What is the idea behind IIdentity and IPrincipal in .NET
问题 So, what is the purpose for existence of both IIdentity and IPrincipal , and not some IIdentityMergedWithPrincipal ? When is it not enough to implement both in same class? Also, to understand purpose, I'd like to know where this concept comes from: It is originated in .Net There is concept of Identity/Principal as design pattern, which System.Security.Principal implemented in those interfaces It is originated somewhere else and supported for compatibility Therefore, does UserPrincipal from