SSL unexpected renegotiation for CGI with PATH_INFO

[Masaoki Kobayashi <ma...@techfirm.co.jp>]

Hi,

I found suspicious behavior with CGI using PATH_INFO when
it is on the client authenticated SSL.

My situation is as follows.

/foo
  SSLVerifyClient none
/bar
  SSLVerifyClient require

Assume here're some files under /foo.

  a.html  -  plain html file
  b.cgi   -  regular cgi (not nph)

Then, I get somes file from browser.

What I could get without certificates are...

  /foo/a.html
  /foo/b.cgi
  /foo/b.cgi/foo  <--- (1)

What SSL session renegotiation runs, so I needed certificates
to access are...

  /bar
  /foo/b.cgi/bar  <--- (2)

Because /foo is configured as "SSLVerifyClient none", so I expect
it does not need any certificates.
What is different between (1) and (2)?

I could see the request is processed twice because the second
request (protocol="INCLUDED") is generated in ap_add_cgi_vars().
The second request issued with uri=path_info, so that it makes
SSL renegotiation only when path_info is under "/bar".

util_script.c
370    if (r->path_info && r->path_info[0]) {
371        /*
372         * To get PATH_TRANSLATED, treat PATH_INFO as a URI path.
373         * Need to re-escape it for this, since the entire URI was
374         * un-escaped before we determined where the PATH_INFO began.
375         */
376        request_rec *pa_req;
377
378        pa_req = ap_sub_req_lookup_uri(ap_escape_uri(r->pool, r->path_info), r,
379                                       NULL);

Does someone have any idea for this?

Masaoki Kobayashi

Re: SSL unexpected renegotiation for CGI with PATH_INFO

[Torsten Foertsch <to...@gmx.net>]

On Mon 07 Dec 2009, Masaoki Kobayashi wrote:
> I found suspicious behavior with CGI using PATH_INFO when
> it is on the client authenticated SSL.
>
> My situation is as follows.
>
> /foo
>   SSLVerifyClient none
> /bar
>   SSLVerifyClient require
>
> Assume here're some files under /foo.
>
>   a.html  -  plain html file
>   b.cgi   -  regular cgi (not nph)
>
> Then, I get somes file from browser.
>
> What I could get without certificates are...
>
>   /foo/a.html
>   /foo/b.cgi
>   /foo/b.cgi/foo  <--- (1)
>
> What SSL session renegotiation runs, so I needed certificates
> to access are...
>
>   /bar
>   /foo/b.cgi/bar  <--- (2)
>
> Because /foo is configured as "SSLVerifyClient none", so I expect
> it does not need any certificates.
> What is different between (1) and (2)?
>
> I could see the request is processed twice because the second
> request (protocol="INCLUDED") is generated in ap_add_cgi_vars().
> The second request issued with uri=path_info, so that it makes
> SSL renegotiation only when path_info is under "/bar".
>
> util_script.c
> 370    if (r->path_info && r->path_info[0]) {
> 371        /*
> 372         * To get PATH_TRANSLATED, treat PATH_INFO as a URI path.
> 373         * Need to re-escape it for this, since the entire URI was
> 374         * un-escaped before we determined where the PATH_INFO
> began. 375         */
> 376        request_rec *pa_req;
> 377
> 378        pa_req = ap_sub_req_lookup_uri(ap_escape_uri(r->pool,
> r->path_info), r, 379                                       NULL);
>
> Does someone have any idea for this?

This is another occurrence of bug #48228. Mod_cgi tries to map PATH_INFO 
to the file system to set an environment variable using a subrequest. 
This subrequest then triggers renegotiation.  

https://issues.apache.org/bugzilla/show_bug.cgi?id=48228

Torsten

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