While not specified in the description, this function, just like mcrypt_enc_get_key_size(), returns the cipher's largest key size in BYTES.
mcrypt_get_key_size
(PHP 4, PHP 5)
mcrypt_get_key_size — Gets the key size of the specified cipher
說明
int mcrypt_get_key_size
( int
$cipher
)
int mcrypt_get_key_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_key_size() is used to get the size
of a key of the specified cipher (in
combination with an encryption mode).
It is more useful to use the mcrypt_enc_get_key_size() function as this uses the resource returned by mcrypt_module_open().
參數
-
cipher -
MCRYPT_ciphername常數中的一個，或者是字串值的演算法名稱。 -
mode -
MCRYPT_MODE_modename常數中的一個，或以下字串中的一個："ecb"，"cbc"，"cfb"，"ofb"，"nofb" 和 "stream"。
回傳值
Returns the maximum supported key size of the algorithm in bytes
或者在失敗時回傳 FALSE.
範例
Example #1 mcrypt_get_key_size() Example
<?php
echo mcrypt_get_key_size('tripledes', 'ecb');
?>
The example above shows how to use this function when linked against libmcrypt 2.4.x or 2.5.x.
上例將輸出：
24
參見
- mcrypt_get_block_size() - Gets the block size of the specified cipher
- mcrypt_enc_get_key_size() - Returns the maximum supported keysize of the opened mode
- mcrypt_encrypt() - Encrypts plaintext with given parameters
add a note
