/** @file
  HII Config Access protocol implementation of SecureBoot configuration module.

Copyright (C) 2024 Advanced Micro Devices, Inc. All rights reserved.<BR>
Copyright (c) 2011 - 2018, Intel Corporation. All rights reserved.<BR>
(C) Copyright 2018 Hewlett Packard Enterprise Development LP<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include "SecureBootConfigImpl.h"
#include <UefiSecureBoot.h>
#include <Protocol/HiiPopup.h>
#include <Protocol/RealTimeClock.h>
#include <Library/BaseCryptLib.h>
#include <Library/SecureBootVariableLib.h>
#include <Library/SecureBootVariableProvisionLib.h>

EFI_STATUS
FormatHelpInfo (
  IN     SECUREBOOT_CONFIG_PRIVATE_DATA  *PrivateData,
  IN     EFI_SIGNATURE_LIST              *ListEntry,
  IN     EFI_SIGNATURE_DATA              *DataEntry,
  OUT EFI_STRING_ID                      *StringId
  );

CHAR16  mSecureBootStorageName[] = L"SECUREBOOT_CONFIGURATION";

SECUREBOOT_CONFIG_PRIVATE_DATA  mSecureBootConfigPrivateDateTemplate = {
  SECUREBOOT_CONFIG_PRIVATE_DATA_SIGNATURE,
  {
    SecureBootExtractConfig,
    SecureBootRouteConfig,
    SecureBootCallback
  }
};

HII_VENDOR_DEVICE_PATH  mSecureBootHiiVendorDevicePath = {
  {
    {
      HARDWARE_DEVICE_PATH,
      HW_VENDOR_DP,
      {
        (UINT8)(sizeof (VENDOR_DEVICE_PATH)),
        (UINT8)((sizeof (VENDOR_DEVICE_PATH)) >> 8)
      }
    },
    SECUREBOOT_CONFIG_FORM_SET_GUID
  },
  {
    END_DEVICE_PATH_TYPE,
    END_ENTIRE_DEVICE_PATH_SUBTYPE,
    {
      (UINT8)(END_DEVICE_PATH_LENGTH),
      (UINT8)((END_DEVICE_PATH_LENGTH) >> 8)
    }
  }
};

BOOLEAN  mIsEnterSecureBootForm = FALSE;

//
// OID ASN.1 Value for Hash Algorithms
//
UINT8  mHashOidValue[] = {
  0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x02, 0x05,       // OBJ_md5
  0x2B, 0x0E, 0x03, 0x02, 0x1A,                         // OBJ_sha1
  0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04, // OBJ_sha224
  0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, // OBJ_sha256
  0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02, // OBJ_sha384
  0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, // OBJ_sha512
};

HASH_TABLE  mHash[] = {
  { L"SHA224", 28, &mHashOidValue[13], 9, NULL,                 NULL,       NULL,         NULL        },
  { L"SHA256", 32, &mHashOidValue[22], 9, Sha256GetContextSize, Sha256Init, Sha256Update, Sha256Final },
  { L"SHA384", 48, &mHashOidValue[31], 9, Sha384GetContextSize, Sha384Init, Sha384Update, Sha384Final },
  { L"SHA512", 64, &mHashOidValue[40], 9, Sha512GetContextSize, Sha512Init, Sha512Update, Sha512Final }
};

//
// Variable Definitions
//
UINT32                               mPeCoffHeaderOffset = 0;
WIN_CERTIFICATE                      *mCertificate       = NULL;
IMAGE_TYPE                           mImageType;
UINT8                                *mImageBase = NULL;
UINTN                                mImageSize  = 0;
UINT8                                mImageDigest[MAX_DIGEST_SIZE];
UINTN                                mImageDigestSize;
EFI_GUID                             mCertType;
EFI_IMAGE_SECURITY_DATA_DIRECTORY    *mSecDataDir = NULL;
EFI_IMAGE_OPTIONAL_HEADER_PTR_UNION  mNtHeader;

//
// Possible DER-encoded certificate file suffixes, end with NULL pointer.
//
CHAR16  *mDerEncodedSuffix[] = {
  L".cer",
  L".der",
  L".crt",
  NULL
};
CHAR16  *mSupportX509Suffix = L"*.cer/der/crt";

//
// Prompt strings during certificate enrollment.
//
CHAR16  *mX509EnrollPromptTitle[] = {
  L"",
  L"ERROR: Unsupported file type!",
  L"ERROR: Unsupported certificate!",
  NULL
};
CHAR16  *mX509EnrollPromptString[] = {
  L"",
  L"Only DER encoded certificate file (*.cer/der/crt) is supported.",
  L"Public key length should be equal to or greater than 2048 bits.",
  NULL
};

SECUREBOOT_CONFIG_PRIVATE_DATA  *gSecureBootPrivateData = NULL;

/**
  This code cleans up enrolled file by closing file & free related resources attached to
  enrolled file.

  @param[in] FileContext            FileContext cached in SecureBootConfig driver

**/
VOID
CloseEnrolledFile (
  IN SECUREBOOT_FILE_CONTEXT  *FileContext
  )
{
  if (FileContext->FHandle != NULL) {
    CloseFile (FileContext->FHandle);
    FileContext->FHandle = NULL;
  }

  if (FileContext->FileName != NULL) {
    FreePool (FileContext->FileName);
    FileContext->FileName = NULL;
  }

  FileContext->FileType = UNKNOWN_FILE_TYPE;
}

/**
  Helper function to populate an EFI_TIME instance.

  @param[in] Time   FileContext cached in SecureBootConfig driver

**/
STATIC
EFI_STATUS
GetCurrentTime (
  IN EFI_TIME  *Time
  )
{
  EFI_STATUS  Status;
  VOID        *TestPointer;

  if (Time == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  Status = gBS->LocateProtocol (&gEfiRealTimeClockArchProtocolGuid, NULL, &TestPointer);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  ZeroMem (Time, sizeof (EFI_TIME));
  Status = gRT->GetTime (Time, NULL);
  if (EFI_ERROR (Status)) {
    DEBUG ((
      DEBUG_ERROR,
      "%a(), GetTime() failed, status = '%r'\n",
      __func__,
      Status
      ));
    return Status;
  }

  Time->Pad1       = 0;
  Time->Nanosecond = 0;
  Time->TimeZone   = 0;
  Time->Daylight   = 0;
  Time->Pad2       = 0;

  return EFI_SUCCESS;
}

/**
  This code checks if the FileSuffix is one of the possible DER-encoded certificate suffix.

  @param[in] FileSuffix            The suffix of the input certificate file

  @retval    TRUE           It's a DER-encoded certificate.
  @retval    FALSE          It's NOT a DER-encoded certificate.

**/
BOOLEAN
IsDerEncodeCertificate (
  IN CONST CHAR16  *FileSuffix
  )
{
  UINTN  Index;

  for (Index = 0; mDerEncodedSuffix[Index] != NULL; Index++) {
    if (StrCmp (FileSuffix, mDerEncodedSuffix[Index]) == 0) {
      return TRUE;
    }
  }

  return FALSE;
}

/**
  This code checks if the file content complies with EFI_VARIABLE_AUTHENTICATION_2 format
The function reads file content but won't open/close given FileHandle.

  @param[in] FileHandle            The FileHandle to be checked

  @retval    TRUE            The content is EFI_VARIABLE_AUTHENTICATION_2 format.
  @retval    FALSE          The content is NOT a EFI_VARIABLE_AUTHENTICATION_2 format.

**/
BOOLEAN
IsAuthentication2Format (
  IN   EFI_FILE_HANDLE  FileHandle
  )
{
  EFI_STATUS                     Status;
  EFI_VARIABLE_AUTHENTICATION_2  *Auth2;
  BOOLEAN                        IsAuth2Format;

  IsAuth2Format = FALSE;

  //
  // Read the whole file content
  //
  Status = ReadFileContent (
             FileHandle,
             (VOID **)&mImageBase,
             &mImageSize,
             0
             );
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  Auth2 = (EFI_VARIABLE_AUTHENTICATION_2 *)mImageBase;
  if (Auth2->AuthInfo.Hdr.wCertificateType != WIN_CERT_TYPE_EFI_GUID) {
    goto ON_EXIT;
  }

  if (CompareGuid (&gEfiCertPkcs7Guid, &Auth2->AuthInfo.CertType)) {
    IsAuth2Format = TRUE;
  }

ON_EXIT:
  //
  // Do not close File. simply check file content
  //
  if (mImageBase != NULL) {
    FreePool (mImageBase);
    mImageBase = NULL;
  }

  return IsAuth2Format;
}

/**
  Set Secure Boot option into variable space.

  @param[in] VarValue              The option of Secure Boot.

  @retval    EFI_SUCCESS           The operation is finished successfully.
  @retval    Others                Other errors as indicated.

**/
EFI_STATUS
SaveSecureBootVariable (
  IN UINT8  VarValue
  )
{
  EFI_STATUS  Status;

  Status = gRT->SetVariable (
                  EFI_SECURE_BOOT_ENABLE_NAME,
                  &gEfiSecureBootEnableDisableGuid,
                  EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS,
                  sizeof (UINT8),
                  &VarValue
                  );
  return Status;
}

/**
  This code checks if the encode type and key strength of X.509
  certificate is qualified.

  @param[in]  X509FileContext     FileContext of X.509 certificate storing
                                  file.
  @param[out] Error               Error type checked in the certificate.

  @return EFI_SUCCESS             The certificate checked successfully.
  @return EFI_INVALID_PARAMETER   The parameter is invalid.
  @return EFI_OUT_OF_RESOURCES    Memory allocation failed.

