Crypt::CipherSaber(3) User Contributed Perl DocumentationCrypt::CipherSaber(3)NAMECrypt::CipherSaber - Perl module implementing CipherSaber encryption.
SYNOPSIS
use Crypt::CipherSaber;
my $cs = Crypt::CipherSaber->new('my pathetic secret key');
my $coded = $cs->encrypt('Here is a secret message for you');
my $decoded = $cs->decrypt($coded);
# encrypt from and to a file
open(INFILE, 'secretletter.txt') or die "Can't open infile: $!";
open(OUTFILE, '>secretletter.cs1') or die "Can't open outfile: $!";
binmode(INFILE);
binmode(OUTFILE);
$cs->fh_crypt(\*INFILE, \*OUTFILE, 1);
# decrypt from and to a file
open(INFILE, 'secretletter.cs1') or die "Can't open infile: $!";
open(OUTFILE, '>secretletter.txt') or die "Can't open outfile: $!";
binmode(INFILE);
binmode(OUTFILE);
$cs->fh_crypt(\*INFILE, \*OUTFILE);
DESCRIPTION
The Crypt::CipherSaber module implements CipherSaber encryption,
described at <http://ciphersaber.gurus.com/>. It is simple, fairly
speedy, and relatively secure algorithm based on RC4.
Encryption and decryption are done based on a secret key, which must be
shared with all intended recipients of a message.
METHODS
new($key, $N)
Initialize a new Crypt::CipherSaber object. $key is a required
parameter: the key used to encrypt or to decrypt messages. $N is
optional. If provided and greater than one, it causes the object
to use CipherSaber-2 encryption (slightly slower but more secure).
If not specified, or equal to 1, the module defaults to
CipherSaber-1 encryption. $N must be a positive integer greater
than one.
encrypt($message)
Encrypt a message. This uses the key stored in the current
Crypt::CipherSaber object. It generates a 10-byte random IV
(Initialization Vector) automatically, as defined in the RC4
specification. This returns a string containing the encrypted
message.
Note that the encrypted message may contain unprintable characters,
as it uses the extended ASCII character set (valid numbers 0
through 255).
decrypt($message)
Decrypt a message. For the curious, the first ten bytes of an
encrypted message are the IV, so this must strip it off first.
This returns a string containing the decrypted message.
The decrypted message may also contain unprintable characters, as
the CipherSaber encryption scheme handles binary filesIf this is
important to you, be sure to treat the results correctly.
crypt($iv, $message)
If you wish to generate the IV with a more cryptographically secure
random string (at least compared to Perl's builtin "rand()"
operator), you may do so separately, passing it to this method
directly. The IV must be a ten-byte string consisting of
characters from the extended ASCII set.
This is generally only useful for encryption, although you may
extract the first ten characters of an encrypted message and pass
them in yourself. You might as well call decrypt(), though. The
more random the IV, the stronger the encryption tends to be. On
some operating systems, you can read from /dev/random. Other
approaches are the Math::TrulyRandom module, or compressing a file,
removing the headers, and compressing it again.
fh_crypt(\*INPUT, \*OUTPUT, ($iv))
For the sake of efficiency, Crypt::CipherSaber can filehandles.
It's not super brilliant, but it's relatively fast and sane. Pass
in a reference to the input file handle and the output filehandle.
If your platform needs to use "binmode()", this is your
responsibility. It is also your responsibility to close the files.
You may also pass in an optional third parameter, an IV. There are
three possibilities here. If you pass no IV, "fh_crypt()" will
pull the first ten bytes from the input filehandle and use that as
an IV. This corresponds to decryption. If you pass in an IV of
your own, it will use that when encrypting the file. If you pass
in the value 1, it will generate a new, random IV for you. This
corresponds to an encryption.
COPYRIGHT AND LICENSE
Copyright (C) 2000 - 2001, 2005 chromatic
This library is free software; you can use, modify, and redistribute it
under the same terms as Perl 5.8.x itself.
AUTHOR
chromatic "chromatic at wgz dot org"
thanks to jlp for testing, moral support, and never fearing the icky
details and to the fine folks at http://perlmonks.org/.
Additional thanks to Olivier Salaun and the Sympa project
(http://www.sympa.org) for testing.
SEE ALSO
the CipherSaber home page at <http://ciphersaber.gurus.com/>
perl(1), rand().
perl v5.14.1 2011-07-20 Crypt::CipherSaber(3)
