Ventoy Secure Boot Policy Update

- Add Ventoy Preload module.

EDK2/edk2_mod/edk2-edk2-stable201911/MdeModulePkg/Application/VtoyShim/VtoyShim.c

@@ -0,0 +1,709 @@
+/******************************************************************************
+ * VtoyShim.c
+ *
+ * Copyright (c) 2017 - 2018, Intel Corporation. All rights reserved.<BR>
+ * SPDX-License-Identifier: BSD-2-Clause-Patent
+ *
+ */
+
+#include <Uefi.h>
+
+#include <Library/DebugLib.h>
+#include <Library/PrintLib.h>
+#include <Library/UefiLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/DevicePathLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiRuntimeServicesTableLib.h>
+#include <Library/UefiApplicationEntryPoint.h>
+#include <Library/PeCoffLib.h>
+#include <Protocol/LoadedImage.h>
+#include <Guid/FileInfo.h>
+#include <Guid/FileSystemInfo.h>
+#include <Protocol/BlockIo.h>
+#include <Protocol/RamDisk.h>
+#include <Protocol/SimpleFileSystem.h>
+#include <Protocol/DevicePathToText.h>
+#include <Protocol/DevicePathFromText.h>
+#include <Protocol/LoadedImage.h>
+#include <Protocol/Security.h>
+#include <Protocol/Security2.h>
+#include <IndustryStandard/PeImage.h>
+#include <VtoyShim.h>
+
+#define CUR_SBAT_VER    1
+
+STATIC EFI_GUID gVtoySbatGUID = { 0xf755068a, 0xe04f, 0x452b, { 0x9d, 0x6d, 0x7c, 0x55, 0x96, 0xb3, 0xc0, 0x7d }};
+STATIC EFI_DEVICE_PATH_TO_TEXT_PROTOCOL *gDpToText = NULL;
+STATIC EFI_DEVICE_PATH_FROM_TEXT_PROTOCOL *gTextToDp = NULL;
+STATIC EFI_SECURITY_FILE_AUTHENTICATION_STATE gSysSecFileAuth = NULL;
+STATIC EFI_SECURITY2_FILE_AUTHENTICATION gSysSec2FileAuth = NULL;
+STATIC BOOLEAN gVtoyByPassSB = FALSE; /* must be FALSE by default for revoke */
+STATIC VTOY_SHIM gVtoyShimProtocol;
+STATIC EFI_HANDLE gVtoyShimProtHandle;
+STATIC SHIM_LOCK *gShimLock = NULL;
+
+STATIC VOID EFIAPI VtoyLog(CONST CHAR16 *Format, ...)
+{
+    VA_LIST         Marker;
+    CHAR16          Buffer[512];
+    UINTN           BufLen = 0;
+
+    Buffer[0] = 0;
+    VA_START(Marker, Format);
+    BufLen = UnicodeVSPrint(Buffer, sizeof(Buffer), Format, Marker);
+    VA_END(Marker);
+
+    if (gST->ConOut && gST->ConOut->OutputString)
+    {
+        gST->ConOut->OutputString(gST->ConOut, Buffer);
+    }
+}
+
+
+STATIC VOID EFIAPI DumpDevicePath(const EFI_DEVICE_PATH_PROTOCOL *DevicePath)
+{
+    CHAR16 *DPStr = NULL;
+
+    DPStr = gDpToText->ConvertDevicePathToText(DevicePath, TRUE, TRUE);
+    if (DPStr)
+    {
+        vLog(L"%s", DPStr);
+        gBS->FreePool(DPStr);
+    }
+    else
+    {
+        vLog(L"NULL");
+    }
+}
+
+STATIC VOID EFIAPI ShowSBWarning(BOOLEAN Reboot, const EFI_DEVICE_PATH_PROTOCOL *DevicePath)
+{
+    UINTN Index = 0;
+
+    vLog(L"\r\n=======================================================");
+    vLog(L"=======================================================\r\n");
+
+    DumpDevicePath(DevicePath);
+
+    vLog(L"\r\n####### Security Boot Violation ##########\r\n");
+
+    vLog(L"=======================================================");
+    vLog(L"=======================================================");
