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OpenSSL: Difference between revisions
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* The <tt>threads(3ssl)</tt> man page is pretty good. | * The <tt>threads(3ssl)</tt> man page is pretty good. | ||
* Unless you're using OpenSSL 0.9.9, the <tt>CRYPTO_set_id_callback(3ssl)</tt> is pretty much broken on [[pthreads]] implementations which don't return an integer value from <tt>pthread_self(3)</tt>. This is true for the [[FreeBSD APIs|FreeBSD]] native implementations (the [[LinuxThreads]] emulation package should work, but is broken in other, more grave, ways). On OpenSSL 0.9.9, <tt>CRYPTO_set_idptr_callback(3ssl)</tt> can be used for implementations which return a pointer or an aggregate. | * Unless you're using OpenSSL 0.9.9, the <tt>CRYPTO_set_id_callback(3ssl)</tt> is pretty much broken on [[pthreads]] implementations which don't return an integer value from <tt>pthread_self(3)</tt>. This is true for the [[FreeBSD APIs|FreeBSD]] native implementations (the [[LinuxThreads]] emulation package should work, but is broken in other, more grave, ways). On OpenSSL 0.9.9, <tt>CRYPTO_set_idptr_callback(3ssl)</tt> can be used for implementations which return a pointer or an aggregate. | ||
** [[libdank]]'s OpenSSL layer handles this via a <tt>pthread_once_t</tt> which installs a class of thread-specific data. If the thread executing the callback has a NULL value for <tt>pthread_get_specific()</tt>, a <tt>static</tt> key is incremented and copied into the TSD. The increment, and copy of the result, forms a <tt>static</tt> mutex-protected critical section. | |||
==See also== | ==See also== | ||
*[http://www.mail-archive.com/openssl-users@openssl.org/msg52117.html "Clarification questions on OpenSSL thread-safe support"], openssl-users mailing list 2008-03-10 | *[http://www.mail-archive.com/openssl-users@openssl.org/msg52117.html "Clarification questions on OpenSSL thread-safe support"], openssl-users mailing list 2008-03-10 | ||
*[http://www.mail-archive.com/openssl-users@openssl.org/msg46161.html "When to use CRYPTO_set_locking_callback() and CRYPTO_set_id_callback()?"], openssl-users mailing list 2006-08-17 | *[http://www.mail-archive.com/openssl-users@openssl.org/msg46161.html "When to use CRYPTO_set_locking_callback() and CRYPTO_set_id_callback()?"], openssl-users mailing list 2006-08-17 | ||
Latest revision as of 03:29, 16 August 2009
Threads
- The threads(3ssl) man page is pretty good.
- Unless you're using OpenSSL 0.9.9, the CRYPTO_set_id_callback(3ssl) is pretty much broken on pthreads implementations which don't return an integer value from pthread_self(3). This is true for the FreeBSD native implementations (the LinuxThreads emulation package should work, but is broken in other, more grave, ways). On OpenSSL 0.9.9, CRYPTO_set_idptr_callback(3ssl) can be used for implementations which return a pointer or an aggregate.
- libdank's OpenSSL layer handles this via a pthread_once_t which installs a class of thread-specific data. If the thread executing the callback has a NULL value for pthread_get_specific(), a static key is incremented and copied into the TSD. The increment, and copy of the result, forms a static mutex-protected critical section.
See also
- "Clarification questions on OpenSSL thread-safe support", openssl-users mailing list 2008-03-10
- "When to use CRYPTO_set_locking_callback() and CRYPTO_set_id_callback()?", openssl-users mailing list 2006-08-17
