一段aes加密代码

科大webvpn的url加解密流程

//种子和偏移量
wrdvpnIV: "wrdvpnisthebest!"
wrdvpnKey: "wrdvpnisthebest!"

var utf8 = aesjs.utils.utf8;
var hex = aesjs.utils.hex
var AesCfb = aesjs.ModeOfOperation.cfb
var wrdvpnKey = ''
var wrdvpnIV = ''
var textRightAppend = function (text, mode) {
   
    var segmentByteSize = mode === 'utf8' ? 16 : 32

    if (text.length % segmentByteSize === 0) {
   
        return text
    }

    var appendLength = segmentByteSize - text.length % segmentByteSize
    var i = 0
    while (i++ < appendLength) {
   
        text += '0'
    }
    return text
}

var encrypt = function (text, key, iv) {
   
    var textLength = text.length
    text = textRightAppend(text, 'utf8')
    var keyBytes = utf8.toBytes(key)
    var ivBytes = utf8.toBytes(iv)
    var textBytes = utf8.toBytes(text)
    var aesCfb = new AesCfb(keyBytes, ivBytes, 16)
    var encryptBytes = aesCfb.encrypt(textBytes)
    return hex.fromBytes(ivBytes) + hex.fromBytes(encryptBytes).slice(0, textLength * 2)
}
var decrypt = function (text, key) {
   
    var textLength = (text.length - 32) / 2
    text = textRightAppend(text, 'hex')
    var keyBytes = utf8.toBytes(key)
    var ivBytes = hex.toBytes(text.slice(0, 32))
    var textBytes = hex.toBytes(text.slice(32))
    var aesCfb = new AesCfb(keyBytes, ivBytes, 16)
    var decryptBytes = aesCfb.decrypt(textBytes)
    return utf8.fromBytes(decryptBytes).slice(0, textLength)
}
var encrypUrl = function (protocol, url) {
   
    var port = "";
    var segments = "";

    if (url.substring(0, 7) == "http://") {
   
        url = url.substr(7);
    } else if (url.substring(0, 8) == "https://") {
   
        url = url.substr(8);
    }


    var v6 = "";
    var match = /\[[0-9a-fA-F:]+?\]/.exec(url);
    if (match) {
   
        v6 = match[0];
        url = url.slice(match[0].length);
    }
    segments = url.split("?")[0].split(":");
    if (segments.length > 1) {
   
        port = segments[1].split("/")[0]
        url = url.substr(0, segments[0].length) + url.substr(segments[0].length + port.length + 1);
    }

    if (protocol != "connection") {
   
        var i = url.indexOf('/');
        if (i == -1) {
   
            if (v6 != "") {
   
                url = v6;
            }
            url = encrypt(url, wrdvpnKey, wrdvpnIV)
        } else {
   
            var host = url.slice(0, i);
            var path = url.slice(i);
            if (v6 != "") {
   
                host = v6;
            }
            url = encrypt(host, wrdvpnKey, wrdvpnIV) + path;
        }
    }
    if (port != "") {
   
        url = "/" + protocol + "-" + port + "/" + url;
    } else {
   
        url = "/" + protocol + "/" + url;
    }
    return url;
}