auth

Paddy 2014-12-06 Parent:8630b108ce35 Child:1dc4e152e3b0

84:4cb65cf90217 Go to Latest

auth/oauth2.go

Start supporting our pluggable grant_type. Define GrantType as a way to bundle information that can be used to validate requests based on their grant_type parameter. Move our validation of the authorization_code grant_type out of GetTokenHandler and into its own function. Define RegisterGrantType as a way to register new grant_type bundles and associate them with the string passed to grant_type. This enables other packages to define RegisterGrantType in their init() functions and plug in new grant types without forking this code. Implement RegisterGrantType for our authorization_code grant type.

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paddy@51 1 package auth
paddy@51 2
paddy@51 3 import (
paddy@82 4 "crypto/sha256"
paddy@79 5 "encoding/hex"
paddy@69 6 "encoding/json"
paddy@69 7 "errors"
paddy@61 8 "html/template"
paddy@77 9 "log"
paddy@51 10 "net/http"
paddy@60 11 "net/url"
paddy@84 12 "sync"
paddy@60 13 "time"
paddy@56 14
paddy@69 15 "code.secondbit.org/pass"
paddy@56 16 "code.secondbit.org/uuid"
paddy@82 17
paddy@82 18 "github.com/gorilla/mux"
paddy@51 19 )
paddy@51 20
paddy@60 21 const (
paddy@69 22 authCookieName = "auth"
paddy@69 23 defaultGrantExpiration = 600 // default to ten minute grant expirations
paddy@60 24 getGrantTemplateName = "get_grant"
paddy@60 25 )
paddy@51 26
paddy@69 27 var (
paddy@69 28 // ErrNoAuth is returned when an Authorization header is not present or is empty.
paddy@69 29 ErrNoAuth = errors.New("no authorization header supplied")
paddy@69 30 // ErrInvalidAuthFormat is returned when an Authorization header is present but not the correct format.
paddy@69 31 ErrInvalidAuthFormat = errors.New("authorization header is not in a valid format")
paddy@69 32 // ErrIncorrectAuth is returned when a user authentication attempt does not match the stored values.
paddy@69 33 ErrIncorrectAuth = errors.New("invalid authentication")
paddy@69 34 // ErrInvalidPassphraseScheme is returned when an undefined passphrase scheme is used.
paddy@69 35 ErrInvalidPassphraseScheme = errors.New("invalid passphrase scheme")
paddy@69 36 // ErrNoSession is returned when no session ID is passed with a request.
paddy@69 37 ErrNoSession = errors.New("no session ID found")
paddy@84 38
paddy@84 39 grantTypesMap = grantTypes{types: map[string]GrantType{}}
paddy@69 40 )
paddy@69 41
paddy@84 42 type grantTypes struct {
paddy@84 43 types map[string]GrantType
paddy@84 44 sync.RWMutex
paddy@84 45 }
paddy@84 46
paddy@84 47 // GrantType defines a set of functions and metadata around a specific authorization grant strategy.
paddy@84 48 //
paddy@84 49 // The Validate function will be called when requests are made that match the GrantType, and should write any
paddy@84 50 // errors to the ResponseWriter. It is responsible for determining if the grant is valid and a token should be issued.
paddy@84 51 // 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
paddy@84 52 // is valid or not. It must not be nil.
paddy@84 53 //
paddy@84 54 // The Invalidate function will be called when the grant has successfully generated a token and the token has successfully
paddy@84 55 // been conveyed to the user. The Invalidate function is always called asynchronously, outside the request. It should take
paddy@84 56 // care of marking the grant as used, if the GrantType requires grants to be one-time only grants. The Invalidate function
paddy@84 57 // can be nil.
paddy@84 58 //
paddy@84 59 // IssuesRefresh determines whether the GrantType should yield a refresh token as well as an access token. If true, the client
paddy@84 60 // will be issued a refresh token.
