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Diffstat (limited to 'internal/module/oauth/oauth.go')
| -rw-r--r-- | internal/module/oauth/oauth.go | 510 |
1 files changed, 510 insertions, 0 deletions
diff --git a/internal/module/oauth/oauth.go b/internal/module/oauth/oauth.go new file mode 100644 index 000000000..4436f7a8d --- /dev/null +++ b/internal/module/oauth/oauth.go @@ -0,0 +1,510 @@ +/* + GoToSocial + Copyright (C) 2021 GoToSocial Authors admin@gotosocial.org + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU Affero General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU Affero General Public License for more details. + + You should have received a copy of the GNU Affero General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +// Package oauth is a module that provides oauth functionality to a router. +// It adds the following paths: +// /api/v1/apps +// /auth/sign_in +// /oauth/token +// /oauth/authorize +// It also includes the oauthTokenMiddleware, which can be attached to a router to authenticate every request by Bearer token. +package oauth + +import ( + "fmt" + "net/http" + "net/url" + + "github.com/gin-contrib/sessions" + "github.com/gin-gonic/gin" + "github.com/google/uuid" + "github.com/gotosocial/gotosocial/internal/db" + "github.com/gotosocial/gotosocial/internal/gtsmodel" + "github.com/gotosocial/gotosocial/internal/module" + "github.com/gotosocial/gotosocial/internal/router" + "github.com/gotosocial/gotosocial/pkg/mastotypes" + "github.com/gotosocial/oauth2/v4" + "github.com/gotosocial/oauth2/v4/errors" + "github.com/gotosocial/oauth2/v4/manage" + "github.com/gotosocial/oauth2/v4/server" + "github.com/sirupsen/logrus" + "golang.org/x/crypto/bcrypt" +) + +const ( + appsPath = "/api/v1/apps" + authSignInPath = "/auth/sign_in" + oauthTokenPath = "/oauth/token" + oauthAuthorizePath = "/oauth/authorize" +) + +// oauthModule is an oauth2 oauthModule that satisfies the ClientAPIModule interface +type oauthModule struct { + oauthManager *manage.Manager + oauthServer *server.Server + db db.DB + log *logrus.Logger +} + +type login struct { + Email string `form:"username"` + Password string `form:"password"` +} + +// New returns a new oauth module +func New(ts oauth2.TokenStore, cs oauth2.ClientStore, db db.DB, log *logrus.Logger) module.ClientAPIModule { + manager := manage.NewDefaultManager() + manager.MapTokenStorage(ts) + manager.MapClientStorage(cs) + manager.SetAuthorizeCodeTokenCfg(manage.DefaultAuthorizeCodeTokenCfg) + sc := &server.Config{ + TokenType: "Bearer", + // Must follow the spec. + AllowGetAccessRequest: false, + // Support only the non-implicit flow. + AllowedResponseTypes: []oauth2.ResponseType{oauth2.Code}, + // Allow: + // - Authorization Code (for first & third parties) + AllowedGrantTypes: []oauth2.GrantType{ + oauth2.AuthorizationCode, + }, + AllowedCodeChallengeMethods: []oauth2.CodeChallengeMethod{oauth2.CodeChallengePlain}, + } + + srv := server.NewServer(sc, manager) + srv.SetInternalErrorHandler(func(err error) *errors.Response { + log.Errorf("internal oauth error: %s", err) + return nil + }) + + srv.SetResponseErrorHandler(func(re *errors.Response) { + log.Errorf("internal response error: %s", re.Error) + }) + + m := &oauthModule{ + oauthManager: manager, + oauthServer: srv, + db: db, + log: log, + } + + m.oauthServer.SetUserAuthorizationHandler(m.userAuthorizationHandler) + m.oauthServer.SetClientInfoHandler(server.ClientFormHandler) + return m +} + +// Route satisfies the RESTAPIModule interface +func (m *oauthModule) Route(s router.Router) error { + s.AttachHandler(http.MethodPost, appsPath, m.appsPOSTHandler) + + s.AttachHandler(http.MethodGet, authSignInPath, m.signInGETHandler) + s.AttachHandler(http.MethodPost, authSignInPath, m.signInPOSTHandler) + + s.AttachHandler(http.MethodPost, oauthTokenPath, m.tokenPOSTHandler) + + s.AttachHandler(http.MethodGet, oauthAuthorizePath, m.authorizeGETHandler) + s.AttachHandler(http.MethodPost, oauthAuthorizePath, m.authorizePOSTHandler) + + s.AttachMiddleware(m.oauthTokenMiddleware) + + return nil +} + +/* + MAIN HANDLERS -- serve these through a server/router +*/ + +// appsPOSTHandler should be served at https://example.org/api/v1/apps +// It is equivalent to: https://docs.joinmastodon.org/methods/apps/ +func (m *oauthModule) appsPOSTHandler(c *gin.Context) { + l := m.log.WithField("func", "AppsPOSTHandler") + l.Trace("entering AppsPOSTHandler") + + form := &mastotypes.ApplicationPOSTRequest{} + if err := c.ShouldBind(form); err != nil { + c.JSON(http.StatusUnprocessableEntity, gin.H{"error": err.Error()}) + return + } + + // permitted length for most