.\" $OpenBSD: OPENSSL_config.3,v 1.16 2023/11/19 21:01:27 tb Exp $ .\" full merge up to: OpenSSL b97fdb57 Nov 11 09:33:09 2016 +0100 .\" .\" This file is a derived work. .\" The changes are covered by the following Copyright and license: .\" .\" Copyright (c) 2018 Ingo Schwarze .\" .\" Permission to use, copy, modify, and distribute this software for any .\" purpose with or without fee is hereby granted, provided that the above .\" copyright notice and this permission notice appear in all copies. .\" .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. .\" .\" The original file was written by Dr. Stephen Henson . .\" Copyright (c) 2004 The OpenSSL Project. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in .\" the documentation and/or other materials provided with the .\" distribution. .\" .\" 3. All advertising materials mentioning features or use of this .\" software must display the following acknowledgment: .\" "This product includes software developed by the OpenSSL Project .\" for use in the OpenSSL Toolkit. (http://www.openssl.org/)" .\" .\" 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to .\" endorse or promote products derived from this software without .\" prior written permission. For written permission, please contact .\" openssl-core@openssl.org. .\" .\" 5. Products derived from this software may not be called "OpenSSL" .\" nor may "OpenSSL" appear in their names without prior written .\" permission of the OpenSSL Project. .\" .\" 6. Redistributions of any form whatsoever must retain the following .\" acknowledgment: .\" "This product includes software developed by the OpenSSL Project .\" for use in the OpenSSL Toolkit (http://www.openssl.org/)" .\" .\" THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY .\" EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR .\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR .\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, .\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; .\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, .\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED .\" OF THE POSSIBILITY OF SUCH DAMAGE. .\" .Dd $Mdocdate: November 19 2023 $ .Dt OPENSSL_CONFIG 3 .Os .Sh NAME .Nm OPENSSL_config , .Nm OPENSSL_no_config .Nd simple crypto and ssl library configuration .Sh SYNOPSIS .In openssl/conf.h .Ft void .Fo OPENSSL_config .Fa "const char *appname" .Fc .Ft void .Fn OPENSSL_no_config void .Sh DESCRIPTION .Fn OPENSSL_config initializes the crypto library and calls .Xr CONF_modules_load_file 3 with the standard configuration file and the given .Fa appname . If .Fa appname is .Dv NULL , then the default name .Sy openssl_conf is used. Any errors are ignored. Further calls to .Fn OPENSSL_config have no effect. .Pp .Fn OPENSSL_no_config suppresses the loading of the standard configuration file, so that any future calls to .Fn OPENSSL_config or to .Xr OPENSSL_init_crypto 3 will ensure the library is initialized but no configuration file will be loaded. .Pp Calling these functions is optional. All required initialization of the crypto libraries happens automatically when needed. .Pp To use a non-standard configuration file, refer to .Xr CONF_modules_load_file 3 . .Pp Internally, .Fn OPENSSL_config calls .Xr OPENSSL_init_crypto 3 and .Xr OPENSSL_load_builtin_modules 3 . .Pp If an application is compiled with the preprocessor symbol .Dv OPENSSL_LOAD_CONF #define'd, .Xr OpenSSL_add_all_algorithms 3 automatically calls .Fn OPENSSL_config . .Pp Applications should free up configuration at application closedown by calling .Xr CONF_modules_free 3 . .Sh FILES .Bl -tag -width /etc/ssl/openssl.cnf -compact .It Pa /etc/ssl/openssl.cnf standard configuration file .El .Sh SEE ALSO .Xr CONF_modules_free 3 , .Xr CONF_modules_load_file 3 , .Xr crypto 3 , .Xr OPENSSL_load_builtin_modules 3 , .Xr OPENSSL_VERSION_NUMBER 3 , .Xr openssl.cnf 5 , .Xr x509v3.cnf 5 .Sh HISTORY .Fn OPENSSL_config and .Fn OPENSSL_no_config first appeared in OpenSSL 0.9.7 and have been available since .Ox 3.2 .