paddy@84 61 type GrantType struct {
paddy@84 62 Validate func(w http.ResponseWriter, r *http.Request, context Context) (scope string, profileID uuid.ID, valid bool)
paddy@84 63 Invalidate func(r *http.Request, context Context) bool
paddy@84 64 IssuesRefresh bool
paddy@84 65 }
paddy@84 66
paddy@69 67 type tokenResponse struct {
paddy@69 68 AccessToken string `json:"access_token"`
paddy@69 69 TokenType string `json:"token_type,omitempty"`
paddy@69 70 ExpiresIn int32 `json:"expires_in,omitempty"`
paddy@69 71 RefreshToken string `json:"refresh_token,omitempty"`
paddy@69 72 }
paddy@69 73
paddy@82 74 type errorResponse struct {
paddy@82 75 Error string `json:"error"`
paddy@82 76 Description string `json:"error_description,omitempty"`
paddy@82 77 URI string `json:"error_uri,omitempty"`
paddy@82 78 }
paddy@82 79
paddy@84 80 // RegisterGrantType associates a string with a GrantType. When the string is used as the value for "grant_type" when obtaining
paddy@84 81 // an access token, the associated GrantType's properties will be used.
paddy@84 82 //
paddy@84 83 // RegisterGrantType should be called in the `init()` function of packages, much like database/sql registers drivers. It will panic
paddy@84 84 // if a GrantType tries to register under a string that already has a GrantType registered for it.
paddy@84 85 func RegisterGrantType(name string, g GrantType) {
paddy@84 86 grantTypesMap.Lock()
paddy@84 87 defer grantTypesMap.Unlock()
paddy@84 88 if _, ok := grantTypesMap.types[name]; ok {
paddy@84 89 panic("Duplicate registration of grant_type " + name)
paddy@84 90 }
paddy@84 91 grantTypesMap.types[name] = g
paddy@84 92 }
paddy@84 93
paddy@84 94 func findGrantType(name string) (GrantType, bool) {
paddy@84 95 grantTypesMap.RLock()
paddy@84 96 defer grantTypesMap.RUnlock()
paddy@84 97 t, ok := grantTypesMap.types[name]
paddy@84 98 return t, ok
paddy@84 99 }
paddy@84 100
paddy@82 101 func renderJSONError(enc *json.Encoder, errorType string) {
paddy@82 102 err := enc.Encode(errorResponse{
paddy@82 103 Error: errorType,
paddy@82 104 })
paddy@82 105 if err != nil {
paddy@82 106 // TODO(paddy): log this or something
paddy@69 107 }
paddy@69 108 }
paddy@69 109
paddy@69 110 func checkCookie(r *http.Request, context Context) (Session, error) {
paddy@69 111 cookie, err := r.Cookie(authCookieName)
paddy@77 112 if err == http.ErrNoCookie {
paddy@77 113 return Session{}, ErrNoSession
paddy@77 114 } else if err != nil {
paddy@77 115 log.Println(err)
paddy@69 116 return Session{}, err
paddy@69 117 }
paddy@69 118 sess, err := context.GetSession(cookie.Value)
paddy@69 119 if err == ErrSessionNotFound {
paddy@69 120 return Session{}, ErrInvalidSession
paddy@69 121 } else if err != nil {
paddy@69 122 return Session{}, err
paddy@69 123 }
paddy@69 124 if !sess.Active {
paddy@69 125 return Session{}, ErrInvalidSession
paddy@69 126 }
paddy@69 127 return sess, nil
paddy@69 128 }
paddy@69 129
paddy@77 130 func buildLoginRedirect(r *http.Request, context Context) string {
paddy@77 131 if context.loginURI == nil {
paddy@77 132 return ""
paddy@77 133 }
paddy@77 134 uri := *context.loginURI
paddy@77 135 q := uri.Query()
paddy@78 136 q.Set("from", r.URL.String())
paddy@77 137 uri.RawQuery = q.Encode()
paddy@77 138 return uri.String()
paddy@77 139 }
paddy@77 140
paddy@69 141 func authenticate(user, passphrase string, context Context) (Profile, error) {
paddy@69 142 profile, err := context.GetProfileByLogin(user)
paddy@69 143 if err != nil {
paddy@79 144 if err == ErrProfileNotFound || err == ErrLoginNotFound {
paddy@69 145 return Profile{}, ErrIncorrectAuth
paddy@69 146 }
paddy@69 147 return Profile{}, err
paddy@69 148 }
paddy@69 149 switch profile.PassphraseScheme {
paddy@69 150 case 1:
paddy@79 151 realPass, err := hex.DecodeString(profile.Passphrase)
paddy@79 152 if err != nil {
paddy@79 153 return Profile{}, err
paddy@79 154 }
paddy@69 155 candidate := pass.Check(sha256.New, profile.Iterations, []byte(passphrase), []byte(profile.Salt))
paddy@79 156 if !pass.Compare(candidate, realPass) {
paddy@69 157 return Profile{}, ErrIncorrectAuth
paddy@69 158 }
paddy@69 159 default:
paddy@69 160 return Profile{}, ErrInvalidPassphraseScheme
paddy@69 161 }
paddy@69 162 return profile, nil
paddy@69 163 }
paddy@69 164
paddy@77 165 func wrap(context Context, f func(w http.ResponseWriter, r *http.Request, context Context)) http.Handler {
paddy@77 166 return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
paddy@77 167 f(w, r, context)
paddy@77 168 })
paddy@77 169 }
paddy@77 170
paddy@77 171 // RegisterOAuth2 adds handlers to the passed router to handle the OAuth2 endpoints.
