// 8ball.js
// 7 Dec 2011
// JavaScript file loaded using Cross-Site Scripting injection
// INFO 343 Autumn 2011, Morgan Doocy
// (from CSE 190 M, Marty Stepp)
// when the page has finished loading...
document.observe('dom:loaded', function() {
// ...attach a 'click' event handler to the ask button
$('ask').observe('click', ask);
// was a 'question' parameter passed?
var matches = location.search.match(/question=([^&]+)/);
if (matches) {
// it was; decode the value in the URL
var question = decodeURI(matches[1]);
// sanitize it for HTML context
question = question.replace(/</g, '<');
question = question.replace(/>/g, '>');
question = question.replace(/'/g, ''');
question = question.replace(/"/g, '"');
// inject it into #questionoutput and #questioninput
$('questioninput').value = $('questionoutput').innerHTML = question;
} else if (matches = location.search.match(/imgfile=([^&]+)/)) {
// look for an 'imgfile' parameter as well: filename
// illustrates vulnerability in a different context: could pass 'empty.gif" onload="...' to exploit
var imgfile = decodeURI(matches[1]);
// sanitize it for HTML context
question = question.replace(/</g, '<');
question = question.replace(/>/g, '>');
question = question.replace(/'/g, ''');
question = question.replace(/"/g, '"');
// compose img tag HTML string with sanitized parameter
var imgcode = '<img src="' + imgfile + '" alt="some descriptive content" />';
$('questionoutput').innerHTML = imgcode;
} else {
// initially hide the response area (if there was no parameter passed)
$('response').hide();
}
});
// displays the question asked, and initiates an AJAX request to fetch possible responses
function ask() {
var question = $('questioninput').value;
$('questionoutput').innerHTML = question;
$('response').show();
$('answer').hide();
new Ajax.Request('sayings.txt', {
method: 'get',
onSuccess: gotResponse,
onFailure: ajaxFailure,
onException: ajaxFailure
});
}
// list of answers has come back from server; select a random response make it appear
function gotResponse(ajax) {
var sayings = ajax.responseText.split(/\r?\n/);
var rand = Math.floor(Math.random() * sayings.length);
$('answer').innerHTML = sayings[rand];
$('answer').appear();
}
// called in case of request failure or JavaScript/DOM exception
function ajaxFailure(ajax, exception) {
alert("Error making Ajax request:" +
"\n\nServer status:\n" + ajax.status + " " + ajax.statusText +
"\n\nServer response text:\n" + ajax.responseText);
if (exception) {
throw exception;
}
}