js中加密及设置cookie

1、设置cookie及有效期时长

//cname:cookie的名称，cvalue：cookie的内容，exdays:cookie有效期时长；
function setCookie(cname, cvalue, exdays) {
    var d = new Date();
//    d.setTime(d.getTime() + (exdays*1000));//设置过期时间是多少天后；
//    d.setTime(d.getTime() + (exdays*60*60*1000));//设置过期时间是多少小时；
    d.setTime(d.getTime() + (exdays*60*60*1000));//设置过期时间是多少小时；
    var expires = "expires="+d.toUTCString();

    document.cookie = cname + "=" + cvalue + "; " + expires;
}
//获取cookie;
function getCookie(cname) {
    var name = cname + "=";
    var ca = document.cookie.split(';');
    for(var i=0; i<ca.length; i++) {
        var c = ca[i];
        while (c.charAt(0)==' ') c = c.substring(1);
        if (c.indexOf(name) != -1) return c.substring(name.length, c.length);
    }
    return null;
}
//清除cookie;
function clearCookie(name) {
    setCookie(name, "", -1);
}

2、在工程中用到的加密：（base64加密）

/*
 * 加密解密
 * */
var base64EncodeChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
var base64DecodeChars = new Array(-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1,
    63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, -1,
    0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,
    20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31,
    32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49,
    50, 51, -1, -1, -1, -1, -1);
//加密
function base64encode(str) {
    var out, i, len;
    var c1, c2, c3;
    len = str.length;
    i = 0;
    out = "";
    while (i < len) {
        c1 = str.charCodeAt(i++) & 0xff;
        if (i == len) {
            out += base64EncodeChars.charAt(c1 >> 2);
            out += base64EncodeChars.charAt((c1 & 0x3) << 4);
            out += "==";
            break;
        }
        c2 = str.charCodeAt(i++);
        if (i == len) {
            out += base64EncodeChars.charAt(c1 >> 2);
            out += base64EncodeChars.charAt(((c1 & 0x3) << 4)
                | ((c2 & 0xF0) >> 4));
            out += base64EncodeChars.charAt((c2 & 0xF) << 2);
            out += "=";
            break;
        }
        c3 = str.charCodeAt(i++);
        out += base64EncodeChars.charAt(c1 >> 2);
        out += base64EncodeChars.charAt(((c1 & 0x3) << 4) | ((c2 & 0xF0) >> 4));
        out += base64EncodeChars.charAt(((c2 & 0xF) << 2) | ((c3 & 0xC0) >> 6));
        out += base64EncodeChars.charAt(c3 & 0x3F);
    }
    return out;
}
//解密
function base64decode(str) {
    var c1, c2, c3, c4;
    var i, len, out;
    len = str.length;
    i = 0;
    out = "";
    while (i < len) {
        /* c1 */
        do {
            c1 = base64DecodeChars[str.charCodeAt(i++) & 0xff];
        } while (i < len && c1 == -1);
        if (c1 == -1)
            break;
        /* c2 */
        do {
            c2 = base64DecodeChars[str.charCodeAt(i++) & 0xff];
        } while (i < len && c2 == -1);
        if (c2 == -1)
            break;
        out += String.fromCharCode((c1 << 2) | ((c2 & 0x30) >> 4));
        /* c3 */
        do {
            c3 = str.charCodeAt(i++) & 0xff;
            if (c3 == 61)
                return out;
            c3 = base64DecodeChars[c3];
        } while (i < len && c3 == -1);
        if (c3 == -1)
            break;
        out += String.fromCharCode(((c2 & 0XF) << 4) | ((c3 & 0x3C) >> 2));
        /* c4 */
        do {
            c4 = str.charCodeAt(i++) & 0xff;
            if (c4 == 61)
                return out;
            c4 = base64DecodeChars[c4];
        } while (i < len && c4 == -1);
        if (c4 == -1)
            break;
        out += String.fromCharCode(((c3 & 0x03) << 6) | c4);
    }
    return out;
}
//编码转换
function utf16to8(str) {
    var out, i, len, c;
    out = "";
    len = str.length;
    for (i = 0; i < len; i++) {
        c = str.charCodeAt(i);
        if ((c >= 0x0001) && (c <= 0x007F)) {
            out += str.charAt(i);
        } else if (c > 0x07FF) {
            out += String.fromCharCode(0xE0 | ((c >> 12) & 0x0F));
            out += String.fromCharCode(0x80 | ((c >> 6) & 0x3F));
            out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));
        } else {
            out += String.fromCharCode(0xC0 | ((c >> 6) & 0x1F));
            out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));
        }
    }
    return out;
}
function utf8to16(str) {
    var out, i, len, c;
    var char2, char3;
    out = "";
    len = str.length;
    i = 0;
    while (i < len) {
        c = str.charCodeAt(i++);
        switch (c >> 4) {
            case 0:
            case 1:
            case 2:
            case 3:
            case 4:
            case 5:
            case 6:
            case 7:
                // 0xxxxxxx
                out += str.charAt(i - 1);
                break;
            case 12:
            case 13:
                // 110x xxxx 10xx xxxx
                char2 = str.charCodeAt(i++);
                out += String.fromCharCode(((c & 0x1F) << 6) | (char2 & 0x3F));
                break;
            case 14:
                // 1110 xxxx 10xx xxxx 10xx xxxx
                char2 = str.charCodeAt(i++);
                char3 = str.charCodeAt(i++);
                out += String.fromCharCode(((c & 0x0F) << 12)
                    | ((char2 & 0x3F) << 6) | ((char3 & 0x3F) << 0));
                break;
        }
    }
    return out;
}

var mingwen="123456";
var miwen='',jiemiMiwen='';
miwen=base64encode(mingwen);
jiemiMiwen=base64decode(miwen);
console.log("加密后的密文:"+miwen);
console.log("解密后的明文:"+jiemiMiwen);

结果是：

加密后的密文:MTIzNDU2
解密后的明文:123456