fields + permittedLength := 64 + // redirect can be a bit bigger because we probably need to encode data in the redirect uri + permittedRedirect := 256 + + // check lengths of fields before proceeding so the user can't spam huge entries into the database + if len(form.ClientName) > permittedLength { + c.JSON(http.StatusBadRequest, gin.H{"error": fmt.Sprintf("client_name must be less than %d bytes", permittedLength)}) + return + } + if len(form.Website) > permittedLength { + c.JSON(http.StatusBadRequest, gin.H{"error": fmt.Sprintf("website must be less than %d bytes", permittedLength)}) + return + } + if len(form.RedirectURIs) > permittedRedirect { + c.JSON(http.StatusBadRequest, gin.H{"error": fmt.Sprintf("redirect_uris must be less than %d bytes", permittedRedirect)}) + return + } + if len(form.Scopes) > permittedLength { + c.JSON(http.StatusBadRequest, gin.H{"error": fmt.Sprintf("scopes must be less than %d bytes", permittedLength)}) + return + } + + // set default 'read' for scopes if it's not set, this follows the default of the mastodon api https://docs.joinmastodon.org/methods/apps/ + var scopes string + if form.Scopes == "" { + scopes = "read" + } else { + scopes = form.Scopes + } + + // generate new IDs for this application and its associated client + clientID := uuid.NewString() + clientSecret := uuid.NewString() + vapidKey := uuid.NewString() + + // generate the application to put in the database + app := >smodel.Application{ + Name: form.ClientName, + Website: form.Website, + RedirectURI: form.RedirectURIs, + ClientID: clientID, + ClientSecret: clientSecret, + Scopes: scopes, + VapidKey: vapidKey, + } + + // chuck it in the db + if err := m.db.Put(app); err != nil { + c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()}) + return + } + + // now we need to model an oauth client from the application that the oauth library can use + oc := &oauthClient{ + ID: clientID, + Secret: clientSecret, + Domain: form.RedirectURIs, + UserID: "", // This client isn't yet associated with a specific user, it's just an app client right now + } + + // chuck it in the db + if err := m.db.Put(oc); err != nil { + c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()}) + return + } + + // done, return the new app information per the spec here: https://docs.joinmastodon.org/methods/apps/ + c.JSON(http.StatusOK, app.ToMastotype()) +} + +// signInGETHandler should be served at https://example.org/auth/sign_in. +// The idea is to present a sign in page to the user, where they can enter their username and password. +// The form will then POST to the sign in page, which will be handled by SignInPOSTHandler +func (m *oauthModule) signInGETHandler(c *gin.Context) { + m.log.WithField("func", "SignInGETHandler").Trace("serving sign in html") + c.HTML(http.StatusOK, "sign-in.tmpl", gin.H{}) +} + +// signInPOSTHandler should be served at https://example.org/auth/sign_in. +// The idea is to present a sign in page to the user, where they can enter their username and password. +// The handler will then redirect to the auth handler served at /auth +func (m *oauthModule) signInPOSTHandler(c *gin.Context) { + l := m.log.WithField("func", "SignInPOSTHandler") + s := sessions.Default(c) + form := &login{} + if err := c.ShouldBind(form); err != nil { + c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()}) + return + } + l.Tracef("parsed form: %+v", form) + + userid, err := m.validatePassword(form.Email, form.Password) + if err != nil { + c.String(http.StatusForbidden, err.Error()) + return + } + + s.Set("userid", userid) + if err := s.Save(); err != nil { + c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()}) + return + } + + l.Trace("redirecting to auth page") + c.Redirect(http.StatusFound, oauthAuthorizePath) +} + +// tokenPOSTHandler should be served as a POST at https://example.org/oauth/token +// The idea here is to serve an oauth access token to a user, which can be used for authorizing against non-public APIs. +// See https://docs.joinmastodon.org/methods/apps/oauth/#obtain-a-token +func (m *oauthModule) tokenPOSTHandler(c *gin.Context) { + l := m.log.WithField("func", "TokenPOSTHandler") + l.Trace("entered TokenPOSTHandler") + if err := m.oauthServer.HandleTokenRequest(c.Writer, c.Request); err != nil { + c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()}) + } +} + +// authorizeGETHandler should be served as GET at https://example.org/oauth/authorize +// The idea here is to present an oauth authorize page to the user, with a button +// that they have to click to accept. See here: https://docs.joinmastodon.org/methods/apps/oauth/#authorize-a-user +func (m *oauthModule) authorizeGETHandler(c *gin.Context) { + l := m.log.WithField("func", "AuthorizeGETHandler") + s := sessions.Default(c) + + // UserID will be set in the session by AuthorizePOSTHandler if the caller has already gone through the authentication flow + // If it's not set, then we don't know yet who the user is, so we need to redirect them to the sign in page. + userID, ok := s.Get("userid").