Crypt Module?

[pmcmicha]

All,

I need to encrypt a file while it is not in use and I am wondering which of the crypt modules out there for PERL is the best. I would prefer not to use the unix implementation of crypt, but I do need it to have the same functionality.

Thanks in advance.

 

[PaulTEG]

AFAIK, crypt is a standard function in Perl. I've used Crypt::Blowfish in the past, and found it pretty good

You can get that from

http://search.cpan.org

HTH
--Paul

It's important in life to always strike a happy medium, so if you see someone with a crystal ball, and a smile on their face ...

 

[usige]

The standard crypt function is not good for file encryption since it is a one-way encryption.

Paul's suggestion is a good one. You can use the various Crypt:: modules from CPAN (I like Crypt::Blowfish or Crypt::Loki97).

Since you are talking about encrypting a file you will want to use Crypt::CBC or some other type of 'cipher block chaining' module. Most encryption routines can only handle a small ammount of data so CBC's allow you to string larger chunks together without having worry about looping and padding the ciphers.

Hope that helps.

 

[pmcmicha]

Thanks for the replies and the advice. After looking into this I have gone with the following implemenation:

Crypt::CBC using 'Blowfish'

I have two small scripts based on the Crypt::CBC module page from cpan.org, but I am unable to get them to work correctly. The test file encrypts, but then when I go to decrypt the encrypted file, it does not decrypt.

==============================================================
enc.pl

#!/usr/bin/perl -w

use Crypt::CBC;
use FileHandle;
use strict;
open(CT,">ct.dat");
open(PT,"<pt.txt");

my $cipher = new Crypt::CBC({'key' => 't1234',
'cipher' => 'Blowfish',
'padding' => 'space'});
undef $/;
print CT $cipher->encrypt(<PT>);

close(CT);
close(PT);
exit(0)
# EOS
============================================================
============================================================
dec.pl

#!/usr/bin/perl -w

use Crypt::CBC;
use FileHandle;
use strict;
open(CT,"<ct.dat");
open(PT,">pt.dat");

my $cipher = new Crypt::CBC({'key' => 't1234',
'cipher' => 'Blowfish',
'padding' => 'space'});
undef $/;
print PT $cipher->decrypt(<CT>);

close(CT);
close(PT);
exit(0)
# EOS
============================================================

Any thoughts as to what I am doing wrong? I shouldn't have to use the $cipher->start('encrypting'); and $cipher->finished(); methods since the $cipher->(encrypt or decrypt)(<TEXT>); method is supposed to take care of this.

Thanks in advance.

 

[pmcmicha]

Nevermind, looks like my LANG variable was set incorrectly.