+
+    if (Reboot)
+    {
+        vLog(L"\r\n###### Press Enter to reboot... ######");
+        gST->ConIn->Reset(gST->ConIn, FALSE);
+        gBS->WaitForEvent(1, &gST->ConIn->WaitForKey, &Index);
+        gRT->ResetSystem(EfiResetWarm, EFI_SECURITY_VIOLATION, 0, NULL);
+    }
+    else
+    {
+        VtoySleep(5);
+    }
+}
+
+
+STATIC VOID * EFIAPI FindShimFuncAddr(UINT64 FuncOffset)
+{
+    EFI_STATUS Status;
+    SHIM_IMAGE_LOADER *ImgLoader = NULL;
+    EFI_GUID ShimImgLoaderGuid = SHIM_IMAGE_LOADER_GUID;
+
+    Status = gBS->LocateProtocol(&ShimImgLoaderGuid, NULL, (VOID **)&ImgLoader);
+    if (EFI_ERROR(Status) || !ImgLoader || !ImgLoader->LoadImage)
+    {
+        vLog(L"Failed to locate shim image loader protocol %lx %p", Status, ImgLoader);
+        return NULL;
+    }
+
+    if (NM_SHIM_LOAD_IMAGE_OFFSET > FuncOffset)
+    {
+        return (UINT8 *)ImgLoader->LoadImage - (NM_SHIM_LOAD_IMAGE_OFFSET - FuncOffset);
+    }
+    else
+    {
+        return (UINT8 *)ImgLoader->LoadImage + (FuncOffset - NM_SHIM_LOAD_IMAGE_OFFSET);
+    }
+}
+
+
+EFI_STATUS EFIAPI LaunchRealGrub(EFI_HANDLE ImageHandle, CONST CHAR16 *FileName)
+{
+    EFI_STATUS Status;
+    UINTN BufferSize = 0;
+    CHAR16 *DevDpStr = NULL;
+    CHAR16 *NewDpStr = NULL;
+    EFI_HANDLE ChildHandle = NULL;
+    EFI_LOADED_IMAGE_PROTOCOL *Li = NULL;
+    EFI_DEVICE_PATH_PROTOCOL *DeviceDP = NULL;
+    EFI_DEVICE_PATH_PROTOCOL *TargetDp = NULL;
+
+    Status = gBS->HandleProtocol(ImageHandle, &gEfiLoadedImageProtocolGuid, (VOID**)&Li);
+    if (EFI_ERROR(Status))
+    {
+        vLog(L"Failed to locate loaded image protocol %lx", Status);
+        return Status;
+    }
+
+    DeviceDP = DevicePathFromHandle(Li->DeviceHandle);
+    if (!DeviceDP || !IsDevicePathValid(DeviceDP, 0))
+    {
+        vLog(L"Failed to get device path of device handle %p", Li->DeviceHandle);
+        Status = EFI_NOT_FOUND;
+        goto END;
+    }
+
+    DevDpStr = gDpToText->ConvertDevicePathToText(DeviceDP, FALSE, TRUE);
+    if (!DevDpStr)
+    {
+        vLog(L"Failed to convert device path to text");
+        Status = EFI_OUT_OF_RESOURCES;
+        goto END;
+    }
+
+    BufferSize = (StrLen(DevDpStr) + 64) * sizeof(CHAR16);
+    NewDpStr = (CHAR16 *)AllocatePool(BufferSize);
+    if (!NewDpStr)
+    {
+        vLog(L"Failed to alloc new device path string buffer size:%lu", BufferSize);
+        Status = EFI_OUT_OF_RESOURCES;
+        goto END;
+    }
+
+    UnicodeSPrint(NewDpStr, BufferSize, L"%s/EFI/BOOT/%s", DevDpStr, FileName);
+
+    TargetDp = gTextToDp->ConvertTextToDevicePath(NewDpStr);
+    if (!TargetDp)
+    {
+        vLog(L"Failed to convert new text <%s> to device path", NewDpStr);
+        Status = EFI_NOT_FOUND;
+        goto END;
+    }
+
+    Status = gBS->LoadImage(FALSE, ImageHandle, TargetDp, NULL, 0, &ChildHandle);
+    if (EFI_ERROR(Status))
+    {
+        vLog(L"Failed to LoadImage %lx", Status);
+        goto END;
+    }
+
+
+    Status = gBS->StartImage(ChildHandle, NULL, NULL);
