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CONF_MODULES_LOAD_FILE(3ossl) OpenSSL CONF_MODULES_LOAD_FILE(3ossl)
NAME
CONF_get1_default_config_file, CONF_modules_load_file_ex,
CONF_modules_load_file, CONF_modules_load - OpenSSL configuration
functions
SYNOPSIS
#include <openssl/conf.h>
char *CONF_get1_default_config_file(void);
int CONF_modules_load_file_ex(OSSL_LIB_CTX *libctx, const char *filename,
const char *appname, unsigned long flags);
int CONF_modules_load_file(const char *filename, const char *appname,
unsigned long flags);
int CONF_modules_load(const CONF *cnf, const char *appname,
unsigned long flags);
DESCRIPTION
The function CONF_get1_default_config_file() determines the default
configuration file pathname as follows. If the OPENSSL_CONF
environment variable is set its value is returned. Else the function
returns the path obtained using X509_get_default_cert_area(3) with the
filename "openssl.cnf" appended. The caller is responsible for freeing
any string returned.
The function CONF_modules_load_file_ex() configures OpenSSL using
library context libctx file filename and application name appname. If
filename is NULL the standard OpenSSL configuration file is used as
determined by calling CONF_get1_default_config_file(). If appname is
NULL the standard OpenSSL application name openssl_conf is used. The
behaviour can be customized using flags. Note that, the error
suppressing can be overridden by config_diagnostics as described in
config(5).
CONF_modules_load_file() is the same as CONF_modules_load_file_ex() but
has a NULL library context.
CONF_modules_load() is identical to CONF_modules_load_file() except it
reads configuration information from cnf.
NOTES
The following flags are currently recognized:
If CONF_MFLAGS_IGNORE_ERRORS is set errors returned by individual
configuration modules are ignored. If not set the first module error is
considered fatal and no further modules are loaded.
Normally any modules errors will add error information to the error
queue. If CONF_MFLAGS_SILENT is set no error information is added.
If CONF_MFLAGS_IGNORE_RETURN_CODES is set the function unconditionally
returns success. This is used by default in OPENSSL_init_crypto(3) to
ignore any errors in the default system-wide configuration file, as
having all OpenSSL applications fail to start when there are
potentially minor issues in the file is too risky. Applications
calling CONF_modules_load_file_ex explicitly should not generally set
this flag.
CONF_MFLAGS_DEFAULT_SECTION if set and appname is not NULL will use the
default section pointed to by openssl_conf if appname does not exist.
By using CONF_modules_load_file_ex() with appropriate flags an
application can customise application configuration to best suit its
needs. In some cases the use of a configuration file is optional and
its absence is not an error: in this case
CONF_MFLAGS_IGNORE_MISSING_FILE would be set.
Errors during configuration may also be handled differently by
different applications. For example in some cases an error may simply
print out a warning message and the application continue. In other
cases an application might consider a configuration file error as fatal
and exit immediately.
Applications can use the CONF_modules_load() function if they wish to
load a configuration file themselves and have finer control over how
errors are treated.
RETURN VALUES
These functions return 1 for success and a zero or negative value for
failure. If module errors are not ignored the return code will reflect
the return value of the failing module (this will always be zero or
negative).
EXAMPLES
Load a configuration file and print out any errors and exit (missing
file considered fatal):
if (CONF_modules_load_file_ex(libctx, NULL, NULL, 0) <= 0) {
fprintf(stderr, "FATAL: error loading configuration file\n");
ERR_print_errors_fp(stderr);
exit(1);
}
Load default configuration file using the section indicated by "myapp",
tolerate missing files, but exit on other errors:
if (CONF_modules_load_file_ex(NULL, NULL, "myapp",
CONF_MFLAGS_IGNORE_MISSING_FILE) <= 0) {
fprintf(stderr, "FATAL: error loading configuration file\n");
ERR_print_errors_fp(stderr);
exit(1);
}
Load custom configuration file and section, only print warnings on
error, missing configuration file ignored:
if (CONF_modules_load_file_ex(NULL, "/something/app.cnf", "myapp",
CONF_MFLAGS_IGNORE_MISSING_FILE) <= 0) {
fprintf(stderr, "WARNING: error loading configuration file\n");
ERR_print_errors_fp(stderr);
}
Load and parse configuration file manually, custom error handling:
FILE *fp;
CONF *cnf = NULL;
cnf = NCONF_new_ex(libctx, NULL);
if (NCONF_load_fp(cnf, fp, &eline) == 0) {
fprintf(stderr, "Error on line %ld of configuration file\n", eline);
ERR_print_errors_fp(stderr);
/* Other malformed configuration file behaviour */
} else if (CONF_modules_load(cnf, "appname", 0) <= 0) {
fprintf(stderr, "Error configuring application\n");
ERR_print_errors_fp(stderr);
/* Other configuration error behaviour */
}
fclose(fp);
NCONF_free(cnf);
}
SEE ALSO
config(5), OPENSSL_config(3), NCONF_new_ex(3)
COPYRIGHT
Copyright 2004-2023 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy
in the file LICENSE in the source distribution or at
<https://www.openssl.org/source/license.html>.
3.0.11 2023-09-19 CONF_MODULES_LOAD_FILE(3ossl)