生成32位或16位MD5哈希值,支持大小写
输入: password
password
32位小写: 5f4dcc3b5aa765d61d8327deb882cf99
5f4dcc3b5aa765d61d8327deb882cf99
32位大写: 5F4DCC3B5AA765D61D8327DEB882CF99
5F4DCC3B5AA765D61D8327DEB882CF99
16位: 5aa765d61d8327deb
5aa765d61d8327deb