[drakma-devel] https through a proxy

[Edi Weitz]

Hi Bill,

Thanks for the patch.  I can't really read it because your email
client broke it, but I think I get the idea.  Yes, I didn't integrate
the old patch and IIRC I didn't do it because it was a LW-only
solution.  Obviously, I don't like the new solution either because it
uses unexported symbols (and you can't change the underlying stream
for a reason).

As far as I understand, all this happens while the headers are still
sent and while chunking isn't really needed.  I haven't really thought
about the details, but maybe it would be possible to change the order
of how and when the streams are wrapped and use only exported
functionality.  In the worst case, one could "unwrap" the stream,
attach SSL, and then "rewrap" it.  Of course, the easiest solution
would be if CL+SSL and AllegroCL had something similar to LispWorks'
comm:attach-ssl.

Anyway, if someone wants to work on a "clean" solution to this
problem, I'll happily review it.  As usual:
http://weitz.de/patches.html

Thanks again,
Edi.


On Wed, May 5, 2010 at 4:41 AM, Bill St. Clair <wws at clozure.com> wrote:
> I have an application where I need to do https requests through a proxy
> server. It hangs in Drakma 1.1.0. I found the fix, for Lispworks only,
> at
> http://www.mail-archive.com/drakma-devel@common-lisp.net/msg00200.html .
> I guess Edi didn't integrate it yet. I made it work in CCL 1.5, meaning
> it will probably work everywhere, but I did't test Allegro. My fix is a
> little ugly, as I'm setting a slot with no writer inside of the chunga
> stream, but it works for me. Patch below.
>
> -Bill St. Clair
> wws at clozure.com
>
> ====
>
> diff -rN old-drakma/request.lisp new-drakma/request.lisp
> 429c429,430
> <     (let (http-stream must-close done)
> ---
>>     (let ((proxying-https? (and proxy (not stream) (eq :https
> (puri:uri-scheme uri))))
>>            http-stream raw-http-stream must-close done)
> 437,438c438,440
> <                   (use-ssl (or force-ssl
> <                                (eq (uri-scheme uri) :https))))
> ---
>>                    (use-ssl (and (not proxying-https?)
>>                                  (or force-ssl
>>                                      (eq (uri-scheme uri) :https)))))
> 470a473
>>               (setq raw-http-stream http-stream)
> 498a502,528
>>               (when proxying-https?
>>                 ;; Setup a tunnel through the proxy server to the
>>                 ;; final destination.
>>                 (write-http-line "CONNECT ~A:~A
> HTTP/1.1"(puri:uri-host uri)
>>                                  (or (puri:uri-port uri) 443))
>>                 (write-http-line "Host: ~A:~A" (puri:uri-host uri)
>>                                  (or (puri:uri-port uri) 443))
>>                 (write-http-line "")
>>                 (force-output http-stream)
>>                 ;; Check we get a 200 response before proceeding.
>>                 (let ((line (read-status-line http-stream
> *header-stream*)))
>>                   (unless (eq (second line) 200)
>>                     (error "Unable to establish HTTPS tunnel through
> proxy.")))
>>                 ;; Got a connection. We have to read a blank line,
>>                 ;; turn on SSL, and then we can transmit.
>>                 (read-line* http-stream)
>>                 #+:lispworks
>>                 (comm:attach-ssl raw-http-stream :ssl-side :client)
>>                 #-lispworks
>>                 (setf (slot-value (flexi-stream-stream http-stream)
> 'chunga::real-stream) ;evil
>>                       #+:allegro
>>                       (socket:make-ssl-client-stream raw-http-stream)
>>                       #-:allegro
>>                       (let ((s raw-http-stream))
>>                         (cl+ssl:make-ssl-client-stream
>>                          (cl+ssl:stream-fd s)
>>                          :close-callback (lambda () (close s))))))
> 513c543
> <                                (cond (proxy (render-uri uri nil))
> ---
>>                                (cond ((and proxy (not
> proxying-https?)) (render-uri uri nil))
>
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