auth

Paddy 2014-12-14 Parent:b0a759e00e6d Child:bc77a315f823

98:09c47387e455 Go to Latest

auth/oauth2.go

Move login concerns to session, add login handler. Move all our helpers for authenticating, building a login redirect, and reading a cookie to session.go. Rewrite our passphrase scheme code so that a scheme is just a struct with three functions for checking a passphrase against a profile object, generating a passphrase, and calculating the number of iterations to use when generating a passphrase. Define an implementation of our passphrase scheme (scheme #1) using PBKDF2 and SHA256. Add a CreateSessionHandler function that logs the user in using their login and passphrase. Add a RegisterSessionHandlers function that adds the session-related handlers (right now, just our CreateSessionHandler) to the specified router.

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paddy@51 1 package auth
paddy@51 2
paddy@51 3 import (
paddy@69 4 "encoding/json"
paddy@69 5 "errors"
paddy@61 6 "html/template"
paddy@77 7 "log"
paddy@51 8 "net/http"
paddy@60 9 "net/url"
paddy@84 10 "sync"
paddy@60 11 "time"
paddy@56 12
paddy@56 13 "code.secondbit.org/uuid"
paddy@82 14
paddy@82 15 "github.com/gorilla/mux"
paddy@51 16 )
paddy@51 17
paddy@60 18 const (
paddy@87 19 authCookieName = "auth"
paddy@87 20 defaultAuthorizationCodeExpiration = 600 // default to ten minute grant expirations
paddy@87 21 getAuthorizationCodeTemplateName = "get_grant"
paddy@60 22 )
paddy@51 23
paddy@69 24 var (
paddy@69 25 // ErrNoAuth is returned when an Authorization header is not present or is empty.
paddy@69 26 ErrNoAuth = errors.New("no authorization header supplied")
paddy@69 27 // ErrInvalidAuthFormat is returned when an Authorization header is present but not the correct format.
paddy@69 28 ErrInvalidAuthFormat = errors.New("authorization header is not in a valid format")
paddy@69 29 // ErrIncorrectAuth is returned when a user authentication attempt does not match the stored values.
paddy@69 30 ErrIncorrectAuth = errors.New("invalid authentication")
paddy@69 31 // ErrInvalidPassphraseScheme is returned when an undefined passphrase scheme is used.
paddy@69 32 ErrInvalidPassphraseScheme = errors.New("invalid passphrase scheme")
paddy@69 33 // ErrNoSession is returned when no session ID is passed with a request.
paddy@69 34 ErrNoSession = errors.New("no session ID found")
paddy@84 35
paddy@84 36 grantTypesMap = grantTypes{types: map[string]GrantType{}}
paddy@69 37 )
paddy@69 38
paddy@84 39 type grantTypes struct {
paddy@84 40 types map[string]GrantType
paddy@84 41 sync.RWMutex
paddy@84 42 }
paddy@84 43
paddy@84 44 // GrantType defines a set of functions and metadata around a specific authorization grant strategy.
paddy@84 45 //
paddy@84 46 // The Validate function will be called when requests are made that match the GrantType, and should write any
paddy@84 47 // errors to the ResponseWriter. It is responsible for determining if the grant is valid and a token should be issued.
paddy@84 48 // 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 49 // is valid or not. It must not be nil.
paddy@84 50 //
paddy@84 51 // The Invalidate function will be called when the grant has successfully generated a token and the token has successfully
paddy@84 52 // been conveyed to the user. The Invalidate function is always called asynchronously, outside the request. It should take
paddy@84 53 // care of marking the grant as used, if the GrantType requires grants to be one-time only grants. The Invalidate function
paddy@84 54 // can be nil.
paddy@84 55 //
paddy@84 56 // IssuesRefresh determines whether the GrantType should yield a refresh token as well as an access token. If true, the client
paddy@84 57 // will be issued a refresh token.
paddy@85 58 //
paddy@85 59 // The ReturnToken will be called when a token is created and needs to be returned to the client. If it returns true, the token
paddy@85 60 // was successfully returned and the Invalidate function will be called asynchronously.
