http://bugs.winehq.org/show_bug.cgi?id=19781
--- Comment #6 from Dmitry Timoshkov dmitry@codeweavers.com 2009-09-30 07:54:41 --- The app does: GetUserNameEx(NameSamCompatible, user_name, &len); RpcBindingSetAuthInfoExW(&binding, user_name, RPC_C_AUTHN_LEVEL_PKT_PRIVACY, RPC_C_AUTHN_WINNT, NULL, RPC_C_AUTHN_DEFAULT, &qos); then an RPC call happens which leads to InitializeSecurityContextW() which fails.
The problem seems to be caused by the fact that the app doesn't pass any authentication info to RpcBindingSetAuthInfoExW, although MSDN states that
"When using the RPC_C_AUTHN_WINNT authentication service AuthIdentity should be a pointer to a SEC_WINNT_AUTH_IDENTITY structure" and "Specify a null value to use the security login context for the current address space."
The app passes NULL as AuthIdentity handle, and RpcBindingSetAuthInfoExW tries to get an existing authentication credentials, and it appears that secur32/ntlm_auth can't cope with that.