+    if (EFI_ERROR(Status))
+    {
+        vLog(L"Failed to StartImage %lx", Status);
+        gBS->UnloadImage(ChildHandle);
+        goto END;
+    }
+
+
+END:
+
+    CheckBSFreePool(DevDpStr);
+    CheckFreePool(NewDpStr);
+    CheckBSFreePool(TargetDp);
+
+    return Status;
+}
+
+
+
+STATIC EFI_STATUS EFIAPI ReadAuthFile
+(
+    const EFI_DEVICE_PATH_PROTOCOL *DevicePathConst,
+    VOID **Buffer,
+    UINT32 *Size
+)
+{
+    EFI_STATUS Status;
+    UINTN TmpSize = 0;
+    CHAR16 *DpStr = NULL;
+	EFI_HANDLE Handle = NULL;
+    EFI_DEVICE_PATH *DevPath = NULL;
+    EFI_DEVICE_PATH *TmpPath = NULL;
+	EFI_FILE_IO_INTERFACE *FileIO = NULL;
+	EFI_FILE *File = NULL;
+	EFI_FILE *Root = NULL;
+    UINT8 *FileData = NULL;
+    EFI_FILE_INFO *FInfo = NULL;
+    UINT8 Buf[1024];
+
+	DevPath	= TmpPath = DuplicateDevicePath(DevicePathConst);
+    if (!DevPath)
+    {
+        Status = EFI_OUT_OF_RESOURCES;
+        goto END;
+    }
+
+	Status = gBS->LocateDevicePath(&gEfiSimpleFileSystemProtocolGuid, &DevPath, &Handle);
+    if (EFI_ERROR(Status))
+    {
+        vLog(L"Failed to locate simple file protocol %lx", Status);
+        goto END;
+    }
+
+    DpStr = gDpToText->ConvertDevicePathToText(DevPath, FALSE, TRUE);
+    if (!DpStr)
+    {
+        Status = EFI_OUT_OF_RESOURCES;
+        goto END;
+    }
+
+    Status = gBS->HandleProtocol(Handle, &gEfiSimpleFileSystemProtocolGuid, (VOID **)&FileIO);
+    if (EFI_ERROR(Status))
+    {
+        vLog(L"Failed to handle simple file protocol %lx", Status);
+        goto END;
+    }
+
+    Status = FileIO->OpenVolume(Handle, &Root);
+	if (EFI_ERROR(Status))
+    {
+		vLog(L"Failed to open drive volume (%lx)\n", Status);
+		goto END;
+	}
+
+    Status = Root->Open(Root, &File, DpStr, EFI_FILE_MODE_READ, 0);
+    if (EFI_ERROR(Status))
+    {
+		vLog(L"Failed to open file (%s) (%lx)\n", DpStr, Status);
+		goto END;
+	}
+
+    FInfo = (EFI_FILE_INFO *)Buf;
+    TmpSize = sizeof(Buf);
+    ZeroMem(FInfo, sizeof(EFI_FILE_INFO));
+
+    Status = File->GetInfo(File, &gEfiFileInfoGuid, &TmpSize, FInfo);
+    if (EFI_ERROR(Status) || FInfo->FileSize == 0 || FInfo->FileSize >= 0xFFFFFFFFUL)
+    {
+		vLog(L"Failed to open file (%s) (%lx) Size(%ld)\n", DpStr, Status, (UINTN)FInfo->FileSize);
+		goto END;
+	}
+
+    FileData = AllocatePool(FInfo->FileSize);
+    if (!FileData)
+    {
+        Status = EFI_OUT_OF_RESOURCES;
+        goto END;
+    }
+
+    TmpSize = FInfo->FileSize;
+    Status = File->Read(File, &TmpSize, FileData);
+    if (EFI_ERROR(Status) || TmpSize != (UINTN)FInfo->FileSize)
+    {
+		vLog(L"Failed to read file (%lx) Read:%ld Size:%ld\n", Status, TmpSize, (UINTN)FInfo->FileSize);
+		goto END;
+	}
+
+
+END:
+
+    if (File)
+    {
+        File->Close(File);
+    }
+
+    if (Root)
+    {
+        Root->Close(Root);
+    }
+
+    CheckFreePool(TmpPath);
+    CheckBSFreePool(DpStr);
+
+    if (EFI_ERROR(Status))
+    {
+        CheckFreePool(FileData);
+    }
+    else
+    {
+        *Buffer = FileData;
