File Coverage

blib/lib/Cisco/Hash.pm

Criterion	Covered	Total	%
statement	30	31	96.7
branch	4	8	50.0
condition	1	3	33.3
subroutine	7	8	87.5
pod	3	3	100.0
total	45	53	84.9

#!/usr/bin/perl

package Cisco::Hash;

use strict;
use warnings;

require Exporter;

our $VERSION = sprintf "%d.%02d", q$Revision: 0.02 $ =~ m/ (\d+) \. (\d+) /xg;

use vars qw[
						@EXPORT_OK
            @XLAT
            $EXLAT
           ];

BEGIN {
	*import    = \&Exporter::import;
	@EXPORT_OK = qw(decrypt encrypt usage);
}

use Carp;

@XLAT = (
	0x64, 0x73, 0x66, 0x64, 0x3b, 0x6b, 0x66, 0x6f,
	0x41, 0x2c, 0x2e, 0x69, 0x79, 0x65, 0x77, 0x72,
	0x6b, 0x6c, 0x64, 0x4a, 0x4b, 0x44, 0x48, 0x53,
	0x55, 0x42, 0x73, 0x67, 0x76, 0x63, 0x61, 0x36,
	0x39, 0x38, 0x33, 0x34, 0x6e, 0x63, 0x78, 0x76,
	0x39, 0x38, 0x37, 0x33, 0x32, 0x35, 0x34, 0x6b,
	0x3b, 0x66, 0x67, 0x38, 0x37
);

$EXLAT = scalar@XLAT;

sub decrypt {
	my $e = shift;

	$e = uc $e;

	die "ERROR: The encrypted string has an odd length but must have an even. Call usage for help."
		if length $e & 1;

	die "ERROR: Invalid character detected. Ensure you only paste the enrcypted password. Call usage for help."
		if $e !~ /^[\dA-F]+$/i;

	my $d;
	my ($eh, $et) = ($e =~ /(..)(.+)/o);

	for(my $i = 0; $i < length $et ; $i += 2) {
		$d .= sprintf "%c", hex( substr $et, $i, 2 )^$XLAT[ $eh++ % $EXLAT ];
	}
	return $d;
}

sub encrypt {
	my ($d, $of) = @_;

	die "ERROR: Insufficient number of Arguments. Call usage for help."
		if @_ != 2;

	die "ERROR: The offset you provided is not supported. Call usage for help."
		if $of < 0 || $of > 52;

	my $e .= sprintf "%02d", $of;

	for(my $i = 0; $i < length $d; $i++) {
		$e .= sprintf "%02x", unpack( 'C', substr $d, $i, 1 )^$XLAT[ $of++ % $EXLAT ];
	}
	return uc $e;
}

sub usage {
	die <

decrypt()

	Paste the encrypted hash without any preceeding information

	Exmaple:
	use Cisco::Hash qw(decrypt);
	decrypt('1511021F0725'); # Will return 'cisco'

encrypt(, )

	You can define any passphrase you like to encrpyt into a encrypted hash.
	Altough it seems that Cisco devices strip of all characters above the
	224th position.

	The offset describes at which position of the translate mask encryption
	should be startet. Due to the length of the mask (which is 53) allowed
	values are 0 to 52 (decimal).

	Example:
	use Cisco::Hash qw(encrypt);
	encrypt('cisco', 15); # will return '1511021F0725'

THIS SOFTWARE IS NEITHER INTENDED FOR MALICIOUS USE NOR FOR THE USE
IN ANY OTHER ILLEGAL PURPOSES.

EOF
}

1;

__END__