https://buuoj.cn/challenges#[FlareOn4]login
document.getElementById("prompt").onclick = function () {
var flag = document.getElementById("flag").value;
var rotFlag = flag.replace(/[a-zA-Z]/g, function(c){return String.fromCharCode((c <= "Z" ? 90 : 122) >= (c = c.charCodeAt(0) + 13) ? c : c - 26);});
if ("PyvragFvqrYbtvafNerRnfl@syner-ba.pbz" == rotFlag) {
alert("Correct flag!");
} else {
alert("Incorrect flag, rot again");
}
}rot加密 中的 rot13
解密得
ClientSideLoginsAreEasy@flare-on.com