(string) + if !ok || userID == "" { + l.Trace("userid was empty, parsing form then redirecting to sign in page") + if err := parseAuthForm(c, l); err != nil { + c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()}) + } else { + c.Redirect(http.StatusFound, authSignInPath) + } + return + } + + // We can use the client_id on the session to retrieve info about the app associated with the client_id + clientID, ok := s.Get("client_id").(string) + if !ok || clientID == "" { + c.JSON(http.StatusInternalServerError, gin.H{"error": "no client_id found in session"}) + return + } + app := >smodel.Application{ + ClientID: clientID, + } + if err := m.db.GetWhere("client_id", app.ClientID, app); err != nil { + c.JSON(http.StatusInternalServerError, gin.H{"error": fmt.Sprintf("no application found for client id %s", clientID)}) + return + } + + // we can also use the userid of the user to fetch their username from the db to greet them nicely <3 + user := >smodel.User{ + ID: userID, + } + if err := m.db.GetByID(user.ID, user); err != nil { + c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()}) + return + } + + acct := >smodel.Account{ + ID: user.AccountID, + } + + if err := m.db.GetByID(acct.ID, acct); err != nil { + c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()}) + return + } + + // Finally we should also get the redirect and scope of this particular request, as stored in the session. + redirect, ok := s.Get("redirect_uri").(string) + if !ok || redirect == "" { + c.JSON(http.StatusInternalServerError, gin.H{"error": "no redirect_uri found in session"}) + return + } + scope, ok := s.Get("scope").(string) + if !ok || scope == "" { + c.JSON(http.StatusInternalServerError, gin.H{"error": "no scope found in session"}) + return + } + + // the authorize template will display a form to the user where they can get some information + // about the app that's trying to authorize, and the scope of the request. + // They can then approve it if it looks OK to them, which will POST to the AuthorizePOSTHandler + l.Trace("serving authorize html") + c.HTML(http.StatusOK, "authorize.tmpl", gin.H{ + "appname": app.Name, + "appwebsite": app.Website, + "redirect": redirect, + "scope": scope, + "user": acct.Username, + }) +} + +// authorizePOSTHandler should be served as POST at https://example.org/oauth/authorize +// At this point we assume that the user has A) logged in and B) accepted that the app should act for them, +// so we should proceed with the authentication flow and generate an oauth token for them if we can. +// See here: https://docs.joinmastodon.org/methods/apps/oauth/#authorize-a-user +func (m *oauthModule) authorizePOSTHandler(c *gin.Context) { + l := m.log.WithField("func", "AuthorizePOSTHandler") + s := sessions.Default(c) + + // At this point we know the user has said 'yes' to allowing the application and oauth client + // work for them, so we can set the + + // We need to retrieve the original form submitted to the authorizeGEThandler, and + // recreate it on the request so that it can be used further by the oauth2 library. + // So first fetch all the values from the session. + forceLogin, ok := s.Get("force_login").(string) + if !ok { + c.JSON(http.StatusBadRequest, gin.H{"error": "session missing force_login"}) + return + } + responseType, ok := s.Get("response_type").(string) + if !ok || responseType == "" { + c.JSON(http.StatusBadRequest, gin.H{"error": "session missing response_type"}) + return + } + clientID, ok := s.Get("client_id").(string) + if !ok || clientID == "" { + c.JSON(http.StatusBadRequest, gin.H{"error": "session missing client_id"}) + return + } + redirectURI, ok := s.Get("redirect_uri").(string) + if !ok || redirectURI == "" { + c.JSON(http.StatusBadRequest, gin.H{"error": "session missing redirect_uri"}) + return + } + scope, ok := s.Get("scope").(string) + if !ok { + c.JSON(http.StatusBadRequest, gin.H{"error": "session missing scope"}) + return + } + userID, ok := s.Get("userid").