OPENSSL_INIT_CRYPTO(3)

NAME
OPENSSL_init_crypto, OPENSSL_init, OPENSSL_cleanup - initialise and shut down the crypto library

SYNOPSIS
libcrypto
#include <openssl/crypto.h>
int
OPENSSL_init_crypto(uint64_t options, const void *dummy);
void
OPENSSL_init(void);
void
OPENSSL_cleanup(void);

DESCRIPTION
OPENSSL_init_crypto() and OPENSSL_init() are deprecated. It is never useful for an application program to call either of them explicitly.

The library automatically calls OPENSSL_init_crypto() internally with an options argument of 0 whenever needed. It is safest to assume that any function may do so.

To enable or disable the standard configuration file, instead use OPENSSL_config(3) or OPENSSL_no_config(3), respectively. To load a non-standard configuration file, refer to CONF_modules_load_file(3).

If OPENSSL_init_crypto() is called before any other crypto or ssl functions, the crypto library is initialised by allocating various internal resources, in particular calling ERR_load_crypto_strings(3).

The following options are supported:

OPENSSL_INIT_LOAD_CONFIG
    At the end of the initialization, call OPENSSL_config(3) with a NULL argument, loading the default configuration file.

OPENSSL_INIT_NO_LOAD_CONFIG
    Ignore any later calls to OPENSSL_config(3).

The other options flags defined by OpenSSL are all ignored by LibreSSL. The dummy argument has no effect.

If this function is called more than once, none of the calls except the first one have any effect.

OPENSSL_init() has no effect at all.

OPENSSL_cleanup() frees process-wide resources allocated by libcrypto. It is intended exclusively for the final shutdown of libcrypto in a process. Before calling it, the application has to ensure that all other threads that may use libcrypto have stopped and that no library component will use libcrypto again. After it returns, libcrypto cannot be reinitialized and no libcrypto or libssl function may be called.

OPENSSL_cleanup() is not a replacement for deprecated cleanup functions such as CRYPTO_cleanup_all_ex_data(3) and must not be called after individual cryptographic operations or when an individual library component is finished with libcrypto.

RETURN VALUES
OPENSSL_init_crypto() is intended to return 1 on success or 0 on error.

SEE ALSO
CONF_modules_load_file(3), OPENSSL_config(3), openssl.cnf(5)

HISTORY
OPENSSL_init() first appeared in OpenSSL 1.0.0e and has been available since OpenBSD 5.3. It stopped having any effect in OpenSSL 1.1.1 and in OpenBSD 5.6.

OPENSSL_init_crypto() first appeared in OpenSSL 1.1.0 and has been available since OpenBSD 6.3.

OPENSSL_cleanup() first appeared in OpenSSL 1.1.0 and has been available since OpenBSD 7.2.

BUGS
OPENSSL_init_crypto() silently ignores almost all kinds of errors. In particular, if memory allocation fails, initialisation is likely to remain incomplete, the library may be in an inconsistent internal state, but the return value will usually indicate success anyway. There is no way for the application program to find out whether library initialisation is actually complete, nor to get back to a consistent state if it isn't.