php man page for mcrypt_cfb

MCRYPT_CFB(3)								 1							     MCRYPT_CFB(3)

mcrypt_cfb - Encrypts/decrypts data in CFB mode

SYNOPSIS
       string mcrypt_cfb (int  $cipher, string	$key, string  $data, int  $mode, string  $iv)

DESCRIPTION
       string mcrypt_cfb (string  $cipher, string  $key, string  $data, int  $mode, [string  $iv])

	The  first prototype is when linked against libmcrypt 2.2.x, the second when linked against libmcrypt 2.4.x or higher. The $mode should be
       either MCRYPT_ENCRYPT or MCRYPT_DECRYPT.

	This function should not be used anymore, see mcrypt_generic(3) and mdecrypt_generic(3) for replacements.

       Warning

	      This function has been DEPRECATED as of PHP 5.5.0 and REMOVED as of PHP 7.0.0.

PHP Documentation Group 													     MCRYPT_CFB(3)