1 files changed, 162 insertions, 0 deletions

diff --git a/debug.c b/debug.c
new file mode 100644
index 0000000..e48a9eb
--- /dev/null
+++ b/debug.c
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+/*
+ * Copyright (c) 2004 Security Architects Corporation. All rights reserved.
+ *
+ * Module Name:
+ *
+ *              debug.c
+ *
+ * Abstract:
+ *
+ *              This module implements various debug hooking routines.
+ *
+ * Author:
+ *
+ *              Eugene Tsyrklevich 23-Apr-2004
+ *
+ * Revision History:
+ *
+ *              None.
+ */
+
+
+#include <NTDDK.h>
+#include "debug.h"
+#include "hookproc.h"
+#include "procname.h"
+#include "learn.h"
+#include "log.h"
+
+
+#ifdef ALLOC_PRAGMA
+#pragma alloc_text (INIT, InitDebugHooks)
+#endif
+
+
+fpZwDebugActiveProcess  OriginalNtDebugActiveProcess = NULL;
+
+
+//XXX http://www.nsfocus.net/index.php?act=magazine&do=view&mid=2108
+
+
+/*
+ * IsDebuggingAllowed()
+ *
+ * Description:
+ *              Check whether the current process is allowed to use debugging functionality.
+ *
+ * Parameters:
+ *              None.
+ *
+ * Returns:
+ *              FALSE if debugging is disabled. TRUE otherwise.
+ */
+
+BOOLEAN
+IsDebuggingAllowed()
+{
+        PIMAGE_PID_ENTRY        CurrentProcess;
+        BOOLEAN                         DebuggingAllowed = FALSE;
+
+
+        /* check the global policy first */
+        if (! IS_DEBUGGING_PROTECTION_ON(gSecPolicy))
+                return TRUE;
+
+
+        /* now check the process specific policy */
+        CurrentProcess = FindImagePidEntry(CURRENT_PROCESS_PID, 0);
+
+        if (CurrentProcess != NULL)
+        {
+                DebuggingAllowed = ! IS_DEBUGGING_PROTECTION_ON(CurrentProcess->SecPolicy);
+        }
+        else
+        {
+                LOG(LOG_SS_DEBUG, LOG_PRIORITY_DEBUG, ("%d IsDebuggingAllowed: CurrentProcess = NULL!\n", CURRENT_PROCESS_PID));
+        }
+
+
+        return DebuggingAllowed;
+}
+
+
+
+/*
+ * HookedNtDebugActiveProcess()
+ *
+ * Description:
+ *              This function mediates the NtDebugActiveProcess() system service and disallows
+ *              debugging.
+ *
+ * Parameters:
+ *              Those of NtDebugActiveProcess().
+ *
+ * Returns:
+ *              STATUS_ACCESS_DENIED if the call does not pass the security policy check.
+ *              Otherwise, NTSTATUS returned by NtDebugActiveProcess().
+ */
+
+NTSTATUS
+NTAPI
+HookedNtDebugActiveProcess
+(
+        UINT32  Unknown1,
+        UINT32  Unknown2
+)
+{
+        HOOK_ROUTINE_ENTER();
+
+
+        LOG(LOG_SS_DEBUG, LOG_PRIORITY_DEBUG, ("HookedNtDebugActiveProcess(%x %x)\n", Unknown1, Unknown2));
+
+        if (LearningMode == FALSE && IsDebuggingAllowed() == FALSE)
+        {
+                LOG(LOG_SS_DEBUG, LOG_PRIORITY_DEBUG, ("%d (%S) HookedNtDebugActiveProcess: disallowing debugging\n", (ULONG) PsGetCurrentProcessId(), GetCurrentProcessName()));
+
+                LogAlert(ALERT_SS_DEBUG, OP_DEBUG, ALERT_RULE_NONE, ACTION_DENY, ALERT_PRIORITY_MEDIUM, NULL, 0, NULL);
+
+                HOOK_ROUTINE_EXIT( STATUS_ACCESS_DENIED );
+        }
+
+
+        ASSERT(OriginalNtDebugActiveProcess);
+
+        rc = OriginalNtDebugActiveProcess(Unknown1, Unknown2);
+
+
+        if (LearningMode == TRUE)
+                TURN_DEBUGGING_PROTECTION_OFF(NewPolicy);
+
+
+        HOOK_ROUTINE_EXIT(rc);
+}
+
+
+
+/*
+ * InitDebugHooks()
+ *
+ * Description:
+ *              Initializes all the mediated debug operation pointers. The "OriginalFunction" pointers
+ *              are initialized by InstallSyscallsHooks() that must be called prior to this function.
+ *
+ *              NOTE: Called once during driver initialization (DriverEntry()).
+ *
+ * Parameters:
+ *              None.
+ *
+ * Returns:
+ *              TRUE to indicate success, FALSE if failed.
+ */
+
+BOOLEAN
+InitDebugHooks()
+{
+        if ( (OriginalNtDebugActiveProcess = (fpZwDebugActiveProcess) ZwCalls[ZW_DEBUG_ACTIVEPROCESS_INDEX].OriginalFunction) == NULL)
+        {
+                /* does not exist on Win2K */
+                LOG(LOG_SS_DEBUG, LOG_PRIORITY_DEBUG, ("InitDebugHooks: OriginalNtDebugActiveProcess is NULL\n"));
+        }
+
+        return TRUE;
+}