libssh2_agent_userauth(3)

💖 libssh2_agent_userauth — bestie edition 💖

okay so this is a page from the libssh2 manual, and today we're learning how to let your little ssh-agent buddy do the whole "yes it's me, let me in" dance for you. no cap, it's lowkey the most satisfying part of the whole agent saga. 🦋

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✨ NAME ✨

libssh2_agent_userauth — authenticate a session with a public key, with the help of ssh-agent

like, it logs you in. with a key. and ssh-agent does the heavy lifting. that's the vibe. 💅

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🌸 SYNOPSIS 🌸

#include <libssh2.h>

int
libssh2_agent_userauth(LIBSSH2_AGENT *agent,
                       const char *username,
                       struct libssh2_agent_publickey *identity);

look at her. three args, one int back. she's giving effortless. ✨

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🎀 DESCRIPTION 🎀

so here's who's who in this little friend group:

• agent — your ssh-agent handle, exactly the one that libssh2_agent_init(3) handed you. she's the main character of this operation. 👑
• username — the remote user name you're trying to authenticate as. yes, the actual human (or service account) on the other end. not optional, bestie.
• identity — the public key you want to authenticate with, as returned by libssh2_agent_get_identity(3). this is the key that's about to get you through the door. 🔑

and what does the function actually do? Attempt public key authentication with the help of ssh-agent. that's it, that's the whole thing. you bring the agent, the username, and the identity, and it goes and asks ssh-agent to do the signing magic on your behalf. you never touch the private key. she never leaves the house. iconic behaviour, fr fr. 💖

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🔥 RETURN VALUE 🔥

• returns 0 if it succeeded — slay, you're in. 🎉
• or a negative value for error — 😭 something went sideways, go check.

no in-between. zero or sad. that's the deal.

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🌈 AVAILABILITY 🌈

added in libssh2 1.2. so if you're on anything older than that… yeah, she's not there yet. sorry bestie. 🫶

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🦋 SEE ALSO 🦋

• libssh2_agent_init(3)
• libssh2_agent_get_identity(3)
• libssh2_agent_sign(3)

read them in order and the whole flow will click, i promise. iykyk. ✨

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real talk: this function is the payoff. init your agent, get your identity, then call her. that's the trilogy. 🎬

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mwah</purl> 💋 that's a wrap on libssh2_agent_userauth(3), straight from the libssh2 manual, dated 23 Dec 2009 — yes she's an elder but she still ate. go authenticate something, bestie, you got this. 💅✨🌸