VOID
SeReleaseSubjectContext (
__inout PSECURITY_SUBJECT_CONTEXT SubjectContext
)
/*++
Routine Description:
This routine releases a subject security context previously captured by
SeCaptureSubjectContext().
Arguments:
SubjectContext - Points to a SECURITY_SUBJECT_CONTEXT data structure
containing a subject's previously captured security context.
Return Value:
none.
--*/
{
PAGED_CODE();
#if DBG || TOKEN_LEAK_MONITOR
if (SubjectContext->PrimaryToken) {
InterlockedDecrement(&((PTOKEN)(SubjectContext->PrimaryToken))->CaptureCount);
if (SubjectContext->PrimaryToken == SepTokenLeakToken)
{
DbgBreakPoint();
}
}
if (SubjectContext->ClientToken) {
InterlockedDecrement(&((PTOKEN)(SubjectContext->ClientToken))->CaptureCount);
if (SubjectContext->ClientToken == SepTokenLeakToken)
{
DbgBreakPoint();
}
}
#endif
PsDereferencePrimaryTokenEx( PsGetCurrentProcess(), SubjectContext->PrimaryToken );
SubjectContext->PrimaryToken = NULL;
PsDereferenceImpersonationToken( SubjectContext->ClientToken );
SubjectContext->ClientToken = NULL;
return;
}
NTSTATUS
SepOpenTokenOfThread(
IN HANDLE ThreadHandle,
IN BOOLEAN OpenAsSelf,
OUT PACCESS_TOKEN *Token,
OUT PETHREAD *Thread,
OUT PBOOLEAN CopyOnOpen,
OUT PBOOLEAN EffectiveOnly,
OUT PSECURITY_IMPERSONATION_LEVEL ImpersonationLevel
)
/*++
Routine Description:
This function does the thread specific processing of
an NtOpenThreadToken() service.
The service validates that the handle has appropriate access
to reference the thread. If so, it goes on to increment
the reference count of the token object to prevent it from
going away while the rest of the NtOpenThreadToken() request
is processed.
NOTE: If this call completes successfully, the caller is responsible
for decrementing the reference count of the target token.
This must be done using PsDereferenceImpersonationToken().
Arguments:
ThreadHandle - Supplies a handle to a thread object.
OpenAsSelf - Is a boolean value indicating whether the access should
be made using the calling thread's current security context, which
may be that of a client (if impersonating), or using the caller's
process-level security context. A value of FALSE indicates the
caller's current context should be used un-modified. A value of
TRUE indicates the request should be fulfilled using the process
level security context.
Token - If successful, receives a pointer to the thread's token
object.
CopyOnOpen - The current value of the Thread->Client->CopyOnOpen field.
EffectiveOnly - The current value of the Thread->Client->EffectiveOnly field.
ImpersonationLevel - The current value of the Thread->Client->ImpersonationLevel
field.
Return Value:
STATUS_SUCCESS - Indicates the call completed successfully.
STATUS_NO_TOKEN - Indicates the referenced thread is not currently
impersonating a client.
STATUS_CANT_OPEN_ANONYMOUS - Indicates the client requested anonymous
impersonation level. An anonymous token can not be openned.
status may also be any value returned by an attemp the reference
the thread object for THREAD_QUERY_INFORMATION access.
--*/
{
NTSTATUS
Status;
KPROCESSOR_MODE
PreviousMode;
SE_IMPERSONATION_STATE
DisabledImpersonationState;
BOOLEAN
RestoreImpersonationState = FALSE;
PreviousMode = KeGetPreviousMode();
//
// Disable impersonation if necessary
//
if (OpenAsSelf) {
RestoreImpersonationState = PsDisableImpersonation(
PsGetCurrentThread(),
&DisabledImpersonationState
);
}
//
// Make sure the handle grants the appropriate access to the specified
// thread.
//
Status = ObReferenceObjectByHandle(
ThreadHandle,
THREAD_QUERY_INFORMATION,
PsThreadType,
PreviousMode,
(PVOID *)Thread,
NULL
);
if (RestoreImpersonationState) {
PsRestoreImpersonation(
PsGetCurrentThread(),
&DisabledImpersonationState
);
}
if (!NT_SUCCESS(Status)) {
return Status;
}
//
// Reference the impersonation token, if there is one
//
(*Token) = PsReferenceImpersonationToken( *Thread,
CopyOnOpen,
EffectiveOnly,
ImpersonationLevel
);
//
// Make sure there is a token
//
if ((*Token) == NULL) {
ObDereferenceObject( *Thread );
(*Thread) = NULL;
return STATUS_NO_TOKEN;
}
//
// Make sure the ImpersonationLevel is high enough to allow
// the token to be openned.
//
if ((*ImpersonationLevel) <= SecurityAnonymous) {
PsDereferenceImpersonationToken( (*Token) );
ObDereferenceObject( *Thread );
(*Thread) = NULL;
(*Token) = NULL;
return STATUS_CANT_OPEN_ANONYMOUS;
}
return STATUS_SUCCESS;
}