**/
EFI_STATUS
CheckX509Certificate (
  IN    SECUREBOOT_FILE_CONTEXT  *X509FileContext,
  OUT   ENROLL_KEY_ERROR         *Error
  )
{
  EFI_STATUS  Status;
  UINT16      *FilePostFix;
  UINTN       NameLength;
  UINT8       *X509Data;
  UINTN       X509DataSize;
  void        *X509PubKey;
  UINTN       PubKeyModSize;

  if (X509FileContext->FileName == NULL) {
    *Error = Unsupported_Type;
    return EFI_INVALID_PARAMETER;
  }

  X509Data      = NULL;
  X509DataSize  = 0;
  X509PubKey    = NULL;
  PubKeyModSize = 0;

  //
  // Parse the file's postfix. Only support DER encoded X.509 certificate files.
  //
  NameLength = StrLen (X509FileContext->FileName);
  if (NameLength <= 4) {
    DEBUG ((DEBUG_ERROR, "Wrong X509 NameLength\n"));
    *Error = Unsupported_Type;
    return EFI_INVALID_PARAMETER;
  }

  FilePostFix = X509FileContext->FileName + NameLength - 4;
  if (!IsDerEncodeCertificate (FilePostFix)) {
    DEBUG ((DEBUG_ERROR, "Unsupported file type, only DER encoded certificate (%s) is supported.\n", mSupportX509Suffix));
    *Error = Unsupported_Type;
    return EFI_INVALID_PARAMETER;
  }

  DEBUG ((DEBUG_INFO, "FileName= %s\n", X509FileContext->FileName));
  DEBUG ((DEBUG_INFO, "FilePostFix = %s\n", FilePostFix));

  //
  // Read the certificate file content
  //
  Status = ReadFileContent (X509FileContext->FHandle, (VOID **)&X509Data, &X509DataSize, 0);
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Error occured while reading the file.\n"));
    goto ON_EXIT;
  }

  //
  // Parse the public key context.
  //
  if (RsaGetPublicKeyFromX509 (X509Data, X509DataSize, &X509PubKey) == FALSE) {
    DEBUG ((DEBUG_ERROR, "Error occured while parsing the pubkey from certificate.\n"));
    Status = EFI_INVALID_PARAMETER;
    *Error = Unsupported_Type;
    goto ON_EXIT;
  }

  //
  // Parse Module size of public key using interface provided by CryptoPkg, which is
  // actually the size of public key.
  //
  if (X509PubKey != NULL) {
    RsaGetKey (X509PubKey, RsaKeyN, NULL, &PubKeyModSize);
    if (PubKeyModSize < CER_PUBKEY_MIN_SIZE) {
      DEBUG ((DEBUG_ERROR, "Unqualified PK size, key size should be equal to or greater than 2048 bits.\n"));
      Status = EFI_INVALID_PARAMETER;
      *Error = Unqualified_Key;
    }

    RsaFree (X509PubKey);
  }

ON_EXIT:
  if (X509Data != NULL) {
    FreePool (X509Data);
  }

  return Status;
}

/**
  Generate the PK signature list from the X509 Certificate storing file (.cer)

  @param[in]   X509File              FileHandle of X509 Certificate storing file.
  @param[out]  PkCert                Point to the data buffer to store the signature list.

  @return EFI_UNSUPPORTED            Unsupported Key Length.
  @return EFI_OUT_OF_RESOURCES       There are not enough memory resources to form the signature list.

**/
EFI_STATUS
CreatePkX509SignatureList (
  IN    EFI_FILE_HANDLE     X509File,
  OUT   EFI_SIGNATURE_LIST  **PkCert
  )
{
  EFI_STATUS          Status;
  UINT8               *X509Data;
  UINTN               X509DataSize;
  EFI_SIGNATURE_DATA  *PkCertData;

  X509Data     = NULL;
  PkCertData   = NULL;
  X509DataSize = 0;

  Status = ReadFileContent (X509File, (VOID **)&X509Data, &X509DataSize, 0);
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  ASSERT (X509Data != NULL);

  //
  // Allocate space for PK certificate list and initialize it.
  // Create PK database entry with SignatureHeaderSize equals 0.
  //
  *PkCert = (EFI_SIGNATURE_LIST *)AllocateZeroPool (
                                    sizeof (EFI_SIGNATURE_LIST) + sizeof (EFI_SIGNATURE_DATA) - 1
                                    + X509DataSize
                                    );
  if (*PkCert == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  (*PkCert)->SignatureListSize = (UINT32)(sizeof (EFI_SIGNATURE_LIST)
                                          + sizeof (EFI_SIGNATURE_DATA) - 1
                                          + X509DataSize);
  (*PkCert)->SignatureSize       = (UINT32)(sizeof (EFI_SIGNATURE_DATA) - 1 + X509DataSize);
  (*PkCert)->SignatureHeaderSize = 0;
  CopyGuid (&(*PkCert)->SignatureType, &gEfiCertX509Guid);
  PkCertData = (EFI_SIGNATURE_DATA *)((UINTN)(*PkCert)
                                      + sizeof (EFI_SIGNATURE_LIST)
                                      + (*PkCert)->SignatureHeaderSize);
  CopyGuid (&PkCertData->SignatureOwner, &gEfiGlobalVariableGuid);
  //
  // Fill the PK database with PKpub data from X509 certificate file.
  //
  CopyMem (&(PkCertData->SignatureData[0]), X509Data, X509DataSize);

ON_EXIT:

  if (X509Data != NULL) {
    FreePool (X509Data);
  }

  if (EFI_ERROR (Status) && (*PkCert != NULL)) {
    FreePool (*PkCert);
    *PkCert = NULL;
  }

  return Status;
}

/**
  Enroll new PK into the System without original PK's authentication.

  The SignatureOwner GUID will be the same with PK's vendorguid.

  @param[in] PrivateData     The module's private data.

  @retval   EFI_SUCCESS            New PK enrolled successfully.
  @retval   EFI_INVALID_PARAMETER  The parameter is invalid.
  @retval   EFI_OUT_OF_RESOURCES   Could not allocate needed resources.

**/
EFI_STATUS
EnrollPlatformKey (
  IN  SECUREBOOT_CONFIG_PRIVATE_DATA  *Private
  )
{
  EFI_STATUS          Status;
  UINT32              Attr;
  UINTN               DataSize;
  EFI_SIGNATURE_LIST  *PkCert;
  EFI_TIME            Time;

  PkCert = NULL;

  Status = SetSecureBootMode (CUSTOM_SECURE_BOOT_MODE);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Prase the selected PK file and generate PK certificate list.
  //
  Status = CreatePkX509SignatureList (
             Private->FileContext->FHandle,
             &PkCert
             );
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  ASSERT (PkCert != NULL);

  //
  // Set Platform Key variable.
  //
  Attr = EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_RUNTIME_ACCESS
         | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS;
  DataSize = PkCert->SignatureListSize;
  Status   = GetCurrentTime (&Time);
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Fail to fetch valid time data: %r", Status));
    goto ON_EXIT;
  }

  Status = CreateTimeBasedPayload (&DataSize, (UINT8 **)&PkCert, &Time);
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Fail to create time-based data payload: %r", Status));
    goto ON_EXIT;
  }

  Status = gRT->SetVariable (
                  EFI_PLATFORM_KEY_NAME,
                  &gEfiGlobalVariableGuid,
                  Attr,
                  DataSize,
                  PkCert
                  );
  if (EFI_ERROR (Status)) {
    if (Status == EFI_OUT_OF_RESOURCES) {
      DEBUG ((DEBUG_ERROR, "Enroll PK failed with out of resource.\n"));
    }

    goto ON_EXIT;
  }

ON_EXIT:

  if (PkCert != NULL) {
    FreePool (PkCert);
  }

  CloseEnrolledFile (Private->FileContext);

  return Status;
}

/**
  Enroll a new KEK item from public key storing file (*.pbk).

  @param[in] PrivateData           The module's private data.

  @retval   EFI_SUCCESS            New KEK enrolled successfully.
  @retval   EFI_INVALID_PARAMETER  The parameter is invalid.
  @retval   EFI_UNSUPPORTED        Unsupported command.
  @retval   EFI_OUT_OF_RESOURCES   Could not allocate needed resources.

