[jira] [Resolved] (GUACAMOLE-2290) White screen with no error message when localStorage GUAC_AUTH_TOKEN is "undefined"

["Nick Couchman (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/GUACAMOLE-2290?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Nick Couchman resolved GUACAMOLE-2290.
--------------------------------------
    Fix Version/s: 1.6.1 [staging]
       Resolution: Fixed

> White screen with no error message when localStorage GUAC_AUTH_TOKEN is "undefined"
> -----------------------------------------------------------------------------------
>
>                 Key: GUACAMOLE-2290
>                 URL: https://issues.apache.org/jira/browse/GUACAMOLE-2290
>             Project: Guacamole
>          Issue Type: Bug
>          Components: guacamole-client
>            Reporter: Per von Zweigbergk
>            Priority: Major
>             Fix For: 1.6.1 [staging]
>
>
> I have run into an issue where Guacamole fails to load and presents the user with a white screen, instead of the expected login page. Refreshing doesn't resolve the issue.
> After some investigation, I found an error message like this in the Javascript console:
> jquery.min.js:2
>  Uncaught SyntaxError: "undefined" is not valid JSON
>     at JSON.parse (<anonymous>)
>     at a.getItem (localStorageService.js:125:25)
>     at h.getCurrentToken (authenticationService.js:466:36)
>     at h.request (authenticationService.js:536:34)
>     at Object.getLanguages (languageService.js:45:38)
>     at v (translationLoader.js:74:25)
>     at translationLoader.js:149:9
>     at Object.invoke (angular.min.js:45:264)
> The relevant code appears to be here:
> [https://github.com/apache/guacamole-client/blame/27922fe19823942e7bc3a6b70560cebabec44e64/guacamole/src/main/frontend/src/app/storage/services/localStorageService.js#L125]
> Investigating the local storage, the {{GUAC_AUTH_TOKEN}} value seems to be set to the string "undefined" whenever this problem occurs.
> I've not been able to figure out *why* the GUAC_AUTH_TOKEN value is set to "undefined". It could be an interaction with the Barracuda WAF we have in front. But either way, it appears there is a specific bug in this part of the code. There is no proper handling of the exception thrown by the JSON.parse(data) call, if data is invalid JSON (in this case, the string "undefined").
> Either way, the fact that guacamole-client itself chokes in case the GUAC_AUTH_TOKEN value ends up being corrupted is a bug in its own right, and could be easy enough to fix by just handling the SyntaxError exception being thrown by JSON.parse and treating it as an empty value in this case.
> As a workaround, I've been telling my users to run the following command in the Javascript console to clear out this state: {{localStorage.removeItem('GUAC_AUTH_TOKEN');}} and this seems to temporarilly fix the issue, which leads me to believe that adding some guards around JSON parsing and treating an unparsable value as missing would properly mask your problem.
> I'm up submitting a PR for this if this approach to the fix is accepted.



--
This message was sent by Atlassian Jira
(v8.20.10#820010)