Initial Commit

database/perl/vendor/lib/Crypt/Cipher.pm

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+package Crypt::Cipher;
+
+use strict;
+use warnings;
+our $VERSION = '0.069';
+
+use Carp;
+$Carp::Internal{(__PACKAGE__)}++;
+use CryptX;
+
+### the following methods/functions are implemented in XS:
+# - new
+# - DESTROY
+# - blocksize
+# - decrypt
+# - default_rounds
+# - encrypt
+# - max_keysize
+# - min_keysize
+
+sub keysize { goto \&max_keysize; } # for Crypt::CBC compatibility
+
+sub CLONE_SKIP { 1 } # prevent cloning
+
+1;
+
+=pod
+
+=head1 NAME
+
+Crypt::Cipher - Generic interface to cipher functions
+
+=head1 SYNOPSIS
+
+   #### example 1 (encrypting single block)
+   use Crypt::Cipher;
+
+   my $key = '...'; # length has to be valid key size for this cipher
+   my $c = Crypt::Cipher->new('AES', $key);
+   my $blocksize  = $c->blocksize;
+   my $ciphertext = $c->encrypt('plain text block'); #encrypt 1 block
+   my $plaintext  = $c->decrypt($ciphertext);         #decrypt 1 block
+
+   ### example 2 (using CBC mode)
+   use Crypt::Mode::CBC;
+
+   my $key = '...'; # length has to be valid key size for this cipher
+   my $iv = '...';  # 16 bytes
+   my $cbc = Crypt::Mode::CBC->new('AES');
+   my $ciphertext = $cbc->encrypt("secret data", $key, $iv);
+
+   #### example 3 (compatibility with Crypt::CBC)
+   use Crypt::CBC;
+   use Crypt::Cipher;
+
+   my $key = '...'; # length has to be valid key size for this cipher
+   my $iv = '...';  # 16 bytes
+   my $cipher = Crypt::Cipher('AES', $key);
+   my $cbc = Crypt::CBC->new( -cipher=>$cipher, -iv=>$iv );
+   my $ciphertext = $cbc->encrypt("secret data");
+
+=head1 DESCRIPTION
+
+Provides an interface to various symmetric cipher algorithms.
+
+B<BEWARE:> This module implements just elementary "one-block-(en|de)cryption" operation - if you want to
+encrypt/decrypt generic data you have to use some of the cipher block modes - check for example
+L<Crypt::Mode::CBC|Crypt::Mode::CBC>, L<Crypt::Mode::CTR|Crypt::Mode::CTR> or L<Crypt::CBC|Crypt::CBC> (which will be slower).
+
+=head1 METHODS
+
+=head2 new
+
+Constructor, returns a reference to the cipher object.
+
+ ## basic scenario
+ $d = Crypt::Cipher->new($name, $key);
+ # $name = one of 'AES', 'Anubis', 'Blowfish', 'CAST5', 'Camellia', 'DES', 'DES_EDE',
+ #                'KASUMI', 'Khazad', 'MULTI2', 'Noekeon', 'RC2', 'RC5', 'RC6',
+ #                'SAFERP', 'SAFER_K128', 'SAFER_K64', 'SAFER_SK128', 'SAFER_SK64',
+ #                'SEED', 'Skipjack', 'Twofish', 'XTEA', 'IDEA', 'Serpent'
+ #                simply any <NAME> for which there exists Crypt::Cipher::<NAME>
+ # $key = binary key (keysize should comply with selected cipher requirements)
+
+ ## some of the ciphers (e.g. MULTI2, RC5, SAFER) allow one to set number of rounds
+ $d = Crypt::Cipher->new('MULTI2', $key, $rounds);
+ # $rounds = positive integer (should comply with selected cipher requirements)
+
+=head2 encrypt
+
+Encrypts $plaintext and returns the $ciphertext where $plaintext and $ciphertext should be of B<blocksize> bytes.
+
+ $ciphertext = $d->encrypt($plaintext);
+
+=head2 decrypt
+
+Decrypts $ciphertext and returns the $plaintext where $plaintext and $ciphertext should be of B<blocksize> bytes.
+
+ $plaintext = $d->encrypt($ciphertext);
+
+=head2 keysize
+
+Just an alias for B<max_keysize> (needed for L<Crypt::CBC|Crypt::CBC> compatibility).
+
+=head2 max_keysize
+
+Returns the maximal allowed key size (in bytes) for given cipher.
+
+ $d->max_keysize;
+ #or
+ Crypt::Cipher->max_keysize('AES');
+ #or
+ Crypt::Cipher::max_keysize('AES');
+
+=head2 min_keysize
+
+Returns the minimal allowed key size (in bytes) for given cipher.
+
+ $d->min_keysize;
+ #or
+ Crypt::Cipher->min_keysize('AES');
+ #or
+ Crypt::Cipher::min_keysize('AES');
+
+=head2 blocksize
+
+Returns block size (in bytes) for given cipher.
+
+ $d->blocksize;
+ #or
+ Crypt::Cipher->blocksize('AES');
+ #or
+ Crypt::Cipher::blocksize('AES');
+
+=head2 default_rounds
+
+Returns default number of rounds for given cipher. NOTE: only some ciphers (e.g. MULTI2, RC5, SAFER) allow one to set number of rounds via new().
+
+ $d->default_rounds;
+ #or
+ Crypt::Cipher->default_rounds('AES');
+ #or
+ Crypt::Cipher::default_rounds('AES');
+
+=head1 SEE ALSO
+
+=over
+
+=item * L<CryptX|CryptX>
+
+=item * Check subclasses like L<Crypt::Cipher::AES|Crypt::Cipher::AES>, L<Crypt::Cipher::Blowfish|Crypt::Cipher::Blowfish>, ...
+
+=back
+
+=cut