1.\" $OpenBSD: CONF_modules_load_file.3,v 1.9 2019/06/14 13:41:31 schwarze Exp $ 2.\" OpenSSL b97fdb57 Nov 11 09:33:09 2016 +0100 3.\" 4.\" This file was written by Dr. Stephen Henson <steve@openssl.org>. 5.\" Copyright (c) 2000, 2015 The OpenSSL Project. All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in 16.\" the documentation and/or other materials provided with the 17.\" distribution. 18.\" 19.\" 3. All advertising materials mentioning features or use of this 20.\" software must display the following acknowledgment: 21.\" "This product includes software developed by the OpenSSL Project 22.\" for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 23.\" 24.\" 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 25.\" endorse or promote products derived from this software without 26.\" prior written permission. For written permission, please contact 27.\" openssl-core@openssl.org. 28.\" 29.\" 5. Products derived from this software may not be called "OpenSSL" 30.\" nor may "OpenSSL" appear in their names without prior written 31.\" permission of the OpenSSL Project. 32.\" 33.\" 6. Redistributions of any form whatsoever must retain the following 34.\" acknowledgment: 35.\" "This product includes software developed by the OpenSSL Project 36.\" for use in the OpenSSL Toolkit (http://www.openssl.org/)" 37.\" 38.\" THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 39.\" EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 40.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 41.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 42.\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 43.\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 44.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 45.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 46.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 47.\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 48.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 49.\" OF THE POSSIBILITY OF SUCH DAMAGE. 50.\" 51.Dd $Mdocdate: June 14 2019 $ 52.Dt CONF_MODULES_LOAD_FILE 3 53.Os 54.Sh NAME 55.Nm CONF_modules_load_file , 56.Nm CONF_modules_load 57.Nd OpenSSL configuration functions 58.Sh SYNOPSIS 59.In openssl/conf.h 60.Ft int 61.Fo CONF_modules_load_file 62.Fa "const char *filename" 63.Fa "const char *appname" 64.Fa "unsigned long flags" 65.Fc 66.Ft int 67.Fo CONF_modules_load 68.Fa "const CONF *cnf" 69.Fa "const char *appname" 70.Fa "unsigned long flags" 71.Fc 72.Sh DESCRIPTION 73The function 74.Fn CONF_modules_load_file 75configures OpenSSL using the file 76.Fa filename 77in 78.Xr openssl.cnf 5 79format and the application name 80.Fa appname . 81If 82.Fa filename 83is 84.Dv NULL , 85the standard OpenSSL configuration file 86.Pa /etc/ssl/openssl.cnf 87is used. 88If 89.Fa appname 90is 91.Dv NULL , 92the standard OpenSSL application name 93.Qq openssl_conf 94is used. 95The behaviour can be customized using 96.Fa flags . 97.Pp 98See the 99.Sx EXAMPLES 100section for additional functions that may need to be called. 101Calling configuration functions in the right order for the intended 102effect can be tricky because many configuration functions internally 103call each other. 104.Pp 105.Fn CONF_modules_load 106is identical to 107.Fn CONF_modules_load_file 108except it reads configuration information from 109.Fa cnf . 110.Pp 111The following 112.Fa flags 113are currently recognized: 114.Bl -tag -width Ds 115.It Dv CONF_MFLAGS_IGNORE_ERRORS 116Ignore errors returned by individual configuration modules. 117By default, the first module error is considered fatal and no further 118modules are loaded. 119.It Dv CONF_MFLAGS_SILENT 120Do not add any error information. 121By default, all module errors add error information to the error queue. 122.It Dv CONF_MFLAGS_NO_DSO 123Disable loading of configuration modules from DSOs. 124.It Dv CONF_MFLAGS_IGNORE_MISSING_FILE 125Let 126.Fn CONF_modules_load_file 127ignore missing configuration files. 128By default, a missing configuration file returns an error. 