CONF_modules_load_file - OpenSSL configuration functions
#include <openssl/conf.h> 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);
OpenSSL CONF_modules_load_file(3openssl)
NAME
CONF_modules_load_file, CONF_modules_load - OpenSSL configuration functions
SYNOPSIS
#include <openssl/conf.h>
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_modules_load_file() configures OpenSSL using file
filename and application name appname. If filename is NULL the standard
OpenSSL configuration file is used. If appname is NULL the standard
OpenSSL application name openssl_conf is used. The behaviour can be
cutomized using flags.
CONF_modules_load() is idential to CONF_modules_load_file() except it
reads configuration information from cnf.
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+--------------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+--------------------------+
|Availability | library/security/openssl |
+---------------+--------------------------+
|Stability | Pass-through uncommitted |
+---------------+--------------------------+
NOTES
The following flags are currently recognized:
CONF_MFLAGS_IGNORE_ERRORS if 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_NO_DSO is set configuration module loading from DSOs is
disabled.
CONF_MFLAGS_IGNORE_MISSING_FILE if set will make
CONF_load_modules_file() ignore missing configuration files. Normally a
missing configuration file return an error.
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.
Applications should call these functions after loading builtin modules
using OPENSSL_load_builtin_modules(), any ENGINEs for example using
ENGINE_load_builtin_engines(), any algorithms for example
OPENSSL_add_all_algorithms() and (if the application uses libssl)
SSL_library_init().
By using CONF_modules_load_file() 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.
Source code for open source software components in Oracle Solaris can
be found at https://www.oracle.com/downloads/opensource/solaris-source-
code-downloads.html.
This software was built from source available at
https://github.com/oracle/solaris-userland. The original community
source was downloaded from
https://www.openssl.org/source/openssl-1.0.2ze.tar.gz.
Further information about this software can be found on the open source
community website at https://www.openssl.org/.
EXAMPLES
Load a configuration file and print out any errors and exit (missing
file considered fatal):
if (CONF_modules_load_file(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(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("/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;
long eline;
fp = fopen("/somepath/app.cnf", "r");
if (fp == NULL) {
fprintf(stderr, "Error opening configuration file\n");
/* Other missing configuration file behaviour */
} else {
cnf = NCONF_new(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);
}
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).
SEE ALSO
conf(5), OPENSSL_config(3), CONF_free(3), err(3)
HISTORY
CONF_modules_load_file and CONF_modules_load first appeared in OpenSSL
0.9.7.
1.0.2ze 2022-05-03
CONF_modules_load_file(3openssl)