+        *Size = (UINT32)FInfo->FileSize;
+    }
+
+    return Status;
+}
+
+
+STATIC BOOLEAN VtoyCheckRevoke(VOID *Buffer, UINTN Size)
+{
+    UINT32 uiVer = 0;
+    EFI_IMAGE_DOS_HEADER *DosHead = (EFI_IMAGE_DOS_HEADER *)Buffer;
+
+    if (Size > sizeof(EFI_IMAGE_DOS_HEADER))
+    {
+        if (CompareMem(DosHead->e_res2, &gVtoySbatGUID, 16) == 0)
+        {
+            CopyMem(&uiVer, DosHead->e_res2 + 8, 4);
+            if (uiVer < CUR_SBAT_VER)
+            {
+                vLog(L"Ventoy EFI file revoke (%u < %u)", uiVer, CUR_SBAT_VER);
+                return FALSE;
+            }
+        }
+    }
+
+    return TRUE;
+}
+
+STATIC EFI_STATUS EFIAPI SecurityPolicyAuth
+(
+	const EFI_SECURITY_ARCH_PROTOCOL *This,
+	UINT32 AuthenticationStatus,
+	const EFI_DEVICE_PATH_PROTOCOL *DevicePathConst
+)
+{
+    EFI_STATUS Status;
+    BOOLEAN bRevokeChkOK = TRUE;
+    UINT32 Size = 0;
+    VOID *Buffer = NULL;
+
+    /* Just return OK if the user choose to bypass SB */
+    if (gVtoyByPassSB)
+    {
+        return EFI_SUCCESS;
+    }
+
+    /*
+     * Step 1:
+     * Use original UEFI firmware auth API.
+     * If it's OK, it may be signed with Microsoft UEFI CA. (e.g. bootmgr/shim/...)
+     */
+    if (gSysSecFileAuth)
+    {
+        Status = gSysSecFileAuth(This, AuthenticationStatus, DevicePathConst);
+        if (!EFI_ERROR(Status))
+        {
+            return EFI_SUCCESS;
+        }
+    }
+
+
+    /*
+     * Step 2:
+     * Use shim verify API.
+     * If it's OK, it may be signed with a MOK key. (e.g. Ventoy EFI files)
+     */
+    if (gShimLock && gShimLock->Verify)
+    {
+        Status = ReadAuthFile(DevicePathConst, &Buffer, &Size);
+        if (!EFI_ERROR(Status))
+        {
+            Status = gShimLock->Verify(Buffer, Size);
+            if (!EFI_ERROR(Status))
+            {
+                bRevokeChkOK = VtoyCheckRevoke(Buffer, Size);
+                if (bRevokeChkOK)
+                {
+                    FreePool(Buffer);
+                    return EFI_SUCCESS;
+                }
+            }
+            FreePool(Buffer);
+        }
+    }
+
+    ShowSBWarning(!bRevokeChkOK, DevicePathConst);
+
+    return EFI_SECURITY_VIOLATION;
+}
+
+STATIC EFI_STATUS EFIAPI Security2PolicyAuth
+(
+	const EFI_SECURITY2_ARCH_PROTOCOL *This,
+	const EFI_DEVICE_PATH_PROTOCOL *DevicePath,
+	VOID *FileBuffer,
+	UINTN FileSize,
+	BOOLEAN	BootPolicy
+)
+{
+    EFI_STATUS Status;
+    BOOLEAN bRevokeChkOK = TRUE;
+
+    /* Just return OK if the user choose to bypass SB */
+    if (gVtoyByPassSB)
+    {
+        return EFI_SUCCESS;
+    }
+
+    /*
+     * Step 1:
+     * Use original UEFI firmware auth API.
+     * If it's OK, it may be signed with Microsoft UEFI CA. (e.g. bootmgr/shim/...)
+     */
+    if (gSysSec2FileAuth)
+    {
+        Status = gSysSec2FileAuth(This, DevicePath, FileBuffer, FileSize, BootPolicy);
+        if (!EFI_ERROR(Status))
+        {
+            return EFI_SUCCESS;
+        }
+    }
+
+
+    /*
+     * Step 2:
+     * Use shim verify API.
