auth
2015-12-14
Parent:581c60f8dd23
auth/oauth2.go
Break out scopes and events. This repo has gotten unwieldy, and there are portions of it that need to be imported by a large number of other packages. For example, scopes will be used in almost every API we write. Rather than importing the entirety of this codebase into every API we write, I've opted to move the scope logic out into a scopes package, with a subpackage for the defined types, which is all most projects actually want to import. We also define some event type constants, and importing those shouldn't require a project to import all our dependencies, either. So I made an events subpackage that just holds those constants. This package has become a little bit of a red-headed stepchild and is do for a refactor, but I'm trying to put that off as long as I can. The refactoring of our scopes stuff has left a bug wherein a token can be granted for scopes that don't exist. I'm going to need to revisit that, and also how to limit scopes to only be granted to the users that should be able to request them. But that's a battle for another day.
1 package auth
3 import (
4 "crypto/rand"
5 "encoding/hex"
6 "encoding/json"
7 "errors"
8 "html/template"
9 "io"
10 "log"
11 "net/http"
12 "net/url"
13 "strconv"
14 "strings"
15 "sync"
16 "time"
18 "code.secondbit.org/scopes.hg/types"
19 "code.secondbit.org/uuid.hg"
20 "github.com/gorilla/mux"
21 )
23 const (
24 defaultAuthorizationCodeExpiration = 600 // default to ten minute grant expirations
25 getAuthorizationCodeTemplateName = "get_grant"
26 )
28 var (
29 // ErrNoAuth is returned when an Authorization header is not present or is empty.
30 ErrNoAuth = errors.New("no authorization header supplied")
31 // ErrInvalidAuthFormat is returned when an Authorization header is present but not the correct format.
32 ErrInvalidAuthFormat = errors.New("authorization header is not in a valid format")
33 // ErrIncorrectAuth is returned when a user authentication attempt does not match the stored values.
34 ErrIncorrectAuth = errors.New("invalid authentication")
35 // ErrInvalidPassphraseScheme is returned when an undefined passphrase scheme is used.
36 ErrInvalidPassphraseScheme = errors.New("invalid passphrase scheme")
37 // ErrNoSession is returned when no session ID is passed with a request.
38 ErrNoSession = errors.New("no session ID found")
40 grantTypesMap = grantTypes{types: map[string]GrantType{}}
41 )
43 type grantTypes struct {
44 types map[string]GrantType
45 sync.RWMutex
46 }
48 // GrantType defines a set of functions and metadata around a specific authorization grant strategy.
49 //
50 // The Validate function will be called when requests are made that match the GrantType, and should write any
51 // errors to the ResponseWriter. It is responsible for determining if the grant is valid and a token should be issued.
52 // It must return the scope the grant was for and the ID of the Profile that issued the grant, as well as if the grant
53 // is valid or not. It must not be nil.
54 //
55 // The Invalidate function will be called when the grant has successfully generated a token and the token has successfully
56 // been conveyed to the user. The Invalidate function is always called asynchronously, outside the request. It should take
57 // care of marking the grant as used, if the GrantType requires grants to be one-time only grants. The Invalidate function
58 // can be nil.
59 //
60 // IssuesRefresh determines whether the GrantType should yield a refresh token as well as an access token. If true, the client
61 // will be issued a refresh token.
62 //
63 // AllowsPublic determines whether the GrantType should allow public clients to use that grant. If true, clients without
64 // credentials will be able to use the grant to obtain a token.
65 //
66 // AuditString should return the string that will be saved in the resulting Token's CreatedFrom field, as an audit log of how
67 // the Token was authorized.
68 //
69 // The ReturnToken will be called when a token is created and needs to be returned to the client. If it returns true, the token
70 // was successfully returned and the Invalidate function will be called asynchronously.
71 type GrantType struct {
72 Validate func(w http.ResponseWriter, r *http.Request, context Context) (scopes scopeTypes.Scopes, profileID uuid.ID, valid bool)
73 Invalidate func(r *http.Request, context Context) error
74 ReturnToken func(w http.ResponseWriter, r *http.Request, token Token, context Context) bool
75 AuditString func(r *http.Request) string
76 IssuesRefresh bool
77 AllowsPublic bool
78 }
80 type tokenResponse struct {
81 AccessToken string `json:"access_token"`
82 TokenType string `json:"token_type,omitempty"`
83 ExpiresIn int32 `json:"expires_in,omitempty"`
84 RefreshToken string `json:"refresh_token,omitempty"`
85 }
87 type errorResponse struct {
88 Error string `json:"error"`
89 Description string `json:"error_description,omitempty"`
90 URI string `json:"error_uri,omitempty"`
91 }
93 // RegisterGrantType associates a string with a GrantType. When the string is used as the value for "grant_type" when obtaining
94 // an access token, the associated GrantType's properties will be used.
