我的配置是（来自phpinfo（））：
PHP Version 5.3.10
Registered Stream Filters: convert.iconv.*, mcrypt.*, mdecrypt.*, string.rot13, string.toupper, string.tolower, string.strip_tags, convert.*, consumed, dechunk, zlib.*, bzip2.*
mcrypt support: enable
mcrypt_filter support: enable
Version: 2.5.8
Supported ciphers: cast-128 gost rijndael-128 twofish cast-256 loki97 rijndael-192 saferplus wake blowfish-compat des rijndael-256 serpent xtea blowfish enigma rc2 tripledes arcfour
Supported modes: cbc cfb ctr ecb ncfb nofb ofb stream
所以你看我启用了mcrypt。
我尝试
mcrypt_module_open('rijndael-256', '', 'ofb', '');
没事的。
但当我尝试这样的东西时
stream_filter_append($fp, 'mcrypt.rijndael-256', STREAM_FILTER_WRITE, $opts);
我有两个警告
stream_filter_append(): Could not open encryption module in ...
stream_filter_append(): unable to create or locate filter "mcrypt.rijndael-256" in ...
我想写是错误的
stream_filter_append($fp, 'rijndael-256', STREAM_FILTER_WRITE, $opts); // without 'mcrypt.*'
但在这种情况下，我只有一个警告
stream_filter_append(): unable to create or locate filter "rijndael-256" in ...
还有最后一件事。加密/描述与"rot13"工作良好
stream_filter_append($fp, "string.rot13", STREAM_FILTER_WRITE);
所以问题是如何使用一些mcrypt方法加密/解密？
很抱歉我忽略了一些重要的细节。再加一个字符串：
$opts = array('iv' => $iv, 'key' => $key, 'mode' => 'stream');
stream_filter_append($fp, 'mcrypt.rijndael-256', STREAM_FILTER_WRITE, $opts);
当然，它失败了，因为在STREAM模式下不支持Rijndael-256。因此，感谢您的评论，很抱歉给您带来麻烦。