Crypt::Eksblowfish::BcUser(Contributed Perl DocumCrypt::Eksblowfish::Bcrypt(3)NAMECrypt::Eksblowfish::Bcrypt - Blowfish-based Unix crypt() password hash
SYNOPSIS
use Crypt::Eksblowfish::Bcryptqw(bcrypt_hash);
$hash = bcrypt_hash({
key_nul => 1,
cost => 8,
salt => $salt,
}, $password);
use Crypt::Eksblowfish::Bcrypt qw(en_base64 de_base64);
$text = en_base64($octets);
$octets = de_base64($text);
use Crypt::Eksblowfish::Bcryptqw(bcrypt);
$hashed_password = bcrypt($password, $settings);
DESCRIPTION
This module implements the Blowfish-based Unix crypt() password hashing
algorithm, known as "bcrypt". This hash uses a variant of Blowfish,
known as "Eksblowfish", modified to have particularly expensive key
scheduling. Eksblowfish and bcrypt were devised by Niels Provos and
David Mazieres for OpenBSD. The design is described in a paper at
<http://www.usenix.org/events/usenix99/provos.html>.
FUNCTIONS
bcrypt_hash(SETTINGS, PASSWORD)
Hashes PASSWORD according to the supplied SETTINGS, and returns the
23-octet hash. SETTINGS must be a reference to a hash, with these
keys:
key_nul
Truth value: whether to append a NUL to the password before
using it as a key. The algorithm as originally devised does
not do this, but it was later modified to do it. The version
that does append NUL is to be preferred; not doing so is
supported only for backward compatibility.
cost
Non-negative integer controlling the cost of the hash function.
The number of operations is proportional to 2^cost.
salt
Exactly sixteen octets of salt.
en_base64(BYTES)
Encodes the octet string textually using the form of base 64 that
is conventionally used with bcrypt.
de_base64(TEXT)
Decodes an octet string that was textually encoded using the form
of base 64 that is conventionally used with bcrypt.
bcrypt(PASSWORD, SETTINGS)
This is a version of "crypt" (see "crypt" in perlfunc) that
implements the bcrypt algorithm. It does not implement any other
hashing algorithms, so if others are desired then it necessary to
examine the algorithm prefix in SETTINGS and dispatch between more
than one version of "crypt".
SETTINGS must be a string which encodes the algorithm parameters,
including salt. It must begin with "$2", optional "a", "$", two
digits, "$", and 22 base 64 digits. The rest of the string is
ignored. The presence of the optional "a" means that a NUL is to
be appended to the password before it is used as a key. The two
digits set the cost parameter. The 22 base 64 digits encode the
salt. The function will "die" if SETTINGS does not have this
format.
The PASSWORD is hashed according to the SETTINGS. The value
returned is a string which encodes the algorithm parameters and the
hash: the parameters are in the same format required in SETTINGS,
and the hash is appended in the form of 31 base 64 digits. This
result is suitable to be used as a SETTINGS string for input to
this function: the hash part of the string is ignored on input.
SEE ALSO
Crypt::Eksblowfish, <http://www.usenix.org/events/usenix99/provos.html>
AUTHOR
Andrew Main (Zefram) <zefram@fysh.org>
COPYRIGHT
Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Andrew Main (Zefram)
<zefram@fysh.org>
LICENSE
This module is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
perl v5.18.2 2014-05-13 Crypt::Eksblowfish::Bcrypt(3)