CRYPT_CHECKSALT(3)

📖 CRYPT_CHECKSALT(3) 💖

✨ NAME ✨

okay so this is the manual page for crypt_checksalt, and it's giving validate a crypt setting string 🫶

🎀 LIBRARY 🎀

This lives in the Crypt Library (libcrypt, -lcrypt) 🧚

💅 SYNOPSIS 💅

#include <crypt.h>

int
crypt_checksalt(const char *setting);

🦋 DESCRIPTION 🦋

bestie, crypt_checksalt checks your setting string against the system configuration and tells you whether the hashing method and parameters it asks for are acceptable 👑 It's built for stuff like login(1), which needs to figure out if the user's passphrase should get re-hashed with the currently preferred method. literally so useful 😭

🌸 RETURN VALUES 🌸

The return value is 0 if nothing is wrong with this setting ✨ Otherwise you get one of these constants:

• CRYPT_SALT_OK — the setting string is fully correct 💖 This constant is guaranteed to equal 0.
• CRYPT_SALT_INVALID — ngl, this one means the setting string is not valid 💀 Either it asks for a hashing method this version of libxcrypt doesn't know, or it passes invalid parameters for the method.
• CRYPT_SALT_METHOD_DISABLED (Not implemented, yet) — this setting uses a hashing method that's totally banned now 🚫 crypt will fail if you pass it this setting. Manual intervention will be required to reactivate the user's account 😬
• CRYPT_SALT_METHOD_LEGACY — this method isn't considered strong enough for new passphrases anymore 🥀 crypt will still authenticate a passphrase against this setting. But if authentication succeeds, the passphrase should be re-hashed using the currently preferred method 🔄
• CRYPT_SALT_TOO_CHEAP (Not implemented, yet) — the cost parameters here are considered too cheap for new passphrases 🍬 crypt will still authenticate against this setting. If that works, the passphrase should be re-hashed using the currently preferred method.

🧚 FEATURE TEST MACROS 🧚

<crypt.h> will define the macro CRYPT_CHECKSALT_AVAILABLE if crypt_checksalt is available in the current version of libxcrypt ✨

🙈 BUGS 🙈

ngl this one's a little sad 🥺 Since full configurability isn't implemented yet, the current implementation will only ever return CRYPT_SALT_OK (0) or CRYPT_SALT_INVALID when invoked.

🍓 PORTABILITY NOTES 🍓

crypt_checksalt is not part of any standard, so don't expect it everywhere 🫠 It was added to libxcrypt in version 4.3.0.

🔥 ATTRIBUTES 🔥

For an explanation of the terms used in this section, check out attributes(7) 🤓

• Interface: crypt_checksalt
• Thread safety: MT-Safe 🧵✨

🌈 SEE ALSO 🌈

crypt(3), crypt_gensalt(3), crypt(5) 💜

libxcrypt, November 8, 2018, CRYPT_CHECKSALT(3) 🦋 that's a wrap, bestie!! 💅✨