我并不十分熟悉的东西，但它似乎是试图
MCRYPT_RIJNDAEL_256替代
MCRYPT_RIJNDAEL_128将是一个明显的下一个步骤…
编辑： 您是对的，这不是您所需要的。
MCRYPT_RIJNDAEL_128实际上是正确的选择。根据您提供的链接，密钥和IV的长度是应有的两倍：
// How do you do 256-bit AES encryption in PHP vs. 128-bit AES encryption???// The answer is: Give it a key that's 32 bytes long as opposed to 16 bytes long.// For example:$key256 = '12345678901234561234567890123456';$key128 = '1234567890123456';// Here's our 128-bit IV which is used for both 256-bit and 128-bit keys.$iv = '1234567890123456';
