net::ERR_CONTENT_LENGTH_MISMATCH 200 (OK)

[garbast]

When opening a form with an included captcha the captcha is shown at first and after a few seconds it gets replace with an broken image icon and the error

net::ERR_CONTENT_LENGTH_MISMATCH 200 (OK)

Which leads to not being able to solve the captcha.

[maikschneider]

Hey, please tell me the versions you are using.
Additionally, which browser are you using, do you have the same issue when using another?
I see that you are logged into the Backend: Does this happen when you are not logged in as well?

[garbast]

bw_captcha v3.1.0, TYPO3 12.4.9, PHP 8.2.7 with Chrome Version 120.0.6099.129 (Offizieller Build) (64-Bit).

Firefox 103.0.1 (64-Bit) does not complain about the content length.

Whats quirky is, that the error does not appear on refreshing the captcha image. It's wierd.

If the image would not vanish i wouldn't care to much, but currently the captcha is not usable as it is.

[garbast]

The problem only occures on the initial load because the Catcha Middleware only sets the Content-Length if the now parameter isn't set. Now only gets set in the refresh of the captcha. So this behaviour is correct.

I changed from:

            $contentLength = floor((strlen($binaryImage) + 2) / 3) * 4;
            $response = $response->withHeader('Content-Length', (string)$contentLength);

to:

$response = $response->withHeader('Content-Length', (string)strlen($binaryImage));

and the error is gone.

I quite do not get the calculation. The Content-Length should always match the binary values of the response body. So why doing math on the string length at all?

[maikschneider]

Ah, okay you're using an old version. This problem looks like #38 (the fix there introduced the problem). In #46 this should have been resolved. Could you please try to update to 4.0.2 and test again?

[garbast]

Sorry for not checking this first. My composer.json was missing ext-gd which resulted in an older version with composer req. I should have checked this first.