Files
team/server/channels/api4/integration_action.go
e3a0587a29 Harden post action request verification (#36840)
* MM-69065 - Authorize post actions against the target post's channel

Require a supplied action cookie to belong to the post named in the request so the authorized channel always matches the channel where the action runs.

* Rename test client variable to nonMember

---------

Co-authored-by: Hanzo Dev <[email protected]>
2026-06-03 08:41:01 -04:00

230 lines
6.7 KiB
Go

// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
// See LICENSE.txt for license information.
package api4
import (
"encoding/json"
"errors"
"io"
"net/http"
"github.com/mattermost/mattermost/server/public/model"
"github.com/mattermost/mattermost/server/public/shared/mlog"
)
func (api *API) InitAction() {
api.BaseRoutes.Post.Handle("/actions/{action_id:[A-Za-z0-9]+}", api.APISessionRequired(doPostAction)).Methods(http.MethodPost)
api.BaseRoutes.APIRoot.Handle("/actions/dialogs/open", api.APIHandler(openDialog)).Methods(http.MethodPost)
api.BaseRoutes.APIRoot.Handle("/actions/dialogs/submit", api.APISessionRequired(submitDialog)).Methods(http.MethodPost)
api.BaseRoutes.APIRoot.Handle("/actions/dialogs/lookup", api.APISessionRequired(lookupDialog)).Methods(http.MethodPost)
}
func doPostAction(c *Context, w http.ResponseWriter, r *http.Request) {
c.RequirePostId()
if c.Err != nil {
return
}
var actionRequest model.DoPostActionRequest
dec := json.NewDecoder(r.Body)
err := dec.Decode(&actionRequest)
if err != nil && !errors.Is(err, io.EOF) {
// Empty body is allowed for backward-compatibility with older clients.
// Any other decode failure means the request cannot be trusted — in
// particular, a wrong-type query would otherwise fall through as nil
// and silently execute the action without the caller's params.
c.SetInvalidParamWithErr("action_request", err)
return
}
if err == nil {
// Reject trailing JSON values after the first object (e.g.
// `{"query":{"k":"v"}}{"cookie":"x"}`). json.Decoder.Decode
// stops at the first complete value and would otherwise silently
// ignore the rest, leaving the caller's intent ambiguous.
var trailing any
if extraErr := dec.Decode(&trailing); !errors.Is(extraErr, io.EOF) {
c.SetInvalidParamWithErr("action_request", extraErr)
return
}
}
var cookie *model.PostActionCookie
if actionRequest.Cookie != "" {
cookie = &model.PostActionCookie{}
cookieStr := ""
cookieStr, err = model.DecryptPostActionCookie(actionRequest.Cookie, c.App.PostActionCookieSecret())
if err != nil {
c.Err = model.NewAppError("DoPostAction", "api.post.do_action.action_integration.app_error", nil, "", http.StatusBadRequest).Wrap(err)
return
}
err = json.Unmarshal([]byte(cookieStr), &cookie)
if err != nil {
c.Err = model.NewAppError("DoPostAction", "api.post.do_action.action_integration.app_error", nil, "", http.StatusBadRequest).Wrap(err)
return
}
if cookie.PostId != c.Params.PostId {
c.SetPermissionError(model.PermissionReadChannelContent)
return
}
channel, err := c.App.GetChannel(c.AppContext, cookie.ChannelId)
if err != nil {
c.Err = err
return
}
if ok, _ := c.App.SessionHasPermissionToReadChannel(c.AppContext, *c.AppContext.Session(), channel); !ok {
c.SetPermissionError(model.PermissionReadChannelContent)
return
}
} else {
if ok, _ := c.App.SessionHasPermissionToReadPost(c.AppContext, *c.AppContext.Session(), c.Params.PostId); !ok {
c.SetPermissionError(model.PermissionReadChannelContent)
return
}
}
var appErr *model.AppError