+     * If it's OK, it may be signed with a MOK key. (e.g. Ventoy EFI files)
+     */
+    if (gShimLock && gShimLock->Verify)
+    {
+        if (FileBuffer && FileSize > 0 && FileSize < 0xFFFFFFFFUL)
+        {
+            Status = gShimLock->Verify(FileBuffer, (UINT32)FileSize);
+            if (!EFI_ERROR(Status))
+            {
+                bRevokeChkOK = VtoyCheckRevoke(FileBuffer, FileSize);
+                if (bRevokeChkOK)
+                {
+                    return EFI_SUCCESS;
+                }
+            }
+        }
+    }
+
+    ShowSBWarning(!bRevokeChkOK, DevicePath);
+
+    return EFI_SECURITY_VIOLATION;
+}
+
+
+STATIC EFI_STATUS EFIAPI HookSecurityPolicy(VOID)
+{
+	EFI_STATUS Status;
+	EFI_STATUS Status2;
+	EFI_SECURITY_ARCH_PROTOCOL *Security = NULL;
+	EFI_SECURITY2_ARCH_PROTOCOL *Security2 = NULL;
+
+	Status = gBS->LocateProtocol(&gEfiSecurityArchProtocolGuid, NULL, (VOID **)&Security);
+	Status2 = gBS->LocateProtocol(&gEfiSecurity2ArchProtocolGuid, NULL, (VOID **)&Security2);
+    if (EFI_ERROR(Status) && EFI_ERROR(Status2))
+    {
+        vLog(L"Failed to locate security or security2 protocol. %lx %lx %p %p",
+             Status, Status2, Security, Security2);
+        return EFI_NOT_FOUND;
+    }
+
+    if (Security2)
+    {
+        gSysSec2FileAuth = Security2->FileAuthentication;
+        Security2->FileAuthentication = Security2PolicyAuth;
+    }
+
+    if (Security)
+    {
+        gSysSecFileAuth = Security->FileAuthenticationState;
+        Security->FileAuthenticationState = SecurityPolicyAuth;
+    }
+
+	return EFI_SUCCESS;
+}
+
+STATIC VOID EFIAPI UnHookSecurityPolicy(VOID)
+{
+	EFI_STATUS Status;
+	EFI_STATUS Status2;
+	EFI_SECURITY_ARCH_PROTOCOL *Security = NULL;
+	EFI_SECURITY2_ARCH_PROTOCOL *Security2 = NULL;
+
+    if (!gSysSec2FileAuth && !gSysSecFileAuth)
+    {
+        return;
+    }
+
+	Status = gBS->LocateProtocol(&gEfiSecurityArchProtocolGuid, NULL, (VOID **)&Security);
+	Status2 = gBS->LocateProtocol(&gEfiSecurity2ArchProtocolGuid, NULL, (VOID **)&Security2);
+    if (EFI_ERROR(Status) && EFI_ERROR(Status2))
+    {
+        vLog(L"Failed to locate security or security2 protocol. %lx %lx %p %p",
+             Status, Status2, Security, Security2);
+        return;
+    }
+
+    if (Security2 && gSysSec2FileAuth)
+    {
+        Security2->FileAuthentication = gSysSec2FileAuth;
+        gSysSec2FileAuth = NULL;
+    }
+
+    if (Security && gSysSecFileAuth)
+    {
+        Security->FileAuthenticationState = gSysSecFileAuth;
+        gSysSecFileAuth = NULL;
+    }
+}
+
+STATIC VOID EFIAPI VtoyByPassSB(VOID)
+{
+    gVtoyByPassSB = TRUE;
+}
+
+STATIC VOID EFIAPI VtoyCheckSB(VOID)
+{
+    gVtoyByPassSB = FALSE;
+}
+
+STATIC VOID EFIAPI UnInstallVtoyShimProtocol(VOID)
+{
+    EFI_GUID Guid = VTOY_SHIM_POLICY_GUID;
+
+    if (gVtoyShimProtHandle)
+    {
+        gBS->UninstallProtocolInterface(gVtoyShimProtHandle, &Guid, &gVtoyShimProtocol);
+        gVtoyShimProtHandle = NULL;
+    }
+}
+
+STATIC EFI_STATUS EFIAPI InstallVtoyShimProtocol(VOID)
+{
+	EFI_STATUS Status;
+    EFI_GUID Guid = VTOY_SHIM_POLICY_GUID;
+    VTOY_SHIM *Prot = NULL;
+
+    gVtoyShimProtocol.ByPassSB = VtoyByPassSB;
