mcrypt_get_block_size

Gets the block size of the specified cipher

&warn.deprecated.function-7-1-0.removed-7-2-0;
&reftitle.description; ``int``false```mcrypt_get_block_size` `int` `cipher` ``int``false```mcrypt_get_block_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_block_size` is used to get the size of a block of the specified `cipher` (in combination with an encryption mode).

It is more useful to use the `mcrypt_enc_get_block_size` function as this uses the resource returned by `mcrypt_module_open`.

&reftitle.parameters;

`cipher`

- &mcrypt.parameter.cipher;

`mode`

- &mcrypt.parameter.mode;
&reftitle.returnvalues;

Returns the algorithm block size in bytes &return.falseforfailure;.

&reftitle.examples;

### `mcrypt_get_block_size` example

This example shows how to use this function when linked against libmcrypt 2.4.x and 2.5.x.

    <?php

    echo mcrypt_get_block_size('tripledes', 'ecb'); // 8

    ?>

&reftitle.seealso;

- `mcrypt_get_key_size`
- `mcrypt_enc_get_block_size`
- `mcrypt_encrypt`