(string) + if !ok { + c.JSON(http.StatusBadRequest, gin.H{"error": "session missing userid"}) + return + } + // we're done with the session so we can clear it now + s.Clear() + + // now set the values on the request + values := url.Values{} + values.Set("force_login", forceLogin) + values.Set("response_type", responseType) + values.Set("client_id", clientID) + values.Set("redirect_uri", redirectURI) + values.Set("scope", scope) + values.Set("userid", userID) + c.Request.Form = values + l.Tracef("values on request set to %+v", c.Request.Form) + + // and proceed with authorization using the oauth2 library + if err := m.oauthServer.HandleAuthorizeRequest(c.Writer, c.Request); err != nil { + c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()}) + } +} + +/* + MIDDLEWARE +*/ + +// oauthTokenMiddleware +func (m *oauthModule) oauthTokenMiddleware(c *gin.Context) { + l := m.log.WithField("func", "ValidatePassword") + l.Trace("entering OauthTokenMiddleware") + if ti, err := m.oauthServer.ValidationBearerToken(c.Request); err == nil { + l.Tracef("authenticated user %s with bearer token, scope is %s", ti.GetUserID(), ti.GetScope()) + c.Set("authenticated_user", ti.GetUserID()) + + } else { + l.Trace("continuing with unauthenticated request") + } +} + +/* + SUB-HANDLERS -- don't serve these directly, they should be attached to the oauth2 server or used inside handler funcs +*/ + +// validatePassword takes an email address and a password. +// The goal is to authenticate the password against the one for that email +// address stored in the database. If OK, we return the userid (a uuid) for that user, +// so that it can be used in further Oauth flows to generate a token/retreieve an oauth client from the db. +func (m *oauthModule) validatePassword(email string, password string) (userid string, err error) { + l := m.log.WithField("func", "ValidatePassword") + + // make sure an email/password was provided and bail if not + if email == "" || password == "" { + l.Debug("email or password was not provided") + return incorrectPassword() + } + + // first we select the user from the database based on email address, bail if no user found for that email + gtsUser := >smodel.User{} + + if err := m.db.GetWhere("email", email, gtsUser); err != nil { + l.Debugf("user %s was not retrievable from db during oauth authorization attempt: %s", email, err) + return incorrectPassword() + } + + // make sure a password is actually set and bail if not + if gtsUser.EncryptedPassword == "" { + l.Warnf("encrypted password for user %s was empty for some reason", gtsUser.Email) + return incorrectPassword() + } + + // compare the provided password with the encrypted one from the db, bail if they don't match + if err := bcrypt.CompareHashAndPassword([]byte(gtsUser.EncryptedPassword), []byte(password)); err != nil { + l.Debugf("password hash didn't match for user %s during login attempt: %s", gtsUser.Email, err) + return incorrectPassword() + } + + // If we've made it this far the email/password is correct, so we can just return the id of the user. + userid = gtsUser.ID + l.Tracef("returning (%s, %s)", userid, err) + return +} + +// incorrectPassword is just a little helper function to use in the ValidatePassword function +func incorrectPassword() (string, error) { + return "", errors.New("password/email combination was incorrect") +} + +// userAuthorizationHandler gets the user's ID from the 'userid' field of the request form, +// or redirects to the /auth/sign_in page, if this key is not present. +func (m *oauthModule) userAuthorizationHandler(w http.ResponseWriter, r *http.Request) (userID string, err error) { + l := m.log.WithField("func", "UserAuthorizationHandler") + userID = r.FormValue("userid") + if userID == "" { + return "", errors.New("userid was empty, redirecting to sign in page") + } + l.Tracef("returning userID %s", userID) + return userID, err +} + +// parseAuthForm parses the OAuthAuthorize form in the gin context, and stores +// the values in the form into the session. +func parseAuthForm(c *gin.Context, l *logrus.Entry) error { + s := sessions.Default(c) + + // first make sure they've filled out the authorize form with the required values + form := &mastotypes.OAuthAuthorize{} + if err := c.ShouldBind(form); err != nil { + return err + } + l.Tracef("parsed form: %+v", form) + + // these fields are *required* so check 'em + if form.ResponseType == "" || form.ClientID == "" || form.RedirectURI == "" { + return errors.New("missing one of: response_type, client_id or redirect_uri") + } + + // set default scope to read + if form.Scope == "" { + form.Scope = "read" + } + + // save these values from the form so we can use them elsewhere in the session + s.Set("force_login", form.ForceLogin) + s.Set("response_type", form.ResponseType) + s.Set("client_id", form.ClientID) + s.Set("redirect_uri", form.RedirectURI) + s.Set("scope", form.Scope) + return s.Save() +} |