+    gVtoyShimProtocol.CheckSB = VtoyCheckSB;
+
+    Status = gBS->LocateProtocol(&Guid, NULL, (VOID**)&Prot);
+    if (!EFI_ERROR(Status))
+    {
+        vLog(L"Ventoy shim already loaded, cannot be nested.");
+        return EFI_ALREADY_STARTED;
+    }
+
+    Status = gBS->InstallProtocolInterface(&gVtoyShimProtHandle, &Guid,
+                    EFI_NATIVE_INTERFACE, &gVtoyShimProtocol);
+    if (EFI_ERROR(Status))
+    {
+        vLog(L"Failed to install protocol %lx", Status);
+    }
+
+    return Status;
+}
+
+STATIC BOOLEAN EFIAPI IsSecureBootEnabled(VOID)
+{
+    UINT8 SecureBoot = 0;
+	UINTN DataSize;
+	EFI_STATUS Status;
+
+	DataSize = sizeof(SecureBoot);
+	Status = gST->RuntimeServices->GetVariable(L"SecureBoot", &gEfiGlobalVariableGuid, NULL,
+				     &DataSize, &SecureBoot);
+	if (EFI_ERROR(Status))
+    {
+        return FALSE;
+    }
+
+	return SecureBoot ? TRUE : FALSE;
+}
+
+STATIC EFI_STATUS EFIAPI EnvInit(VOID)
+{
+    EFI_STATUS Status;
+    EFI_GUID Guid = SHIM_LOCK_GUID;
+
+    Status = gBS->LocateProtocol(&gEfiDevicePathToTextProtocolGuid, NULL, (VOID**)&gDpToText);
+	if (EFI_ERROR(Status) || !gDpToText || !gDpToText->ConvertDevicePathToText)
+    {
+        vLog(L"Failed to locate PathToText Protocol %lx", Status);
+        return Status;
+    }
+
+    Status = gBS->LocateProtocol(&gEfiDevicePathFromTextProtocolGuid, NULL, (VOID**)&gTextToDp);
+	if (EFI_ERROR(Status) || !gTextToDp || !gTextToDp->ConvertTextToDevicePath)
+    {
+        vLog(L"Failed to locate PathFromText Protocol %lx", Status);
+        return Status;
+    }
+
+    Status = gBS->LocateProtocol(&Guid, NULL, (VOID**)&gShimLock);
+    if (EFI_ERROR(Status) || !gShimLock)
+    {
+        vLog(L"Failed to locate SHIM LOCK Protocol %lx", Status);
+        return Status;
+    }
+
+    return EFI_SUCCESS;
+}
+
+
+EFI_STATUS EFIAPI VtoyShimEfiMain
+(
+    IN EFI_HANDLE         ImageHandle,
+    IN EFI_SYSTEM_TABLE  *SystemTable
+)
+{
+    EFI_STATUS Status;
+    unhook_system_services_pf Func = NULL;
+
+    /* If secure boot is not enabled, nothing needed, just launch Ventoy grub */
+    if (!IsSecureBootEnabled())
+    {
+        return LaunchRealGrub(ImageHandle, REAL_GRUB_FILE);
+    }
+
+    Status = EnvInit();
+	if (EFI_ERROR(Status))
+    {
+        vErr(L"Failed to prepare env");
+        return Status;
+    }
+
+    Status = InstallVtoyShimProtocol();
+    if (EFI_ERROR(Status))
+    {
+        vErr(L"Failed to install ventoy shim protocol");
+        return Status;
+    }
+
+
+    /*
+     * IMPORTANT: All recent shim implementations hook the UEFI Boot Services
+     * (e.g. LoadImage, StartImage) to enforce signature verification.
+     *
+     * We must restore the original system service pointers here. If we fail to do this,
+     * we will be unable to launch Ventoy-signed EFI binaries or any other unsigned
+     * EFI applications later, even when the user has explicitly opted to disable
+     * all Secure Boot validation checks.
+     *
+     * To the best of my knowledge, there is no official way to remove these hooks.
+     * This is a tricky hack that relies on shim's internal implementation details.
+     * It may break in future versions of shim, and a better approach may exist.
