UPSCLI_SSL_CAPS(3)

✨ UPSCLI_SSL_CAPS(3) ✨

okay so bestie, this is a page from the NUT Manual and it's literally all about finding out whether your libupsclient build can do SSL, and if so, which kind 💅 no cap, that's the whole vibe.

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🌸 NAME 🌸

upscli_ssl_caps, upscli_ssl_caps_descr — report the SSL capabilities of the current libupsclient build, either as a bitmap or as a string 🎀

🦋 SYNOPSIS 🦋

        #include <upsclient.h>

        /* Header above defines bitmap values:
         * UPSCLI_SSL_CAPS_NONE         - No ability to use SSL
         * UPSCLI_SSL_CAPS_OPENSSL      - Can use OpenSSL-specific setup
         * UPSCLI_SSL_CAPS_NSS          - Can use Mozilla NSS-specific setup
         */

        int upscli_ssl_caps(void);
        const char *upscli_ssl_caps_descr(void);

like, the header literally hands you the bitmap values, iykyk — UPSCLI_SSL_CAPS_NONE means no SSL ability at all, UPSCLI_SSL_CAPS_OPENSSL means you can do the OpenSSL-specific setup, and UPSCLI_SSL_CAPS_NSS means you can do the Mozilla NSS-specific setup ✨

💖 DESCRIPTION 💖

k so upscli_ssl_caps() returns an int, and that int is a bitmap of SSL capability flags 🔥 like, these are the flags that might actually matter to you if you're consuming the upsclient(3) library — think stuff like how to set up your cryptographic material storage, and whether that should even have any effect when you're initializing connections 👑

then we have upscli_ssl_caps_descr(), which returns a string with that same kind of info, but this one is primarily intended for humans 🫶 — for example, it's the perfect thing to drop into NUT client program banners 🌈

and ngl, if there's no built-in SSL support, you're not stuck — you can go explore alternative methods like SSH tunnels or the stunnel tool 🧚 bestie there are options fr fr.

⭐ RETURN VALUE ⭐

so here's the tea ☕ — upscli_ssl_caps() effectively returns:

• 0 — if SSL support is missing entirely 😭
• 1 — if OpenSSL can be used 💚
• 2 — if Mozilla NSS can be used 💜

and the reason it's like this is that, currently, the backends are exclusive — and that lowkey matters a lot because they're differently capable 👀 periodt.

in the future? it may return -1 in the event of an error, or, like, 3 if both OpenSSL and Mozilla NSS could be supported simultaneously — but the current code structure does not allow for that though 🙈 so don't get your hopes up yet.

🎀 SEE ALSO 🎀

• upscli_ssl(3)
• upscli_report_build_details(3)

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ngl this one's short but she's iconic 💅 go read the SEE ALSOs, bestie, they're giving main character energy 👑

Network UPS Tools 2.8.5 🌸 06/21/2026 — mwah, that's the version and date, love u, bye 🫶💜