OPENSSL_config(3)

NAME

OPENSSL_config, OPENSSL_no_config — simple crypto and ssl library configuration

SYNOPSIS

/* -lcrypto */
#include <openssl/conf.h>

void
OPENSSL_config(const char *appname);

void
OPENSSL_no_config(void);

DESCRIPTION

OPENSSL_config() initializes the crypto library and calls CONF_modules_load_file(3) with the standard configuration file and the given appname. If appname is NULL, then the default name openssl_conf is used. Any errors are ignored. Further calls to OPENSSL_config() have no effect.

OPENSSL_no_config() suppresses the loading of the standard configuration file, so that any future calls to OPENSSL_config() or to OPENSSL_init_crypto(3) will ensure the library is initialized but no configuration file will be loaded.

Calling these functions is optional. All required initialization of the crypto libraries happens automatically when needed.

To use a non-standard configuration file, refer to CONF_modules_load_file(3).

Internally, OPENSSL_config() calls OPENSSL_init_crypto(3).

If an application is compiled with the preprocessor symbol OPENSSL_LOAD_CONF defined, OpenSSL_add_all_algorithms(3) automatically calls OPENSSL_config().

Applications should free up configuration at application closedown by calling CONF_modules_free(3).

FILES

/etc/ssl/openssl.cnf

standard configuration file

SEE ALSO

CONF_modules_free(3), CONF_modules_load_file(3), crypto(3), OPENSSL_VERSION_NUMBER(3), openssl.cnf(5), x509v3.cnf(5)

HISTORY

OPENSSL_config() and OPENSSL_no_config() first appeared in OpenSSL 0.9.7 and have been available since OpenBSD 3.2.