Crypt::Cipher(3)      User Contributed Perl Documentation     Crypt::Cipher(3)


NAME
       Crypt::Cipher - Generic interface to cipher functions

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");

DESCRIPTION
       Provides an interface to various symmetric cipher algorithms.

       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 Crypt::Mode::CBC, Crypt::Mode::CTR or Crypt::CBC (which will be
       slower).

METHODS
   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)

   encrypt
       Encrypts $plaintext and returns the $ciphertext where $plaintext and
       $ciphertext should be of blocksize bytes.

        $ciphertext = $d->encrypt($plaintext);

   decrypt
       Decrypts $ciphertext and returns the $plaintext where $plaintext and
       $ciphertext should be of blocksize bytes.

        $plaintext = $d->decrypt($ciphertext);

   keysize
       Just an alias for max_keysize (needed for Crypt::CBC compatibility).

   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');

   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');

   blocksize
       Returns block size (in bytes) for given cipher.

        $d->blocksize;
        #or
        Crypt::Cipher->blocksize('AES');
        #or
        Crypt::Cipher::blocksize('AES');

   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');

SEE ALSO
       o   CryptX

       o   Check subclasses like Crypt::Cipher::AES, Crypt::Cipher::Blowfish,
           ...

perl v5.40.0                      2024-10-20                  Crypt::Cipher(3)