+     *
+     */
+    Func = FindShimFuncAddr(NM_UNHOOK_SYSTEM_SERVICES_OFFSET);
+    if (!Func)
+    {
+        vErr(L"Can not find shim unhook_system_services");
+        Status = EFI_NOT_FOUND;
+        goto END;
+    }
+
+    Func(); /* call shim unhook_system_services() */
+
+
+    /* Hook the system security policy */
+    Status = HookSecurityPolicy();
+    if (EFI_ERROR(Status))
+    {
+        vErr(L"Failed to hook system security policy");
+        goto END;
+    }
+
+    /* Finally launch Ventoy grub */
+    Status = LaunchRealGrub(ImageHandle, REAL_GRUB_FILE);
+
+END:
+
+    /* UnHook system security policy */
+    UnHookSecurityPolicy();
+
+    UnInstallVtoyShimProtocol();
+
+    return Status;
+}
+

EDK2/edk2_mod/edk2-edk2-stable201911/MdeModulePkg/Application/VtoyShim/VtoyShim.h

@@ -0,0 +1,121 @@
+/******************************************************************************
+ * VtoyShim.h
+ *
+ * Copyright (c) 2017 - 2018, Intel Corporation. All rights reserved.<BR>
+ * SPDX-License-Identifier: BSD-2-Clause-Patent
+ *
+ */
+
+#ifndef __VTOYSHIM_H__
+#define __VTOYSHIM_H__
+
+#if defined (MDE_CPU_IA32)
+#define REAL_GRUB_FILE    L"grubia32_real.efi"
+#elif defined (MDE_CPU_X64)
+#define REAL_GRUB_FILE    L"grubx64_real.efi"
+#elif defined (MDE_CPU_AARCH64)
+#define REAL_GRUB_FILE    L"grubaa64_real.efi"
+#else
+#error "Not supported now"
+#endif
+
+
+/* The following definations are copied from shim source code */
+
+#define SHIM_LOCK_GUID  {0x605dab50, 0xe046, 0x4300, {0xab, 0xb6, 0x3d, 0xd8, 0x10, 0xdd, 0x8b, 0x23 } };
+
+typedef
+EFI_STATUS
+(*EFI_SHIM_LOCK_VERIFY) (
+	IN VOID *buffer,
+	IN UINT32 size
+	);
+
+typedef
+EFI_STATUS
+(*EFI_SHIM_LOCK_HASH) (
+	IN char *data,
+	IN int datasize,
+	PE_COFF_LOADER_IMAGE_CONTEXT *context,
+	UINT8 *sha256hash,
+	UINT8 *sha1hash
+	);
+
+typedef
+EFI_STATUS
+(*EFI_SHIM_LOCK_CONTEXT) (
+	IN VOID *data,
+	IN unsigned int datasize,
+	PE_COFF_LOADER_IMAGE_CONTEXT *context
+	);
+
+typedef struct _SHIM_LOCK {
+	EFI_SHIM_LOCK_VERIFY Verify;
+	EFI_SHIM_LOCK_HASH Hash;
+	EFI_SHIM_LOCK_CONTEXT Context;
+} SHIM_LOCK;
+
+
+
+#define SHIM_IMAGE_LOADER_GUID {0x1f492041, 0xfadb, 0x4e59, {0x9e, 0x57, 0x7c, 0xaf, 0xe7, 0x3a, 0x55, 0xab } }
+
+typedef struct _SHIM_IMAGE_LOADER {
+	EFI_IMAGE_LOAD LoadImage;
+	EFI_IMAGE_START StartImage;
+	EFI_EXIT Exit;
+	EFI_IMAGE_UNLOAD UnloadImage;
+} SHIM_IMAGE_LOADER;
+
+typedef VOID (*unhook_system_services_pf)(VOID);
+
+
+/*
+ * The two offset here are extract from the shim file which used in Ventoy.
+ * nm BOOTX64.EFI | grep shim_load_image
+ * nm BOOTX64.EFI | grep unhook_system_services
+ *
+ * It means that they must be updated every time Ventoy update the shim file.
