NAME
PBKDF2::Tiny - Minimalist PBKDF2 (RFC 2898) with HMAC-SHA1 or HMAC-SHA2
VERSION
version 0.005
SYNOPSIS
use PBKDF2::Tiny qw/derive verify/;
my $dk = derive( 'SHA-1', $pass, $salt, $iters );
if ( verify( $dk, 'SHA-1', $pass, $salt, $iters ) ) {
# password is correct
}
DESCRIPTION
This module provides an RFC 2898 <https://tools.ietf.org/html/rfc2898>
compliant PBKDF2 implementation using HMAC-SHA1 or HMAC-SHA2 in under
100 lines of code. If you are using Perl 5.10 or later, it uses only
core Perl modules. If you are on an earlier version of Perl, you need
Digest::SHA or Digest::SHA::PurePerl.
All documented functions are optionally exported. No functions are
exported by default.
FUNCTIONS
derive
$dk = derive( $type, $password, $salt, $iterations, $dk_length )
The "derive" function outputs a binary string with the derived key. The
first argument indicates the digest function to use. It must be one of:
SHA-1, SHA-224, SHA-256, SHA-384, or SHA-512.
If a password or salt are not provided, they default to the empty
string, so don't do that! RFC 2898 recommends
<https://tools.ietf.org/html/rfc2898#section-4.1> a random salt of at
least 8 octets. If you need a cryptographically strong salt, consider
Crypt::URandom.
The password and salt should encoded as octet strings. If not (i.e. if
Perl's internal 'UTF8' flag is on), then an exception will be thrown.
The number of iterations defaults to 1000 if not provided. If the
derived key length is not provided, it defaults to the output size of
the digest function.
derive_hex
Works just like "derive" but outputs a hex string.
verify
$bool = verify( $dk, $type, $password, $salt, $iterations, $dk_length );
The "verify" function checks that a given derived key (in binary form)
matches the password and other parameters provided using a constant-time
comparison function.
The first parameter is the derived key to check. The remaining
parameters are the same as for "derive".
verify_hex
Works just like "verify" but the derived key must be a hex string
(without a leading "0x").
digest_fcn
($fcn, $block_size, $digest_length) = digest_fcn('SHA-1');
$digest = $fcn->($data);
This function is used internally by PBKDF2::Tiny, but made available in
case it's useful to someone.
Given one of the valid digest types, it returns a function reference
that digests a string of data. It also returns block size and digest
length for that digest type.
hmac
$key = $digest_fcn->($key) if length($key) > $block_size;
$hmac = hmac( $data, $key, $digest_fcn, $block_size );
This function is used internally by PBKDF2::Tiny, but made available in
case it's useful to someone.
The first two arguments are the data and key inputs to the HMAC
function. Both should be encoded as octet strings, as underlying
HMAC/digest functions may croak or may give unexpected results if Perl's
internal UTF-8 flag is on.
Note: if the key is longer than the digest block size, it must be
preprocessed using the digesting function.
The third and fourth arguments must be a digesting code reference (from
"digest_fcn") and block size.
SEE ALSO
* Crypt::PBKDF2
* Digest::PBDKF2
SUPPORT
Bugs / Feature Requests
Please report any bugs or feature requests through the issue tracker at
<https://github.com/dagolden/PBKDF2-Tiny/issues>. You will be notified
automatically of any progress on your issue.
Source Code
This is open source software. The code repository is available for
public review and contribution under the terms of the license.
<https://github.com/dagolden/PBKDF2-Tiny>
git clone https://github.com/dagolden/PBKDF2-Tiny.git
AUTHOR
David Golden <dagolden@cpan.org>
COPYRIGHT AND LICENSE
This software is Copyright (c) 2014 by David Golden.
This is free software, licensed under:
The Apache License, Version 2.0, January 2004