JavaScript log-in validation by-passed by IE8 - javascript

I have a log-in web page that uses JavaScript for name and password validation. It works fine in Mozilla Firefox, but IE8 allows logging in without entering name and or password. It posts a script-restriction warning which, when you click on it, you can chose to enable the JavaScript. That's fine except you can just bypass that step by clicking the Log In button on the web page and you're in. That's a big problem. So it's not running the JavaScript. That defeats the whole purpose of the page.
This (xhtml) form tag calls the JavaScript:
form name="form1" action="TestAccess.htm" onsubmit="return butCheck_onclick()"
This input tag contains the log-in button:
input type="submit" class="center" value="Log In"
I need some kind of work-around so that I can fool IE into either running the JavaScript before loading the next page or some way of stopping the HTML from allowing the next page to load before it runs the JavaScript. But then why would I need the JavaScript if I could implement such restrictions in HTML? I hope I'm making sense. Thanks for any help you can give. ---Andy V.
Here's the JavaScript function I have:
<script language="javascript">
var global="";
function butCheck_onclick()
{
var password = document.form1.password.value;
var Name = document.form1.memName.value;
/*if(Name=="")
{
alert("Enter User name and password.");
} */
var swFound= "NF";
var valName= new Array();
valName[0]= "Roland";
valName[1]= "Korg";
valName[2]= "Peavy";
var valpassword= new Array();
valpassword[0]= "123";
valpassword[1]= "456";
valpassword[2]= "789";
for(var loop=0; loop < valName.length; loop++)
{
if(Name==valName[loop])
{
swFound="F";
if(Name!=valName[loop])
{
swFound="NF";
}
if(password!=valpassword[loop])
{
alert("Invalid password. Please enter a valid password.")
document.form1.password.focus();
document.form1.password.select();
return false;
}
}
}
if (swFound!="F")
{
alert("Invalid last name entry. Please enter a valid last name.")
document.form1.memName.focus();
document.form1.memName.select();
return false;
}
}
</script>

You should never do authentication on the client side. Always do your username/password check on the server side.
In your code, for example, all I would have to do is view the source of the page and copy/paste the username and password.
or even just copy paste the destination url.
Furthermore, simply disabling javascript would clearly be enough.
The only validation you might do on the clientside is determining (at registration time) if the entered values are of the right length, etc. (and duplicated on the server side)
EDIT:
see The definitive guide to form-based website authentication for some good advice from SO users on website authentication.

You can use this code:
form name="form1" action="TestAccess.htm"
input type="button" class="center" value="Log In" onclick="butCheck_onclick()"
function butCheck_onclick() {
// do validation returnig false if something is wrong
// when all is good submit the form
form1.submit();
}
IMPORTANT notes:
You force your users to have
javascript enabled. Maybe this is
not a problem in your project.
Do you realize that anyone who does a
"View source" will see the usernames
and passwords?

What's the purpose of JavaScript embedded passwords? "As is" anyone can see these just by doing "View Source"?
But basically you need return false not FROM within for loop but AFTER if your condition fails

Related

How would I save input from a text box and then move to the next page? (Javascript/HTML)

As part of my new job, I'm creating a small form where users answer a question and this is then saved and output at the end of the pages.
I started off with having a prompt where users were asked to explain their answers (which worked perfectly!), however I've been asked to change this to an input box.
Essentially the process I need to do is:
User enters in text box -> Clicks next button -> save input to session variable and move to next page
So far, I have the following HTML in the body:
<form name="next" action='#' method=post>
Explanation:<input type="text" id="xp" required><br>
<button class="nextButton" onclick="return explanation()">Next</button>
</form>
with the corresponding javascript:
function explanation() {
var exp = document.getElementById('xp').value;
sessionStorage.setItem("p1_reason", exp);
alert(exp);
document.location.href = 'page2.html';
}
So far the result of this is:
The text box is cleared, but nothing is saved or displayed onscreen
The next page is not displayed.
Any help/advice would be appreciated. I'm relatively new to js so I'd be grateful! I'm well aware that there are similar questions around, I just can't seem to see where I'm going wrong.
#David is right. You can add event.preventDefault() function to prevent the form from its default behaviour, which is submitting. Otherwise your code seems to work.
function explanation() {
event.preventDefault(); // <-- add here
var exp = document.getElementById('xp').value;
sessionStorage.setItem("p1_reason", exp);
alert(exp);
window.location.href = 'page2.html';
}
Also, don't use document.location.href, it's deprecated. It's better to use window.location.href instead.
When you click on nextButton, the browser run explanation() and then try to execute the action of your form. Because your action is action='#' it just try to reload the page, preventing document.location.href for working properly.
Actually, you can try to don't enter nothing on the box and click on the button. The redirect will work because the form is empty, so there is nothing to submit.

