#
# Crypt::PasswdMD5: Module to provide an interoperable crypt() 
#	function for modern Unix O/S. This is based on the code for
#
# /usr/src/libcrypt/crypt.c
#
# on a FreeBSD 2.2.5-RELEASE system, which included the following
# notice.
#
# ----------------------------------------------------------------------------
# "THE BEER-WARE LICENSE" (Revision 42):
# <phk@login.dknet.dk> wrote this file.  As long as you retain this notice you
# can do whatever you want with this stuff. If we meet some day, and you think
# this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
# ----------------------------------------------------------------------------
#
# $Id: PasswdMD5.pm,v 1.3 2004/02/17 11:21:38 lem Exp $
#
################

package Crypt::PasswdMD5;
$VERSION='1.3';
require 5.000;
require Exporter;
@ISA = qw(Exporter);
@EXPORT = qw(unix_md5_crypt apache_md5_crypt);

=head1 NAME

Crypt::PasswdMD5 - Provides interoperable MD5-based crypt() functions

=head1 SYNOPSIS

    use Crypt::PasswdMD5;

    $cryptedpassword = unix_md5_crypt($password, $salt);
    $apachepassword = apache_md5_crypt($password, $salt);


=head1 DESCRIPTION

the C<unix_md5_crypt()> provides a crypt()-compatible interface to the
rather new MD5-based crypt() function found in modern operating systems.
It's based on the implementation found on FreeBSD 2.2.[56]-RELEASE and
contains the following license in it:

 "THE BEER-WARE LICENSE" (Revision 42):
 <phk@login.dknet.dk> wrote this file.  As long as you retain this notice you
 can do whatever you want with this stuff. If we meet some day, and you think
 this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp

C<apache_md5_crypt()> provides a function compatible with Apache's
C<.htpasswd> files. This was contributed by Bryan Hart <bryan@eai.com>.
As suggested by William A. Rowe, Jr. <wrowe@lnd.com>, it is 
exported by default.

For both functions, if a salt value is not supplied, a random salt will be
generated.  Contributed by John Peacock <jpeacock@cpan.org>.

=cut

$Magic = q/$1$/;			# Magic string
$itoa64 = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

use Digest::MD5;

sub to64 {
    my ($v, $n) = @_;
    my $ret = '';
    while (--$n >= 0) {
	$ret .= substr($itoa64, $v & 0x3f, 1);
	$v >>= 6;
    }
    $ret;
}

sub apache_md5_crypt {
	# change the Magic string to match the one used by Apache
	local $Magic = q/$apr1$/;
	
	unix_md5_crypt(@_);
}

sub unix_md5_crypt {
    my($pw, $salt) = @_;
    my $passwd;

    if ( defined $salt ) {

	$salt =~ s/^\Q$Magic//;	# Take care of the magic string if
				# if present.

	$salt =~ s/^(.*)\$.*$/$1/;	# Salt can have up to 8 chars...
	$salt = substr($salt, 0, 8);
    }
    else {
	$salt = '';	 	# in case no salt was proffered
	$salt .= substr($itoa64,int(rand(64)+1),1)
			while length($salt) < 8;
    }