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