Javascript and php execution priority in different browsers

I have a simple JS statement, which kind of "protects" me from using special characters in a login form on my website:
$("#login_button").click(function(){
formChecker();
});
function formChecker() {
var checkLogin = document.forms["loginForm"]["username"].value;
if ((checkLogin.indexOf("!") > -1) || (checkLogin.indexOf("#") > -1) || (checkLogin.indexOf("#") > -1)) {
alert("Special characters not allowed! Please use A-Z and numbers.");
document.location = "http://mywebsite.com/";
}
}
It works fine in Chrome. Whenever someone is using one of these characters, he is getting redirected instantly, so the php login script is not executed.
The problem occures when I am using it in Internet Explorer. It actually redirects my page but the php script is executed anyway. I have also tried window.location but it doesnt work at all in IE. What is the problem with this browser? Is the scipt priority different in different browsers?
What I mean is that on IE, even though the user is redirected, when he comes back to the website, he is logged in, but he shouldnt be. The chrome browser does not log in the user because page is redirected and it is how it should work.
This is not how to do form validation. There is no guarantee that click will be called on the button (eg the form might be submitted by pressing Enter); you aren't preventing the form from being submitted by doing a redirect (it's a race condition which might happen first); and also alert-and-redirect is pretty user-hostile.
You should be picking up the submit event on the form itself, and cancelling the event if you don't want the form to submit. For example add a div with id="formErrorMessage" to the page and then:
var goodUsernamePattern = /^[a-zA-Z0-9_-]+$/;
$('#loginForm').on('submit', function(event) {
if (!goodUsernamePattern.test(this.username.value)) {
event.preventDefault();
$('#formErrorMessage').text('Please enter a good username blah');
}
});

how to click the button the go to some page with javascript?

Is it possible to this?
http://url/jsp/index.jsp?id=xxx&password=xxx
I will include it in button, so when user click the button they go to some page also login with the id and password.
First: Putting an id and password in the page (whether in a link, in variables in code, or whatever) is a really bad idea. I strongly recommend you don't do that.
Assuming you really want to pass the id and password as query string parameters, yes it's possible:
<input type="button" onclick="location = 'http://url/jsp/index.jsp?id=xxx&password=xxx'" value="Login">
...but...this is what links are for.
Login
(You can style the link to look like a button if you want.)
If your goal is to go to that URL where access to the resource is protected by authentication (e.g., the browser would pop up a window asking for the username and password), then it depends on what kind of authentication is being used. For username and password ones, then you can, you just format the link differently:
http://username:password#url/jsp/index.jsp
(Not anymore, thankfully. As Jeremy Miller points out below, neither IE nor Chrome supports this (any more), and if the others haven't already followed suit, I wouldn't be surprised if they did at some point...)
But again, it's a really bad idea.
It is possible by this solution.
<button id="buttonID" link="your login url">login</button>
$(document).ready(function() {
$('#buttonID').click(function() {
var link = $(this).attr("link");
if(link ) {
window.location = link;
}
});
});
Assign the id to your button and replace "buttonID" with your actual button id. In click event do the above. The url must call the login function (controller function if it is MVC) which should accepts these parameters, do authentication and redirects to the landing page.