95 //
96 // RegisterGrantType should be called in the `init()` function of packages, much like database/sql registers drivers. It will panic
97 // if a GrantType tries to register under a string that already has a GrantType registered for it.
98 func RegisterGrantType(name string, g GrantType) {
99 grantTypesMap.Lock()
100 defer grantTypesMap.Unlock()
101 if _, ok := grantTypesMap.types[name]; ok {
102 panic("Duplicate registration of grant_type " + name)
103 }
104 grantTypesMap.types[name] = g
105 }
107 func findGrantType(name string) (GrantType, bool) {
108 grantTypesMap.RLock()
109 defer grantTypesMap.RUnlock()
110 t, ok := grantTypesMap.types[name]
111 return t, ok
112 }
114 func renderJSONError(enc *json.Encoder, errorType string) {
115 err := enc.Encode(errorResponse{
116 Error: errorType,
117 })
118 if err != nil {
119 log.Println(err)
120 }
121 }
123 // RenderJSONToken is an implementation of the ReturnToken function for GrantTypes. It returns the token using JSON
124 // according to the spec. See RFC 6479, Section 4.1.4.
125 func RenderJSONToken(w http.ResponseWriter, r *http.Request, token Token, context Context) bool {
126 enc := json.NewEncoder(w)
127 resp := tokenResponse{
128 AccessToken: token.AccessToken,
129 RefreshToken: token.RefreshToken,
130 ExpiresIn: token.ExpiresIn,
131 TokenType: token.TokenType,
132 }
133 w.Header().Set("Content-Type", "application/json")
134 err := enc.Encode(resp)
135 if err != nil {
136 log.Println(err)
137 return false
138 }
139 return true
140 }
142 // RegisterOAuth2 adds handlers to the passed router to handle the OAuth2 endpoints.
143 func RegisterOAuth2(r *mux.Router, context Context) {
144 r.Handle("/authorize", wrap(context, GetAuthorizationCodeHandler))
145 r.Handle("/token", wrap(context, GetTokenHandler))
146 }
148 // GetAuthorizationCodeHandler presents and processes the page for asking a user to grant access
149 // to their data. See RFC 6749, Section 4.1.
150 func GetAuthorizationCodeHandler(w http.ResponseWriter, r *http.Request, context Context) {
151 session, err := checkCookie(r, context)
152 if err != nil {
153 if err == ErrNoSession || err == ErrInvalidSession {
154 redir := buildLoginRedirect(r, context)
155 if redir == "" {
156 log.Println("No login URL configured.")
157 w.WriteHeader(http.StatusInternalServerError)
158 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
159 "internal_error": template.HTML("Missing login URL."),
160 })
161 return
162 }
163 http.Redirect(w, r, redir, http.StatusFound)
164 return
165 }
166 log.Println(err.Error())
167 w.WriteHeader(http.StatusInternalServerError)
168 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
169 "internal_error": template.HTML(err.Error()),
170 })
171 return
172 }
173 if r.URL.Query().Get("client_id") == "" {
174 w.WriteHeader(http.StatusBadRequest)
175 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
176 "error": template.HTML("Client ID must be specified in the request."),
177 })
178 return
179 }
180 clientID, err := uuid.Parse(r.URL.Query().Get("client_id"))
181 if err != nil {
182 w.WriteHeader(http.StatusBadRequest)
183 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
184 "error": template.HTML("client_id is not a valid Client ID."),
185 })
186 return
187 }
188 redirectURI := r.URL.Query().Get("redirect_uri")
189 client, err := context.GetClient(clientID)
190 if err != nil {
191 if err == ErrClientNotFound {
192 w.WriteHeader(http.StatusBadRequest)
193 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
194 "error": template.HTML("The specified Client couldn’t be found."),
195 })
196 } else {
197 log.Println(err.Error())
198 w.WriteHeader(http.StatusInternalServerError)
199 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
200 "internal_error": template.HTML(err.Error()),
201 })
202 }
203 return
204 }
205 // BUG(paddy): Checking if the redirect URI is valid should be a helper function.