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@90 63 Invalidate func(r *http.Request, context Context) error
paddy@85 64 ReturnToken func(w http.ResponseWriter, r *http.Request, token Token, context Context) bool
paddy@84 65 IssuesRefresh bool
paddy@84 66 }
paddy@84 67
paddy@69 68 type tokenResponse struct {
paddy@69 69 AccessToken string `json:"access_token"`
paddy@69 70 TokenType string `json:"token_type,omitempty"`
paddy@69 71 ExpiresIn int32 `json:"expires_in,omitempty"`
paddy@69 72 RefreshToken string `json:"refresh_token,omitempty"`
paddy@69 73 }
paddy@69 74
paddy@82 75 type errorResponse struct {
paddy@82 76 Error string `json:"error"`
paddy@82 77 Description string `json:"error_description,omitempty"`
paddy@82 78 URI string `json:"error_uri,omitempty"`
paddy@82 79 }
paddy@82 80
paddy@84 81 // RegisterGrantType associates a string with a GrantType. When the string is used as the value for "grant_type" when obtaining
paddy@84 82 // an access token, the associated GrantType's properties will be used.
paddy@84 83 //
paddy@84 84 // RegisterGrantType should be called in the `init()` function of packages, much like database/sql registers drivers. It will panic
paddy@84 85 // if a GrantType tries to register under a string that already has a GrantType registered for it.
paddy@84 86 func RegisterGrantType(name string, g GrantType) {
paddy@84 87 grantTypesMap.Lock()
paddy@84 88 defer grantTypesMap.Unlock()
paddy@84 89 if _, ok := grantTypesMap.types[name]; ok {
paddy@84 90 panic("Duplicate registration of grant_type " + name)
paddy@84 91 }
paddy@84 92 grantTypesMap.types[name] = g
paddy@84 93 }
paddy@84 94
paddy@84 95 func findGrantType(name string) (GrantType, bool) {
paddy@84 96 grantTypesMap.RLock()
paddy@84 97 defer grantTypesMap.RUnlock()
paddy@84 98 t, ok := grantTypesMap.types[name]
paddy@84 99 return t, ok
paddy@84 100 }
paddy@84 101
paddy@82 102 func renderJSONError(enc *json.Encoder, errorType string) {
paddy@82 103 err := enc.Encode(errorResponse{
paddy@82 104 Error: errorType,
paddy@82 105 })
paddy@82 106 if err != nil {
paddy@90 107 log.Println(err)
paddy@69 108 }
paddy@69 109 }
paddy@69 110
paddy@86 111 // RenderJSONToken is an implementation of the ReturnToken function for GrantTypes. It returns the token using JSON
paddy@86 112 // according to the spec. See RFC 6479, Section 4.1.4.
paddy@85 113 func RenderJSONToken(w http.ResponseWriter, r *http.Request, token Token, context Context) bool {
paddy@85 114 enc := json.NewEncoder(w)
paddy@85 115 resp := tokenResponse{
paddy@85 116 AccessToken: token.AccessToken,
paddy@85 117 RefreshToken: token.RefreshToken,
paddy@85 118 ExpiresIn: token.ExpiresIn,
paddy@85 119 TokenType: token.TokenType,
paddy@85 120 }
paddy@85 121 err := enc.Encode(resp)
paddy@85 122 if err != nil {
paddy@90 123 log.Println(err)
paddy@85 124 return false
paddy@85 125 }
paddy@85 126 return true
paddy@85 127 }
paddy@85 128
paddy@77 129 func wrap(context Context, f func(w http.ResponseWriter, r *http.Request, context Context)) http.Handler {
paddy@77 130 return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
paddy@77 131 f(w, r, context)
paddy@77 132 })
paddy@77 133 }
paddy@77 134
paddy@77 135 // RegisterOAuth2 adds handlers to the passed router to handle the OAuth2 endpoints.
