OPENSSL_INIT_CRYPTO(3) | Library Functions Manual | OPENSSL_INIT_CRYPTO(3)

# NAME

`OPENSSL_init_crypto`, `OPENSSL_init` — initialise the crypto library

# SYNOPSIS

library “libcrypto”
`#include <openssl/crypto.h>`

int
`OPENSSL_init_crypto`(uint64_t options, const void *dummy);

void
`OPENSSL_init`(void);

# DESCRIPTION

These functions 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.

# 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.

# 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.

June 9, 2025 | Debian