New()
+	hasher.Write([]byte(signingString))
+
+	// Sign the string and return the encoded bytes
+	if sigBytes, err := rsa.SignPKCS1v15(rand.Reader, rsaKey, m.Hash, hasher.Sum(nil)); err == nil {
+		return EncodeSegment(sigBytes), nil
+	} else {
+		return "", err
+	}
+}

vendor/github.com/dgrijalva/jwt-go/rsa_pss.go

+// +build go1.4
+
+package jwt
+
+import (
+	"crypto"
+	"crypto/rand"
+	"crypto/rsa"
+)
+
+// Implements the RSAPSS family of signing methods signing methods
+type SigningMethodRSAPSS struct {
+	*SigningMethodRSA
+	Options *rsa.PSSOptions
+}
+
+// Specific instances for RS/PS and company
+var (
+	SigningMethodPS256 *SigningMethodRSAPSS
+	SigningMethodPS384 *SigningMethodRSAPSS
+	SigningMethodPS512 *SigningMethodRSAPSS
+)
+
+func init() {
+	// PS256
+	SigningMethodPS256 = &SigningMethodRSAPSS{
+		&SigningMethodRSA{
+			Name: "PS256",
+			Hash: crypto.SHA256,
+		},
+		&rsa.PSSOptions{
+			SaltLength: rsa.PSSSaltLengthAuto,
+			Hash:       crypto.SHA256,
+		},
+	}
+	RegisterSigningMethod(SigningMethodPS256.Alg(), func() SigningMethod {
+		return SigningMethodPS256
+	})
+
+	// PS384
+	SigningMethodPS384 = &SigningMethodRSAPSS{
+		&SigningMethodRSA{
+			Name: "PS384",
+			Hash: crypto.SHA384,
+		},
+		&rsa.PSSOptions{
+			SaltLength: rsa.PSSSaltLengthAuto,
+			Hash:       crypto.SHA384,
+		},
+	}
+	RegisterSigningMethod(SigningMethodPS384.Alg(), func() SigningMethod {
+		return SigningMethodPS384
+	})
+
+	// PS512
+	SigningMethodPS512 = &SigningMethodRSAPSS{
+		&SigningMethodRSA{
+			Name: "PS512",
+			Hash: crypto.SHA512,
+		},
+		&rsa.PSSOptions{
+			SaltLength: rsa.PSSSaltLengthAuto,
+			Hash:       crypto.SHA512,
+		},
+	}
+	RegisterSigningMethod(SigningMethodPS512.Alg(), func() SigningMethod {
+		return SigningMethodPS512
+	})
+}
+
+// Implements the Verify method from SigningMethod
+// For this verify method, key must be an rsa.PublicKey struct
+func (m *SigningMethodRSAPSS) Verify(signingString, signature string, key interface{}) error {
+	var err error
+
+	// Decode the signature
+	var sig []byte
+	if sig, err = DecodeSegment(signature); err != nil {
+		return err
+	}
+
+	var rsaKey *rsa.PublicKey
+	switch k := key.(type) {
+	case *rsa.PublicKey:
+		rsaKey = k
+	default:
+		return ErrInvalidKey
+	}
+
+	// Create hasher
+	if !m.Hash.Available() {
+		return ErrHashUnavailable
+	}
+	hasher := m.Hash.New()
+	hasher.Write([]byte(signingString))
+
+	return rsa.VerifyPSS(rsaKey, m.Hash, hasher.Sum(nil), sig, m.Options)
+}
+
+// Implements the Sign method from SigningMethod
+// For this signing method, key must be an rsa.PrivateKey struct
+func (m *SigningMethodRSAPSS) Sign(signingString string, key interface{}) (string, error) {
+	var rsaKey *rsa.PrivateKey
+
+	switch k := key.(type) {
+	case *rsa.PrivateKey:
+		rsaKey = k
+	default:
+		return "", ErrInvalidKeyType
+	}
+
+	// Create the hasher
+	if !m.Hash.Available() {
+		return "", ErrHashUnavailable
+	}
+
+	hasher := m.Hash.New()
+	hasher.Write([]byte(signingString))
+
+	// Sign the string and return the encoded bytes
+	if sigBytes, err := rsa.SignPSS(rand.Reader, rsaKey, m.Hash, hasher.Sum(nil), m.Options); err == nil {
+		return EncodeSegment(sigBytes), nil
+	} else {
+		return "", err
+	}
+}

