openssl_cipher_key_length

Gets the cipher key length

&reftitle.description; ``int``false```openssl_cipher_key_length` `string` `cipher_algo`

Gets the cipher key length.

&reftitle.parameters;

`cipher_algo`

- The cipher method, see `openssl_get_cipher_methods` for a list of potential values.

&reftitle.returnvalues;

Returns the cipher length on success, &return.falseforfailure;.

&reftitle.errors;

Emits an `E_WARNING` level error when the cipher algorithm is unknown.

&reftitle.examples;

### `openssl_cipher_key_length` example

    <?php
    $method = 'AES-128-CBC';

    var_dump(openssl_cipher_key_length($method));
    ?>

&example.outputs.similar;

    int(16)