.\"
.\"	$OpenBSD: SSL_library_init.3,v 1.2 2014/12/02 14:11:01 jmc Exp $
.\"
.Dd $Mdocdate: December 2 2014 $
.Dt SSL_LIBRARY_INIT 3
.Os
.Sh NAME
.Nm SSL_library_init ,
.Nm OpenSSL_add_ssl_algorithms ,
.Nm SSLeay_add_ssl_algorithms
.Nd initialize SSL library by registering algorithms
.Sh SYNOPSIS
.In openssl/ssl.h
.Ft int
.Fn SSL_library_init void
.Fd #define OpenSSL_add_ssl_algorithms() SSL_library_init()
.Fd #define SSLeay_add_ssl_algorithms() SSL_library_init()
.Sh DESCRIPTION
.Fn SSL_library_init
registers the available SSL/TLS ciphers and digests.
.Pp
.Fn OpenSSL_add_ssl_algorithms
and
.Fn SSLeay_add_ssl_algorithms
are synonyms for
.Fn SSL_library_init .
.Sh NOTES
.Fn SSL_library_init
must be called before any other action takes place.
.Fn SSL_library_init
is not reentrant.
.Sh WARNING
.Fn SSL_library_init
adds ciphers and digests used directly and indirectly by SSL/TLS.
.Sh RETURN VALUES
.Fn SSL_library_init
always returns 1, so it is safe to discard the return value.
.Sh EXAMPLES
A typical TLS/SSL application will start with the library initialization, and
provide readable error messages.
.Bd -literal
SSL_load_error_strings();                /* readable error messages */
SSL_library_init();                      /* initialize library */
.Ed
.Sh NOTES
OpenSSL 0.9.8o and 1.0.0a and later added SHA2 algorithms to
.Fn SSL_library_init .
Applications which need to use SHA2 in earlier versions of OpenSSL should call
.Fn OpenSSL_add_all_algorithms
as well.
.Sh SEE ALSO
.Xr RAND_add 3 ,
.Xr ssl 3 ,
.Xr SSL_load_error_strings 3