paddy@77 172 func RegisterOAuth2(r *mux.Router, context Context) {
paddy@77 173 r.Handle("/authorize", wrap(context, GetGrantHandler))
paddy@77 174 r.Handle("/token", wrap(context, GetTokenHandler))
paddy@77 175 }
paddy@77 176
paddy@57 177 // GetGrantHandler presents and processes the page for asking a user to grant access
paddy@57 178 // to their data. See RFC 6749, Section 4.1.
paddy@51 179 func GetGrantHandler(w http.ResponseWriter, r *http.Request, context Context) {
paddy@69 180 session, err := checkCookie(r, context)
paddy@69 181 if err != nil {
paddy@76 182 if err == ErrNoSession || err == ErrInvalidSession {
paddy@77 183 redir := buildLoginRedirect(r, context)
paddy@77 184 if redir == "" {
paddy@77 185 log.Println("No login URL configured.")
paddy@77 186 w.WriteHeader(http.StatusInternalServerError)
paddy@77 187 context.Render(w, getGrantTemplateName, map[string]interface{}{
paddy@77 188 "internal_error": template.HTML("Missing login URL."),
paddy@77 189 })
paddy@77 190 return
paddy@77 191 }
paddy@77 192 http.Redirect(w, r, redir, http.StatusFound)
paddy@77 193 return
paddy@69 194 }
paddy@77 195 log.Println(err.Error())
paddy@77 196 w.WriteHeader(http.StatusInternalServerError)
paddy@77 197 context.Render(w, getGrantTemplateName, map[string]interface{}{
paddy@77 198 "internal_error": template.HTML(err.Error()),
paddy@77 199 })
paddy@77 200 return
paddy@69 201 }
paddy@56 202 if r.URL.Query().Get("client_id") == "" {
paddy@56 203 w.WriteHeader(http.StatusBadRequest)
paddy@56 204 context.Render(w, getGrantTemplateName, map[string]interface{}{
paddy@61 205 "error": template.HTML("Client ID must be specified in the request."),
paddy@56 206 })
paddy@56 207 return
paddy@56 208 }
paddy@56 209 clientID, err := uuid.Parse(r.URL.Query().Get("client_id"))
paddy@56 210 if err != nil {
paddy@56 211 w.WriteHeader(http.StatusBadRequest)
paddy@56 212 context.Render(w, getGrantTemplateName, map[string]interface{}{
paddy@61 213 "error": template.HTML("client_id is not a valid Client ID."),
paddy@56 214 })
paddy@56 215 return
paddy@56 216 }
paddy@64 217 redirectURI := r.URL.Query().Get("redirect_uri")
paddy@64 218 redirectURL, err := url.Parse(redirectURI)
paddy@64 219 if err != nil {
paddy@64 220 w.WriteHeader(http.StatusBadRequest)
paddy@64 221 context.Render(w, getGrantTemplateName, map[string]interface{}{
paddy@64 222 "error": template.HTML("The redirect_uri specified is not valid."),
paddy@64 223 })
paddy@64 224 return
paddy@64 225 }
paddy@56 226 client, err := context.GetClient(clientID)
paddy@56 227 if err != nil {
paddy@59 228 if err == ErrClientNotFound {
paddy@59 229 w.WriteHeader(http.StatusBadRequest)
paddy@59 230 context.Render(w, getGrantTemplateName, map[string]interface{}{
paddy@61 231 "error": template.HTML("The specified Client couldn’t be found."),
paddy@59 232 })
paddy@59 233 } else {
paddy@77 234 log.Println(err.Error())
paddy@59 235 w.WriteHeader(http.StatusInternalServerError)
paddy@59 236 context.Render(w, getGrantTemplateName, map[string]interface{}{
paddy@61 237 "internal_error": template.HTML(err.Error()),
paddy@59 238 })
paddy@59 239 }
paddy@56 240 return
paddy@56 241 }
paddy@56 242 // whether a redirect URI is valid or not depends on the number of endpoints
paddy@56 243 // the client has registered
paddy@56 244 numEndpoints, err := context.CountEndpoints(clientID)
paddy@56 245 if err != nil {
paddy@77 246 log.Println(err.Error())
paddy@56 247 w.WriteHeader(http.StatusInternalServerError)
paddy@56 248 context.Render(w, getGrantTemplateName, map[string]interface{}{
paddy@61 249 "internal_error": template.HTML(err.Error()),
paddy@56 250 })
paddy@56 251 return
paddy@56 252 }
paddy@56 253 var validURI bool
paddy@58 254 if redirectURI != "" {
paddy@58 255 // BUG(paddy): We really should normalize URIs before trying to compare them.
