gotosocial/internal/api/client/auth/authorize.go
2021-07-07 15:46:42 +02:00

210 lines
7.4 KiB
Go

/*
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 auth
import (
"errors"
"fmt"
"net/http"
"net/url"
"github.com/gin-contrib/sessions"
"github.com/gin-gonic/gin"
"github.com/sirupsen/logrus"
"github.com/superseriousbusiness/gotosocial/internal/api/model"
"github.com/superseriousbusiness/gotosocial/internal/db"
"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
)
// 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 *Module) AuthorizeGETHandler(c *gin.Context) {
l := m.log.WithField("func", "AuthorizeGETHandler")
s := sessions.Default(c)
s.Options(sessions.Options{
MaxAge: 120, // give the user 2 minutes to sign in before expiring their session
})
// 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 := &gtsmodel.Application{
ClientID: clientID,
}
if err := m.db.GetWhere([]db.Where{{Key: "client_id", Value: 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 := &gtsmodel.User{
ID: userID,
}
if err := m.db.GetByID(user.ID, user); err != nil {
c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
return
}
acct := &gtsmodel.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 *Module) AuthorizePOSTHandler(c *gin.Context) {
l := m.log.WithField("func", "AuthorizePOSTHandler")
s := sessions.Default(c)
// 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()
if err := s.Save(); err != nil {
c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
return
}
// 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.server.HandleAuthorizeRequest(c.Writer, c.Request); err != nil {
c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
}
}
// 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 := &model.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()
}