+ *
+ */
+#define NM_SHIM_LOAD_IMAGE_OFFSET             0x2dc12
+#define NM_UNHOOK_SYSTEM_SERVICES_OFFSET      0x2e278
+
+
+
+
+#define VtoySleep(sec)      gBS->Stall(1000000 * (sec))
+#define vLog(fmt, ...)      VtoyLog(fmt "\r\n", ##__VA_ARGS__)
+#define vErr(fmt, ...)      VtoyLog(fmt "\r\n", ##__VA_ARGS__); VtoySleep(5)
+
+#define CheckFreePool(p) \
+do { \
+    if (p) { \
+        FreePool(p); \
+        (p) = NULL; \
+    }\
+} while (0)
+
+#define CheckBSFreePool(p) \
+do { \
+    if (p) { \
+        gBS->FreePool(p); \
+        (p) = NULL; \
+    }\
+} while (0)
+
+
+
+#define VTOY_SHIM_POLICY_GUID    {0x90a29d14, 0x3968, 0x48fe, { 0x85, 0x81, 0x6b, 0x7f, 0x7d, 0xc4, 0x70, 0x55 }};
+
+
+typedef VOID (EFIAPI *VTOY_BYPASS_SB)(VOID);
+typedef VOID (EFIAPI *VTOY_CHECK_SB)(VOID);
+typedef struct _VTOY_SHIM{
+	VTOY_BYPASS_SB ByPassSB;
+	VTOY_BYPASS_SB CheckSB;
+} VTOY_SHIM;
+
+CONST UINT8 * ventoy_get_der_data(UINT32 *Len);
+
+#endif
+

EDK2/edk2_mod/edk2-edk2-stable201911/MdeModulePkg/Application/VtoyShim/VtoyShim.inf

@@ -0,0 +1,83 @@
+#************************************************************************************
+# Copyright (c) 2026, longpanda <admin@ventoy.net>
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, see <http://www.gnu.org/licenses/>.
+#
+#************************************************************************************
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = VtoyShim
+  FILE_GUID                      = 6d7c7406-b32c-461f-8454-ddaa5243d93d
+  MODULE_TYPE                    = UEFI_APPLICATION
+  VERSION_STRING                 = 1.0
+  ENTRY_POINT                    = VtoyShimEfiMain
+  
+[BuildOptions]
+  # Force standard GNU ld to pack and align ELF segments to 4KB page boundaries
+  GCC:*_*_*_DLINK_FLAGS = -Wl,-z,common-page-size=0x1000 -Wl,-z,max-page-size=0x1000
+
+[Sources]
+  VtoyShim.h
+  VtoyShim.c
+  
+[Packages]
+  MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  ShellPkg/ShellPkg.dec
+
+[LibraryClasses]
+  UefiApplicationEntryPoint
+  UefiLib
+  DevicePathLib
+  DebugLib
+
+[Guids]
+  gEfiGlobalVariableGuid
+  gShellVariableGuid
+  gEfiVirtualCdGuid
+  gEfiFileInfoGuid
+
+[Protocols]
+  gEfiSecurityArchProtocolGuid
+  gEfiSecurity2ArchProtocolGuid
+  gEfiLoadedImageProtocolGuid
+  gEfiBlockIoProtocolGuid
+  gEfiDevicePathProtocolGuid
+  gEfiDevicePathToTextProtocolGuid
+  gEfiDevicePathFromTextProtocolGuid
+  gEfiSimpleFileSystemProtocolGuid
+  gEfiRamDiskProtocolGuid
+  gEfiAbsolutePointerProtocolGuid
+  gEfiAcpiTableProtocolGuid
+  gEfiBlockIo2ProtocolGuid
+  gEfiBusSpecificDriverOverrideProtocolGuid
+  gEfiComponentNameProtocolGuid
+  gEfiComponentName2ProtocolGuid
+  gEfiDriverBindingProtocolGuid
+  gEfiDiskIoProtocolGuid
+  gEfiDiskIo2ProtocolGuid
+  gEfiGraphicsOutputProtocolGuid
+  gEfiHiiConfigAccessProtocolGuid
+  gEfiHiiFontProtocolGuid
+  gEfiLoadFileProtocolGuid
+  gEfiLoadFile2ProtocolGuid
+  gEfiLoadedImageProtocolGuid
+  gEfiLoadedImageDevicePathProtocolGuid
+  gEfiPciIoProtocolGuid
+  gEfiSerialIoProtocolGuid
+  gEfiSimpleTextInProtocolGuid
+  gEfiSimpleTextInputExProtocolGuid
+  gEfiSimpleTextOutProtocolGuid
+

EDK2/edk2_mod/edk2-edk2-stable201911/MdeModulePkg/Application/VtoyShim/sbat.csv

@@ -0,0 +1,2 @@
+sbat,1,SBAT Version,sbat,1,https://github.com/rhboot/shim/blob/main/SBAT.md
+ventoy-shim,1,Ventoy,ventoy-shim,1.0,https://www.ventoy.net/