Broswer prompts user before leving page if a form is filled up and not submited

I have seen some sites that apparently execute some type of browser function that prompts the user if he/she wants to leave the page because there is a form not submitted:
"This page is asking you to confirm that you want to leave - data you have entered may not be saved."
I know this can be programmed in JS, but is there a native function or option that suggests the browser to detect this kind of scenarios?
I believe there is one because I have seen several websites (like facebook) reacting in the same way and they all seem to use this kind of browser option.
like autocomplete="on / off" allows the browser to fill up a form or not automatically
Thanks
<script language="JavaScript" type="text/javascript">
//<![CDATA[
window.onbeforeunload = function(){
// Check the state of the form
if(form_changed){
return false;
}else{
return true;
}
};
//]]>
</script>
When the function returns false to window.onbeforeunload, the browser automatically prompts the following question: "This page is asking you to confirm that you want to leave - data you have entered may not be saved." (firefox)

Disable pasting text into HTML form

Is there a way using JavaScript to disable the ability to paste text into a text field on an HTML form?
E.g.
I have a simple registration form where the user is required to input their email twice. The second email entry is to verify there are no typos in the first email entry. However if the user copy/pastes their email then that defeats the purpose and I've been experiencing users having problems because they've input the wrong email and copy/pasted it.
Maybe I wasn't clear on my question but I am not trying to prevent people from copying (or drag selecting) text on their browser. I just want to stop them from pasting input into a text field to minimize user error.
Perhaps instead of using this "hack" you can suggest another solution to the core problem of what I'm trying to solve here? I've done less than half a dozen user tests and this has already happened twice. My audience does not have a high level of computer proficiency.
Don't do it. Don't mess with the user's browser. By Copy + Pasting into an E-Mail confirmation field, the user accepts responsibility over what they type. If they are dumb enough to copy + paste a faulty address (it has happened to me) then it's their own damn fault.
If you want to make sure that the E-Mail confirmation works out, have the user check their E-Mail while your site waits ("Please open your webmail program in a new window"). Show the E-Mail address in big fat letters ("The confirmation E-Mail was sent to.... made an error? CLick here to change).
Even better, if you can, let the user have some kind of limited access without confirming. That way, they can log in straight away and you improve your chances to keep in touch with the visitor even if the confirmation mail is blocked due to other reasons (e.g. spam filters).
Add a class of 'disablecopypaste' to the inputs you want to disable the copy paste functionality on and add this jQuery script
$(document).ready(function () {
$('input.disablecopypaste').bind('copy paste', function (e) {
e.preventDefault();
});
});
I recently had to begrudgingly disable pasting in a form element. To do so, I wrote a cross-browser* implementation of Internet Explorer's (and others') onpaste event handler. My solution had to be independent of any third-party JavaScript libraries.
Here's what I came up with. It doesn't completely disable pasting (the user can paste a single character at a time, for example), but it meets my needs and avoids having to deal with keyCodes, etc.
// Register onpaste on inputs and textareas in browsers that don't
// natively support it.
(function () {
var onload = window.onload;
window.onload = function () {
if (typeof onload == "function") {
onload.apply(this, arguments);
}
var fields = [];
var inputs = document.getElementsByTagName("input");
var textareas = document.getElementsByTagName("textarea");
for (var i = 0; i < inputs.length; i++) {
fields.push(inputs[i]);
}
for (var i = 0; i < textareas.length; i++) {
fields.push(textareas[i]);
}
for (var i = 0; i < fields.length; i++) {
var field = fields[i];
if (typeof field.onpaste != "function" && !!field.getAttribute("onpaste")) {
field.onpaste = eval("(function () { " + field.getAttribute("onpaste") + " })");
}
if (typeof field.onpaste == "function") {
var oninput = field.oninput;
field.oninput = function () {
if (typeof oninput == "function") {
oninput.apply(this, arguments);
}
if (typeof this.previousValue == "undefined") {
this.previousValue = this.value;
}
var pasted = (Math.abs(this.previousValue.length - this.value.length) > 1 && this.value != "");
if (pasted && !this.onpaste.apply(this, arguments)) {
this.value = this.previousValue;
}
this.previousValue = this.value;
};
if (field.addEventListener) {
field.addEventListener("input", field.oninput, false);
} else if (field.attachEvent) {
field.attachEvent("oninput", field.oninput);
}
}
}
}
})();
To make use of this in order to disable pasting:
<input type="text" onpaste="return false;" />
