OPENSSLconfig(3) OpenSSL OPENSSLconfig(3)

NAME
       OPENSSLconfig, OPENSSLnoconfig - simple OpenSSL configuration
       functions

SYNOPSIS
        #include 

        void OPENSSLconfig(const char *configname);
        void OPENSSLnoconfig(void);

DESCRIPTION
       OPENSSLconfig() configures OpenSSL using the standard ooppeennssssll..ccnnff
       configuration file name using ccoonnffiiggnnaammee. If ccoonnffiiggnnaammee is NULL then
       the default name ooppeennssssllccoonnff will be used. Any errors are ignored.
       Further calls to OPENSSLconfig() will have no effect. The
       configuration file format is documented in the conf(5) manual page.

       OPENSSLnoconfig() disables configuration. If called before
       OPENSSLconfig() no configuration takes place.

NNOOTTEESS
       It is ssttrroonnggllyy recommended that aallll new applications call
       OPENSSLconfig() or the more sophisticated functions such as
       CONFmodulesload() during initialization (that is before starting any
       threads). By doing this an application does not need to keep track of
       all configuration options and some new functionality can be supported
       automatically.

       It is also possible to automatically call OPENSSLconfig() when an
       application calls OPENSSLaddallalgorithms() by compiling an
       application with the preprocessor symbol OOPPEENNSSSSLLLLOOAADDCCOONNFF #define'd.
       In this way configuration can be added without source changes.

       The environment variable OOPPEENNSSSSLLCCOONNFF can be set to specify the
       location of the configuration file.

       Currently ASN1 OBJECTs and ENGINE configuration can be performed future
       versions of OpenSSL will add new configuration options.

       There are several reasons why calling the OpenSSL configuration
       routines is advisable. For example new ENGINE functionality was added
       to OpenSSL 0.9.7.  In OpenSSL 0.9.7 control functions can be supported
       by ENGINEs, this can be used (among other things) to load dynamic
       ENGINEs from shared libraries (DSOs).  However very few applications
       currently support the control interface and so very few can load and
       use dynamic ENGINEs. Equally in future more sophisticated ENGINEs will
       require certain control operations to customize them. If an application
       calls OPENSSLconfig() it doesn't need to know or care about ENGINE
       control operations because they can be performed by editing a
       configuration file.

       Applications should free up configuration at application closedown by
       calling CONFmodulesfree().

RREESSTTRRIICCTTIIOONNSS
       The OPENSSLconfig() function is designed to be a very simple "call it
       and forget it" function. As a result its behaviour is somewhat limited.
       It ignores all errors silently and it can only load from the standard
       configuration file location for example.

       It is however mmuucchh better than nothing. Applications which need finer
       control over their configuration functionality should use the
       configuration functions such as CONFloadmodules() directly.

RETURN VALUES
       Neither OPENSSLconfig() nor OPENSSLnoconfig() return a value.

SEE ALSO
       conf(5), CONFloadmodulesfile(3),
       CONFmodulesfree(3),CONFmodulesfree(3)

HISTORY       OPENSSLconfig() and OPENSSLnoconfig() first appeared in OpenSSL
       0.9.7



0.9.7l                            2005-06-02                 OPENSSLconfig(3)