paddy@58 256 validURI, err = context.CheckEndpoint(clientID, redirectURI)
paddy@56 257 if err != nil {
paddy@77 258 log.Println(err.Error())
paddy@56 259 w.WriteHeader(http.StatusInternalServerError)
paddy@56 260 context.Render(w, getGrantTemplateName, map[string]interface{}{
paddy@61 261 "internal_error": template.HTML(err.Error()),
paddy@56 262 })
paddy@56 263 return
paddy@56 264 }
paddy@56 265 } else if redirectURI == "" && numEndpoints == 1 {
paddy@56 266 // if we don't specify the endpoint and there's only one endpoint, the
paddy@56 267 // request is valid, and we're redirecting to that one endpoint
paddy@56 268 validURI = true
paddy@56 269 endpoints, err := context.ListEndpoints(clientID, 1, 0)
paddy@56 270 if err != nil {
paddy@77 271 log.Println(err.Error())
paddy@56 272 w.WriteHeader(http.StatusInternalServerError)
paddy@56 273 context.Render(w, getGrantTemplateName, map[string]interface{}{
paddy@61 274 "internal_error": template.HTML(err.Error()),
paddy@56 275 })
paddy@56 276 return
paddy@56 277 }
paddy@56 278 if len(endpoints) != 1 {
paddy@56 279 validURI = false
paddy@56 280 } else {
paddy@66 281 u := endpoints[0].URI // Copy it here to avoid grabbing a pointer to the memstore
paddy@66 282 redirectURI = u.String()
paddy@66 283 redirectURL = &u
paddy@56 284 }
paddy@56 285 } else {
paddy@56 286 validURI = false
paddy@56 287 }
paddy@56 288 if !validURI {
paddy@56 289 w.WriteHeader(http.StatusBadRequest)
paddy@56 290 context.Render(w, getGrantTemplateName, map[string]interface{}{
paddy@61 291 "error": template.HTML("The redirect_uri specified is not valid."),
paddy@56 292 })
paddy@56 293 return
paddy@56 294 }
paddy@60 295 scope := r.URL.Query().Get("scope")
paddy@60 296 state := r.URL.Query().Get("state")
paddy@56 297 if r.URL.Query().Get("response_type") != "code" {
paddy@65 298 q := redirectURL.Query()
paddy@65 299 q.Add("error", "invalid_request")
paddy@65 300 q.Add("state", state)
paddy@65 301 redirectURL.RawQuery = q.Encode()
paddy@60 302 http.Redirect(w, r, redirectURL.String(), http.StatusFound)
paddy@60 303 return
paddy@56 304 }
paddy@56 305 if r.Method == "POST" {
paddy@63 306 // BUG(paddy): We need to implement CSRF protection when obtaining a grant code.
