You might see that the Dropbox Community team have been busy working on some major updates to the Community itself! So, here is some info on what’s changed, what’s staying the same and what you can expect from the Dropbox Community overall.

Forum Discussion

Miikka's avatar
Miikka
Explorer | Level 3
3 years ago

Violation of RFC2616 on some of the Dropbox servers in relation to authentication page

Hello,

 

Since 19th of January 2022 the Dropbox backend servers have started to respond differently to the HTTP request to https://www.dropbox.com/oauth2/authorize?client_id=[censored] - at least some (if not all) of the servers responding add the header:

"Content-Encoding: br"

... i.e. utilize the br-compression for the returned response, even if the requesting client has set only:

“Accept-encoding: gzip, deflate”

Based on RFC 2616, server should obey the guidance given by the client on supported transfer-encodings.

In practice, this makes the login page access fail for clients (browsers) which do not have the "br" support enabled or supported.

The content which seems to use br compression always is coming from the server https://cfl.dropboxstatic.com/static/css - which are refered by the dropbox.com main login page.

 

This is a problem for a device in market currently, all new Dropbox logins fail.

 

Can you please see that the backend servers would work as IETF RFCs dictate - i.e. if client does not promote support for br encoding, do not force it.

 

Thank you and best regards,

Miikka

 

  • This should be working properly again now. Please let us know if you're still seeing any issues. Thanks!

  • Здравко's avatar
    Здравко
    Legendary | Level 20

    Hmm... 🤔 Yes, that's correct. There is some misconfiguration probably.

    Just for more reference follows example request:

    GET /static/fonts/opensans/OpenSans-Bold-webfont.ttf HTTP/2
    Host: cfl.dropboxstatic.com
    User-Agent: Utility
    Accept: application/font-woff2;q=1.0,application/font-woff;q=0.9,*/*;q=0.8
    Accept-Language: en-US;q=0.7,en;q=0.3
    Accept-Encoding: gzip, deflate
    Origin: null
    DNT: 1
    Connection: keep-alive
    Sec-Fetch-Dest: font
    Sec-Fetch-Mode: no-cors
    Sec-Fetch-Site: cross-site
    Pragma: no-cache
    Cache-Control: no-cache
    TE: trailers

    ... and corresponding response coming from Dropbox:

    HTTP/2 200 OK
    date: Fri, 21 Jan 2022 13:04:38 GMT
    content-type: application/x-font-ttf
    last-modified: Mon, 10 Jan 2022 18:30:05 GMT
    vary: Accept-Encoding
    etag: W/"61dc7b2d-2892c"
    x-dropbox-request-id: b26e2c1dffc9fdf9cc92a2bb53939e94
    x-content-type-options: nosniff
    expires: Fri, 21 Jan 2022 15:51:03 GMT
    cache-control: max-age=86400
    access-control-allow-origin: *
    timing-allow-origin: https://www.dropbox.com
    content-encoding: br
    cf-cache-status: HIT
    age: 73841
    expect-ct: max-age=604800, report-uri="https://report-uri.cloudflare.com/cdn-cgi/beacon/expect-ct"
    server: cloudflare
    cf-ray: 6d10bfe0cd898ef3-SOF
    X-Firefox-Spdy: h2

    🤷 Technical support staff should fix this!

    • Greg-DB's avatar
      Greg-DB
      Icon for Dropbox Staff rankDropbox Staff

      Thanks for the detailed report! I'm raising this with the team. I'll follow up here once I have an update on this.

      • Greg-DB's avatar
        Greg-DB
        Icon for Dropbox Staff rankDropbox Staff

        This should be working properly again now. Please let us know if you're still seeing any issues. Thanks!

About Dropbox API Support & Feedback

Node avatar for Dropbox API Support & Feedback

Find help with the Dropbox API from other developers.

5,910 PostsLatest Activity: 4 days ago
333 Following

If you need more help you can view your support options (expected response time for an email or ticket is 24 hours), or contact us on X or Facebook.

For more info on available support options for your Dropbox plan, see this article.

If you found the answer to your question in this Community thread, please 'like' the post to say thanks and to let us know it was useful!