OPENSSL_CONFIG(3)

📦 version 4.4.0, in alpine 3.24, arch rolling

💅 OPENSSL_CONFIG — a manual page, but make it cute

okay so bestie, this is OPENSSL_CONFIG(3) from the Library Functions Manual, and it's literally about giving your crypto and ssl libraries a little configuration moment. it's giving "getting ready" energy. let's go 🎀

✨ SYNOPSIS ✨

like, first you need the library:

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

then the two functions, which are, and i cannot stress this enough, extremely simple:

void
OPENSSL_config(const char *appname);

void
OPENSSL_no_config(void);

🌸 DESCRIPTION 🌸

OPENSSL_config() initializes the crypto library and then calls CONF_modules_load_file(3) with the standard configuration file and the appname you passed in. if appname is NULL, then the default name openssl_conf gets used instead. no cap. 🫶

💀 and here's the thing — any errors are ignored. like, it does not care. it's not gonna tell you. it's just gonna move on with its life.

also, further calls to OPENSSL_config() have no effect. once is enough, bestie. main character energy, but only one entrance.

OPENSSL_no_config() suppresses the loading of the standard configuration file. so any future calls to OPENSSL_config() or to OPENSSL_init_crypto(3) will still make sure the library is initialized — but no configuration file will be loaded. periodt. it's literally "we're initialized but we're not doing the config thing."

calling these functions is optional. like genuinely optional. all required initialization of the crypto libraries happens automatically when needed. she's independent. she doesn't need you. 😭✨

if you want to use a non-standard configuration file, go refer to CONF_modules_load_file(3). that's her domain, not this one's.

internally, OPENSSL_config() calls OPENSSL_init_crypto(3). just so you know. iykyk. 🔥

if an application is compiled with the preprocessor symbol OPENSSL_LOAD_CONF defined, then OpenSSL_add_all_algorithms(3) automatically calls OPENSSL_config(). sneaky lil automatic vibe. 🙈

and applications should free up configuration at application closedown by calling CONF_modules_free(3). clean up after yourself, bestie, it's not cute to leave your config lying around. 🧹💖

🦋 FILES 🦋

  • /etc/ssl/openssl.cnf — the standard configuration file. the classic. the icon. 👑

⭐ SEE ALSO ⭐

go read those, bestie, they're all part of the same friend group. 🌈

🎀 HISTORY 🎀

OPENSSL_config() and OPENSSL_no_config() first appeared in OpenSSL 0.9.7, and have been available since OpenBSD 3.2. they've been around. they've seen things. 💜

and that's the page! Debian build, dated June 9, 2025, OPENSSL_CONFIG(3) — mwah, slay, go configure your crypto responsibly bestie 🫶💅✨

📦 where this page comes from