From: Mate Kukri <mate.kukri@canonical.com>
Date: Wed, 6 Dec 2023 15:47:42 +0000
Subject: Shell: Disable the Shell when SecureBoot is enabled and not in
 SetupMode

Signed-off-by: Mate Kukri <mate.kukri@canonical.com>
---
 ShellPkg/Application/Shell/Shell.c   | 14 ++++++++++++++
 ShellPkg/Application/Shell/Shell.h   |  3 +++
 ShellPkg/Application/Shell/Shell.inf |  2 ++
 ShellPkg/ShellPkg.dsc                |  1 +
 4 files changed, 20 insertions(+)

diff --git a/ShellPkg/Application/Shell/Shell.c b/ShellPkg/Application/Shell/Shell.c
index f95c799..502013d 100644
--- a/ShellPkg/Application/Shell/Shell.c
+++ b/ShellPkg/Application/Shell/Shell.c
@@ -357,6 +357,20 @@ UefiMain (
   EFI_HANDLE                      ConInHandle;
   EFI_SIMPLE_TEXT_INPUT_PROTOCOL  *OldConIn;
   SPLIT_LIST                      *Split;
+  UINT8                           SetupMode;
+
+  //
+  // Check for Secure Boot mode
+  //
+  if (IsSecureBootEnabled()) {
+    Status = GetSetupMode (&SetupMode);
+    if (EFI_ERROR (Status)) {
+        return (Status);
+    }
+    if (SetupMode != 1) {
+      return (EFI_SECURITY_VIOLATION);
+    }
+  }
 
   if (PcdGet8 (PcdShellSupportLevel) > 3) {
     return (EFI_UNSUPPORTED);
diff --git a/ShellPkg/Application/Shell/Shell.h b/ShellPkg/Application/Shell/Shell.h
index 89b4ac6..595ec79 100644
--- a/ShellPkg/Application/Shell/Shell.h
+++ b/ShellPkg/Application/Shell/Shell.h
@@ -11,9 +11,11 @@
 #define _SHELL_INTERNAL_HEADER_
 
 #include <Uefi.h>
+#include <UefiSecureBoot.h>
 
 #include <Guid/ShellVariableGuid.h>
 #include <Guid/ShellAliasGuid.h>
+#include <Guid/ImageAuthentication.h>
 
 #include <Protocol/LoadedImage.h>
 #include <Protocol/SimpleTextOut.h>
@@ -42,6 +44,7 @@
 #include <Library/HandleParsingLib.h>
 #include <Library/FileHandleLib.h>
 #include <Library/UefiHiiServicesLib.h>
+#include <Library/SecureBootVariableLib.h>
 
 #include "ShellParametersProtocol.h"
 #include "ShellProtocol.h"
diff --git a/ShellPkg/Application/Shell/Shell.inf b/ShellPkg/Application/Shell/Shell.inf
index f1e41de..340585f 100644
--- a/ShellPkg/Application/Shell/Shell.inf
+++ b/ShellPkg/Application/Shell/Shell.inf
@@ -47,6 +47,7 @@
   MdePkg/MdePkg.dec
   ShellPkg/ShellPkg.dec
   MdeModulePkg/MdeModulePkg.dec
+  SecurityPkg/SecurityPkg.dec
 
 [LibraryClasses]
   BaseLib
@@ -66,6 +67,7 @@
   SortLib
   HandleParsingLib
   UefiHiiServicesLib
+  SecureBootVariableLib
 
 [Guids]
   gShellVariableGuid                                      ## SOMETIMES_CONSUMES ## GUID
diff --git a/ShellPkg/ShellPkg.dsc b/ShellPkg/ShellPkg.dsc
index dd0d886..28d6a87 100644
--- a/ShellPkg/ShellPkg.dsc
+++ b/ShellPkg/ShellPkg.dsc
@@ -64,6 +64,7 @@
   DxeServicesTableLib|MdePkg/Library/DxeServicesTableLib/DxeServicesTableLib.inf
   DxeServicesLib|MdePkg/Library/DxeServicesLib/DxeServicesLib.inf
   ReportStatusCodeLib|MdePkg/Library/BaseReportStatusCodeLibNull/BaseReportStatusCodeLibNull.inf
+  SecureBootVariableLib|SecurityPkg/Library/SecureBootVariableLib/SecureBootVariableLib.inf
 
 [LibraryClasses.ARM,LibraryClasses.AARCH64]
   #