NAME
Crypt::Blowfish::Mod - Another Blowfish Algorithm
VERSION
version 0.05
SYNOPSIS
use Crypt::Blowfish::Mod;
my $cipher = new Crypt::Blowfish::Mod $key;
my $ciphertext = $cipher->encrypt($plaintext);
$plaintext = $cipher->decrypt($ciphertext);DESCRIPTION
Crypt::Blowfish::Mod implements the Blowfish algorithm using functions adapted from examples from Bruce Schneier and other authors.
Crypt::Blowfish::Mod has an interface similar to Crypt::Blowfish, but produces different results. This module is endianness sensitive, making sure that it gives the same encription/decription results in different architectures.
Also, this module accepts variable length keys up to 256 bytes. By default, it assumes the key is a Base64 string. And all text encrypted or decrypted is also in Base64.
METHODS
new
Usage:
## the key should be base64
my $b = Crypt::Blowfish::Mod->new('YaKjsKjY0+');
## same as before:
my $b = Crypt::Blowfish::Mod->new( key => 'YaKjsKjY0+');
## or use a raw key:
my $b = Crypt::Blowfish::Mod->new( key_raw=>'this_is_a_raw_key9k&$!djf29389238928938' );
my $enc = $b->encrypt( 'secret text' );
my $dec = $b->decrypt( $enc );If you prefer, work with raw encrypted strings:
my $enc = $b->encrypt_raw( 'secret text' );
my $dec = $b->decrypt_raw( $enc );Or just call it even more raw (Big Endian):
my $enc = Crypt::Blowfish::Mod::b_encrypt( $key, $str, 1 );
my $dec = Crypt::Blowfish::Mod::b_decrypt( $key, $enc, 1 );encrypt
Returns a encrypted string encoded in Base64.
decrypt
Decodes a base64 encoded blowfish encrypted string.
encrypt_raw
Returns a raw encrypted string.
decrypt_raw
Decodes a raw encoded blowfish encrypted string.
encrypt_legacy
This is the legacy encrypt method, which behaves like encrypt() in version 0.04 and earlier.
Before 0.05 encryption was performed by the XS module using C's signed chars. This is a bug that prevented utf-8 strings from being decrypted. This bug was solved in 0.05.
So, if you updated to version 0.05 or greater and still need to encrypt data as the old version did, use this method.
# works fine
my $enc = $b->encrypt_legacy( 'secret text' );
my $dec = $b->decrypt( $enc );
is( $enc, $dec );
# fails!
my $str = 'déjà-vu';
my $enc = $b->encrypt_legacy( $str );
my $dec = $b->decrypt( $enc );
is( $str, $dec ); # not!b_encrypt( Str $text, Str $key, Bool is_big_endian, Bool is_signed )
Raw C decrypt function.
b_decrypt( Str $text, Str $key, Bool is_big_endian, Bool is_signed )
Raw C decrypt function.
NOTES
The Blowfish algorithm is highly dependent on the endianness of your architecture. This module attempts to detect the correct endianness for your architecture, otherwise it will most likely default to little-endian.
You may override this behavior by setting the endianness on instantiation:
# force little-endian
my $b = Crypt::Blowfish::Mod->new( key=>'YaKjsKjY0./', endianness=>'little' );Intel-based architectures are typically Little-Endian.
BREAKING CHANGES
Version 0.05 contains breaking changes.
Previous to version 0.05 any strings containing utf-8 or extended ascii characters were not encrypted correctly.
If you were storing encrypted utf8 strings but not decrypting them with earlier versions (0.04 or before), if you try to compare the output of the older encrypt() and the current (fixed) encrypt() method the result will not match! They do match fine if no utf8 or extended ascii codes were in the string being encrypted. This may be a problem if you were storing encrypted data, then comparing them to validate, authenticate, etc.
Use encrypt_legacy() if you still need to encrypt data that outputs strings that match the old algorithm.
SEE ALSO
This algorithm has been implemented in other languages:
http://www.schneier.com/blowfish-download.html
AUTHOR
Rodrigo de Oliveira