js实现加密解密

废话不多说,直接上代码:

 
        if (pwd == null || pwd.length  10) {
            prand = (parseInt(prand.substring(0, 10)) + parseInt(prand.substring(10, prand.length))).toString();
        }
        prand = (mult * prand + incr) % modu;
        var enc_chr = "";
        var enc_str = "";
        for (var i = 0; i < str.length; i++) {
            enc_chr = parseInt(str.charCodeAt(i) ^ Math.floor((prand / modu) * 255));
            if (enc_chr < 16) {
                enc_str += "0" + enc_chr.toString(16);
            } else enc_str += enc_chr.toString(16);
            prand = (mult * prand + incr) % modu;
        }
        salt = salt.toString(16);
        while (salt.length < 8) salt = "0" + salt;
        enc_str += salt;
        return enc_str;
    }

    function decrypt(str, pwd) {
        if (str == null || str.length < 8) {
            alert("A salt value could not be extracted from the encrypted message because it's length is too short. The message cannot be decrypted.");
            return;
        }
        if (pwd == null || pwd.length  10) {
            prand = (parseInt(prand.substring(0, 10)) + parseInt(prand.substring(10, prand.length))).toString();
        }
        prand = (mult * prand + incr) % modu;
        var enc_chr = "";
        var enc_str = "";
        for (var i = 0; i < str.length; i += 2) {
            enc_chr = parseInt(parseInt(str.substring(i, i + 2), 16) ^ Math.floor((prand / modu) * 255));
            enc_str += String.fromCharCode(enc_chr);
            prand = (mult * prand + incr) % modu;
        }
        return enc_str;
    }
    // End -->