OPENSSL_INIT_SSL(3) | Library Functions Manual | OPENSSL_INIT_SSL(3)

# NAME

`OPENSSL_init_ssl` — initialise the crypto and ssl libraries

# SYNOPSIS

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

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

# DESCRIPTION

This function is deprecated. It is never useful for any application program to call it explicitly. The library automatically calls it 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).

`OPENSSL_init_ssl`() calls OPENSSL_init_crypto(3), SSL_load_error_strings(3), and SSL_library_init(3).

The options argument is passed on to OPENSSL_init_crypto(3) and the dummy argument is ignored.

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

# RETURN VALUES

`OPENSSL_init_ssl`() is intended to return 1 on success or 0 on error.

# SEE ALSO

CONF_modules_load_file(3), OPENSSL_config(3), ssl(3)

# HISTORY

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

# BUGS

`OPENSSL_init_ssl`() silently ignores even more configuration failures than OPENSSL_init_crypto(3).

June 8, 2025 | Debian