paddy@77 136 func RegisterOAuth2(r *mux.Router, context Context) {
paddy@87 137 r.Handle("/authorize", wrap(context, GetAuthorizationCodeHandler))
paddy@77 138 r.Handle("/token", wrap(context, GetTokenHandler))
paddy@77 139 }
paddy@77 140
paddy@87 141 // GetAuthorizationCodeHandler presents and processes the page for asking a user to grant access
paddy@57 142 // to their data. See RFC 6749, Section 4.1.
paddy@87 143 func GetAuthorizationCodeHandler(w http.ResponseWriter, r *http.Request, context Context) {
paddy@69 144 session, err := checkCookie(r, context)
paddy@69 145 if err != nil {
paddy@76 146 if err == ErrNoSession || err == ErrInvalidSession {
paddy@77 147 redir := buildLoginRedirect(r, context)
paddy@77 148 if redir == "" {
paddy@77 149 log.Println("No login URL configured.")
paddy@77 150 w.WriteHeader(http.StatusInternalServerError)
paddy@87 151 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
paddy@77 152 "internal_error": template.HTML("Missing login URL."),
paddy@77 153 })
paddy@77 154 return
paddy@77 155 }
paddy@77 156 http.Redirect(w, r, redir, http.StatusFound)
paddy@77 157 return
paddy@69 158 }
paddy@77 159 log.Println(err.Error())
paddy@77 160 w.WriteHeader(http.StatusInternalServerError)
paddy@87 161 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
paddy@77 162 "internal_error": template.HTML(err.Error()),
paddy@77 163 })
paddy@77 164 return
paddy@69 165 }
paddy@56 166 if r.URL.Query().Get("client_id") == "" {
paddy@56 167 w.WriteHeader(http.StatusBadRequest)
paddy@87 168 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
paddy@61 169 "error": template.HTML("Client ID must be specified in the request."),
paddy@56 170 })
paddy@56 171 return
paddy@56 172 }
paddy@56 173 clientID, err := uuid.Parse(r.URL.Query().Get("client_id"))
paddy@56 174 if err != nil {
paddy@56 175 w.WriteHeader(http.StatusBadRequest)
paddy@87 176 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
paddy@61 177 "error": template.HTML("client_id is not a valid Client ID."),
paddy@56 178 })
paddy@56 179 return
paddy@56 180 }
paddy@64 181 redirectURI := r.URL.Query().Get("redirect_uri")
paddy@64 182 redirectURL, err := url.Parse(redirectURI)
paddy@64 183 if err != nil {
paddy@64 184 w.WriteHeader(http.StatusBadRequest)
paddy@87 185 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
paddy@64 186 "error": template.HTML("The redirect_uri specified is not valid."),
paddy@64 187 })
paddy@64 188 return
paddy@64 189 }
paddy@56 190 client, err := context.GetClient(clientID)
paddy@56 191 if err != nil {
paddy@59 192 if err == ErrClientNotFound {
paddy@59 193 w.WriteHeader(http.StatusBadRequest)
paddy@87 194 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
paddy@61 195 "error": template.HTML("The specified Client couldn’t be found."),
paddy@59 196 })
paddy@59 197 } else {
paddy@77 198 log.Println(err.Error())
paddy@59 199 w.WriteHeader(http.StatusInternalServerError)
paddy@87 200 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
paddy@61 201 "internal_error": template.HTML(err.Error()),
paddy@59 202 })
paddy@59 203 }
paddy@56 204 return
paddy@56 205 }
paddy@95 206 // TODO(paddy): checking if the redirect URI is valid should be a helper function
paddy@56 207 // whether a redirect URI is valid or not depends on the number of endpoints
paddy@56 208 // the client has registered
paddy@56 209 numEndpoints, err := context.CountEndpoints(clientID)
paddy@56 210 if err != nil {
paddy@77 211 log.Println(err.Error())
paddy@56 212 w.WriteHeader(http.StatusInternalServerError)
paddy@87 213 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
paddy@61 214 "internal_error": template.HTML(err.Error()),
paddy@56 215 })
paddy@56 216 return
paddy@56 217 }
paddy@56 218 var validURI bool
paddy@58 219 if redirectURI != "" {
paddy@58 220 // BUG(paddy): We really should normalize URIs before trying to compare them.