paddy@56 307 if r.PostFormValue("grant") == "approved" {
paddy@60 308 code := uuid.NewID().String()
paddy@60 309 grant := Grant{
paddy@60 310 Code: code,
paddy@60 311 Created: time.Now(),
paddy@60 312 ExpiresIn: defaultGrantExpiration,
paddy@60 313 ClientID: clientID,
paddy@60 314 Scope: scope,
paddy@69 315 RedirectURI: r.URL.Query().Get("redirect_uri"),
paddy@60 316 State: state,
paddy@69 317 ProfileID: session.ProfileID,
paddy@60 318 }
paddy@60 319 err := context.SaveGrant(grant)
paddy@60 320 if err != nil {
paddy@66 321 q := redirectURL.Query()
paddy@66 322 q.Add("error", "server_error")
paddy@66 323 q.Add("state", state)
paddy@66 324 redirectURL.RawQuery = q.Encode()
paddy@60 325 http.Redirect(w, r, redirectURL.String(), http.StatusFound)
paddy@60 326 return
paddy@60 327 }
paddy@66 328 q := redirectURL.Query()
paddy@66 329 q.Add("code", code)
paddy@66 330 q.Add("state", state)
paddy@66 331 redirectURL.RawQuery = q.Encode()
paddy@60 332 http.Redirect(w, r, redirectURL.String(), http.StatusFound)
paddy@60 333 return
paddy@56 334 }
paddy@66 335 q := redirectURL.Query()
paddy@66 336 q.Add("error", "access_denied")
paddy@66 337 q.Add("state", state)
paddy@66 338 redirectURL.RawQuery = q.Encode()
paddy@60 339 http.Redirect(w, r, redirectURL.String(), http.StatusFound)
paddy@60 340 return
paddy@56 341 }
paddy@51 342 w.WriteHeader(http.StatusOK)
paddy@56 343 context.Render(w, getGrantTemplateName, map[string]interface{}{
paddy@56 344 "client": client,
paddy@56 345 })
paddy@51 346 }
paddy@68 347
paddy@69 348 // GetTokenHandler allows a client to exchange an authorization grant for an
paddy@69 349 // access token. See RFC 6749 Section 4.1.3.
paddy@69 350 func GetTokenHandler(w http.ResponseWriter, r *http.Request, context Context) {
paddy@69 351 enc := json.NewEncoder(w)
paddy@69 352 grantType := r.PostFormValue("grant_type")
paddy@84 353 gt, ok := findGrantType(grantType)
paddy@84 354 if !ok {
paddy@82 355 w.WriteHeader(http.StatusBadRequest)
paddy@82 356 renderJSONError(enc, "invalid_request")
paddy@69 357 return
paddy@69 358 }
paddy@84 359 scope, profileID, valid := gt.Validate(w, r, context)
paddy@84 360 if !valid {
paddy@69 361 return
paddy@69 362 }
paddy@84 363 refresh := ""
paddy@84 364 if gt.IssuesRefresh {
paddy@84 365 refresh = uuid.NewID().String()
paddy@69 366 }
paddy@69 367 token := Token{
paddy@69 368 AccessToken: uuid.NewID().String(),
paddy@84 369 RefreshToken: refresh,
paddy@69 370 Created: time.Now(),
paddy@69 371 ExpiresIn: defaultTokenExpiration,
paddy@81 372 TokenType: "bearer",
paddy@84 373 Scope: scope,
paddy@84 374 ProfileID: profileID,
paddy@69 375 }
paddy@84 376 err := context.SaveToken(token)
paddy@69 377 if err != nil {
paddy@82 378 w.WriteHeader(http.StatusInternalServerError)
paddy@82 379 renderJSONError(enc, "server_error")
paddy@81 380 return
paddy@69 381 }
paddy@69 382 resp := tokenResponse{
paddy@69 383 AccessToken: token.AccessToken,
paddy@69 384 RefreshToken: token.RefreshToken,
paddy@69 385 ExpiresIn: token.ExpiresIn,
paddy@69 386 TokenType: token.TokenType,
paddy@69 387 }
paddy@69 388 err = enc.Encode(resp)
paddy@69 389 if err != nil {
paddy@69 390 // TODO(paddy): log this or something
paddy@69 391 return
paddy@69 392 }
paddy@81 393 // BUG(paddy): we need to invalidate the grant for future requests
paddy@69 394 }
paddy@69 395
paddy@68 396 // TODO(paddy): exchange user credentials for access token
paddy@68 397 // TODO(paddy): exchange client credentials for access token
paddy@68 398 // TODO(paddy): implicit grant for access token
paddy@68 399 // TODO(paddy): exchange refresh token for access token