Machine Key for ASP.NET core applications in Webfarm

     

Scenario:

MVC issue with 'The antiforgery token could not be decrypted' in web farm.

Solution:

Generate a machine key and use the same key in web.config across all instances in the web farm

1. IIS Management console

2. Go to your site -> Machine Key -> Generate Keys -> Apply

    a. Validation method = "SHA1"

b. Encryption Method = "AES"

3. The machine key would be saved to the web.config file as below

<machineKey  
    validationKey="WDFDSFSDFSDF23423423423423WEREWRWERWEREWREW9F67897SDFDS89F7SD89F78SD97F98S7D89F7SD98F7SD98F7S9D"           
    decryptionKey="FSDGSDGSDFG6767FDSGFGFDGFDG78FD7G97FD98G"
    validation="SHA1"
    decryption="AES"
/>