paddy@58 221 validURI, err = context.CheckEndpoint(clientID, redirectURI)
paddy@56 222 if err != nil {
paddy@77 223 log.Println(err.Error())
paddy@56 224 w.WriteHeader(http.StatusInternalServerError)
paddy@87 225 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
paddy@61 226 "internal_error": template.HTML(err.Error()),
paddy@56 227 })
paddy@56 228 return
paddy@56 229 }
paddy@56 230 } else if redirectURI == "" && numEndpoints == 1 {
paddy@56 231 // if we don't specify the endpoint and there's only one endpoint, the
paddy@56 232 // request is valid, and we're redirecting to that one endpoint
paddy@56 233 validURI = true
paddy@56 234 endpoints, err := context.ListEndpoints(clientID, 1, 0)
paddy@56 235 if err != nil {
paddy@77 236 log.Println(err.Error())
paddy@56 237 w.WriteHeader(http.StatusInternalServerError)
paddy@87 238 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
paddy@61 239 "internal_error": template.HTML(err.Error()),
paddy@56 240 })
paddy@56 241 return
paddy@56 242 }
paddy@56 243 if len(endpoints) != 1 {
paddy@56 244 validURI = false
paddy@56 245 } else {
paddy@66 246 u := endpoints[0].URI // Copy it here to avoid grabbing a pointer to the memstore
paddy@66 247 redirectURI = u.String()
paddy@66 248 redirectURL = &u
paddy@56 249 }
paddy@56 250 } else {
paddy@56 251 validURI = false
paddy@56 252 }
paddy@56 253 if !validURI {
paddy@56 254 w.WriteHeader(http.StatusBadRequest)
paddy@87 255 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
paddy@61 256 "error": template.HTML("The redirect_uri specified is not valid."),
paddy@56 257 })
paddy@56 258 return
paddy@56 259 }
paddy@60 260 scope := r.URL.Query().Get("scope")
paddy@60 261 state := r.URL.Query().Get("state")
paddy@56 262 if r.URL.Query().Get("response_type") != "code" {
paddy@65 263 q := redirectURL.Query()
paddy@65 264 q.Add("error", "invalid_request")
paddy@65 265 q.Add("state", state)
paddy@65 266 redirectURL.RawQuery = q.Encode()
paddy@60 267 http.Redirect(w, r, redirectURL.String(), http.StatusFound)
paddy@60 268 return
paddy@56 269 }
paddy@56 270 if r.Method == "POST" {
paddy@63 271 // BUG(paddy): We need to implement CSRF protection when obtaining a grant code.