**/
EFI_STATUS
EnrollRsa2048ToKek (
  IN SECUREBOOT_CONFIG_PRIVATE_DATA  *Private
  )
{
  EFI_STATUS          Status;
  UINT32              Attr;
  UINTN               DataSize;
  EFI_SIGNATURE_LIST  *KekSigList;
  UINTN               KeyBlobSize;
  UINT8               *KeyBlob;
  CPL_KEY_INFO        *KeyInfo;
  EFI_SIGNATURE_DATA  *KEKSigData;
  UINTN               KekSigListSize;
  UINT8               *KeyBuffer;
  UINTN               KeyLenInBytes;
  EFI_TIME            Time;

  Attr           = 0;
  DataSize       = 0;
  KeyBuffer      = NULL;
  KeyBlobSize    = 0;
  KeyBlob        = NULL;
  KeyInfo        = NULL;
  KEKSigData     = NULL;
  KekSigList     = NULL;
  KekSigListSize = 0;

  //
  // Form the KeKpub certificate list into EFI_SIGNATURE_LIST type.
  // First, We have to parse out public key data from the pbk key file.
  //
  Status = ReadFileContent (
             Private->FileContext->FHandle,
             (VOID **)&KeyBlob,
             &KeyBlobSize,
             0
             );
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  ASSERT (KeyBlob != NULL);
  KeyInfo = (CPL_KEY_INFO *)KeyBlob;
  if (KeyInfo->KeyLengthInBits / 8 != WIN_CERT_UEFI_RSA2048_SIZE) {
    DEBUG ((DEBUG_ERROR, "Unsupported key length, Only RSA2048 is supported.\n"));
    Status = EFI_UNSUPPORTED;
    goto ON_EXIT;
  }

  //
  // Convert the Public key to fix octet string format represented in RSA PKCS#1.
  //
  KeyLenInBytes = KeyInfo->KeyLengthInBits / 8;
  KeyBuffer     = AllocateZeroPool (KeyLenInBytes);
  if (KeyBuffer == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  Int2OctStr (
    (UINTN *)(KeyBlob + sizeof (CPL_KEY_INFO)),
    KeyLenInBytes / sizeof (UINTN),
    KeyBuffer,
    KeyLenInBytes
    );
  CopyMem (KeyBlob + sizeof (CPL_KEY_INFO), KeyBuffer, KeyLenInBytes);

  //
  // Form an new EFI_SIGNATURE_LIST.
  //
  KekSigListSize = sizeof (EFI_SIGNATURE_LIST)
                   + sizeof (EFI_SIGNATURE_DATA) - 1
                   + WIN_CERT_UEFI_RSA2048_SIZE;

  KekSigList = (EFI_SIGNATURE_LIST *)AllocateZeroPool (KekSigListSize);
  if (KekSigList == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  KekSigList->SignatureListSize = sizeof (EFI_SIGNATURE_LIST)
                                  + sizeof (EFI_SIGNATURE_DATA) - 1
                                  + WIN_CERT_UEFI_RSA2048_SIZE;
  KekSigList->SignatureHeaderSize = 0;
  KekSigList->SignatureSize       = sizeof (EFI_SIGNATURE_DATA) - 1 + WIN_CERT_UEFI_RSA2048_SIZE;
  CopyGuid (&KekSigList->SignatureType, &gEfiCertRsa2048Guid);

  KEKSigData = (EFI_SIGNATURE_DATA *)((UINT8 *)KekSigList + sizeof (EFI_SIGNATURE_LIST));
  CopyGuid (&KEKSigData->SignatureOwner, Private->SignatureGUID);
  CopyMem (
    KEKSigData->SignatureData,
    KeyBlob + sizeof (CPL_KEY_INFO),
    WIN_CERT_UEFI_RSA2048_SIZE
    );

  //
  // Check if KEK entry has been already existed.
  // If true, use EFI_VARIABLE_APPEND_WRITE attribute to append the
  // new KEK to original variable.
  //
  Attr = EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_RUNTIME_ACCESS
         | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS;
  Status = GetCurrentTime (&Time);
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Fail to fetch valid time data: %r", Status));
    goto ON_EXIT;
  }

  Status = CreateTimeBasedPayload (&KekSigListSize, (UINT8 **)&KekSigList, &Time);
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Fail to create time-based data payload: %r", Status));
    goto ON_EXIT;
  }

  Status = gRT->GetVariable (
                  EFI_KEY_EXCHANGE_KEY_NAME,
                  &gEfiGlobalVariableGuid,
                  NULL,
                  &DataSize,
                  NULL
                  );
  if (Status == EFI_BUFFER_TOO_SMALL) {
    Attr |= EFI_VARIABLE_APPEND_WRITE;
  } else if (Status != EFI_NOT_FOUND) {
    goto ON_EXIT;
  }

  //
  // Done. Now we have formed the correct KEKpub database item, just set it into variable storage,
  //
  Status = gRT->SetVariable (
                  EFI_KEY_EXCHANGE_KEY_NAME,
                  &gEfiGlobalVariableGuid,
                  Attr,
                  KekSigListSize,
                  KekSigList
                  );
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

ON_EXIT:

  CloseEnrolledFile (Private->FileContext);

  if (Private->SignatureGUID != NULL) {
    FreePool (Private->SignatureGUID);
    Private->SignatureGUID = NULL;
  }

  if (KeyBlob != NULL) {
    FreePool (KeyBlob);
  }

  if (KeyBuffer != NULL) {
    FreePool (KeyBuffer);
  }

  if (KekSigList != NULL) {
    FreePool (KekSigList);
  }

  return Status;
}

/**
  Enroll a new KEK item from X509 certificate file.

  @param[in] PrivateData           The module's private data.

  @retval   EFI_SUCCESS            New X509 is enrolled successfully.
  @retval   EFI_INVALID_PARAMETER  The parameter is invalid.
  @retval   EFI_UNSUPPORTED        Unsupported command.
  @retval   EFI_OUT_OF_RESOURCES   Could not allocate needed resources.

**/
EFI_STATUS
EnrollX509ToKek (
  IN SECUREBOOT_CONFIG_PRIVATE_DATA  *Private
  )
{
  EFI_STATUS          Status;
  UINTN               X509DataSize;
  VOID                *X509Data;
  EFI_SIGNATURE_DATA  *KEKSigData;
  EFI_SIGNATURE_LIST  *KekSigList;
  UINTN               DataSize;
  UINTN               KekSigListSize;
  UINT32              Attr;
  EFI_TIME            Time;

  X509Data       = NULL;
  X509DataSize   = 0;
  KekSigList     = NULL;
  KekSigListSize = 0;
  DataSize       = 0;
  KEKSigData     = NULL;

  Status = ReadFileContent (
             Private->FileContext->FHandle,
             &X509Data,
             &X509DataSize,
             0
             );
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  ASSERT (X509Data != NULL);

  KekSigListSize = sizeof (EFI_SIGNATURE_LIST) + sizeof (EFI_SIGNATURE_DATA) - 1 + X509DataSize;
  KekSigList     = (EFI_SIGNATURE_LIST *)AllocateZeroPool (KekSigListSize);
  if (KekSigList == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  //
  // Fill Certificate Database parameters.
  //
  KekSigList->SignatureListSize   = (UINT32)KekSigListSize;
  KekSigList->SignatureHeaderSize = 0;
  KekSigList->SignatureSize       = (UINT32)(sizeof (EFI_SIGNATURE_DATA) - 1 + X509DataSize);
  CopyGuid (&KekSigList->SignatureType, &gEfiCertX509Guid);

  KEKSigData = (EFI_SIGNATURE_DATA *)((UINT8 *)KekSigList + sizeof (EFI_SIGNATURE_LIST));
  CopyGuid (&KEKSigData->SignatureOwner, Private->SignatureGUID);
  CopyMem (KEKSigData->SignatureData, X509Data, X509DataSize);

  //
  // Check if KEK been already existed.
  // If true, use EFI_VARIABLE_APPEND_WRITE attribute to append the
  // new kek to original variable
  //
  Attr = EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_RUNTIME_ACCESS
         | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS;
  Status = GetCurrentTime (&Time);
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Fail to fetch valid time data: %r", Status));
    goto ON_EXIT;
  }

  Status = CreateTimeBasedPayload (&KekSigListSize, (UINT8 **)&KekSigList, &Time);
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Fail to create time-based data payload: %r", Status));
    goto ON_EXIT;
  }

  Status = gRT->GetVariable (
                  EFI_KEY_EXCHANGE_KEY_NAME,
                  &gEfiGlobalVariableGuid,
                  NULL,
                  &DataSize,
                  NULL
                  );
  if (Status == EFI_BUFFER_TOO_SMALL) {
    Attr |= EFI_VARIABLE_APPEND_WRITE;
  } else if (Status != EFI_NOT_FOUND) {
    goto ON_EXIT;
  }

  Status = gRT->SetVariable (
                  EFI_KEY_EXCHANGE_KEY_NAME,
                  &gEfiGlobalVariableGuid,
                  Attr,
                  KekSigListSize,
                  KekSigList
                  );
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

ON_EXIT:

  CloseEnrolledFile (Private->FileContext);

  if (Private->SignatureGUID != NULL) {
    FreePool (Private->SignatureGUID);
    Private->SignatureGUID = NULL;
  }

  if (KekSigList != NULL) {
    FreePool (KekSigList);
  }

  return Status;
}

/**
  Enroll new KEK into the System without PK's authentication.
  The SignatureOwner GUID will be Private->SignatureGUID.

  @param[in] PrivateData     The module's private data.

  @retval   EFI_SUCCESS            New KEK enrolled successful.
  @retval   EFI_INVALID_PARAMETER  The parameter is invalid.
  @retval   others                 Fail to enroll KEK data.

**/
EFI_STATUS
EnrollKeyExchangeKey (
  IN SECUREBOOT_CONFIG_PRIVATE_DATA  *Private
  )
{
  UINT16      *FilePostFix;
  EFI_STATUS  Status;
  UINTN       NameLength;

  if ((Private->FileContext->FHandle == NULL) || (Private->FileContext->FileName == NULL) || (Private->SignatureGUID == NULL)) {
    return EFI_INVALID_PARAMETER;
  }

  Status = SetSecureBootMode (CUSTOM_SECURE_BOOT_MODE);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Parse the file's postfix. Supports DER-encoded X509 certificate,
  // and .pbk as RSA public key file.
  //
  NameLength = StrLen (Private->FileContext->FileName);
  if (NameLength <= 4) {
    return EFI_INVALID_PARAMETER;
  }

  FilePostFix = Private->FileContext->FileName + NameLength - 4;
  if (IsDerEncodeCertificate (FilePostFix)) {
    return EnrollX509ToKek (Private);
  } else if (CompareMem (FilePostFix, L".pbk", 4) == 0) {
    return EnrollRsa2048ToKek (Private);
  } else {
    //
    // File type is wrong, simply close it
    //
    CloseEnrolledFile (Private->FileContext);

    return EFI_INVALID_PARAMETER;
  }
}

/**
  Enroll a new X509 certificate into Signature Database (DB or DBX or DBT) without
  KEK's authentication.

