Proxy header exceeds server limit

lawsonke
edited 21 days ago
For multiple sites including ScienceDirect, I'm receiving error 400 Bad Request - "Your browser sent a request that this server could not understand. Size of a request header field exceeds server limit." Disabling the Firefox Zotero Connector's proxy redirection allows the site to load, so it's pretty clear this is the issue. My Zotero Connector version is 5.0.164, and I submitted error report ID 918262024 and Debug ID D49609753. I already cleared Firefox's cache and cookies, and confirmed they were cleared entirely for ScienceDirect, with no change to the error.

I'm not seeing this issue in Brave (Chrome-based) even for the same exact article. If it helps, my Zotero Connector version in Chrome is 5.0.164 also. This suggests it might be an issue with the Firefox Zotero Connector.

In general, I find proxy redirection really useful, so I would hate to turn it off entirely for Firefox! It would be great to have an option for "reload without proxy", similar to the current option "reload via proxy". Alternatively, is there a way to specify sites to exclude from the proxy redirect? Thanks!
  • dstillman
    Do you see this with all other browser extensions disabled?
  • lawsonke
    Yes
  • dstillman
    Can you go to Tools → Browser Tools → Web Developer Tools → Network, reproduce this, right-click on the line with a 400 under Status, Save All As HAR, and send the file to support@zotero.org with a link to this thread?
  • lawsonke
    Done - sorry for the delay!
  • dstillman
    edited 3 days ago
    When you say that disabling the Zotero Connector's proxy redirection allows the site to load, you mean not going through the proxy? This error is from your proxy server, so that's not meaningful. You'd want to test manually logging into a site via the same proxy in Firefox.

    The Cookie header being sent — which is determined by the cookies previously set by the proxy server — is indeed over the default limit of 8K characters for this web server, so the error is expected. It's not impossible the Zotero Connector is contributing here, but it looks like your IT department's SSO system just set too many large cookies.

    If a manual proxy request fails with the same error, you should share the HAR file with your IT department.

    In the meantime, I'd guess that clearing cookies for your university domain in Firefox (search for "cookies" in the Firefox settings and click on "Manage Data…") would fix this.
  • dstillman
    edited 3 days ago
    Actually, looking more closely, the error response isn't even from the proxy URL that the Zotero Connector redirects to. It's from some "ezproxyauth" URL that the proxy server itself redirects to, on a different library server — presumably a login page.

    I would expect that you could trigger the same error in Firefox just by trying to load a site via the proxy manually with the Zotero Connector disabled. Assuming that's the case, clearing cookies for your university domain would fix it, but I'd recommend that you first generate a HAR file that way and send it to your IT department without even mentioning Zotero. They need to either fix their system to not set so many large cookies or increase the web server's request header length limit.
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