What is the difference between Forms Authentication in ASP.NET Web Forms and ASP.NET MVC Framework.

Question

ICSM Computer · Answer

The core mechanism of Forms Authentication in ASP.NET Web Forms and
ASP.NET MVC (both in the .NET Framework) is essentially 
the same, because both are built on the same underlying ASP.NET pipeline. However, there are some
key differences in how it is used or integrated in each framework.
1. Authentication Engine – Same Infrastructure
Feature
ASP.NET Web Forms
ASP.NET MVC
Uses andlt;authentication mode="Forms"andgt; in web.config
Yes
Yes
Uses Forms Authentication cookie
Yes
Yes
Handles login with FormsAuthentication.SetAuthCookie() or 
Encrypt()
Yes
Yes
Handles logout with FormsAuthentication.SignOut()
Yes
Yes
Conclusion: The authentication backend is identical (Forms Auth in System.Web.Security).
2. Login Workflow – Procedural vs MVC Pattern
Aspect
ASP.NET Web Forms
ASP.NET MVC
User login form
Typically in .aspx page with Login control or custom logic
Razor View with controller action for POST
Login handler
In code-behind (e.g., Login.aspx.cs)
Controller action (e.g., AccountController.Login)
Navigation after login
Set via Response.Redirect() or andlt;forms loginUrl="..."andgt;
Use RedirectToAction() or Redirect() in controller
3. Role-based Authorization Usage
Feature
Web Forms
MVC
Use andlt;authorizationandgt; in web.config
Common
Works
Use [Authorize(Roles = "...")] attribute
Not applicable
Native to MVC
Assign roles from Forms ticket
(via Application_AuthenticateRequest)
Same method used
4. Extensibility and Patterns
Aspect
Web Forms
MVC
Logic separation (UI, business, data)
Weak (tightly coupled)
Strong (MVC pattern)
Testability
Poor
Good
Customizing authentication logic
More coupled with UI
Easier with filters, controllers, middleware logic
5. Anti-Forgery and Security Practices
Feature
Web Forms
MVC
CSRF protection
Manual or with ViewState
Built-in with [ValidateAntiForgeryToken]
Built-in AntiForgery support
NO
Yes via @Html.AntiForgeryToken()
Summary
Feature
ASP.NET Web Forms
ASP.NET MVC
Authentication mechanism
Same (FormsAuthentication)
Same (FormsAuthentication)
Login implementation
Page-based (code-behind)
Controller-based (MVC pattern)
Authorization config
andlt;authorizationandgt; in web.config
[Authorize] attribute or web.config
Role assignment
Via UserData and GenericPrincipal in both
and 
Logout
FormsAuthentication.SignOut()
FormsAuthentication.SignOut()
Separation of concerns
Weak
Strong
CSRF protection
Manual
Built-in support

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What is the difference between Forms Authentication in ASP.NET Web Forms and ASP.NET MVC Framework.

ICSM Computer

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1 Answers

1. Authentication Engine – Same Infrastructure

2. Login Workflow – Procedural vs MVC Pattern

3. Role-based Authorization Usage

4. Extensibility and Patterns

5. Anti-Forgery & Security Practices

Summary

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Feature	ASP.NET Web Forms	ASP.NET MVC
Uses `<authentication mode="Forms">` in `web.config`	Yes	Yes
Uses Forms Authentication cookie	Yes	Yes
Handles login with `FormsAuthentication.SetAuthCookie()` or `Encrypt()`	Yes	Yes
Handles logout with `FormsAuthentication.SignOut()`	Yes	Yes

Aspect	ASP.NET Web Forms	ASP.NET MVC
User login form	Typically in `.aspx` page with `Login` control or custom logic	Razor View with controller action for `POST`
Login handler	In code-behind (e.g., `Login.aspx.cs`)	Controller action (e.g., `AccountController.Login`)
Navigation after login	Set via `Response.Redirect()` or `<forms loginUrl="...">`	Use `RedirectToAction()` or `Redirect()` in controller

Feature	Web Forms	MVC
Use `<authorization>` in `web.config`	Common	Works
Use `[Authorize(Roles = "...")]` attribute	Not applicable	Native to MVC
Assign roles from Forms ticket	(via `Application_AuthenticateRequest`)	Same method used

Aspect	Web Forms	MVC
Logic separation (UI, business, data)	Weak (tightly coupled)	Strong (MVC pattern)
Testability	Poor	Good
Customizing authentication logic	More coupled with UI	Easier with filters, controllers, middleware logic

Feature	Web Forms	MVC
CSRF protection	Manual or with ViewState	Built-in with `[ValidateAntiForgeryToken]`
Built-in AntiForgery support	NO	Yes via `@Html.AntiForgeryToken()`

Feature	ASP.NET Web Forms	ASP.NET MVC
Authentication mechanism	Same (FormsAuthentication)	Same (FormsAuthentication)
Login implementation	Page-based (code-behind)	Controller-based (MVC pattern)
Authorization config	`<authorization>` in `web.config`	`[Authorize]` attribute or web.config
Role assignment	Via `UserData` and `GenericPrincipal` in both
Logout	`FormsAuthentication.SignOut()`	`FormsAuthentication.SignOut()`
Separation of concerns	Weak	Strong
CSRF protection	Manual	Built-in support