Blowfish(3) User Contributed Perl Documentation Blowfish(3)NAMECrypt::Blowfish - Perl Blowfish encryption module
SYNOPSIS
use Crypt::Blowfish;
my $cipher = new Crypt::Blowfish $key;
my $ciphertext = $cipher->encrypt($plaintext);
my $plaintext = $cipher->decrypt($ciphertext);
DESCRIPTION
Blowfish is capable of strong encryption and can use key sizes up to 56
bytes (a 448 bit key). You're encouraged to take advantage of the full
key size to ensure the strongest encryption possible from this module.
Crypt::Blowfish has the following methods:
blocksize()keysize()encrypt()decrypt()FUNCTIONS
blocksize
Returns the size (in bytes) of the block cipher.
Crypt::Blowfish doesn't return a key size due to its ability to use
variable-length keys. (well, more accurately, it won't as of 2.09
.. for now, it does. expect that to change)
new
my $cipher = new Crypt::Blowfish $key;
This creates a new Crypt::Blowfish BlockCipher object, using $key,
where $key is a key of "keysize()" bytes (minimum of eight bytes).
encrypt
my $cipher = new Crypt::Blowfish $key;
my $ciphertext = $cipher->encrypt($plaintext);
This function encrypts $plaintext and returns the $ciphertext where
$plaintext and $ciphertext must be of "blocksize()" bytes. (hint:
Blowfish is an 8 byte block cipher)
decrypt
my $cipher = new Crypt::Blowfish $key;
my $plaintext = $cipher->decrypt($ciphertext);
This function decrypts $ciphertext and returns the $plaintext where
$plaintext and $ciphertext must be of "blocksize()" bytes. (hint:
see previous hint)
EXAMPLE
my $key = pack("H16", "0123456789ABCDEF"); # min. 8 bytes
my $cipher = new Crypt::Blowfish $key;
my $ciphertext = $cipher->encrypt("plaintex"); # SEE NOTES
print unpack("H16", $ciphertext), "\n";
PLATFORMS
Please see the README document for platforms and performance
tests.
NOTES
The module is capable of being used with Crypt::CBC. You're encouraged
to read the perldoc for Crypt::CBC if you intend to use this module for
Cipher Block Chaining modes. In fact, if you have any intentions of
encrypting more than eight bytes of data with this, or any other block
cipher, you're going to need some type of block chaining help.
Crypt::CBC tends to be very good at this. If you're not going to
encrypt more than eight bytes, your data must be exactly eight bytes
long. If need be, do your own padding. "\0" as a null byte is
perfectly valid to use for this. Additionally, the current maintainer
for Crypt::Blowfish may or may not release Crypt::CBC_R which replaces
the default 'RandomIV' initialization vector in Crypt::CBC with a
random initialization vector. (to the limits of /dev/urandom and
associates) In either case, please email amused@pobox.com for
Crypt::CBC_R.
SEE ALSO
Crypt::CBC, Crypt::DES, Crypt::IDEA
Bruce Schneier, Applied Cryptography, 1995, Second Edition, published
by John Wiley & Sons, Inc.
COPYRIGHT
The implementation of the Blowfish algorithm was developed by, and is
copyright of, A.M. Kuchling.
Other parts of the perl extension and module are copyright of Systemics
Ltd ( http://www.systemics.com/ ).
Code revisions, updates, and standalone release are copyright 1999-2001
W3Works, LLC.
AUTHOR
Original algorithm, Bruce Shneier. Original implementation, A.M.
Kuchling. Original Perl implementation, Systemics Ltd. Current
maintenance by W3Works, LLC.
Current revision and maintainer: Dave Paris <amused@pobox.com>
perl v5.14.0 2005-12-02 Blowfish(3)
