VOID
NTAPI
NpFreeClientSecurityContext(IN PSECURITY_CLIENT_CONTEXT ClientContext)
{
TOKEN_TYPE TokenType;
PVOID ClientToken;
if (!ClientContext) return;
TokenType = SeTokenType(ClientContext->ClientToken);
ClientToken = ClientContext->ClientToken;
if ((TokenType == TokenPrimary) || (ClientToken))
{
ObDereferenceObject(ClientToken);
}
ExFreePool(ClientContext);
}
NTSTATUS FspFsvolSetSecurityPrepare(
PIRP Irp, FSP_FSCTL_TRANSACT_REQ *Request)
{
PAGED_CODE();
NTSTATUS Result;
SECURITY_SUBJECT_CONTEXT SecuritySubjectContext;
SECURITY_QUALITY_OF_SERVICE SecurityQualityOfService;
SECURITY_CLIENT_CONTEXT SecurityClientContext;
HANDLE UserModeAccessToken;
PEPROCESS Process;
/* duplicate the subject context access token into an impersonation token */
SecurityQualityOfService.Length = sizeof SecurityQualityOfService;
SecurityQualityOfService.ImpersonationLevel = SecurityIdentification;
SecurityQualityOfService.ContextTrackingMode = SECURITY_STATIC_TRACKING;
SecurityQualityOfService.EffectiveOnly = FALSE;
SeCaptureSubjectContext(&SecuritySubjectContext);
SeLockSubjectContext(&SecuritySubjectContext);
Result = SeCreateClientSecurityFromSubjectContext(&SecuritySubjectContext,
&SecurityQualityOfService, FALSE, &SecurityClientContext);
SeUnlockSubjectContext(&SecuritySubjectContext);
SeReleaseSubjectContext(&SecuritySubjectContext);
if (!NT_SUCCESS(Result))
return Result;
ASSERT(TokenImpersonation == SeTokenType(SecurityClientContext.ClientToken));
/* get a user-mode handle to the impersonation token */
Result = ObOpenObjectByPointer(SecurityClientContext.ClientToken,
0, 0, TOKEN_QUERY, *SeTokenObjectType, UserMode, &UserModeAccessToken);
SeDeleteClientSecurity(&SecurityClientContext);
if (!NT_SUCCESS(Result))
return Result;
/* get a pointer to the current process so that we can close the impersonation token later */
Process = PsGetCurrentProcess();
ObReferenceObject(Process);
/* send the user-mode handle to the user-mode file system */
FspIopRequestContext(Request, RequestAccessToken) = UserModeAccessToken;
FspIopRequestContext(Request, RequestProcess) = Process;
Request->Req.SetSecurity.AccessToken = (UINT_PTR)UserModeAccessToken;
return STATUS_SUCCESS;
}