| CONF_modules_load_file(3SSL) - phpMan
CONF_modules_load_file(3SSL) OpenSSL CONF_modules_load_file(3SSL)
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.
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.
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.
1.0.1t 2016-05-03 CONF_modules_load_file(3SSL)
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