mcrypt_get_key_size(3) [php man page]

MCRYPT_GET_KEY_SIZE(3)							 1						    MCRYPT_GET_KEY_SIZE(3)

mcrypt_get_key_size - Gets the key size of the specified cipher

SYNOPSIS

       int mcrypt_get_key_size (int  $cipher)

DESCRIPTION

       int mcrypt_get_key_size (string	$cipher, string  $mode)

	The first prototype is when linked against libmcrypt 2.2.x, the second when linked against libmcrypt 2.4.x or 2.5.x.

       mcrypt_get_key_size(3) is used to get the size of a key of the specified $cipher (in combination with an encryption mode).

	It is more useful to use the mcrypt_enc_get_key_size(3) function as this uses the resource returned by mcrypt_module_open(3).

PARAMETERS

	      o $cipher
		-One of the MCRYPT_ciphername constants, or the name of the algorithm as string.

	      o $mode
		-One of the MCRYPT_MODE_modename constants, or one of the following strings: "ecb", "cbc", "cfb", "ofb", "nofb" or "stream".

RETURN VALUES

	Returns the maximum supported key size of the algorithm in bytes or FALSE on failure.

EXAMPLES

       Example #1

	      mcrypt_get_key_size(3) Example

	      <?php
		  echo mcrypt_get_key_size('tripledes', 'ecb');
	      ?>

	       The example above shows how to use this function when linked against libmcrypt 2.4.x or 2.5.x.

	      The above example will output:

	      24

SEE ALSO

       mcrypt_get_block_size(3), mcrypt_enc_get_key_size(3), mcrypt_encrypt(3).

PHP Documentation Group 												    MCRYPT_GET_KEY_SIZE(3)

Mcrypt(3)						User Contributed Perl Documentation						 Mcrypt(3)

NAME

       Mcrypt - Perl extension for the Mcrypt cryptography library

SYNOPSIS

	 use Mcrypt;

	 # Procedural routines

	 $td = Mcrypt::mcrypt_load($algorithm, $algorithm_dir,
				   $mode, $mode_dir);

	 Mcrypt::mcrypt_get_key_size($td);   # in bytes
	 Mcrypt::mcrypt_get_iv_size($td);    # in bytes
	 Mcrypt::mcrypt_get_block_size($td); # in bytes

	 Mcrypt::mcrypt_init($td, $key, $iv);

	 $encryptedstr = Mcrypt::mcrypt_encrypt($td, $decryptedstr);
	 $decryptedstr = Mcrypt::mcrypt_decrypt($td, $encryptedstr);

	 Mcrypt::mcrypt_end($td);

	 # Object-oriented methods

	 $td = Mcrypt->new( algorithm => $algorithm,
			    mode => $mode );

	 $keysize = $td->{KEY_SIZE};
	 $ivsize  = $td->{IV_SIZE};
	 $blksize = $td->{BLOCK_SIZE};

	 $td->init($key, $iv);

	 $encryptedstr = $td->encrypt($decryptedstr);
	 $decryptedstr = $td->decrypt($encryptedstr);

	 # If the $td goes out of context,
	 # the destructor will do this for you
	 $td->end();

DESCRIPTION

       This module wraps the libmcrypt encryption library for easy and convenient use from within perl.  Encryption and decryption using a variety
       of algorithms is as easy as a few simple lines of perl.

Exported constants
       The predefined groups of exports in the use statements are as follows:

       use Mcrypt qw(:ALGORITHMS);

       Exports the BLOWFISH DES 3DES GOST CAST_128 XTEA RC2 TWOFISH CAST_256 SAFERPLUS LOKI97 SERPENT RIJNDAEL_128 RIJNDAEL_192 RIJNDAEL_256
       ENIGMA ARCFOUR WAKE libmcrypt algorithms.  See the mcrypt(3) man page for more details.

       use Mcrypt qw(:MODES);

       Exports the CBC ECB CFB OFB bOFB STREAM modes of encryption.  See the mcrypt(3) man page for more details.

       use Mcrypt qw(:FUNCS);

       Exports the following functions: mcrypt_load, mcrypt_unload, mcrypt_init, mcrypt_end, mcrypt_encrypt, mcrypt_decrypt,
       mcrypt_get_block_size, mcrypt_get_iv_size, mcrypt_get_key_size.

EXAMPLES

	 # Procedural approach:
	 # create an ecryption descriptor:
	 #   ALGORITHM: blowfish (256 bit key + 16 byte IV)
	 #   MODE:	cfb
	 # The user application has set:
	 #   $method to either "encrypt" or "decrypt"
	 #   $infile to the input filename
	 #   $outfile to the output filename
	 my($td) = Mcrypt::mcrypt_load( Mcrypt::BLOWFISH, '',
					Mcrypt::CFB, '' );
	 my($key) = "32 bytes of your apps secret key";  # secret key
	 my($iv) = "16 bytes of rand"; # shared initialization vector
	 Mcrypt::mcrypt_init($td, $key, $iv) || die "Could not initialize td";
	 print Mcrypt::mcrypt_encrypt($td, $_) while(<>);
	 Mcrypt::mcrypt_end($td);

	 # OO approach of the above except decrypting
	 my($td) = Mcrypt->new( algorithm => Mcrypt::BLOWFISH,
				mode => Mcrypt::CFB,
				verbose => 0 );
	 my($key) = "k" x $td->{KEY_SIZE};
	 my($iv) = "i" x $td->{IV_SIZE};
	 $td->init($key, $iv);
	 print $td->decrypt($_) while (<>);
	 $td->end();

AUTHOR

       Theo Schlossnagle <jesus@omniti.com>

SEE ALSO

       The libmcrypt man page: mcrypt(3).  Other libmcrypt information is available at http://mcrypt.hellug.gr/.

perl v5.12.1							    2010-07-05								 Mcrypt(3)