  @param[in] PrivateData     The module's private data.
  @param[in] VariableName    Variable name of signature database, must be
                             EFI_IMAGE_SECURITY_DATABASE or EFI_IMAGE_SECURITY_DATABASE1.

  @retval   EFI_SUCCESS            New X509 is enrolled successfully.
  @retval   EFI_OUT_OF_RESOURCES   Could not allocate needed resources.

**/
EFI_STATUS
EnrollX509toSigDB (
  IN SECUREBOOT_CONFIG_PRIVATE_DATA  *Private,
  IN CHAR16                          *VariableName
  )
{
  EFI_STATUS          Status;
  UINTN               X509DataSize;
  VOID                *X509Data;
  EFI_SIGNATURE_LIST  *SigDBCert;
  EFI_SIGNATURE_DATA  *SigDBCertData;
  VOID                *Data;
  UINTN               DataSize;
  UINTN               SigDBSize;
  UINT32              Attr;
  EFI_TIME            Time;

  X509DataSize  = 0;
  SigDBSize     = 0;
  DataSize      = 0;
  X509Data      = NULL;
  SigDBCert     = NULL;
  SigDBCertData = NULL;
  Data          = NULL;

  Status = ReadFileContent (
             Private->FileContext->FHandle,
             &X509Data,
             &X509DataSize,
             0
             );
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  ASSERT (X509Data != NULL);

  SigDBSize = sizeof (EFI_SIGNATURE_LIST) + sizeof (EFI_SIGNATURE_DATA) - 1 + X509DataSize;

  Data = AllocateZeroPool (SigDBSize);
  if (Data == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  //
  // Fill Certificate Database parameters.
  //
  SigDBCert                      = (EFI_SIGNATURE_LIST *)Data;
  SigDBCert->SignatureListSize   = (UINT32)SigDBSize;
  SigDBCert->SignatureHeaderSize = 0;
  SigDBCert->SignatureSize       = (UINT32)(sizeof (EFI_SIGNATURE_DATA) - 1 + X509DataSize);
  CopyGuid (&SigDBCert->SignatureType, &gEfiCertX509Guid);

  SigDBCertData = (EFI_SIGNATURE_DATA *)((UINT8 *)SigDBCert + sizeof (EFI_SIGNATURE_LIST));
  CopyGuid (&SigDBCertData->SignatureOwner, Private->SignatureGUID);
  CopyMem ((UINT8 *)(SigDBCertData->SignatureData), X509Data, X509DataSize);

  //
  // Check if signature database entry has been already existed.
  // If true, use EFI_VARIABLE_APPEND_WRITE attribute to append the
  // new signature data to original variable
  //
  Attr = EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_RUNTIME_ACCESS
         | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS;
  Status = GetCurrentTime (&Time);
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Fail to fetch valid time data: %r", Status));
    goto ON_EXIT;
  }

  Status = CreateTimeBasedPayload (&SigDBSize, (UINT8 **)&Data, &Time);
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Fail to create time-based data payload: %r", Status));
    goto ON_EXIT;
  }

  Status = gRT->GetVariable (
                  VariableName,
                  &gEfiImageSecurityDatabaseGuid,
                  NULL,
                  &DataSize,
                  NULL
                  );
  if (Status == EFI_BUFFER_TOO_SMALL) {
    Attr |= EFI_VARIABLE_APPEND_WRITE;
  } else if (Status != EFI_NOT_FOUND) {
    goto ON_EXIT;
  }

  Status = gRT->SetVariable (
                  VariableName,
                  &gEfiImageSecurityDatabaseGuid,
                  Attr,
                  SigDBSize,
                  Data
                  );
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

ON_EXIT:

  CloseEnrolledFile (Private->FileContext);

  if (Private->SignatureGUID != NULL) {
    FreePool (Private->SignatureGUID);
    Private->SignatureGUID = NULL;
  }

  if (Data != NULL) {
    FreePool (Data);
  }

  if (X509Data != NULL) {
    FreePool (X509Data);
  }

  return Status;
}

/**
  Check whether signature is in specified database.

  @param[in]  VariableName        Name of database variable that is searched in.
  @param[in]  Signature           Pointer to signature that is searched for.
  @param[in]  SignatureSize       Size of Signature.

  @return TRUE                    Found the signature in the variable database.
  @return FALSE                   Not found the signature in the variable database.

**/
BOOLEAN
IsSignatureFoundInDatabase (
  IN CHAR16  *VariableName,
  IN UINT8   *Signature,
  IN UINTN   SignatureSize
  )
{
  EFI_STATUS          Status;
  EFI_SIGNATURE_LIST  *CertList;
  EFI_SIGNATURE_DATA  *Cert;
  UINTN               DataSize;
  UINT8               *Data;
  UINTN               Index;
  UINTN               CertCount;
  BOOLEAN             IsFound;

  //
  // Read signature database variable.
  //
  IsFound  = FALSE;
  Data     = NULL;
  DataSize = 0;
  Status   = gRT->GetVariable (VariableName, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, NULL);
  if (Status != EFI_BUFFER_TOO_SMALL) {
    return FALSE;
  }

  Data = (UINT8 *)AllocateZeroPool (DataSize);
  if (Data == NULL) {
    return FALSE;
  }

  Status = gRT->GetVariable (VariableName, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, Data);
  if (EFI_ERROR (Status)) {
    goto Done;
  }

  //
  // Enumerate all signature data in SigDB to check if signature exists for executable.
  //
  CertList = (EFI_SIGNATURE_LIST *)Data;
  while ((DataSize > 0) && (DataSize >= CertList->SignatureListSize)) {
    CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;
    Cert      = (EFI_SIGNATURE_DATA *)((UINT8 *)CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
    if ((CertList->SignatureSize == sizeof (EFI_SIGNATURE_DATA) - 1 + SignatureSize) && (CompareGuid (&CertList->SignatureType, &gEfiCertX509Guid))) {
      for (Index = 0; Index < CertCount; Index++) {
        if (CompareMem (Cert->SignatureData, Signature, SignatureSize) == 0) {
          //
          // Find the signature in database.
          //
          IsFound = TRUE;
          break;
        }

        Cert = (EFI_SIGNATURE_DATA *)((UINT8 *)Cert + CertList->SignatureSize);
      }

      if (IsFound) {
        break;
      }
    }

    DataSize -= CertList->SignatureListSize;
    CertList  = (EFI_SIGNATURE_LIST *)((UINT8 *)CertList + CertList->SignatureListSize);
  }

Done:
  if (Data != NULL) {
    FreePool (Data);
  }

  return IsFound;
}

/**
  Calculate the hash of a certificate data with the specified hash algorithm.

  @param[in]    CertData  The certificate data to be hashed.
  @param[in]    CertSize  The certificate size in bytes.
  @param[in]    HashAlg   The specified hash algorithm.
  @param[out]   CertHash  The output digest of the certificate

  @retval TRUE            Successfully got the hash of the CertData.
  @retval FALSE           Failed to get the hash of CertData.

**/
BOOLEAN
CalculateCertHash (
  IN  UINT8   *CertData,
  IN  UINTN   CertSize,
  IN  UINT32  HashAlg,
  OUT UINT8   *CertHash
  )
{
  BOOLEAN  Status;
  VOID     *HashCtx;
  UINTN    CtxSize;
  UINT8    *TBSCert;
  UINTN    TBSCertSize;

  HashCtx = NULL;
  Status  = FALSE;

  if (HashAlg >= HASHALG_MAX) {
    return FALSE;
  }

  //
  // Retrieve the TBSCertificate for Hash Calculation.
  //
  if (!X509GetTBSCert (CertData, CertSize, &TBSCert, &TBSCertSize)) {
    return FALSE;
  }

  //
  // 1. Initialize context of hash.
  //
  CtxSize = mHash[HashAlg].GetContextSize ();
  HashCtx = AllocatePool (CtxSize);
  ASSERT (HashCtx != NULL);

  //
  // 2. Initialize a hash context.
  //
  Status = mHash[HashAlg].HashInit (HashCtx);
  if (!Status) {
    goto Done;
  }

  //
  // 3. Calculate the hash.
  //
  Status = mHash[HashAlg].HashUpdate (HashCtx, TBSCert, TBSCertSize);
  if (!Status) {
    goto Done;
  }

  //
  // 4. Get the hash result.
  //
  ZeroMem (CertHash, mHash[HashAlg].DigestLength);
  Status = mHash[HashAlg].HashFinal (HashCtx, CertHash);

Done:
  if (HashCtx != NULL) {
    FreePool (HashCtx);
  }

  return Status;
}

/**
  Check whether the hash of an X.509 certificate is in forbidden database (DBX).

  @param[in]  Certificate       Pointer to X.509 Certificate that is searched for.
  @param[in]  CertSize          Size of X.509 Certificate.

  @return TRUE               Found the certificate hash in the forbidden database.
  @return FALSE              Certificate hash is Not found in the forbidden database.

