我需要使用Keccak-256算法（而不是 SHA3）创建哈希值。
我正在运行PHP 7.1，当我调用hash_algos()时，会返回已注册的算法，但 Keccak-256 不存在。
支持的算法有：
[0] => md2
[1] => md4
[2] => md5
[3] => sha1
[4] => sha224
[5] => sha256
[6] => sha384
[7] => sha512/224
[8] => sha512/256
[9] => sha512
[10] => sha3-224
[11] => sha3-256
[12] => sha3-384
[13] => sha3-512
[14] => ripemd128
[15] => ripemd160
[16] => ripemd256
[17] => ripemd320
[18] => whirlpool
[19] => tiger128,3
[20] => tiger160,3
[21] => …