NAME
Crypt::Cisco - Commands for Cisco Type 7 Passwords
SYNOPSIS
use Crypt::Cisco;
my $clear = cisco_decrypt('121A0C041104');
my $crypt = cisco_encrypt('cisco');DESCRIPTION
The following subs implement the type-7 password encryption / decryption. The algorithm is freely available on the Internet on several sites; thus, I can/will NOT take credit or ANY liability for its use.
FUNCTIONS
NOTE: The legacy functions are deprecated and will be removed from a future release:
- password_decrypt
- password_encrypt
Use the following instead:
cisco_decrypt() - decrypt a Cisco type 7 password
my $passwd = cisco_decrypt('00071A150754');Where 00071A150754 is the encrypted Cisco password in this example.
cisco_encrypt() - encrypt a Cisco type 7 password
my $passwd = cisco_encrypt('cleartext'[,# | *]);
print "$_\n" for (@{$passwd});Where cleartext is the clear text string to encrypt. The second optional argument is a number in the range of 0 - 52 inclusive or random text.
Returns an array of all possible encryptions if random text is the second argument.
Option Description Action
------ ----------- -------
No argument provided Return a random encryption.
# Number 0-52 inclusive Return password encrypted with # index.
(other) Random text Return all 53 possibilities in array.NOTE: Cisco routers by default only seem to use the first 16 indexes (0 - 15) to encrypt passwords. You notice this by looking at the first two characters of any type 7 encrypted password in a Cisco router configuration. However, testing on IOS 12.x and later shows that manually entering a password encrypted with a higher index (generated from this script) to a Cisco configuration will not only be allowed, but will function normally for authentication. This may be a form of "security through obscurity" given that some older Cisco password decrypters don't use the entire translation index and limit 'valid' passwords to those starting with the fist 16 indexes (0 - 15). Using passwords with an encryption index of 16 - 52 inclusive may render older Cisco password decrypters useless.
Additionally, the Cisco router command prompt seems to be limited to 254 characters, making the largest password 250 characters (254 - 4 characters for the pas (followed by space) command to enter the password).
EXPORTS
Load them: use Crypt::Cisco qw(:subs);
- cisco_decrypt
- cisco_encrypt
EXAMPLES
This distribution comes with a script (installed to the default bin install directory) that not only demonstrates example uses but also provides functional execution.
LICENSE
This software is released under the same terms as Perl itself. If you don't know what that means visit http://perl.com/.
AUTHOR
Copyright (C) Michael Vincent 2010, 2017
All rights reserved