NETTLE-PBKDF2(1)

✨ NAME ✨

nettle-pbkdf2 — the command-line password-based key derivation tool, bestie 💖 (from the Nettle tools family, section 1 of the manual, iykyk)

🌸 SYNOPSIS 🌸

nettle-pbkdf2 [OPTIONS] SALT

🦋 DESCRIPTION 🦋

okay so, this manual page is giving you the ✨brief✨ rundown of the nettle-pbkdf2 command. fun fact: this page was written for the Debian GNU/Linux distribution because the original program literally does not have a manual page. so we're all just doing our best here 💅

nettle-pbkdf2 is a front-end for Nettle's PBKDF2 (that's Password-Based Key Derivation Function 2, say it with your chest) implementation. what PBKDF2 does is take a pseudo-random function and apply it to a passphrase together with a salt, which spits out a derived key of arbitrary length. and the way that it iterates the process so many times, feeding the output of each round in as the input of the next round? that's the whole point — it makes brute-force cracking of the password take correspondingly longer. no cap, it's just expensive on purpose 🔥

and the salt? the salt makes it harder to use dictionaries or rainbow tables. iconic behaviour honestly. plus as computers become more powerful, you can just increase the number of iterations without changing anything else about the algorithm. future-proof queen 👑

the pseudo-random function used by this tool is currently HMAC-SHA256.

the password is read from standard input and the resulting derived key is written to standard output in groups of 16 hexadecimal digits, unless the --raw option is used. and listen — the salt and the number of iterations are not included in the output. so don't go looking for them there 🙈

🎀 OPTIONS 🎀

this program follows the usual GNU command line syntax, with long options starting with two dashes (`-`). a summary of options is included below, and yes bestie we're going through all of them 🫶

• -l, --length=length — desired output length in octets. pick your size, main character 💖
• --raw — output the derived key in raw binary format. no hex, just vibes (well, just bytes) 🔥
• --hex-salt — specifies that SALT is provided in hexadecimal format. so like, heads up, your salt is hex-encoded, act accordingly ✨
• --help — show a summary of options. when in doubt, ask for help bestie 😭
• -V, --version — show the version of the program. slay 💅

🌈 SEE ALSO 🌈

• mkpasswd(1)
• https://en.wikipedia.org/wiki/PBKDF2

💜 AUTHOR 💜

this manual page was originally written by Magnus Holmgren <holmgren@debian.org>, for the Debian GNU/Linux system (but may be used by others). periodt 💖

and that's the whole page bestie!! this was Nettle 3.0, dated June 2014, from the NETTLE-PBKDF2(1) page itself 🌸 stay salty (in the cryptographic sense) 🧚💜