SSL_CONF_CTX_SET1_PREFIX(3ossl)

📦 version 3.5.0, in opensuse-leap 16.0

💅 SSL_CONF_CTX_set1_prefix — the OpenSSL 3ossl era, bestie

Okay so real talk, this is one of those tiny little OpenSSL manual pages (from the 3ossl manual set, obviously) that does exactly one thing and does it slayfully. It sets a command prefix. That's it. That's the whole personality. Let's get into it 🎀

✨ NAME ✨

SSL_CONF_CTX_set1_prefix — set the configuration context command prefix. Iconic, brief, to the point. We love a function that knows what it is 💅

🌸 SYNOPSIS 🌸

#include <openssl/ssl.h>

unsigned int SSL_CONF_CTX_set1_prefix(SSL_CONF_CTX *cctx, const char *prefix);

That's literally the whole vibe. One include, one function, two arguments. Chef's kiss ✨

🦋 DESCRIPTION 🦋

So SSL_CONF_CTX_set1_prefix() sets the command prefix of cctx to prefix. Super straightforward, no cap.

And if prefix is NULL? It gets restored to the default value. Cute little reset button, we stan 🫶

⭐ NOTES ⭐

Okay this is the part where it gets juicy, so pay attention bestie 👑

Command prefixes alter the commands recognised by subsequent SSL_CONF_cmd() calls. Like, they change what the parser is even willing to look at. Main character energy for real.

Example time — for files, if the prefix "SSL" is set, then command names such as "SSLProtocol", "SSLOptions" etc. are recognised instead of "Protocol" and "Options". Similarly for command lines: if the prefix is "--ssl-" then "--ssl-no_tls1_2" is recognised instead of "-no_tls1_2". See how that works? The prefix is like the little name tag the command has to wear to get into the club 💀

Now, the flag-dependent tea ☕:

  • If the SSL_CONF_FLAG_CMDLINE flag is set, then prefix checks are case sensitive and "-" is the default.
  • In the unlikely event an application explicitly wants to set no prefix, it must be explicitly set to "".
Bestie, note the "unlikely event" wording — that's the manpage being shady, and honestly? Fair. Also note that an empty string "" is not the same as NULL. NULL restores the default; "" means genuinely no prefix. Different girlies, different jobs 🙈
  • If the SSL_CONF_FLAG_FILE flag is set, then prefix checks are case insensitive and no prefix is the default.

So like, command line = picky and case sensitive, file = chill and case insensitive. The duality of woman 💖

🔥 RETURN VALUES 🔥

SSL_CONF_CTX_set1_prefix() returns 1 for success and 0 for failure.

That's it. Binary queen. No errno drama, no negative values, just yes or no 🌈

🧚 SEE ALSO 🧚

Go read these next, they're all in the same friend group:

👑 HISTORY 👑

These functions were added in OpenSSL 1.0.2. Vintage but still thriving, we love a legacy icon 💜

Copyright 2012-2016 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at <https://www.openssl.org/source/license.html>.

Aaaand that's the page, bestie 🎀 This little writeup is living in the 3.5.0 era, dated 2026-09-25, filed under SSL_CONF_CTX_SET1_PREFIX(3ossl). Go forth and prefix responsibly 💅✨

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