Verify Content-Length matches request body
mdounin at mdounin.ru
Thu Mar 12 15:15:24 UTC 2015
On Thu, Mar 12, 2015 at 11:01:46AM -0400, Max Rothman wrote:
> Is there a way for nginx to verify that the Content-Length header isn't
> exceeded by the actual size of the request body?
This can't happen. Anything after the Content-Length is a next
> Context: I'm working on an upload endpoint with a maximum upload size, and
> it seems that client_max_body_size only checks the Content-Length header,
> not the actual body. Additionally, from my testing it appears that
> nginx accepts
> the entire request body regardless of what the Content-Length is set to. I
> want to be able to defend against a potential slowloris-style attack where
> all of my workers could get tied up with overly-large uploads.
After the body is read, nginx will either read the next request
(if allowed as per keepalive_timeout/keepalive_requests, as well
as internal state), or will close the connection. When closing
the connection it will use lingering_timeout / lingering_time
settings to read and discard additional data (if any), if allowed
by the lingering_close directive, see
http://nginx.org/r/lingering_close for details.
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