How to Prevent User to change html textbox value using developer tool in browser

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I want crate calculation form i have 3 textbox
1- Quantity
2- Rate
3- Total Amount (this textbox is readonly)
Total Amount = (Quentity * Rate) but after calculation i can change TotalAmount value using browser inspect element.
So I want user can't change textbox value, i am using MVC Razor.

Posted 23-Sep-15 0:17am

Ravi Kant Rajput--From-Kanpur

Updated 20-Mar-20 2:11am

v2

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aarif moh shaikh 23-Sep-15 6:31am

you can disable right click of browsers

ZurdoDev 20-Mar-20 8:22am

That won't help. User can still click F12 or use other browsers.

2 solutions

Solution 3

You can't stop people using dev tools etc, the solution to your problem is to use html and http properly. If you want the total amount field to be one you control and not the user, then that's what you do. Show it as a label or text rather than a textbox. In your form actions when you want the total amount you calculate it from the amount * quantity.

Posted 23-Sep-15 2:07am

F-ES Sitecore

v2

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Ravi Kant Rajput--From-Kanpur 23-Sep-15 8:26am

Thanks for response

But i want calculate value on textbox change event and on submit button click we want store in database

F-ES Sitecore 23-Sep-15 8:30am

You can re-calculate on the change events of the textbox if you want, but update the html of the label rather than the value of a textbox. The value you actually use should be calculated from the quantity and amount, and you shouldn't represent the amount as a textbox either. You should be submitting a quantity (textbox), a product ID (or whatever it is you're adding) and in your action you get the amount from the ID and multiply that by the given quantity and that is your total. Never trust data that comes from the client....that is how you secure your site. Not by disabling F12 or right-clicks or by adding reams of javascript that hackers will disable anyway.

Richard Deeming 23-Sep-15 9:08am

+50 for that! :)

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Sisir Patro · Accepted Answer · 2015-09-23T00:35:00

Solution 1

Hi,

You can disable right click and the F12 button to prevent the issue.
Follow the below links.

1.) Disable right click
2.) Disable F12 button

Thanks,
Sisir Patro

Posted 23-Sep-15 0:35am

Sisir Patro

Comments

Ravi Kant Rajput--From-Kanpur 23-Sep-15 7:53am

Hi,

In Asp.net we do not face this type of problem but currently i switch in mvc razor we face lot of security problem in mvc . please suggest me i want create simple calculation form using razor.

[no name] 23-Sep-15 7:59am

I am not sure about the razor. If you will handle this using the javascript or jquery I believe it will work for all.

Ravi Kant Rajput--From-Kanpur 23-Sep-15 8:02am

Thank You Sir

[no name] 23-Sep-15 8:04am

You are welcome dear... :)

Richard Deeming 23-Sep-15 9:07am

Disabling the context menu and the F12 key will not stop anyone from using the developer tools!

Firstly, there are other key combinations to bring up the tools. For example, in Firefox, Ctrl+Shift+K

Secondly, even if you manage to disable every key combination, you can still use the menu to bring up the developer tools. Javascript code is not able to interfere with the browser's menu, as that would be a major security risk.

[no name] 23-Sep-15 9:24am

Yes, I do agree. We need to take care of all the possible combinations in code explicitly. I had already updated this to the User.