129.It CONF_MFLAGS_DEFAULT_SECTION 130If 131.Fa appname 132is not 133.Dv NULL 134but does not exist, fall back to the default section 135.Qq openssl_conf . 136.El 137.Pp 138By using 139.Fn CONF_modules_load_file 140with appropriate flags, an application can customise application 141configuration to best suit its needs. 142In some cases the use of a configuration file is optional and its 143absence is not an error: in this case 144.Dv CONF_MFLAGS_IGNORE_MISSING_FILE 145would be set. 146.Pp 147Errors during configuration may also be handled differently by 148different applications. 149For example in some cases an error may simply print out a warning 150message and the application may continue. 151In other cases an application might consider a configuration file 152error fatal and exit immediately. 153.Pp 154Applications can use the 155.Fn CONF_modules_load 156function if they wish to load a configuration file themselves and 157have finer control over how errors are treated. 158.Sh RETURN VALUES 159These functions return 1 for success and zero or a negative value for 160failure. 161If module errors are not ignored, the return code will reflect the return 162value of the failing module (this will always be zero or negative). 163.Sh FILES 164.Bl -tag -width /etc/ssl/openssl.cnf -compact 165.It Pa /etc/ssl/openssl.cnf 166standard configuration file 167.El 168.Sh EXAMPLES 169Load a configuration file and print out any errors and exit (missing 170file considered fatal): 171.Bd -literal 172if (CONF_modules_load_file(NULL, NULL, 0) <= 0) { 173 fprintf(stderr, "FATAL: error loading configuration file\en"); 174 ERR_print_errors_fp(stderr); 175 exit(1); 176} 177.Ed 178.Pp 179Load default configuration file using the section indicated 180by "myapp", tolerate missing files, but exit on other errors: 181.Bd -literal 182if (CONF_modules_load_file(NULL, "myapp", 183 CONF_MFLAGS_IGNORE_MISSING_FILE) <= 0) { 184 fprintf(stderr, "FATAL: error loading configuration file\en"); 185 ERR_print_errors_fp(stderr); 186 exit(1); 187} 188.Ed 189.Pp 190Load custom configuration file and section instead of the standard one, 191only print warnings on error, missing configuration file ignored: 192.Bd -literal 193OPENSSL_no_config(); 194ENGINE_load_builtin_engines(); 195OPENSSL_load_builtin_modules(); 196if (CONF_modules_load_file("/something/app.cnf", "myapp", 197 CONF_MFLAGS_IGNORE_MISSING_FILE) <= 0) { 198 fprintf(stderr, "WARNING: error loading configuration file\en"); 199 ERR_print_errors_fp(stderr); 200} 201.Ed 202.Pp 203In the previous example, the call to 204.Xr OPENSSL_no_config 3 205is required first to suppress automatic loading 206of the standard configuration file, and the calls to 207.Xr ENGINE_load_builtin_engines 3 208and 209.Xr OPENSSL_load_builtin_modules 3 210are needed so that the configuration of builtin modules and engines 211is also loaded in addition to the configuration of 212.Qq myapp . 213.Pp 214Load and parse configuration file manually, custom error handling: 215.Bd -literal 216FILE *fp; 217CONF *cnf = NULL; 218long eline; 219 220fp = fopen("/somepath/app.cnf", "r"); 221if (fp == NULL) { 222 fprintf(stderr, "Error opening configuration file\en"); 223 /* Other missing configuration file behaviour */ 224} else { 225 cnf = NCONF_new(NULL); 226 if (NCONF_load_fp(cnf, fp, &eline) == 0) { 227 fprintf(stderr, "Error on line %ld of configuration file\en", 228 eline); 229 ERR_print_errors_fp(stderr); 230 /* Other malformed configuration file behaviour */ 231 } else if (CONF_modules_load(cnf, "appname", 0) <= 0) { 232 fprintf(stderr, "Error configuring application\en"); 233 ERR_print_errors_fp(stderr); 234 /* Other configuration error behaviour */ 235 } 236 fclose(fp); 237 NCONF_free(cnf); 238} 239.Ed 240.Sh SEE ALSO 241.Xr CONF_modules_free 3 , 242.Xr ENGINE_load_builtin_engines 3 , 243.Xr ERR 3 , 244.Xr OPENSSL_config 3 , 245.Xr OPENSSL_load_builtin_modules 3 246.Sh HISTORY 247.Fn CONF_modules_load_file 248and 249.Fn CONF_modules_load 250first appeared in OpenSSL 0.9.7 and have been available since 251.Ox 3.2 . 252