207 // whether a redirect URI is valid or not depends on the number of endpoints
208 // the client has registered
209 numEndpoints, err := context.CountEndpoints(clientID)
210 if err != nil {
211 log.Println(err.Error())
212 w.WriteHeader(http.StatusInternalServerError)
213 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
214 "internal_error": template.HTML(err.Error()),
215 })
216 return
217 }
218 var validURI bool
219 if redirectURI != "" {
220 validURI, err = context.CheckEndpoint(clientID, redirectURI)
221 if err != nil {
222 if err == ErrEndpointURINotURL {
223 w.WriteHeader(http.StatusBadRequest)
224 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
225 "error": template.HTML("The redirect_uri specified is not valid."),
226 })
227 return
228 }
229 log.Println(err.Error())
230 w.WriteHeader(http.StatusInternalServerError)
231 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
232 "internal_error": template.HTML(err.Error()),
233 })
234 return
235 }
236 } else if redirectURI == "" && numEndpoints == 1 {
237 // if we don't specify the endpoint and there's only one endpoint, the
238 // request is valid, and we're redirecting to that one endpoint
239 validURI = true
240 endpoints, err := context.ListEndpoints(clientID, 1, 0)
241 if err != nil {
242 log.Println(err.Error())
243 w.WriteHeader(http.StatusInternalServerError)
244 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
245 "internal_error": template.HTML(err.Error()),
246 })
247 return
248 }
249 if len(endpoints) != 1 {
250 validURI = false
251 } else {
252 redirectURI = endpoints[0].URI
253 }
254 } else {
255 validURI = false
256 }
257 if !validURI {
258 w.WriteHeader(http.StatusBadRequest)
259 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
260 "error": template.HTML("The redirect_uri specified is not valid."),
261 })
262 return
263 }
264 redirectURL, err := url.Parse(redirectURI)
265 if err != nil {
266 w.WriteHeader(http.StatusBadRequest)
267 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
268 "error": template.HTML("The redirect_uri specified is not valid."),
269 })
270 return
271 }
272 state := r.URL.Query().Get("state")
273 responseType := r.URL.Query().Get("response_type")
274 q := redirectURL.Query()
275 q.Add("state", state)
276 if responseType != "code" && responseType != "token" {
277 q.Add("error", "invalid_request")
278 redirectURL.RawQuery = q.Encode()
279 http.Redirect(w, r, redirectURL.String(), http.StatusFound)
280 return
281 }
282 scopes := scopeTypes.StringsToScopes(strings.Split(r.URL.Query().Get("scope"), " "))
283 // BUG(paddy): need to check if Scopes actually exist
284 /*if err == ErrScopeNotFound {
285 q.Add("error", "invalid_scope")
286 redirectURL.RawQuery = q.Encode()
287 http.Redirect(w, r, redirectURL.String(), http.StatusFound)
288 return
289 }
290 log.Println("Error retrieving scopes:", err)
291 q.Add("error", "server_error")
292 redirectURL.RawQuery = q.Encode()
293 http.Redirect(w, r, redirectURL.String(), http.StatusFound)
294 return
295 */
296 if r.Method == "POST" {
297 if checkCSRF(r, session) != nil {
298 log.Println("CSRF attempt detected.")