paddy@56 272 if r.PostFormValue("grant") == "approved" {
paddy@60 273 code := uuid.NewID().String()
paddy@87 274 authCode := AuthorizationCode{
paddy@60 275 Code: code,
paddy@60 276 Created: time.Now(),
paddy@87 277 ExpiresIn: defaultAuthorizationCodeExpiration,
paddy@60 278 ClientID: clientID,
paddy@60 279 Scope: scope,
paddy@69 280 RedirectURI: r.URL.Query().Get("redirect_uri"),
paddy@60 281 State: state,
paddy@69 282 ProfileID: session.ProfileID,
paddy@60 283 }
paddy@87 284 err := context.SaveAuthorizationCode(authCode)
paddy@60 285 if err != nil {
paddy@66 286 q := redirectURL.Query()
paddy@66 287 q.Add("error", "server_error")
paddy@66 288 q.Add("state", state)
paddy@66 289 redirectURL.RawQuery = q.Encode()
paddy@60 290 http.Redirect(w, r, redirectURL.String(), http.StatusFound)
paddy@60 291 return
paddy@60 292 }
paddy@66 293 q := redirectURL.Query()
paddy@66 294 q.Add("code", code)
paddy@66 295 q.Add("state", state)
paddy@66 296 redirectURL.RawQuery = q.Encode()
paddy@60 297 http.Redirect(w, r, redirectURL.String(), http.StatusFound)
paddy@60 298 return
paddy@56 299 }
paddy@66 300 q := redirectURL.Query()
paddy@66 301 q.Add("error", "access_denied")
paddy@66 302 q.Add("state", state)
paddy@66 303 redirectURL.RawQuery = q.Encode()
paddy@60 304 http.Redirect(w, r, redirectURL.String(), http.StatusFound)
paddy@60 305 return
paddy@56 306 }
paddy@85 307 profile, err := context.GetProfileByID(session.ProfileID)
paddy@85 308 if err != nil {
paddy@85 309 q := redirectURL.Query()
paddy@85 310 q.Add("error", "server_error")
paddy@85 311 q.Add("state", state)
paddy@85 312 redirectURL.RawQuery = q.Encode()
paddy@85 313 http.Redirect(w, r, redirectURL.String(), http.StatusFound)
paddy@85 314 return
paddy@85 315 }
paddy@51 316 w.WriteHeader(http.StatusOK)
paddy@87 317 context.Render(w, getAuthorizationCodeTemplateName, map[string]interface{}{
paddy@85 318 "client": client,
paddy@85 319 "redirectURL": redirectURL,
paddy@85 320 "scope": scope,
paddy@85 321 "profile": profile,
paddy@56 322 })
paddy@51 323 }
paddy@68 324
paddy@69 325 // GetTokenHandler allows a client to exchange an authorization grant for an
paddy@69 326 // access token. See RFC 6749 Section 4.1.3.
paddy@69 327 func GetTokenHandler(w http.ResponseWriter, r *http.Request, context Context) {
paddy@69 328 enc := json.NewEncoder(w)
paddy@69 329 grantType := r.PostFormValue("grant_type")
paddy@84 330 gt, ok := findGrantType(grantType)
paddy@84 331 if !ok {
paddy@82 332 w.WriteHeader(http.StatusBadRequest)
paddy@82 333 renderJSONError(enc, "invalid_request")
paddy@69 334 return
paddy@69 335 }
paddy@84 336 scope, profileID, valid := gt.Validate(w, r, context)
paddy@84 337 if !valid {
paddy@69 338 return
paddy@69 339 }
paddy@84 340 refresh := ""
paddy@84 341 if gt.IssuesRefresh {
paddy@84 342 refresh = uuid.NewID().String()
paddy@69 343 }
paddy@69 344 token := Token{
paddy@88 345 AccessToken: uuid.NewID().String(),
paddy@88 346 RefreshToken: refresh,
paddy@88 347 Created: time.Now(),
paddy@88 348 ExpiresIn: defaultTokenExpiration,
paddy@88 349 RefreshExpiresIn: defaultRefreshTokenExpiration,
paddy@88 350 TokenType: "bearer",
paddy@88 351 Scope: scope,
paddy@88 352 ProfileID: profileID,
paddy@69 353 }
paddy@84 354 err := context.SaveToken(token)
paddy@69 355 if err != nil {
paddy@82 356 w.WriteHeader(http.StatusInternalServerError)
paddy@82 357 renderJSONError(enc, "server_error")
paddy@81 358 return
paddy@69 359 }
paddy@85 360 if gt.ReturnToken(w, r, token, context) && gt.Invalidate != nil {
paddy@85 361 go gt.Invalidate(r, context)
paddy@69 362 }
paddy@69 363 }
paddy@69 364
paddy@68 365 // TODO(paddy): exchange user credentials for access token
paddy@68 366 // TODO(paddy): exchange client credentials for access token
paddy@68 367 // TODO(paddy): implicit grant for access token
paddy@68 368 // TODO(paddy): exchange refresh token for access token