Created attachment 24576 [details]
Adds dynamic locking callbacks to TCNative for use by openssl engines

Hello;
   The attached patch adds dynamic locking callbacks needed by certain engines in OpenSSL (chil, specifically). Most of this code was poached from HTTPD 2.2.x mod_ssl (ssl_util.c). The notable differences to TCNative after applying the patch are that the call to ssl_thread_setup had to be moved before the engine is initialized since the callbacks must be set before engine init, and the dynamic callback functions were added to ssl_thread_setup.

The issue:
When utilizing an OpenSSL engine that requires the locking callback, no locks will be found causing the vendor's native library to exit. When using chil, this only happens when an assertion fails and detects that multiple threads are active, but no upcalls are provided. I am unsure what other engines require this functionality.

The solution:
Add the callback functions to use APR locks. Register them with OpenSSL via the CRYPTO_set_dyn..... functions.


Note:
This is the first TCNative patch I have submitted and was informed that there should be a xdocs/miscellaneous/changelog.xml file. This patch is against the tomcat-native-1.1.16-src.tar.gz file which does not include such a document. In any event, I think the CHANGELOG.txt entry should read:
Improvement: Add dynamic locking callbacks for openssl engines (druggeri)