node.js 的crypto模块，加密cookie

var crypto = require('crypto');

function encrypt(str,secret) {
    var cipher = crypto.createCipher('aes192', secret);
    var enc = cipher.update(str,'utf8','hex');
    enc += cipher.final('hex');
    return enc;
}
function decrypt(str,secret) {
    var decipher = crypto.createDecipher('aes192', secret);
    var dec = decipher.update(str,'hex','utf8');
    dec += decipher.final('utf8');
    return dec;
}