The idea in mod_ssl is mainly the following: because mod_ssl provides mostly a superset of the functionality of all other solutions we can easily provide backward compatibility for most of the cases. Actually there are three compatibility areas we currently address: configuration directives, environment variables and custom log functions.
Configuration DirectivesFor backward compatibility to the configuration directives of other SSL solutions we do an on-the-fly mapping: directives which have a direct counterpart in mod_ssl are mapped silently while other directives lead to a warning message in the logfiles. The currently implemented directive mapping is listed in Table 1. Currently full backward compatibilty is provided only for Apache-SSL 1.x and mod_ssl 2.0.x. Compatibility to Sioux 1.x and Stronghold 2.x is only partial because of special functionality in these interfaces which mod_ssl (still) doesn't provide.
Environment VariablesWhen you use ``
Custom Log FunctionsWhen mod_ssl is built into Apache or at least loaded (under DSO situation) additional functions exist for the Custom Log Format of mod_log_config as documented in the Reference Chapter. Beside the ``