Understanding the Forms Authentication Ticket and Cookie
来源:互联网 发布:电脑做图软件 编辑:程序博客网 时间:2024/06/04 19:37
http://support.microsoft.com/kb/910443
ASP.NET Support Voice Column
Understanding the Forms Authentication Ticket and Cookie
To customize this column to your needs, we want to invite you to submit your ideas about topics that interest you and issues that you want to see addressed in future Knowledge Base articles and Support Voice columns. You can submit your ideas and feedback using theAsk For It form. There's also a link to the form at the bottom of this column.On This Page
Introduction
Welcome to the Microsoft ASP.NET Support Voice column! I am Nilay B. Shah with the ASP.NET developer support team. I have been working with ASP.NET support for more than one and a half years. Forms Authentication is really a cool authentication feature. This article covers some issues that users have found confusing with forms authentication, such as the relationship of the forms authentication ticket and the forms authentication cookie and their relevant settings. I would like to thank Jerry Orman, technical lead for the ASP.NET support team, for his incredible help!People sometimes wonder about forms authentication "tickets" and "cookies" because they are closely related. I have come across questions such as these: Can anyone explain the difference between the cookie expiration and the ticket expiration? When the cookie expires, the user will be redirected to the logon page. What happens when the ticket expires? Will it also make the cookie expire? What does SlidingUpdate actually update?
I will focus on these two aspects of Forms Authentication in this article to answer the following questions:
- What is forms authentication ticket and forms authentication cookie? How are they related?
- What is the role of a ticket in Forms Authentication?
- How are cookie expiration and ticket expiration related?
- How does sliding expiration work in the context of forms authentication ticket and forms authentication cookie?
- Where can the time-out property of the forms authentication cookie and forms authentication ticket be set?
- Issue scenario: The forms authentication may time out before the timeout attribute value that is set in the configuration file
Back to the top | Give Feedback
What is forms authentication ticket and forms authentication cookie? How are they related?
Forms authentication cookie is nothing but the container for forms authentication ticket. The ticket is passed as the value of the forms authentication cookie with each request and is used by forms authentication, on the server, to identify an authenticated user.However, if we choose to use cookieless forms authentication, the ticket will be passed in the URL in an encrypted format. Cookieless forms authentication is used because sometimes the client browsers block cookies. This feature is introduced in the Microsoft .NET Framework 2.0.
For more information, visit the following Microsoft Developer Network (MSDN) Web site:
http://msdn2.microsoft.com/en-us/library/system.web.configuration.formsauthenticationconfiguration.cookieless.aspx
What is the role of a ticket in Forms Authentication?
The forms authentication ticket is used to tell the ASP.NET application who you are. Thus, ticket is building block of Forms Authentication's security.The ticket is encrypted and signed using the <machineKey> configuration elementof the server's Machine.config file. ASP.NET 2.0 uses the decryptionKey and the new decryption attribute of the <machineKey> element to encrypt forms authentication tickets. The decryption attribute lets you specify the encryption algorithm to use. ASP.NET 1.1 and 1.0 use 3DES encryption, which is not configurable. Tampering with the ticket value is determined by a failure to decrypt the ticket on the server. As a result, the user will be redirected to the logon page.
If the application is deployed in a Web farm, you must make sure that the configuration files on each server share the same value for the validationKey and decryptionKey attributes in the <machineKey> tag, which are used for hashing and decryption of the ticket respectively. You must do this because you cannot guarantee which server will handle successive requests. For more information about FormsAuthenticationTicket encryption and Web farm deployment considerations, visit the following MSDN Web site:
http://msdn2.microsoft.com/en-us/library/ms998288.aspx
A walk through of methods to manually generate keys can be found in the following Microsoft Knowledge Base articles:312906 How to create keys by using Visual C# .NET for use in Forms Authentication
313091 How to create keys by using Visual Basic .NET for use in Forms Authentication
Forms authentication tickets can be generated manually by using the FormsAuthenticationTicket class. For more information, visit the following MSDN Web site:http://msdn2.microsoft.com/en-us/library/system.web.security.formsauthenticationticket.aspx
How are cookie expiration and ticket expiration related?
In case of non-persistent cookie, if the ticket is expired, cookie will also expire, and the user will be redirected to the logon page. On the other side, if the ticket is marked as persistent, where the cookie is stored on the client box, browsers can use the same authentication cookie to log on to the Web site any time. However, we can use the FormsAuthentication.SignOutmethod to delete persistent or non-persistent cookies explicitly.For more information about the FormsAuthentication.SignOut method, visit the following MSDN Web site:
http://msdn2.microsoft.com/en-us/library/system.web.security.formsauthentication.signout.aspx
With cookieless forms authentication, if the browser is closed, the ticket is lost and a new ticket will be generated on the next request.How does sliding expiration work in the context of forms authentication ticket and forms authentication cookie?
