Hello,
Every time I add my own set of parameters to OAuthRequest.GetAuthorizationQuery() they are stripped off the resulting query string. However, the signature is being calculated taking them into consideration. This results in wrong authorization query being returned.
I believe the issue exists since 2.X. The issue lies in line 214 of OauthRequest.cs as my parameters do not begin with oauth_ and I the official standard says nothing about such a restriction