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Re: Threads & OpenSSL - Mutex what? Examples?

From: Toby Peterson <>
Date: Thu, 26 Feb 2009 16:38:52 -0800

On Feb 26, 2009, at 4:18 PM, John D wrote:
> On Thu, Feb 26, 2009 at 4:11 PM, Toby Peterson <> wrote:

>> On Feb 26, 2009, at 4:04 PM, John D wrote:
>>> Hello
>>> I would like to know what part of the an easy set operation that
>>> occurs in a thread
>>> which involves libcurl accessing an SSL url needs a mutex.
>>> Is there any code out there that actually shows a
>>> CRYPTO_set_locking_callback & CRYPTO_set_id_callback
>>> specifically in relation to the use with curl_easy_setopt code.
>>> It's understandable to not provide a specific thread safe
>>> mechanism given the choice of ssl options,
>>> but not having anything short of a slung together example that
>>> does not really address the cause of the problem does not fly.
>>> Again and please; How do I specifically avoid crashes when using
>>> libcurl built with OpenSSL to access an HTTPS page using multiple
>>> threads.
>>> Thank you,
>>> john
> Thanks Tony!
> However that does ziltch to actually demonstrate what I am requesting.
> This is not a complete stand-alone example. Confirms that.
> I need to know how to interface the openssl locks with
> curl_easy_setopt code.
> My current option is to mutex curl_easy_perform directly
> which is largely thanks to not a complete stand-alone examples/
> pseudo code.
> Thanks all the same Tony.
> John

Please don't top-post:

Anyway, to further expand upon that example... you do not need to
"interface" OpenSSL and libcurl directly. libcurl will use OpenSSL
behind the scenes, so if you're using threads you need those callbacks
set up ahead of time.

- Toby (note the B)
Received on 2009-02-27