mcrypt_module_get_algo_key_size
  Returns the maximum supported keysize of the opened mode
  
 
  WarningThis function has been
DEPRECATED as of PHP 7.1.0. Relying on this function
is highly discouraged.
 
  
 
  Description
  
   int mcrypt_module_get_algo_key_size
    ( string $algorithm
   [, string $lib_dir
  ] )
  
  
 
  Parameters
  
   
    
     - 
algorithm
- 
      
       The algorithm name.
       
- 
lib_dir
- 
      
       This optional parameter can contain the location where the mode module
       is on the system.
       
 
 
  Return Values
  
   This function returns the maximum supported key size of the
   algorithm specified in bytes.