Crypt::Cipher::SM4(3)                      User Contributed Perl Documentation


NAME
       Crypt::Cipher::SM4 - Symmetric cipher SM4, key size: 128 bits

SYNOPSIS
         ### example 1
         use Crypt::Mode::CBC;

         my $key = '...'; # length must be a valid key size for this cipher
         my $iv = '...';  # 16 bytes
         my $cbc = Crypt::Mode::CBC->new('SM4');
         my $ciphertext = $cbc->encrypt("secret data", $key, $iv);

         ### example 2 (slower)
         use Crypt::CBC;
         use Crypt::Cipher::SM4;

         my $key = '...'; # length must be a valid key size for this cipher
         my $iv = '...';  # 16 bytes
         my $cbc = Crypt::CBC->new( -cipher=>'Cipher::SM4', -key=>$key, -iv=>$iv );
         my $ciphertext = $cbc->encrypt("secret data");

DESCRIPTION
       This module implements the SM4 cipher. Its interface is compatible with
       Crypt::CBC.

       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 $c = Crypt::Cipher::SM4->new($key);

   new
        my $c = Crypt::Cipher::SM4->new($key);
        #or
        my $c = Crypt::Cipher::SM4->new($key, $rounds);

        # $key .... [binary string] key of an accepted length (see keysize, min_keysize, max_keysize)
        # $rounds . [integer] optional, number of rounds (if supported by the cipher; croaks on invalid value)

   encrypt
       Encrypts exactly one block of plaintext. The length of $plaintext must
       equal "blocksize"; croaks otherwise. An empty string is accepted and
       returned unchanged.

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

       Returns the encrypted block as a binary string (raw bytes).

   decrypt
       Decrypts exactly one block of ciphertext. The length of $ciphertext
       must equal "blocksize"; croaks otherwise. An empty string is accepted
       and returned unchanged.

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

       Returns the decrypted block as a binary string (raw bytes).

   keysize
       Just an alias for "max_keysize".

         $c->keysize;
         #or
         Crypt::Cipher::SM4->keysize;
         #or
         Crypt::Cipher::SM4::keysize;

   blocksize
       Returns the cipher block size (in bytes).

         $c->blocksize;
         #or
         Crypt::Cipher::SM4->blocksize;
         #or
         Crypt::Cipher::SM4::blocksize;

   max_keysize
       Returns the maximum key size (in bytes).

         $c->max_keysize;
         #or
         Crypt::Cipher::SM4->max_keysize;
         #or
         Crypt::Cipher::SM4::max_keysize;

   min_keysize
       Returns the minimum key size (in bytes).

         $c->min_keysize;
         #or
         Crypt::Cipher::SM4->min_keysize;
         #or
         Crypt::Cipher::SM4::min_keysize;

   default_rounds
       Returns the cipher's default round count.

         $c->default_rounds;
         #or
         Crypt::Cipher::SM4->default_rounds;
         #or
         Crypt::Cipher::SM4::default_rounds;

SEE ALSO
       o   CryptX, Crypt::Cipher

       o   <https://en.wikipedia.org/wiki/SM4_(cipher)>

perl v5.42.2                      2026-05-12             Crypt::Cipher::SM4(3)