The same problem without PHP callback, using CURLOPT_READDATA to read request body from a file:

<?php
$ch = curl_init();
curl_setopt($ch, CURLOPT_POST, true);

// This should be some URL protected by HTTP digest auth!
curl_setopt($ch, CURLOPT_URL, 'http://www.example.com/digest/');
curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_DIGEST);
curl_setopt($ch, CURLOPT_USERPWD, 'user:password');

curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Length: ' . filesize('./postdata')));
curl_setopt($ch, CURLOPT_READDATA, fopen('./postdata', 'rb'));

if (!curl_exec($ch)) {
    echo 'Error #' . curl_errno($ch) . ': ' . curl_error($ch);
}
?>

This also prints "Error #65: necessary data rewind wasn't possible"

This problem not only occurs when negotiating HTTP Auth. It's much 
easier to provoke by posting to a URL that answers with a redirect.

Any valid HTTP redirect (be it 302, 303 or 307) lets curl rewind its 
request body before following the Location header. Thus 
CURLOPT_READFUNCTION is pretty useless for accessing web servers in 
the wild. Therefore I think it's rather a bug than a feature.

Reproduce:
Both examples above with an extra
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
and a URL answering with a redirect.

(Tested with PHP 5.2.9 and curl 7.19.5)


Proposal:
Instead of adding CURLOPT_IOCTLFUNCTION to the PHP extension, this bug 
could be fixed by adding the CURLTOP_SEEKFUNCTION functionality. If 
set, curl uses this to rewind the body, too (see Curl_readrewind() in 
transfer.c). But the seek_func callback is also used for resuming 
uploads which might be a nice side effect.

Marking this as "cURL related" to increase visibility.

Recategorized, this is not a bug.

since, this is a feature, this will probably apply only for 5.3 onwards. 

While adding PHP-side support for CURLOPT_IOCTLFUNCTION is indeed a feature request, complete inability for curl extension to handle redirects / digest authentication when using CURLOPT_INFILE (CURLOPT_READDATA) looks like a genuine bug to me.

The problem lies with Curl extension registering a custom callback curl_read() as CURLOPT_READFUNCTION (it handles both reading from a stream provided as CURLOPT_INFILE and calling PHP callback provided as CURLOPT_READFUNCTION) but failing to implement custom callback for rewinding the data, at least for the case when stream is used.

...also note that while this problem can be worked around by using CURLOPT_POSTFIELDS with POST request, other request methods (e.g. PUT) only allow using CURLOPT_INFILE as request body.

Unknown Error (code: The cURL request was retried 3 times and did no succeed. cURL was unable to rewind the body of the request and subsequent retries resulted in the same error. Turn on the debug option to see what went wrong. See https://bugs.php.net/bug.php?id=47204 for more information.). To fix this, redo the plugin setup.

Hai my wordpress pannel has some issue plugin not install in my wordpress pannel .. showing error code 
Error: The cURL request was retried 3 times and did no succeed. cURL was unable to rewind the body of the request and subsequent retries resulted in the same error. Turn on the debug option to see what went wrong. See https://bugs.php.net/bug.php?id=47204 for more information.

Please fix this issue

Error: The cURL request was retried 3 times and did no succeed. cURL was unable to rewind the body of the request and subsequent retries resulted in the same error. Turn on the debug option to see what went wrong. See https://bugs.php.net/bug.php?id=47204 for more information.