Sliding expiration works exactly the same way!Let us take an example: If the logon page is accessed at 5:00 00:00:00 PM, it should expire at 5:10 00:00:00 PM if the timeoutattribute is 10 and the slidingExpiration attribute is set to TRUE. Now, if any Web page is browsed again at 5:05 00:00:00 PM, the cookies and ticket time-out period will be reset to 5:15 00:00:00 PM.
Note If the Web page is accessed before half of the expiration time passes, the ticket expiration time will not be reset. Fore example, if any Web page is accessed again at 5:04 00:00:00 PM, the cookies and ticket timeout period will not be reset.
For more information, visit the following MSDN Web site:
http://msdn2.microsoft.com/en-us/library/1d3t3c61(vs.71).aspx
Where can the time-out value of the forms authentication cookie and forms authentication ticket be set?
The only setting that you can make is in the Web.config file or the Machine.config file, in the <forms> tag. This change will determine the time-out period of forms authentication in the context of a ticket or cookie unless the ticket is generated manually.<!--forms Attributes: name="[cookie name]" - Sets the name of the cookie used for Forms Authentication.loginUrl="[url]" - Sets the URL to redirect client to for authentication.protection="[All|None|Encryption|Validation]" - Sets the protection mode for data in cookie.timeout="[minutes]" - Sets the duration of time for cookie to be valid (reset on each request).path="/" - Sets the path for the cookie.requireSSL="[true|false]" - Should the forms authentication cookie be sent only over SSL?slidingExpiration="[true|false]" - Should the forms authentication cookie and ticket be reissued if they are about to expire?-->
http://msdn2.microsoft.com/en-us/library/1d3t3c61.aspx
If the ticket is generated manually by using the FormsAuthenticationTicket class, the time-out can be set through theExpiration attribute. This value will override the timeout attribute value specified in configuration files.For more information about FormsAuthenticationTicket members, visit the following MSDN Web site:
http://msdn2.microsoft.com/en-us/library/system.web.security.formsauthenticationticket_members.aspx
Issue scenario: The forms authentication may time out before the timeout attribute value that is set in the configuration file
If the forms authentication ticket is manually generated, the time-out property of the ticket will override the value that is set in the configuration file. Therefore, if that value is less than the value in the configuration file, the forms authentication ticket will expire before the configuration file timeout attribute value and vice-versa. For example, let's assume that the <forms>timeoutattribute is set to 30 in the Web.config file and the Expiration value of the ticket is set to 20 minutes. In this case, the forms authentication ticket will expire after 20 minutes and the user will have to log on again after that.Back to the top | Give Feedback
Related links
910439 Troubleshoot Forms Authentication
891032 Troubleshooting ASP.NET
301240 How to implement forms-based authentication in your ASP.NET application by using C# .NET
308157 How to implement forms-based authentication in your ASP.NET application by using Visual Basic .NET
I hope you found this information helpful in easing some of the confusion involved with ASP.NET forms authentication ticket and cookie. Remember, the Support Voice columns are for you! As always, feel free to submit ideas on topics you want addressed in future columns or in the Microsoft Knowledge Base using the Ask For It form.Back to the top | Give Feedback
- Understanding the Forms Authentication Ticket and Cookie
- forms authentication failed the ticket supplied was invalid错误 (Windows Server 2008 + IIS 7.5)
- 没有生成forms authentication cookie
- Understanding the PS_TOKEN Cookie
- Luba And The Ticket CodeForces
- Understanding and Configuring PPP CHAP Authentication
- How to authenticate against the Active Directory by using Forms authentication and Visual C# .NET
- [转贴]Forms authentication and role-based security
- ASP.NET Forms Authentication所生成Cookie的安全性
- ASP.NET Forms Authentication所生成Cookie的安全性
- ASP.NET Forms Authentication所生成Cookie的安全性
- ASP.NET Forms Authentication所生成Cookie的安全性
- ASP.NET Forms Authentication所生成Cookie的安全性
- ASP.NET Forms Authentication所生成Cookie的安全性
- ASP.NET Forms Authentication所生成Cookie的安全性
- codeforces 845B Luba And The Ticket
- Codeforces 845 B Luba And The Ticket
- codeforces 845B.Luba And The Ticket
- 中继卫星与用户航天器之间星间链路的研究
- 黑马程序员_面向对象2
- Div绝对定位js代码
- Flex开发ArcGIS问题集锦五:怎样显示本地地图
- 【Linux基础】无名管道
- Understanding the Forms Authentication Ticket and Cookie
- VC调试器高级应用----系统函数,DLL段点
- wampserver 多域名绑定+泛绑定
- 关于解耦/松散耦合,你可能忽略的一些视角
- 原来硬盘每个磁道的扇区数不一样
- 树索引(1)
- install 使用详解
- jstl——自定义标签步骤
- Apache启用性能优化——启用Gzip,JS压缩