vendor/github.com/dgrijalva/jwt-go/rsa_utils.go

+package jwt
+
+import (
+	"crypto/rsa"
+	"crypto/x509"
+	"encoding/pem"
+	"errors"
+)
+
+var (
+	ErrKeyMustBePEMEncoded = errors.New("Invalid Key: Key must be PEM encoded PKCS1 or PKCS8 private key")
+	ErrNotRSAPrivateKey    = errors.New("Key is not a valid RSA private key")
+	ErrNotRSAPublicKey     = errors.New("Key is not a valid RSA public key")
+)
+
+// Parse PEM encoded PKCS1 or PKCS8 private key
+func ParseRSAPrivateKeyFromPEM(key []byte) (*rsa.PrivateKey, error) {
+	var err error
+
+	// Parse PEM block
+	var block *pem.Block
+	if block, _ = pem.Decode(key); block == nil {
+		return nil, ErrKeyMustBePEMEncoded
+	}
+
+	var parsedKey interface{}
+	if parsedKey, err = x509.ParsePKCS1PrivateKey(block.Bytes); err != nil {
+		if parsedKey, err = x509.ParsePKCS8PrivateKey(block.Bytes); err != nil {
+			return nil, err
+		}
+	}
+
+	var pkey *rsa.PrivateKey
+	var ok bool
+	if pkey, ok = parsedKey.(*rsa.PrivateKey); !ok {
+		return nil, ErrNotRSAPrivateKey
+	}
+
+	return pkey, nil
+}
+
+// Parse PEM encoded PKCS1 or PKCS8 public key
+func ParseRSAPublicKeyFromPEM(key []byte) (*rsa.PublicKey, error) {
+	var err error
+
+	// Parse PEM block
+	var block *pem.Block
+	if block, _ = pem.Decode(key); block == nil {
+		return nil, ErrKeyMustBePEMEncoded
+	}
+
+	// Parse the key
+	var parsedKey interface{}
+	if parsedKey, err = x509.ParsePKIXPublicKey(block.Bytes); err != nil {
+		if cert, err := x509.ParseCertificate(block.Bytes); err == nil {
+			parsedKey = cert.PublicKey
+		} else {
+			return nil, err
+		}
+	}
+
+	var pkey *rsa.PublicKey
+	var ok bool
+	if pkey, ok = parsedKey.(*rsa.PublicKey); !ok {
+		return nil, ErrNotRSAPublicKey
+	}
+
+	return pkey, nil
+}

vendor/github.com/dgrijalva/jwt-go/signing_method.go

+package jwt
+
+import (
+	"sync"
+)
+
+var signingMethods = map[string]func() SigningMethod{}
+var signingMethodLock = new(sync.RWMutex)
+
+// Implement SigningMethod to add new methods for signing or verifying tokens.
+type SigningMethod interface {
+	Verify(signingString, signature string, key interface{}) error // Returns nil if signature is valid
+	Sign(signingString string, key interface{}) (string, error)    // Returns encoded signature or error
+	Alg() string                                                   // returns the alg identifier for this method (example: 'HS256')
+}
+
+// Register the "alg" name and a factory function for signing method.
+// This is typically done during init() in the method's implementation
+func RegisterSigningMethod(alg string, f func() SigningMethod) {
+	signingMethodLock.Lock()
+	defer signingMethodLock.Unlock()
+
+	signingMethods[alg] = f
+}
+
+// Get a signing method from an "alg" string
+func GetSigningMethod(alg string) (method SigningMethod) {
+	signingMethodLock.RLock()
+	defer signingMethodLock.RUnlock()
+
+	if methodF, ok := signingMethods[alg]; ok {
+		method = methodF()
+	}
+	return
+}

