Difference between revisions of "Setting the Machine Key"
(New page: There are several ways to get around this problem: 1) Host your site on a server that never restarts or recycles! Obviously, this is impossible! 2) Disable ViewstateMac by putting this ...) |
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| + | Sometimes when using ASP.NET enabled website you may get the following error | ||
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| + | '''Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that <machineKey> configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster.''' | ||
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There are several ways to get around this problem: | There are several ways to get around this problem: | ||
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3) Configure ASP.NET to not use Auto-Generated Key but rather a predefined key. This is the preferred method. | 3) Configure ASP.NET to not use Auto-Generated Key but rather a predefined key. This is the preferred method. | ||
| − | The third option is the most secure and the best one. There is a free Machine Key generator tool available at the following link | + | The third option is the most secure and the best one and we suggest to use this. There is a free Machine Key generator tool available at the following link |
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http://aspnetresources.com/tools/keycreator.aspx | http://aspnetresources.com/tools/keycreator.aspx | ||
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In order to generate the key using this tool Leave the defaults in place, validation key length 64, encryption key length 24, type sha1. Then Click Generate to create a random machine key for you and copy the result. | In order to generate the key using this tool Leave the defaults in place, validation key length 64, encryption key length 24, type sha1. Then Click Generate to create a random machine key for you and copy the result. | ||
Revision as of 18:08, 12 August 2008
Sometimes when using ASP.NET enabled website you may get the following error
Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that <machineKey> configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster.
There are several ways to get around this problem:
1) Host your site on a server that never restarts or recycles! Obviously, this is impossible!
2) Disable ViewstateMac by putting this “enableViewStateMac="false"” in your web.config. This approach is not 100% secure.
3) Configure ASP.NET to not use Auto-Generated Key but rather a predefined key. This is the preferred method.
The third option is the most secure and the best one and we suggest to use this. There is a free Machine Key generator tool available at the following link
http://aspnetresources.com/tools/keycreator.aspx
In order to generate the key using this tool Leave the defaults in place, validation key length 64, encryption key length 24, type sha1. Then Click Generate to create a random machine key for you and copy the result.
Now open the web.config file from your site. Find around line which shows <system.web> And paste in the <machineKey ... /> on the next line. Save that file.