resp := &model.PostActionAPIResponse{Status: "OK"}
resp.TriggerId, appErr = c.App.DoPostActionWithCookie(c.AppContext, c.Params.PostId, c.Params.ActionId, c.AppContext.Session().UserId,
actionRequest.SelectedOption, cookie, actionRequest.Query)
if appErr != nil {
c.Err = appErr
return
}
err = json.NewEncoder(w).Encode(resp)
if err != nil {
c.Logger.Warn("Error writing response", mlog.Err(err))
}
}
func openDialog(c *Context, w http.ResponseWriter, r *http.Request) {
var dialog model.OpenDialogRequest
err := json.NewDecoder(r.Body).Decode(&dialog)
if err != nil {
c.SetInvalidParamWithErr("dialog", err)
return
}
if dialog.URL == "" {
c.SetInvalidParam("url")
return
}
if appErr := c.App.OpenInteractiveDialog(c.AppContext, dialog); appErr != nil {
c.Err = appErr
return
}
ReturnStatusOK(w)
}
func submitDialog(c *Context, w http.ResponseWriter, r *http.Request) {
var submit model.SubmitDialogRequest
jsonErr := json.NewDecoder(r.Body).Decode(&submit)
if jsonErr != nil {
c.SetInvalidParamWithErr("dialog", jsonErr)
return
}
if submit.URL == "" {
c.SetInvalidParam("url")
return
}
submit.UserId = c.AppContext.Session().UserId
channel, err := c.App.GetChannel(c.AppContext, submit.ChannelId)
if err != nil {
c.Err = err
return
}
if ok, _ := c.App.SessionHasPermissionToReadChannel(c.AppContext, *c.AppContext.Session(), channel); !ok {
c.SetPermissionError(model.PermissionReadChannelContent)
return
}
if !c.App.SessionHasPermissionToTeam(*c.AppContext.Session(), submit.TeamId, model.PermissionViewTeam) {
c.SetPermissionError(model.PermissionViewTeam)
return
}
resp, err := c.App.SubmitInteractiveDialog(c.AppContext, submit)
if err != nil {
c.Err = err
return
}
b, _ := json.Marshal(resp)
if _, err := w.Write(b); err != nil {
c.Logger.Warn("Error while writing response", mlog.Err(err))
}
}
// lookupDialog handles API requests for dynamic dialog element lookups.
// It validates the request URL for security, checks user permissions, and
// delegates to the app layer for the actual lookup operation.
func lookupDialog(c *Context, w http.ResponseWriter, r *http.Request) {
var lookup model.SubmitDialogRequest
jsonErr := json.NewDecoder(r.Body).Decode(&lookup)
if jsonErr != nil {
c.SetInvalidParamWithErr("dialog", jsonErr)
return
}
if lookup.URL == "" {
c.SetInvalidParam("url")
return
}
// Validate URL for security
if !model.IsValidLookupURL(lookup.URL) {
c.SetInvalidParam("url")
return
}
lookup.UserId = c.AppContext.Session().UserId
channel, err := c.App.GetChannel(c.AppContext, lookup.ChannelId)
if err != nil {
c.Err = err
return
}
if ok, _ := c.App.SessionHasPermissionToReadChannel(c.AppContext, *c.AppContext.Session(), channel); !ok {
c.SetPermissionError(model.PermissionReadChannelContent)
return
}
if !c.App.SessionHasPermissionToTeam(*c.AppContext.Session(), lookup.TeamId, model.PermissionViewTeam) {
c.SetPermissionError(model.PermissionViewTeam)
return
}
c.Logger.Debug("Performing lookup dialog request",
mlog.String("url", lookup.URL),
mlog.String("user_id", lookup.UserId),
mlog.String("channel_id", lookup.ChannelId),
mlog.String("team_id", lookup.TeamId),
mlog.Any("selected_field", lookup.Submission["selected_field"]),
mlog.Any("query", lookup.Submission["query"]),
)
resp, err := c.App.LookupInteractiveDialog(c.AppContext, lookup)
if err != nil {
c.Logger.Error("Error performing lookup dialog", mlog.Err(err))
c.Err = err
return
}
b, _ := json.Marshal(resp)
if _, err := w.Write(b); err != nil {
c.Logger.Warn("Error while writing response", mlog.Err(err))
}
}