**/
BOOLEAN
IsCertHashFoundInDbx (
  IN  UINT8  *Certificate,
  IN  UINTN  CertSize
  )
{
  BOOLEAN             IsFound;
  EFI_STATUS          Status;
  EFI_SIGNATURE_LIST  *DbxList;
  EFI_SIGNATURE_DATA  *CertHash;
  UINTN               CertHashCount;
  UINTN               Index;
  UINT32              HashAlg;
  UINT8               CertDigest[MAX_DIGEST_SIZE];
  UINT8               *DbxCertHash;
  UINTN               SiglistHeaderSize;
  UINT8               *Data;
  UINTN               DataSize;

  IsFound = FALSE;
  HashAlg = HASHALG_MAX;
  Data    = NULL;

  //
  // Read signature database variable.
  //
  DataSize = 0;
  Status   = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, NULL);
  if (Status != EFI_BUFFER_TOO_SMALL) {
    return FALSE;
  }

  Data = (UINT8 *)AllocateZeroPool (DataSize);
  if (Data == NULL) {
    return FALSE;
  }

  Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, Data);
  if (EFI_ERROR (Status)) {
    goto Done;
  }

  //
  // Check whether the certificate hash exists in the forbidden database.
  //
  DbxList = (EFI_SIGNATURE_LIST *)Data;
  while ((DataSize > 0) && (DataSize >= DbxList->SignatureListSize)) {
    //
    // Determine Hash Algorithm of Certificate in the forbidden database.
    //
    if (CompareGuid (&DbxList->SignatureType, &gEfiCertX509Sha256Guid)) {
      HashAlg = HASHALG_SHA256;
    } else if (CompareGuid (&DbxList->SignatureType, &gEfiCertX509Sha384Guid)) {
      HashAlg = HASHALG_SHA384;
    } else if (CompareGuid (&DbxList->SignatureType, &gEfiCertX509Sha512Guid)) {
      HashAlg = HASHALG_SHA512;
    } else {
      DataSize -= DbxList->SignatureListSize;
      DbxList   = (EFI_SIGNATURE_LIST *)((UINT8 *)DbxList + DbxList->SignatureListSize);
      continue;
    }

    //
    // Calculate the hash value of current db certificate for comparision.
    //
    if (!CalculateCertHash (Certificate, CertSize, HashAlg, CertDigest)) {
      goto Done;
    }

    SiglistHeaderSize = sizeof (EFI_SIGNATURE_LIST) + DbxList->SignatureHeaderSize;
    CertHash          = (EFI_SIGNATURE_DATA *)((UINT8 *)DbxList + SiglistHeaderSize);
    CertHashCount     = (DbxList->SignatureListSize - SiglistHeaderSize) / DbxList->SignatureSize;
    for (Index = 0; Index < CertHashCount; Index++) {
      //
      // Iterate each Signature Data Node within this CertList for verify.
      //
      DbxCertHash = CertHash->SignatureData;
      if (CompareMem (DbxCertHash, CertDigest, mHash[HashAlg].DigestLength) == 0) {
        //
        // Hash of Certificate is found in forbidden database.
        //
        IsFound = TRUE;
        goto Done;
      }

      CertHash = (EFI_SIGNATURE_DATA *)((UINT8 *)CertHash + DbxList->SignatureSize);
    }

    DataSize -= DbxList->SignatureListSize;
    DbxList   = (EFI_SIGNATURE_LIST *)((UINT8 *)DbxList + DbxList->SignatureListSize);
  }

Done:
  if (Data != NULL) {
    FreePool (Data);
  }

  return IsFound;
}

/**
  Check whether the signature list exists in given variable data.

  It searches the signature list for the certificate hash by CertType.
  If the signature list is found, get the offset of Database for the
  next hash of a certificate.

  @param[in]  Database      Variable data to save signature list.
  @param[in]  DatabaseSize  Variable size.
  @param[in]  SignatureType The type of the signature.
  @param[out] Offset        The offset to save a new hash of certificate.

  @return TRUE       The signature list is found in the forbidden database.
  @return FALSE      The signature list is not found in the forbidden database.
**/
BOOLEAN
GetSignaturelistOffset (
  IN  EFI_SIGNATURE_LIST  *Database,
  IN  UINTN               DatabaseSize,
  IN  EFI_GUID            *SignatureType,
  OUT UINTN               *Offset
  )
{
  EFI_SIGNATURE_LIST  *SigList;
  UINTN               SiglistSize;

  if ((Database == NULL) || (DatabaseSize == 0)) {
    *Offset = 0;
    return FALSE;
  }

  SigList     = Database;
  SiglistSize = DatabaseSize;
  while ((SiglistSize > 0) && (SiglistSize >= SigList->SignatureListSize)) {
    if (CompareGuid (&SigList->SignatureType, SignatureType)) {
      *Offset = DatabaseSize - SiglistSize;
      return TRUE;
    }

    SiglistSize -= SigList->SignatureListSize;
    SigList      = (EFI_SIGNATURE_LIST *)((UINT8 *)SigList + SigList->SignatureListSize);
  }

  *Offset = 0;
  return FALSE;
}

/**
  Enroll a new X509 certificate hash into Signature Database (dbx) without
  KEK's authentication.

  @param[in] PrivateData      The module's private data.
  @param[in] HashAlg          The hash algorithm to enroll the certificate.
  @param[in] RevocationDate   The revocation date of the certificate.
  @param[in] RevocationTime   The revocation time of the certificate.
  @param[in] AlwaysRevocation Indicate whether the certificate is always revoked.

  @retval   EFI_SUCCESS            New X509 is enrolled successfully.
  @retval   EFI_INVALID_PARAMETER  The parameter is invalid.
  @retval   EFI_OUT_OF_RESOURCES   Could not allocate needed resources.

**/
EFI_STATUS
EnrollX509HashtoSigDB (
  IN SECUREBOOT_CONFIG_PRIVATE_DATA  *Private,
  IN UINT32                          HashAlg,
  IN EFI_HII_DATE                    *RevocationDate,
  IN EFI_HII_TIME                    *RevocationTime,
  IN BOOLEAN                         AlwaysRevocation
  )
{
  EFI_STATUS          Status;
  UINTN               X509DataSize;
  VOID                *X509Data;
  EFI_SIGNATURE_LIST  *SignatureList;
  UINTN               SignatureListSize;
  UINT8               *Data;
  UINT8               *NewData;
  UINTN               DataSize;
  UINTN               DbSize;
  UINT32              Attr;
  EFI_SIGNATURE_DATA  *SignatureData;
  UINTN               SignatureSize;
  EFI_GUID            SignatureType;
  UINTN               Offset;
  UINT8               CertHash[MAX_DIGEST_SIZE];
  UINT16              *FilePostFix;
  UINTN               NameLength;
  EFI_TIME            *Time;
  EFI_TIME            NewTime;

  X509DataSize  = 0;
  DbSize        = 0;
  X509Data      = NULL;
  SignatureData = NULL;
  SignatureList = NULL;
  Data          = NULL;
  NewData       = NULL;

  if ((Private->FileContext->FileName == NULL) || (Private->FileContext->FHandle == NULL) || (Private->SignatureGUID == NULL)) {
    return EFI_INVALID_PARAMETER;
  }

  Status = SetSecureBootMode (CUSTOM_SECURE_BOOT_MODE);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Parse the file's postfix.
  //
  NameLength = StrLen (Private->FileContext->FileName);
  if (NameLength <= 4) {
    return EFI_INVALID_PARAMETER;
  }

  FilePostFix = Private->FileContext->FileName + NameLength - 4;
  if (!IsDerEncodeCertificate (FilePostFix)) {
    //
    // Only supports DER-encoded X509 certificate.
    //
    return EFI_INVALID_PARAMETER;
  }

  //
  // Get the certificate from file and calculate its hash.
  //
  Status = ReadFileContent (
             Private->FileContext->FHandle,
             &X509Data,
             &X509DataSize,
             0
             );
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  ASSERT (X509Data != NULL);

  if (!CalculateCertHash (X509Data, X509DataSize, HashAlg, CertHash)) {
    goto ON_EXIT;
  }

  //
  // Get the variable for enrollment.
  //
  DataSize = 0;
  Status   = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, NULL);
  if (Status == EFI_BUFFER_TOO_SMALL) {
    Data = (UINT8 *)AllocateZeroPool (DataSize);
    if (Data == NULL) {
      return EFI_OUT_OF_RESOURCES;
    }

    Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, Data);
    if (EFI_ERROR (Status)) {
      goto ON_EXIT;
    }
  }

  //
  // Allocate memory for Signature and fill the Signature
  //
  SignatureSize = sizeof (EFI_SIGNATURE_DATA) - 1 + sizeof (EFI_TIME) + mHash[HashAlg].DigestLength;
  SignatureData = (EFI_SIGNATURE_DATA *)AllocateZeroPool (SignatureSize);
  if (SignatureData == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  CopyGuid (&SignatureData->SignatureOwner, Private->SignatureGUID);
  CopyMem (SignatureData->SignatureData, CertHash, mHash[HashAlg].DigestLength);

  //
  // Fill the time.
  //
  if (!AlwaysRevocation) {
    Time         = (EFI_TIME *)(&SignatureData->SignatureData + mHash[HashAlg].DigestLength);
    Time->Year   = RevocationDate->Year;
    Time->Month  = RevocationDate->Month;
    Time->Day    = RevocationDate->Day;
    Time->Hour   = RevocationTime->Hour;
    Time->Minute = RevocationTime->Minute;
    Time->Second = RevocationTime->Second;
  }

  //
  // Determine the GUID for certificate hash.
  //
  switch (HashAlg) {
    case HASHALG_SHA256:
      SignatureType = gEfiCertX509Sha256Guid;
      break;
    case HASHALG_SHA384:
      SignatureType = gEfiCertX509Sha384Guid;
      break;
    case HASHALG_SHA512:
      SignatureType = gEfiCertX509Sha512Guid;
      break;
    default:
      return FALSE;
  }

