I'm contacting a web service using a certificate stored in Machine and in user space "myUser". When I contact the web service impersonating "myUser" from a win application all works well.
But when I contact this using SharePoint context (I have only 1 frontend) I have only sometimes the following error:
Could not establish trust relationship for the SSL/TLS secure channel with authority 'server.host:4443'
I verified that the web service is invoked using user "myUser" as expected but in SharePoint context sometimes this method crashes.
I don't know what can be the problem. It seems related to SharePoint/ASP.NET security context but all seems to be ok. Any suggestion?