Question

I have a problem (or at least I think I do). I am attempting to set the machine key of a site in it’s web.config in order to prepare for future sharing of the forms authentication data between sites. I first set the following in the web.config:

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

As a test, I wrote the following to test new machineKey element in the web.config:

var machineConfigMachineKey = (MachineKeySection)WebConfigurationManager.OpenMachineConfiguration().SectionGroups["system.web"].Sections["machineKey"];
var webConfigMachineKey = (MachineKeySection)WebConfigurationManager.OpenWebConfiguration("").SectionGroups["system.web"].Sections["machineKey"];
Response.Write("<pre>");
Response.Write("<b>machine.config decrypt:  </b>" + machineConfigMachineKey.DecryptionKey + "<br />");
Response.Write("<b>web.config decrypt:      </b>" + webConfigMachineKey.DecryptionKey + "<br />");
Response.Write("<br />");
Response.Write("<b>machine.config validate: </b>" + machineConfigMachineKey.ValidationKey + "<br />");
Response.Write("<b>web.config validate:     </b>" + webConfigMachineKey.ValidationKey + "<br />");
Response.Write("</pre>");
Response.End();

… which results in this display:

machine.config decrypt:  AutoGenerate,IsolateApps
web.config decrypt:      AutoGenerate,IsolateApps

machine.config validate: AutoGenerate,IsolateApps
web.config validate:     AutoGenerate,IsolateApps

Obviously I am super confused by this, as I was expecting to see the custom values from the new machineKey element in the web.config instead of “AutoGenerate,IsolateApps”.

Am I missing something here that should be brutally obvious to me?

Thanks 🙂

Answer 1

Use the static API WebConfigurationManager.GetSection("system.web/machineKey") instead. It automatically performs the logic of traversing the config hierarchy, finding the most applicable one (generally ~/Web.config for the current application), and pulling out its specific values.