  //
  // Add signature into the new variable data buffer
  //
  if (GetSignaturelistOffset ((EFI_SIGNATURE_LIST *)Data, DataSize, &SignatureType, &Offset)) {
    //
    // Add the signature to the found signaturelist.
    //
    DbSize  = DataSize + SignatureSize;
    NewData = AllocateZeroPool (DbSize);
    if (NewData == NULL) {
      Status = EFI_OUT_OF_RESOURCES;
      goto ON_EXIT;
    }

    SignatureList     = (EFI_SIGNATURE_LIST *)(Data + Offset);
    SignatureListSize = (UINTN)ReadUnaligned32 ((UINT32 *)&SignatureList->SignatureListSize);
    CopyMem (NewData, Data, Offset + SignatureListSize);

    SignatureList = (EFI_SIGNATURE_LIST *)(NewData + Offset);
    WriteUnaligned32 ((UINT32 *)&SignatureList->SignatureListSize, (UINT32)(SignatureListSize + SignatureSize));

    Offset += SignatureListSize;
    CopyMem (NewData + Offset, SignatureData, SignatureSize);
    CopyMem (NewData + Offset + SignatureSize, Data + Offset, DataSize - Offset);

    FreePool (Data);
    Data     = NewData;
    DataSize = DbSize;
  } else {
    //
    // Create a new signaturelist, and add the signature into the signaturelist.
    //
    DbSize  = DataSize + sizeof (EFI_SIGNATURE_LIST) + SignatureSize;
    NewData = AllocateZeroPool (DbSize);
    if (NewData == NULL) {
      Status = EFI_OUT_OF_RESOURCES;
      goto ON_EXIT;
    }

    //
    // Fill Certificate Database parameters.
    //
    SignatureList     = (EFI_SIGNATURE_LIST *)(NewData + DataSize);
    SignatureListSize = sizeof (EFI_SIGNATURE_LIST) + SignatureSize;
    WriteUnaligned32 ((UINT32 *)&SignatureList->SignatureListSize, (UINT32)SignatureListSize);
    WriteUnaligned32 ((UINT32 *)&SignatureList->SignatureSize, (UINT32)SignatureSize);
    CopyGuid (&SignatureList->SignatureType, &SignatureType);
    CopyMem ((UINT8 *)SignatureList + sizeof (EFI_SIGNATURE_LIST), SignatureData, SignatureSize);
    if ((DataSize != 0) && (Data != NULL)) {
      CopyMem (NewData, Data, DataSize);
      FreePool (Data);
    }

    Data     = NewData;
    DataSize = DbSize;
  }

  Status = GetCurrentTime (&NewTime);
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Fail to fetch valid time data: %r", Status));
    goto ON_EXIT;
  }

  Status = CreateTimeBasedPayload (&DataSize, (UINT8 **)&Data, &NewTime);
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  Attr = EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_RUNTIME_ACCESS
         | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS;
  Status = gRT->SetVariable (
                  EFI_IMAGE_SECURITY_DATABASE1,
                  &gEfiImageSecurityDatabaseGuid,
                  Attr,
                  DataSize,
                  Data
                  );
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

ON_EXIT:

  CloseEnrolledFile (Private->FileContext);

  if (Private->SignatureGUID != NULL) {
    FreePool (Private->SignatureGUID);
    Private->SignatureGUID = NULL;
  }

  if (Data != NULL) {
    FreePool (Data);
  }

  if (SignatureData != NULL) {
    FreePool (SignatureData);
  }

  if (X509Data != NULL) {
    FreePool (X509Data);
  }

  return Status;
}

/**
  Check whether a certificate from a file exists in dbx.

  @param[in] PrivateData     The module's private data.
  @param[in] VariableName    Variable name of signature database, must be
                             EFI_IMAGE_SECURITY_DATABASE1.

  @retval   TRUE             The X509 certificate is found in dbx successfully.
  @retval   FALSE            The X509 certificate is not found in dbx.
**/
BOOLEAN
IsX509CertInDbx (
  IN SECUREBOOT_CONFIG_PRIVATE_DATA  *Private,
  IN CHAR16                          *VariableName
  )
{
  EFI_STATUS  Status;
  UINTN       X509DataSize;
  VOID        *X509Data;
  BOOLEAN     IsFound;

  //
  //  Read the certificate from file
  //
  X509DataSize = 0;
  X509Data     = NULL;
  Status       = ReadFileContent (
                   Private->FileContext->FHandle,
                   &X509Data,
                   &X509DataSize,
                   0
                   );
  if (EFI_ERROR (Status)) {
    return FALSE;
  }

  //
  // Check the raw certificate.
  //
  IsFound = FALSE;
  if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, X509Data, X509DataSize)) {
    IsFound = TRUE;
    goto ON_EXIT;
  }

  //
  // Check the hash of certificate.
  //
  if (IsCertHashFoundInDbx (X509Data, X509DataSize)) {
    IsFound = TRUE;
    goto ON_EXIT;
  }

ON_EXIT:
  if (X509Data != NULL) {
    FreePool (X509Data);
  }

  return IsFound;
}

/**
  Reads contents of a PE/COFF image in memory buffer.

  Caution: This function may receive untrusted input.
  PE/COFF image is external input, so this function will make sure the PE/COFF image content
  read is within the image buffer.

  @param  FileHandle      Pointer to the file handle to read the PE/COFF image.
  @param  FileOffset      Offset into the PE/COFF image to begin the read operation.
  @param  ReadSize        On input, the size in bytes of the requested read operation.
                          On output, the number of bytes actually read.
  @param  Buffer          Output buffer that contains the data read from the PE/COFF image.

  @retval EFI_SUCCESS     The specified portion of the PE/COFF image was read and the size
**/
EFI_STATUS
EFIAPI
SecureBootConfigImageRead (
  IN     VOID   *FileHandle,
  IN     UINTN  FileOffset,
  IN OUT UINTN  *ReadSize,
  OUT    VOID   *Buffer
  )
{
  UINTN  EndPosition;

  if ((FileHandle == NULL) || (ReadSize == NULL) || (Buffer == NULL)) {
    return EFI_INVALID_PARAMETER;
  }

  if (MAX_ADDRESS - FileOffset < *ReadSize) {
    return EFI_INVALID_PARAMETER;
  }

  EndPosition = FileOffset + *ReadSize;
  if (EndPosition > mImageSize) {
    *ReadSize = (UINT32)(mImageSize - FileOffset);
  }

  if (FileOffset >= mImageSize) {
    *ReadSize = 0;
  }

  CopyMem (Buffer, (UINT8 *)((UINTN)FileHandle + FileOffset), *ReadSize);

  return EFI_SUCCESS;
}

/**
  Load PE/COFF image information into internal buffer and check its validity.

  @retval   EFI_SUCCESS         Successful
  @retval   EFI_UNSUPPORTED     Invalid PE/COFF file
  @retval   EFI_ABORTED         Serious error occurs, like file I/O error etc.

**/
EFI_STATUS
LoadPeImage (
  VOID
  )
{
  EFI_IMAGE_DOS_HEADER          *DosHdr;
  EFI_IMAGE_NT_HEADERS32        *NtHeader32;
  EFI_IMAGE_NT_HEADERS64        *NtHeader64;
  PE_COFF_LOADER_IMAGE_CONTEXT  ImageContext;
  EFI_STATUS                    Status;

  NtHeader32 = NULL;
  NtHeader64 = NULL;

  ZeroMem (&ImageContext, sizeof (ImageContext));
  ImageContext.Handle    = (VOID *)mImageBase;
  ImageContext.ImageRead = (PE_COFF_LOADER_READ_FILE)SecureBootConfigImageRead;

  //
  // Get information about the image being loaded
  //
  Status = PeCoffLoaderGetImageInfo (&ImageContext);
  if (EFI_ERROR (Status)) {
    //
    // The information can't be got from the invalid PeImage
    //
    DEBUG ((DEBUG_INFO, "SecureBootConfigDxe: PeImage invalid. \n"));
    return Status;
  }

  //
  // Read the Dos header
  //
  DosHdr = (EFI_IMAGE_DOS_HEADER *)(mImageBase);
  if (DosHdr->e_magic == EFI_IMAGE_DOS_SIGNATURE) {
    //
    // DOS image header is present,
    // So read the PE header after the DOS image header
    //
    mPeCoffHeaderOffset = DosHdr->e_lfanew;
  } else {
    mPeCoffHeaderOffset = 0;
  }

  //
  // Read PE header and check the signature validity and machine compatibility
  //
  NtHeader32 = (EFI_IMAGE_NT_HEADERS32 *)(mImageBase + mPeCoffHeaderOffset);
  if (NtHeader32->Signature != EFI_IMAGE_NT_SIGNATURE) {
    return EFI_UNSUPPORTED;
  }

  mNtHeader.Pe32 = NtHeader32;

  //
  // Check the architecture field of PE header and get the Certificate Data Directory data
  // Note the size of FileHeader field is constant for both IA32 and X64 arch
  //
  if (  (NtHeader32->FileHeader.Machine == EFI_IMAGE_MACHINE_IA32)
     || (NtHeader32->FileHeader.Machine == EFI_IMAGE_MACHINE_EBC))
  {
    //
    // 32-bits Architecture
    //
    mImageType  = ImageType_IA32;
    mSecDataDir = (EFI_IMAGE_SECURITY_DATA_DIRECTORY *)&(NtHeader32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY]);
  } else if (  (NtHeader32->FileHeader.Machine == EFI_IMAGE_MACHINE_IA64)
            || (NtHeader32->FileHeader.Machine == EFI_IMAGE_MACHINE_X64)
            || (NtHeader32->FileHeader.Machine == EFI_IMAGE_MACHINE_AARCH64))
  {
    //
    // 64-bits Architecture
    //
    mImageType  = ImageType_X64;
    NtHeader64  = (EFI_IMAGE_NT_HEADERS64 *)(mImageBase + mPeCoffHeaderOffset);
    mSecDataDir = (EFI_IMAGE_SECURITY_DATA_DIRECTORY *)&(NtHeader64->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY]);
  } else {
    return EFI_UNSUPPORTED;
  }

  return EFI_SUCCESS;
}

/**
  Calculate hash of Pe/Coff image based on the authenticode image hashing in
  PE/COFF Specification 8.0 Appendix A

  Notes: PE/COFF image has been checked by BasePeCoffLib PeCoffLoaderGetImageInfo() in
  the function LoadPeImage ().

