LocalStorage 加密原理

LocalStorage

要做可靠的本地数据加密，只能依靠单向加密算法如DES、AES或HMAC等 需要时secret随服务器响应发送到客户端进行解密

示例:本地localStorage aes加密

const key = CryptoJS.enc.Utf8.parse("N2841A3412APCD6F"); //十六位十六进制数作为密钥const iv = CryptoJS.enc.Utf8.parse("AUCDTF12H41P34Y2"); //十六位十六进制数作为密钥偏移量//解密方法function Decrypt (word) {    let encryptedHexStr = CryptoJS.enc.Hex.parse(word);    let srcs = CryptoJS.enc.Base64.stringify(encryptedHexStr);    let decrypt = CryptoJS.AES.decrypt(srcs, key, {        iv: iv,        mode: CryptoJS.mode.CBC,        padding: CryptoJS.pad.Pkcs7,    });    let decryptedStr = decrypt.toString(CryptoJS.enc.Utf8);    return decryptedStr.toString();}//加密方法function Encrypt (word) {    let srcs = CryptoJS.enc.Utf8.parse(word);    let encrypted = CryptoJS.AES.encrypt(srcs, key, {        iv: iv,        mode: CryptoJS.mode.CBC,        padding: CryptoJS.pad.Pkcs7,    });    return encrypted.ciphertext.toString().toUpperCase();}
/** 存入本地*/function setToken (key, stringVal) {    try {        if (!localStorage) {            return false;        }        var tem = new Date() - 1; // 当前的时间搓        var today = new Date();        let ZeroTime = new Date(new Date().toLocaleDateString()).getTime(); // 今天0点的时间戳        var time = ZeroTime + 22 * 60 * 60 * 1000; // 晚上十点的时间戳        // var time = new Date(today.getFullYear(), today.getMonth() + 1, today.getDate(), 22).getTime() // 过期时间        if (time > tem) {            //当前的时间戳大于过期的 时间戳            var cacheExpireDate = time;        } else {            var cacheExpireDate = time + 24 * 60 * 60 * 1000; // 过期时间        }        var cacheVal = { val: stringVal, exp: cacheExpireDate };        localStorage.setItem(Encrypt(key), Encrypt(JSON.stringify(cacheVal))); // 存入缓存值        // console.log(key+":存入缓存，"+new Date(cacheExpireDate)+"到期");    } catch (e) {        console.log(e);    }}function getToken (key) {    // 取    try {        if (!localStorage) {            return false;        }        var cacheVal = localStorage.getItem(Encrypt(key));        var result = JSON.parse(Decrypt(cacheVal));        var now = new Date() - 1; // 当前时间搓        if (!result) {            return null;        } //缓存不存在 // 本地时间        if (now > result.exp) {            //缓存过期            console.log(Encrypt(key));            removelocalStorage(Encrypt(key));            return "";        }        return result.val;    } catch (e) {        removelocalStorage(key);        return null;    }}
/**移除缓存，一般情况不手动调用，缓存过期自动调用*/function removelocalStorage (key) {    if (!localStorage) {        return false;    }    localStorage.removeItem(key);}