299 w.WriteHeader(http.StatusInternalServerError)
300 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
301 "error": template.HTML("There was an error authenticating your request."),
302 })
303 return
304 }
305 if r.PostFormValue("grant") == "approved" {
306 var fragment bool
307 switch responseType {
308 case "code":
309 code := make([]byte, 16)
310 _, err := io.ReadFull(rand.Reader, code)
311 if err != nil {
312 log.Printf("Error generating code: %#+v\n", err)
313 q.Add("error", "server_error")
314 break
315 }
316 authCode := AuthorizationCode{
317 Code: hex.EncodeToString(code),
318 Created: time.Now(),
319 ExpiresIn: defaultAuthorizationCodeExpiration,
320 ClientID: clientID,
321 Scopes: scopes,
322 RedirectURI: r.URL.Query().Get("redirect_uri"),
323 State: state,
324 ProfileID: session.ProfileID,
325 }
326 err = context.SaveAuthorizationCode(authCode)
327 if err != nil {
328 log.Println("Error saving authorization code:", err)
329 q.Add("error", "server_error")
330 break
331 }
332 q.Add("code", authCode.Code)
333 case "token":
334 token := Token{
335 Created: time.Now(),
336 CreatedFrom: "implicit",
337 ExpiresIn: defaultTokenExpiration,
338 TokenType: "bearer",
339 Scopes: scopes,
340 ProfileID: session.ProfileID,
341 ClientID: clientID,
342 }
343 access, err := token.GenerateAccessToken(context.config.JWTPrivateKey)
344 if err != nil {
345 log.Printf("Error signing token: %+v\n", err)
346 q.Add("error", "server_error")
347 break
348 }
349 token.AccessToken = access
350 err = context.SaveToken(token)
351 if err != nil {
352 log.Println("Error saving token:", err)
353 q.Add("error", "server_error")
354 break
355 }
356 q = url.Values{} // we're not altering the querystring, so don't clone it
357 q.Add("access_token", token.AccessToken)
358 q.Add("token_type", token.TokenType)
359 q.Add("expires_in", strconv.FormatInt(int64(token.ExpiresIn), 10))
360 q.Add("scope", strings.Join(token.Scopes.Strings(), " "))
361 q.Add("state", state) // we wiped out the old values, so we need to set the state again
362 fragment = true
363 }
364 if fragment {
365 redirectURL.Fragment = q.Encode()
366 } else {
367 redirectURL.RawQuery = q.Encode()
368 }
369 http.Redirect(w, r, redirectURL.String(), http.StatusFound)
370 return
371 }
372 q.Add("error", "access_denied")
373 redirectURL.RawQuery = q.Encode()
374 http.Redirect(w, r, redirectURL.String(), http.StatusFound)
375 return
376 }
377 profile, err := context.GetProfileByID(session.ProfileID)
378 if err != nil {
379 log.Println("Error getting profile from session:", err)
380 q.Add("error", "server_error")
381 redirectURL.RawQuery = q.Encode()
382 http.Redirect(w, r, redirectURL.String(), http.StatusFound)
383 return
384 }
385 w.WriteHeader(http.StatusOK)
386 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
387 "client": client,
388 "redirectURL": redirectURL,
389 "scopes": scopes,
390 "profile": profile,
391 "csrftoken": session.CSRFToken,
392 })
393 }
395 // GetTokenHandler allows a client to exchange an authorization grant for an
396 // access token. See RFC 6749 Section 4.1.3.
397 func GetTokenHandler(w http.ResponseWriter, r *http.Request, context Context) {
398 enc := json.NewEncoder(w)
399 grantType := r.PostFormValue("grant_type")
400 gt, ok := findGrantType(grantType)
401 if !ok {
402 w.WriteHeader(http.StatusBadRequest)
403 renderJSONError(enc, "invalid_request")
404 return
405 }
406 clientID, success := verifyClient(w, r, gt.AllowsPublic, context)
407 if !success {
408 return
409 }
410 scopes, profileID, valid := gt.Validate(w, r, context)
411 if !valid {
412 return
413 }
414 refresh := ""
415 if gt.IssuesRefresh {
416 refresh = uuid.NewID().String()
417 }
418 token := Token{
419 AccessToken: uuid.NewID().String(),
420 RefreshToken: refresh,
421 Created: time.Now(),
422 CreatedFrom: gt.AuditString(r),
423 ExpiresIn: defaultTokenExpiration,
424 TokenType: "bearer",
425 Scopes: scopes,
426 ProfileID: profileID,
427 ClientID: clientID,
428 }
429 access, err := token.GenerateAccessToken(context.config.JWTPrivateKey)
430 if err != nil {
431 log.Printf("Error signing token: %+v\n", err)
432 w.WriteHeader(http.StatusInternalServerError)
433 renderJSONError(enc, "server_error")
434 return
435 }
436 token.AccessToken = access
437 err = context.SaveToken(token)
438 if err != nil {
439 w.WriteHeader(http.StatusInternalServerError)
440 renderJSONError(enc, "server_error")
441 return
442 }
443 if gt.ReturnToken(w, r, token, context) && gt.Invalidate != nil {
444 go gt.Invalidate(r, context)
445 }
446 }