  @param[in]    HashAlg   Hash algorithm type.

  @retval TRUE            Successfully hash image.
  @retval FALSE           Fail in hash image.

**/
BOOLEAN
HashPeImage (
  IN  UINT32  HashAlg
  )
{
  BOOLEAN                   Status;
  EFI_IMAGE_SECTION_HEADER  *Section;
  VOID                      *HashCtx;
  UINTN                     CtxSize;
  UINT8                     *HashBase;
  UINTN                     HashSize;
  UINTN                     SumOfBytesHashed;
  EFI_IMAGE_SECTION_HEADER  *SectionHeader;
  UINTN                     Index;
  UINTN                     Pos;

  HashCtx       = NULL;
  SectionHeader = NULL;
  Status        = FALSE;

  if ((HashAlg >= HASHALG_MAX)) {
    return FALSE;
  }

  //
  // Initialize context of hash.
  //
  ZeroMem (mImageDigest, MAX_DIGEST_SIZE);

  switch (HashAlg) {
    case HASHALG_SHA256:
      mImageDigestSize = SHA256_DIGEST_SIZE;
      mCertType        = gEfiCertSha256Guid;
      break;

    case HASHALG_SHA384:
      mImageDigestSize = SHA384_DIGEST_SIZE;
      mCertType        = gEfiCertSha384Guid;
      break;

    case HASHALG_SHA512:
      mImageDigestSize = SHA512_DIGEST_SIZE;
      mCertType        = gEfiCertSha512Guid;
      break;

    default:
      return FALSE;
  }

  CtxSize = mHash[HashAlg].GetContextSize ();

  HashCtx = AllocatePool (CtxSize);
  ASSERT (HashCtx != NULL);

  // 1.  Load the image header into memory.

  // 2.  Initialize a SHA hash context.
  Status = mHash[HashAlg].HashInit (HashCtx);
  if (!Status) {
    goto Done;
  }

  //
  // Measuring PE/COFF Image Header;
  // But CheckSum field and SECURITY data directory (certificate) are excluded
  //

  //
  // 3.  Calculate the distance from the base of the image header to the image checksum address.
  // 4.  Hash the image header from its base to beginning of the image checksum.
  //
  HashBase = mImageBase;
  if (mNtHeader.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
    //
    // Use PE32 offset.
    //
    HashSize = (UINTN)(&mNtHeader.Pe32->OptionalHeader.CheckSum) - (UINTN)HashBase;
  } else {
    //
    // Use PE32+ offset.
    //
    HashSize = (UINTN)(&mNtHeader.Pe32Plus->OptionalHeader.CheckSum) - (UINTN)HashBase;
  }

  Status = mHash[HashAlg].HashUpdate (HashCtx, HashBase, HashSize);
  if (!Status) {
    goto Done;
  }

  //
  // 5.  Skip over the image checksum (it occupies a single ULONG).
  // 6.  Get the address of the beginning of the Cert Directory.
  // 7.  Hash everything from the end of the checksum to the start of the Cert Directory.
  //
  if (mNtHeader.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
    //
    // Use PE32 offset.
    //
    HashBase = (UINT8 *)&mNtHeader.Pe32->OptionalHeader.CheckSum + sizeof (UINT32);
    HashSize = (UINTN)(&mNtHeader.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY]) - (UINTN)HashBase;
  } else {
    //
    // Use PE32+ offset.
    //
    HashBase = (UINT8 *)&mNtHeader.Pe32Plus->OptionalHeader.CheckSum + sizeof (UINT32);
    HashSize = (UINTN)(&mNtHeader.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY]) - (UINTN)HashBase;
  }

  Status = mHash[HashAlg].HashUpdate (HashCtx, HashBase, HashSize);
  if (!Status) {
    goto Done;
  }

  //
  // 8.  Skip over the Cert Directory. (It is sizeof(IMAGE_DATA_DIRECTORY) bytes.)
  // 9.  Hash everything from the end of the Cert Directory to the end of image header.
  //
  if (mNtHeader.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
    //
    // Use PE32 offset
    //
    HashBase = (UINT8 *)&mNtHeader.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY + 1];
    HashSize = mNtHeader.Pe32->OptionalHeader.SizeOfHeaders - ((UINTN)(&mNtHeader.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY + 1]) - (UINTN)mImageBase);
  } else {
    //
    // Use PE32+ offset.
    //
    HashBase = (UINT8 *)&mNtHeader.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY + 1];
    HashSize = mNtHeader.Pe32Plus->OptionalHeader.SizeOfHeaders - ((UINTN)(&mNtHeader.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY + 1]) - (UINTN)mImageBase);
  }

  Status = mHash[HashAlg].HashUpdate (HashCtx, HashBase, HashSize);
  if (!Status) {
    goto Done;
  }

  //
  // 10. Set the SUM_OF_BYTES_HASHED to the size of the header.
  //
  if (mNtHeader.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
    //
    // Use PE32 offset.
    //
    SumOfBytesHashed = mNtHeader.Pe32->OptionalHeader.SizeOfHeaders;
  } else {
    //
    // Use PE32+ offset
    //
    SumOfBytesHashed = mNtHeader.Pe32Plus->OptionalHeader.SizeOfHeaders;
  }

  //
  // 11. Build a temporary table of pointers to all the IMAGE_SECTION_HEADER
  //     structures in the image. The 'NumberOfSections' field of the image
  //     header indicates how big the table should be. Do not include any
  //     IMAGE_SECTION_HEADERs in the table whose 'SizeOfRawData' field is zero.
  //
  SectionHeader = (EFI_IMAGE_SECTION_HEADER *)AllocateZeroPool (sizeof (EFI_IMAGE_SECTION_HEADER) * mNtHeader.Pe32->FileHeader.NumberOfSections);
  ASSERT (SectionHeader != NULL);
  //
  // 12.  Using the 'PointerToRawData' in the referenced section headers as
  //      a key, arrange the elements in the table in ascending order. In other
  //      words, sort the section headers according to the disk-file offset of
  //      the section.
  //
  Section = (EFI_IMAGE_SECTION_HEADER *)(
                                         mImageBase +
                                         mPeCoffHeaderOffset +
                                         sizeof (UINT32) +
                                         sizeof (EFI_IMAGE_FILE_HEADER) +
                                         mNtHeader.Pe32->FileHeader.SizeOfOptionalHeader
                                         );
  for (Index = 0; Index < mNtHeader.Pe32->FileHeader.NumberOfSections; Index++) {
    Pos = Index;
    while ((Pos > 0) && (Section->PointerToRawData < SectionHeader[Pos - 1].PointerToRawData)) {
      CopyMem (&SectionHeader[Pos], &SectionHeader[Pos - 1], sizeof (EFI_IMAGE_SECTION_HEADER));
      Pos--;
    }

    CopyMem (&SectionHeader[Pos], Section, sizeof (EFI_IMAGE_SECTION_HEADER));
    Section += 1;
  }

  //
  // 13.  Walk through the sorted table, bring the corresponding section
  //      into memory, and hash the entire section (using the 'SizeOfRawData'
  //      field in the section header to determine the amount of data to hash).
  // 14.  Add the section's 'SizeOfRawData' to SUM_OF_BYTES_HASHED .
  // 15.  Repeat steps 13 and 14 for all the sections in the sorted table.
  //
  for (Index = 0; Index < mNtHeader.Pe32->FileHeader.NumberOfSections; Index++) {
    Section = &SectionHeader[Index];
    if (Section->SizeOfRawData == 0) {
      continue;
    }

    HashBase = mImageBase + Section->PointerToRawData;
    HashSize = (UINTN)Section->SizeOfRawData;

    Status = mHash[HashAlg].HashUpdate (HashCtx, HashBase, HashSize);
    if (!Status) {
      goto Done;
    }

    SumOfBytesHashed += HashSize;
  }

  //
  // 16.  If the file size is greater than SUM_OF_BYTES_HASHED, there is extra
  //      data in the file that needs to be added to the hash. This data begins
  //      at file offset SUM_OF_BYTES_HASHED and its length is:
  //             FileSize  -  (CertDirectory->Size)
  //
  if (mImageSize > SumOfBytesHashed) {
    HashBase = mImageBase + SumOfBytesHashed;
    if (mNtHeader.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
      //
      // Use PE32 offset.
      //
      HashSize = (UINTN)(
                         mImageSize -
                         mNtHeader.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY].Size -
                         SumOfBytesHashed);
    } else {
      //
      // Use PE32+ offset.
      //
      HashSize = (UINTN)(
                         mImageSize -
                         mNtHeader.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY].Size -
                         SumOfBytesHashed);
    }

    Status = mHash[HashAlg].HashUpdate (HashCtx, HashBase, HashSize);
    if (!Status) {
      goto Done;
    }
  }

  Status = mHash[HashAlg].HashFinal (HashCtx, mImageDigest);

Done:
  if (HashCtx != NULL) {
    FreePool (HashCtx);
  }

  if (SectionHeader != NULL) {
    FreePool (SectionHeader);
  }

  return Status;
}

/**
  Recognize the Hash algorithm in PE/COFF Authenticode and calculate hash of
  Pe/Coff image based on the authenticated image hashing in PE/COFF Specification
  8.0 Appendix A

  @retval EFI_UNSUPPORTED             Hash algorithm is not supported.
  @retval EFI_SUCCESS                 Hash successfully.

