mcrypt_module_get_algo_block_size

PHP 4 >= 4.0.2, PHP 5, PHP 7 < 7.2.0, PECL mcrypt >= 1.0.0
mcrypt_module_get_algo_block_size - Returns the blocksize of the specified algorithm
Manual

mcrypt_module_get_algo_block_size( string$algorithm, [string$lib_dir] ): int

Gets the blocksize of the specified algorithm.

Parameters

algorithm

The algorithm name.

lib_dir

This optional parameter can contain the location where the mode module is on the system.

Return Values

Returns the block size of the algorithm specified in bytes.