1=pod 2 3=head1 NAME 4 5CONF_get1_default_config_file, 6CONF_modules_load_file_ex, CONF_modules_load_file, CONF_modules_load 7- OpenSSL configuration functions 8 9=head1 SYNOPSIS 10 11 #include <openssl/conf.h> 12 13 char *CONF_get1_default_config_file(void); 14 int CONF_modules_load_file_ex(OSSL_LIB_CTX *libctx, const char *filename, 15 const char *appname, unsigned long flags); 16 int CONF_modules_load_file(const char *filename, const char *appname, 17 unsigned long flags); 18 int CONF_modules_load(const CONF *cnf, const char *appname, 19 unsigned long flags); 20 21=head1 DESCRIPTION 22 23The function CONF_get1_default_config_file() determines the default 24configuration file pathname as follows. 25If the B<OPENSSL_CONF> environment variable is set its value is returned. 26Else the function returns the path obtained using 27L<X509_get_default_cert_area(3)> with the filename C<"openssl.cnf"> appended. 28The caller is responsible for freeing any string returned. 29 30The function CONF_modules_load_file_ex() configures OpenSSL using 31library context B<libctx> file B<filename> and application name B<appname>. 32If B<filename> is NULL the standard OpenSSL configuration file is used 33as determined by calling CONF_get1_default_config_file(). 34If B<appname> is NULL the standard OpenSSL application name B<openssl_conf> is 35used. 36The behaviour can be customized using B<flags>. Note that, the error suppressing 37can be overridden by B<config_diagnostics> as described in L<config(5)>. 38 39CONF_modules_load_file() is the same as CONF_modules_load_file_ex() but 40has a NULL library context. 41 42CONF_modules_load() is identical to CONF_modules_load_file() except it 43reads configuration information from B<cnf>. 44 45=head1 NOTES 46 47The following B<flags> are currently recognized: 48 49If B<CONF_MFLAGS_IGNORE_ERRORS> is set errors returned by individual 50configuration modules are ignored. If not set the first module error is 51considered fatal and no further modules are loaded. 52 53Normally any modules errors will add error information to the error queue. If 54B<CONF_MFLAGS_SILENT> is set no error information is added. 55 56If B<CONF_MFLAGS_IGNORE_RETURN_CODES> is set the function unconditionally 57returns success. 58This is used by default in L<OPENSSL_init_crypto(3)> to ignore any errors in 59the default system-wide configuration file, as having all OpenSSL applications 60fail to start when there are potentially minor issues in the file is too risky. 61Applications calling B<CONF_modules_load_file_ex> explicitly should not 62generally set this flag. 63 64If B<CONF_MFLAGS_NO_DSO> is set configuration module loading from DSOs is 65disabled. 66 67B<CONF_MFLAGS_IGNORE_MISSING_FILE> if set will make CONF_load_modules_file() 68ignore missing configuration files. Normally a missing configuration file 69return an error. 70 71B<CONF_MFLAGS_DEFAULT_SECTION> if set and B<appname> is not NULL will use the 72default section pointed to by B<openssl_conf> if B<appname> does not exist. 73 74By using CONF_modules_load_file_ex() with appropriate flags an 75application can customise application configuration to best suit its needs. 76In some cases the use of a configuration file is optional and its absence is not 77an error: in this case B<CONF_MFLAGS_IGNORE_MISSING_FILE> would be set. 78 79Errors during configuration may also be handled differently by different 80applications. For example in some cases an error may simply print out a warning 81message and the application continue. In other cases an application might 82consider a configuration file error as fatal and exit immediately. 83 84Applications can use the CONF_modules_load() function if they wish to load a 85configuration file themselves and have finer control over how errors are 86treated. 87 88=head1 RETURN VALUES 89 90These functions return 1 for success and a zero or negative value for 91failure. If module errors are not ignored the return code will reflect the 92return value of the failing module (this will always be zero or negative). 93 94=head1 EXAMPLES 95 96Load a configuration file and print out any errors and exit (missing file 97considered fatal): 98 99 if (CONF_modules_load_file_ex(libctx, NULL, NULL, 0) <= 0) { 100 fprintf(stderr, "FATAL: error loading configuration file\n"); 101 ERR_print_errors_fp(stderr); 102 exit(1); 103 } 104 105Load default configuration file using the section indicated by "myapp", 106tolerate missing files, but exit on other errors: 107 108 if (CONF_modules_load_file_ex(NULL, NULL, "myapp", 109 CONF_MFLAGS_IGNORE_MISSING_FILE) <= 0) { 110 fprintf(stderr, "FATAL: error loading configuration file\n"); 111 ERR_print_errors_fp(stderr); 112 exit(1); 113 } 114 115Load custom configuration file and section, only print warnings on error, 116missing configuration file ignored: 117 118 if (CONF_modules_load_file_ex(NULL, "/something/app.cnf", "myapp", 119 CONF_MFLAGS_IGNORE_MISSING_FILE) <= 0) { 120 fprintf(stderr, "WARNING: error loading configuration file\n"); 121 ERR_print_errors_fp(stderr); 122 } 123 124Load and parse configuration file manually, custom error handling: 125 126 FILE *fp; 127 CONF *cnf = NULL; 128 long eline; 129 130 fp = fopen("/somepath/app.cnf", "r"); 131 if (fp == NULL) { 132 fprintf(stderr, "Error opening configuration file\n"); 133 /* Other missing configuration file behaviour */ 134 } else { 135 cnf = NCONF_new_ex(libctx, NULL); 136 if (NCONF_load_fp(cnf, fp, &eline) == 0) { 137 fprintf(stderr, "Error on line %ld of configuration file\n", eline); 138 ERR_print_errors_fp(stderr); 139 /* Other malformed configuration file behaviour */ 140 } else if (CONF_modules_load(cnf, "appname", 0) <= 0) { 141 fprintf(stderr, "Error configuring application\n"); 142 ERR_print_errors_fp(stderr); 143 /* Other configuration error behaviour */ 144 } 145 fclose(fp); 146 NCONF_free(cnf); 147 } 148 149=head1 SEE ALSO 150 151L<config(5)>, 152L<OPENSSL_config(3)>, 153L<NCONF_new_ex(3)> 154 155=head1 COPYRIGHT 156 157Copyright 2004-2023 The OpenSSL Project Authors. All Rights Reserved. 158 159Licensed under the Apache License 2.0 (the "License"). You may not use 160this file except in compliance with the License. You can obtain a copy 161in the file LICENSE in the source distribution or at 162L<https://www.openssl.org/source/license.html>. 163 164=cut 165