HRESULT IServerSecurity::ImpersonateClient();
This method allows a server to impersonate a client for the duration of a call. The server may impersonate the client on any secure call at identify, impersonate, or delegate level. At identify level, the server may only find out the clients name and perform ACL checks; it may not access system objects as the client. At delegate level the server may make off computer calls while impersonating the client. The impersonation information only lasts until the end of the current method call. At that time, IServerSecurity::RevertToSelf will automatically be called if necessary.
Impersonation information is not normally nested. The last call to any Win32 impersonation mechanism overrides any previous impersonation. However, in the apartment model, impersonation is maintained during nested calls. Thus if the server A receives a call from B, impersonates, calls C, receives a call from D, impersonates, reverts, and receives the reply from C, the impersonation will be set back to B, not A.
If IServerSecurity::ImpersonateClient is called on a thread other then the one that received the call, the impersonation will not automatically be revoked. It will be valid past the end of the call. However, IServerSecurity::ImpersonateClient must be called before the original call completes.
Argument
Type
Description
Returns
S_OK
Success.
E_FAIL
The caller can not impersonate the client identified by this ISeverSecurity object.