* I know oninput isn't part of the W3C DOM spec, but all of the browsers I've tested this code with—Chrome 2, Safari 4, Firefox 3, Opera 10, IE6, IE7—support either oninput or onpaste. Out of all these browsers, only Opera doesn't support onpaste, but it does support oninput.
Note: This won't work on a console or other system that uses an on-screen keyboard (assuming the on-screen keyboard doesn't send keys to the browser when each key is selected). If it's possible your page/app could be used by someone with an on-screen keyboard and Opera (e.g.: Nintendo Wii, some mobile phones), don't use this script unless you've tested to make sure the on-screen keyboard sends keys to the browser after each key selection.
Just got this, we can achieve it using onpaste:"return false", thanks to: http://sumtips.com/2011/11/prevent-copy-cut-paste-text-field.html
We have various other options available as listed below.
<input type="text" onselectstart="return false" onpaste="return false;" onCopy="return false" onCut="return false" onDrag="return false" onDrop="return false" autocomplete=off/><br>
You can..... but don't.
You should not be altering the default behaviour of a users browser. It really is bad usability for your web application. Also if a user wants to disable this hack then they can just disable javascript on their browser.
Just add these attributes to the textbox
ondragstart=”return false” onselectstart=”return false”
Crazy idea: Require the user to send you an email as part of the signup process. This would obviously be inconvenient when clicking on a mailto link doesn't work (if they're using webmail, for example), but I see it as a way to simultaneously guarantee against typos and confirm the email address.
It would go like this: They fill out most of the form, entering their name, password, and whatnot. When they push submit, they're actually clicking a link to send mail to your server. You've already saved their other information, so the message just includes a token saying which account this is for.
You can use jquery
HTML file
<input id="email" name="email">
jquery code
$('#email').bind('copy paste', function (e) {
e.preventDefault();
});
How about sending a confirmation email to the email address that the user has just entered twice in which there is a link to a confirmation URL on your site, then you know that they have got the message?
Anyone that doesn't click to confirm the receipt of the email may have entered their email address incorrectly.
Not a perfect solution, but just some ideas.
Extending #boycs answer, I would recommend also using "on".
$('body').on('copy paste', 'input', function (e) { e.preventDefault(); });
Functional approach with VanillaJS
function pasteNotAllowFunc(xid){
let myInput = document.getElementById(xid);
myInput.onpaste = (e) => e.preventDefault();
}
function copyNotAllowFunc(xid){
let myInput = document.getElementById(xid);
myInput.oncopy = (e) => e.preventDefault();
}
copyNotAllowFunc('copyInput')
pasteNotAllowFunc('pasteInput')
Copy
<input id="copyInput" value="copy not allow" />
<hr/>
Paste
<input id="pasteInput" value="paste not allow"/>
<hr/>
Textarea
<textarea id="test" value="Paste here"></textarea>
if you have to use 2 email fields and are concerned about the user incorrectly pasting the same mistyped email from field 1 to field 2 then i'd say show an alert (or something more subtle) if the user pastes something into the second email field
document.querySelector('input.email-confirm').onpaste = function(e) {
alert('Are you sure the email you\'ve entered is correct?');
}
this way you don't disable paste, you just give them a friendly reminder to check what they've presumably typed in the first field and then pasted to the second field is correct.
however, perhaps a single email field with autocomplete on is all that's needed. chances are they've filled their email in correctly before on another site at some point and the browser will suggest to fill the field with that email
<input type="email" name="email" required autocomplete="email">
You could attach a "keydown" listener to the input box to detect whether or not the Ctrl + V keys are being pressed and, if so, stop the event or set the input box's value to ''.
That wouldn't handle right clicking and pasting or pasting from the Edit menu of the browser, though. You may need to add a "last length" counter to the keydown listener and use an interval to check the field's current length to see if it increase since the last keystroke.
Neither is recommended, though. Form fields with paste disabled are extremely frustrating. I'm capable of typing my email correctly the first time, so I reserve the right to paste it into the second box.
Add a second step to your registration process. First page as usual, but on reload, display a second page and ask the email again. If it's that important, the user can handle it.
Simple solution: just reverse the registration process: instead of requiring confirmation at the end of registration process, request confirmation at the beginning of it! I.e. the registration process started with a simple form asking for e-mail address and nothing else. Upon submitting, an e-mail with link to a confirmation page unique to the e-mail address sent out. The user go to that page, then the rest of information for the registration (user name, full name, etc.) will be requested.