vendor/github.com/dgrijalva/jwt-go/token.go

+package jwt
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"strings"
+	"time"
+)
+
+// TimeFunc provides the current time when parsing token to validate "exp" claim (expiration time).
+// You can override it to use another time value.  This is useful for testing or if your
+// server uses a different time zone than your tokens.
+var TimeFunc = time.Now
+
+// Parse methods use this callback function to supply
+// the key for verification.  The function receives the parsed,
+// but unverified Token.  This allows you to use properties in the
+// Header of the token (such as `kid`) to identify which key to use.
+type Keyfunc func(*Token) (interface{}, error)
+
+// A JWT Token.  Different fields will be used depending on whether you're
+// creating or parsing/verifying a token.
+type Token struct {
+	Raw       string                 // The raw token.  Populated when you Parse a token
+	Method    SigningMethod          // The signing method used or to be used
+	Header    map[string]interface{} // The first segment of the token
+	Claims    Claims                 // The second segment of the token
+	Signature string                 // The third segment of the token.  Populated when you Parse a token
+	Valid     bool                   // Is the token valid?  Populated when you Parse/Verify a token
+}
+
+// Create a new Token.  Takes a signing method
+func New(method SigningMethod) *Token {
+	return NewWithClaims(method, MapClaims{})
+}
+
+func NewWithClaims(method SigningMethod, claims Claims) *Token {
+	return &Token{
+		Header: map[string]interface{}{
+			"typ": "JWT",
+			"alg": method.Alg(),
+		},
+		Claims: claims,
+		Method: method,
+	}
+}
+
+// Get the complete, signed token
+func (t *Token) SignedString(key interface{}) (string, error) {
+	var sig, sstr string
+	var err error
+	if sstr, err = t.SigningString(); err != nil {
+		return "", err
+	}
+	if sig, err = t.Method.Sign(sstr, key); err != nil {
+		return "", err
+	}
+	return strings.Join([]string{sstr, sig}, "."), nil
+}
+
+// Generate the signing string.  This is the
+// most expensive part of the whole deal.  Unless you
+// need this for something special, just go straight for
+// the SignedString.
+func (t *Token) SigningString() (string, error) {
+	var err error
+	parts := make([]string, 2)
+	for i, _ := range parts {
+		var jsonValue []byte
+		if i == 0 {
+			if jsonValue, err = json.Marshal(t.Header); err != nil {
+				return "", err
+			}
+		} else {
+			if jsonValue, err = json.Marshal(t.Claims); err != nil {
+				return "", err
+			}
+		}
+
+		parts[i] = EncodeSegment(jsonValue)
+	}
+	return strings.Join(parts, "."), nil
+}
+
+// Parse, validate, and return a token.
+// keyFunc will receive the parsed token and should return the key for validating.
+// If everything is kosher, err will be nil
+func Parse(tokenString string, keyFunc Keyfunc) (*Token, error) {
+	return new(Parser).Parse(tokenString, keyFunc)
+}
+
+func ParseWithClaims(tokenString string, claims Claims, keyFunc Keyfunc) (*Token, error) {
+	return new(Parser).ParseWithClaims(tokenString, claims, keyFunc)
+}
+
+// Encode JWT specific base64url encoding with padding stripped
+func EncodeSegment(seg []byte) string {
+	return strings.TrimRight(base64.URLEncoding.EncodeToString(seg), "=")
+}
+
+// Decode JWT specific base64url encoding with padding stripped
+func DecodeSegment(seg string) ([]byte, error) {
+	if l := len(seg) % 4; l > 0 {
+		seg += strings.Repeat("=", 4-l)
+	}
+
+	return base64.URLEncoding.DecodeString(seg)
+}