phc-discussions - Interest in specification of modular crypt format

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date: Sun, 6 Sep 2015 17:20:10 +0100
From: Hugo Landau <hlandau@...ever.net>
To: discussions@...sword-hashing.net
Subject: Interest in specification of modular crypt format

Greetings.

Now that a winner has been announced, I wondered if the PHC has any
interest in specifying a modular crypt format to supplement the final
specification for Argon2?

The modular crypt format is used by UNIX-like systems to encode
passwords in system databases (sha256-crypt is "$5$", sha512-crypt is
"$6$" etc.), but is also more widely used as a password storage format.
Specifying the modular crypt format early as part of the specification
itself would avoid any risk of balkanization of a supposed standard and
encourage adoption.

The most exhaustive documentation of the modular crypt format that I am
aware of is that maintained by the Python passlib project:
https://pythonhosted.org/passlib/lib/passlib.hash.html#unix-modular-crypt-hashes

Take note of PBKDF2, which, while a standard, appears to have numerous
different incompatible formats: Passlib's PBKDF2, cta_pbkdf2_sha1,
dlitz_pbkdf2_sha1, etc.
Specifying a format is trivial but may be highly advantageous.

Hugo Landau