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 = '1234567890abcdef'; # 16 bytes, valid for AES-128
          my $plaintext_block = '1234567890123456'; # one AES block (16 bytes)
          my $c = Crypt::Cipher->new('AES', $key);
          my $blocksize  = $c->blocksize;
          my $ciphertext = $c->encrypt($plaintext_block);   # encrypt 1 block
          my $plaintext  = $c->decrypt($ciphertext);         #decrypt 1 block

          ### example 2 (using CBC mode)
          use Crypt::Mode::CBC;

          my $cbc_key = '1234567890abcdef'; # 16 bytes, valid for AES-128
          my $iv = 'fedcba0987654321';      # 16 bytes
          my $cbc = Crypt::Mode::CBC->new('AES');
          my $cbc_ciphertext = $cbc->encrypt("secret data", $cbc_key, $iv);

          #### example 3 (compatibility with Crypt::CBC)
          use Crypt::CBC;
          use Crypt::Cipher;

          my $compat_key = '1234567890abcdef'; # 16 bytes, valid for AES-128
          my $compat_iv = 'fedcba0987654321';  # 16 bytes
          my $cipher = Crypt::Cipher->new('AES', $compat_key);
          my $compat_cbc = Crypt::CBC->new( -cipher=>$cipher, -iv=>$compat_iv );
          my $compat_ciphertext = $compat_cbc->encrypt("secret data");

DESCRIPTION
       Provides an interface to various symmetric cipher algorithms.

       Note: This module only implements single-block encryption and
       decryption.  For general data, use a block mode such as
       Crypt::Mode::CBC, Crypt::Mode::CTR, or Crypt::CBC (which is slower).

METHODS
       Unless noted otherwise, assume $c is an existing cipher object created
       via "new", for example:

        my $c = Crypt::Cipher->new('AES', '1234567890abcdef');

   new
       Constructor. Returns a reference to the cipher object.

        ## basic scenario
        my $c = Crypt::Cipher->new($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', 'SM4', 'Skipjack', 'Twofish', 'XTEA', 'IDEA', 'Serpent'
        #                or any <NAME> for which there is a Crypt::Cipher::<NAME> module
        # $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
        my $c = Crypt::Cipher->new('MULTI2', $key, $rounds);
        # $rounds = positive integer (should comply with selected cipher requirements)

   encrypt
       Encrypts $plaintext and returns $ciphertext. An empty string is
       accepted and returned unchanged; otherwise $plaintext must be exactly
       blocksize bytes long.

        my $ciphertext = $c->encrypt($plaintext);

   decrypt
       Decrypts $ciphertext and returns $plaintext. An empty string is
       accepted and returned unchanged; otherwise $ciphertext must be exactly
       blocksize bytes long.

        my $plaintext = $c->decrypt($ciphertext);

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

   max_keysize
       Returns the maximum allowed key size in bytes for the given cipher.

        $c->max_keysize;
        #or
        Crypt::Cipher->max_keysize('AES');
        #or
        Crypt::Cipher::max_keysize('AES');

   min_keysize
       Returns the minimum allowed key size in bytes for the given cipher.

        $c->min_keysize;
        #or
        Crypt::Cipher->min_keysize('AES');
        #or
        Crypt::Cipher::min_keysize('AES');

   blocksize
       Returns the block size in bytes for the given cipher.

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

   default_rounds
       Returns the default number of rounds for the given cipher. Only some
       ciphers, such as MULTI2, RC5, and SAFER, let you set the number of
       rounds via new().

        $c->default_rounds;
        #or
        Crypt::Cipher->default_rounds('AES');
        #or
        Crypt::Cipher::default_rounds('AES');

SEE ALSO
       o   CryptX

       o   See subclasses such as Crypt::Cipher::AES, Crypt::Cipher::Blowfish,
           ...

perl v5.42.2                      2026-08-10                  Crypt::Cipher(3)