This is simple since the website does not even need to store anything before confirmation, the e-mail address can be encrypted with a key and attached as part of the confirmation page address.
from
Some may suggest using Javascript to capture the users' actions, like right-clicking the mouse or the Ctrl+C / Ctrl+V key combinations and then stopping the operation. But this is obviously not the best or simplest solution.
The solution is integrated in the input field properties itself together with some event capturing using Javascript.
In order to disabled the browsers' autocomplete, simply add the attribute to the input field. It should look something like this:
<input type="text" autocomplete="off">
And if you want to deny Copy and Paste for that field, simply add the Javascript event capturing calls oncopy, onpaste, and oncut and make them return false, like so:
<input type="text" oncopy="return false;" onpaste="return false;" oncut="return false;">
The next step is using onselectstart to deny the input field's content selection from the user, but be warned: this only works for Internet Explorer. The rest of the above work great on all the major browsers: Internet Explorer, Mozilla Firefox, Apple Safari (on Windows OS, at least) and Google Chrome.
Check validity of the MX record of the host of the given email. This can eliminate errors to the right of the # sign.
You could do this with an AJAX call before submit and/or server side after the form is submitted.
Using jquery, you can avoid copy paste and cut using this
$('.textboxClass').on('copy paste cut', function(e) {
e.preventDefault();
});
I use this vanilla JS solution:
const element = document.getElementById('textfield')
element.addEventListener('paste', e => e.preventDefault())
With Jquery you can do this with one simple codeline.
HTML:
<input id="email" name="email">
Code:
$(email).on('paste', false);
JSfiddle: https://jsfiddle.net/ZjR9P/2/
You can disable the copy paste option with jQuery by the below script:
jQuery("input").attr("onpaste","return false;");
of by using the bellow oppaste attribute into the input fields.
onpaste="return false;"
what about using CSS on UIWebView? something like
<style type="text/css">
<!—-
* {
-webkit-user-select: none;
}
-->
</style>
also you can read detail about block copy-paste using CSS
http://rakaz.nl/2009/09/iphone-webapps-101-getting-safari-out-of-the-way.html
I did something similar to this for http://bookmarkchamp.com - there I wanted to detect when a user copied something into an HTML field. The implementation I came up with was to check the field constantly to see if at any time there was suddenly a whole lot of text in there.
In other words: if once milisecond ago there was no text, and now there are more than 5 chars... then the user probably pasted something in the field.
If you want to see this working in Bookmarkchamp (you need to be registered), paste a URL into the URL field (or drag and drop a URL in there).
The way that I would resolve the issue of confirming an email address is as follows:
Before going through the main process - say registering the user - first ask them to enter their email address.
Generate a unique code and send it to that email address.
If user has entered the correct email address, they will get the code.
User must enter that code along with their email address, and their other required information, so they can complete the registration. - Please note that if this time they enter a wrong email address (or a wrong code), because it will not match with the code, the registration will not go through, and the user will be informed right away.
If the email address, the code, and other registration information have been entered correctly, the registration is complete and user can start using the system immediately. - no need to to respond to any other email address in order to activate their account
For better security, the code should have a limited lifetime, and it should be allowed only once in the registration process.
Also, in order to prevent any malicious robot applications, it is better to accompany the first step with captcha or a similar mechanism.
if you are using angular
<input type="number" (keydown)="refuseInvalid($event) (input)="refuseInvalid($event)" (paste)="refuseInvalid($event)"> </input>
then in your javascript or typescript
refuseInvalid(event) {
if (event.type == 'input' || event.type == 'paste') {
event.preventDefault()
return false;
}
if (["-", "+", "e", "."].includes(event.key)) {
event.preventDefault();
return false
}
}
Please note the use of ".". It will disallow decimal point numbers too.
Hope below code will work :
<!--Disable Copy And Paste-->
<script language='JavaScript1.2'>
function disableselect(e){
return false
}
function reEnable(){
return true
}
document.onselectstart=new Function ("return false")
if (window.sidebar){
document.onmousedown=disableselect
document.onclick=reEnable
}
</script>

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