Re: [libmicrohttpd] POST with chunked encoding fails

[Christian Grothoff]

On 12/18/2012 08:33 PM, Eivind Sarto wrote:
> I was was having problems receiving data from a client using POST with 
> chunked encoding.
> It turns out this client is violating the HTTP spec by setting the 
> "Transfer-Encoding: Chunked"
> as well as "Content-Length: 0"
> 
> Here are the client headers:
>   POST /ee4/live.isml/Streams(Encoder1) HTTP/1.1
>   Transfer-Encoding: Chunked
>   User-Agent: ExpressionEncoder
>   Host: 10.11.1.29
>   Content-Length: 0
>   Connection: Keep-Alive
>   Cache-Control: no-cache
> 
> This is what HTTP 1.1 spec says (in section 4.4):
>   Messages MUST NOT include both a Content-Length header field and a 
> non-identity transfer-coding. If the message does include
>   a non- identity transfer-coding, the Content-Length MUST be ignored.
> 
> libmicrohttpd does the opposite of what the 4.4 section says if both headers 
> are present.  It only uses the content-length and ignores the
> chunked encoding.
> I patched libmicrohttpd with the attached patch that does the opposite.  It 
> ignores the content-length if chunked encoding is also specified.
> And with that patch libmicrohttpd can be a publishing point for MS Expression 
> Encoder.
> 
> What is your take on this?

This one is easy.  We should follow the spec! ;-)

=> in SVN 25536, patched as suggested
(and #MHD_VERSION bumped to 0x91702).


Now, one could possibly convince me that if MHD_USE_PEDANTIC_CHECKS is
set, we should instead generate a hard error.  If you want this to be
able to easily test for such bad clients, I'm open for it.


Happy hacking!

Christian