**/
EFI_STATUS
HashPeImageByType (
  VOID
  )
{
  UINT8                     Index;
  WIN_CERTIFICATE_EFI_PKCS  *PkcsCertData;
  UINT32                    PkcsCertSize;

  PkcsCertData = (WIN_CERTIFICATE_EFI_PKCS *)(mImageBase + mSecDataDir->Offset);
  PkcsCertSize = mSecDataDir->SizeOfCert;

  //
  // Check the Hash algorithm in PE/COFF Authenticode.
  //    According to PKCS#7 Definition:
  //        SignedData ::= SEQUENCE {
  //            version Version,
  //            digestAlgorithms DigestAlgorithmIdentifiers,
  //            contentInfo ContentInfo,
  //            .... }
  //    The DigestAlgorithmIdentifiers can be used to determine the hash algorithm in PE/COFF hashing
  //    This field has the fixed offset (+32) in final Authenticode ASN.1 data.
  //    Fixed offset (+32) is calculated based on two bytes of length encoding.
  //
  if ((PkcsCertSize > 1) && ((*(PkcsCertData->CertData + 1) & TWO_BYTE_ENCODE) != TWO_BYTE_ENCODE)) {
    //
    // Only support two bytes of Long Form of Length Encoding.
    //
    return EFI_BAD_BUFFER_SIZE;
  }

  for (Index = 0; Index < HASHALG_MAX; Index++) {
    if (PkcsCertSize < 32 + mHash[Index].OidLength) {
      continue;
    }

    if (CompareMem (PkcsCertData->CertData + 32, mHash[Index].OidValue, mHash[Index].OidLength) == 0) {
      break;
    }
  }

  if (Index == HASHALG_MAX) {
    return EFI_UNSUPPORTED;
  }

  //
  // HASH PE Image based on Hash algorithm in PE/COFF Authenticode.
  //
  if (!HashPeImage (Index)) {
    return EFI_UNSUPPORTED;
  }

  return EFI_SUCCESS;
}

/**
  Enroll a new signature of executable into Signature Database.

  @param[in] PrivateData     The module's private data.
  @param[in] VariableName    Variable name of signature database, must be
                             EFI_IMAGE_SECURITY_DATABASE, EFI_IMAGE_SECURITY_DATABASE1
                             or EFI_IMAGE_SECURITY_DATABASE2.

  @retval   EFI_SUCCESS            New signature is enrolled successfully.
  @retval   EFI_INVALID_PARAMETER  The parameter is invalid.
  @retval   EFI_UNSUPPORTED        Unsupported command.
  @retval   EFI_OUT_OF_RESOURCES   Could not allocate needed resources.

**/
EFI_STATUS
EnrollAuthentication2Descriptor (
  IN SECUREBOOT_CONFIG_PRIVATE_DATA  *Private,
  IN CHAR16                          *VariableName
  )
{
  EFI_STATUS  Status;
  VOID        *Data;
  UINTN       DataSize;
  UINT32      Attr;

  Data = NULL;

  //
  // DBT only support DER-X509 Cert Enrollment
  //
  if (StrCmp (VariableName, EFI_IMAGE_SECURITY_DATABASE2) == 0) {
    return EFI_UNSUPPORTED;
  }

  //
  // Read the whole file content
  //
  Status = ReadFileContent (
             Private->FileContext->FHandle,
             (VOID **)&mImageBase,
             &mImageSize,
             0
             );
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  ASSERT (mImageBase != NULL);

  Attr = EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_RUNTIME_ACCESS
         | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS;

  //
  // Check if SigDB variable has been already existed.
  // If true, use EFI_VARIABLE_APPEND_WRITE attribute to append the
  // new signature data to original variable
  //
  DataSize = 0;
  Status   = gRT->GetVariable (
                    VariableName,
                    &gEfiImageSecurityDatabaseGuid,
                    NULL,
                    &DataSize,
                    NULL
                    );
  if (Status == EFI_BUFFER_TOO_SMALL) {
    Attr |= EFI_VARIABLE_APPEND_WRITE;
  } else if (Status != EFI_NOT_FOUND) {
    goto ON_EXIT;
  }

  //
  // Directly set AUTHENTICATION_2 data to SetVariable
  //
  Status = gRT->SetVariable (
                  VariableName,
                  &gEfiImageSecurityDatabaseGuid,
                  Attr,
                  mImageSize,
                  mImageBase
                  );

  DEBUG ((DEBUG_INFO, "Enroll AUTH_2 data to Var:%s Status: %x\n", VariableName, Status));

ON_EXIT:

  CloseEnrolledFile (Private->FileContext);

  if (Data != NULL) {
    FreePool (Data);
  }

  if (mImageBase != NULL) {
    FreePool (mImageBase);
    mImageBase = NULL;
  }

  return Status;
}

/**
  Enroll a new signature of executable into Signature Database.

  @param[in] PrivateData     The module's private data.
  @param[in] VariableName    Variable name of signature database, must be
                             EFI_IMAGE_SECURITY_DATABASE, EFI_IMAGE_SECURITY_DATABASE1
                             or EFI_IMAGE_SECURITY_DATABASE2.

  @retval   EFI_SUCCESS            New signature is enrolled successfully.
  @retval   EFI_INVALID_PARAMETER  The parameter is invalid.
  @retval   EFI_UNSUPPORTED        Unsupported command.
  @retval   EFI_OUT_OF_RESOURCES   Could not allocate needed resources.

**/
EFI_STATUS
EnrollImageSignatureToSigDB (
  IN SECUREBOOT_CONFIG_PRIVATE_DATA  *Private,
  IN CHAR16                          *VariableName
  )
{
  EFI_STATUS                 Status;
  EFI_SIGNATURE_LIST         *SigDBCert;
  EFI_SIGNATURE_DATA         *SigDBCertData;
  VOID                       *Data;
  UINTN                      DataSize;
  UINTN                      SigDBSize;
  UINT32                     Attr;
  WIN_CERTIFICATE_UEFI_GUID  *GuidCertData;
  EFI_TIME                   Time;
  UINT32                     HashAlg;

  Data         = NULL;
  GuidCertData = NULL;

  if (StrCmp (VariableName, EFI_IMAGE_SECURITY_DATABASE2) == 0) {
    return EFI_UNSUPPORTED;
  }

  //
  // Form the SigDB certificate list.
  // Format the data item into EFI_SIGNATURE_LIST type.
  //
  // We need to parse signature data of executable from specified signed executable file.
  // In current implementation, we simply trust the pass-in signed executable file.
  // In reality, it's OS's responsibility to verify the signed executable file.
  //

  //
  // Read the whole file content
  //
  Status = ReadFileContent (
             Private->FileContext->FHandle,
             (VOID **)&mImageBase,
             &mImageSize,
             0
             );
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  ASSERT (mImageBase != NULL);

  Status = LoadPeImage ();
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  if (mSecDataDir->SizeOfCert == 0) {
    Status  = EFI_SECURITY_VIOLATION;
    HashAlg = sizeof (mHash) / sizeof (HASH_TABLE);
    while (HashAlg > 0) {
      HashAlg--;
      if ((mHash[HashAlg].GetContextSize == NULL) || (mHash[HashAlg].HashInit == NULL) || (mHash[HashAlg].HashUpdate == NULL) || (mHash[HashAlg].HashFinal == NULL)) {
        continue;
      }

      if (HashPeImage (HashAlg)) {
        Status = EFI_SUCCESS;
        break;
      }
    }

    if (EFI_ERROR (Status)) {
      DEBUG ((DEBUG_ERROR, "Fail to get hash digest: %r", Status));
      goto ON_EXIT;
    }
  } else {
    //
    // Read the certificate data
    //
    mCertificate = (WIN_CERTIFICATE *)(mImageBase + mSecDataDir->Offset);

    if (mCertificate->wCertificateType == WIN_CERT_TYPE_EFI_GUID) {
      GuidCertData = (WIN_CERTIFICATE_UEFI_GUID *)mCertificate;
      if (CompareMem (&GuidCertData->CertType, &gEfiCertTypeRsa2048Sha256Guid, sizeof (EFI_GUID)) != 0) {
        Status = EFI_ABORTED;
        goto ON_EXIT;
      }

      if (!HashPeImage (HASHALG_SHA256)) {
        Status = EFI_ABORTED;
        goto ON_EXIT;
      }
    } else if (mCertificate->wCertificateType == WIN_CERT_TYPE_PKCS_SIGNED_DATA) {
      Status = HashPeImageByType ();
      if (EFI_ERROR (Status)) {
        goto ON_EXIT;
      }
    } else {
      Status = EFI_ABORTED;
      goto ON_EXIT;
    }
  }

  //
  // Create a new SigDB entry.
  //
  SigDBSize = sizeof (EFI_SIGNATURE_LIST)
              + sizeof (EFI_SIGNATURE_DATA) - 1
              + (UINT32)mImageDigestSize;

  Data = (UINT8 *)AllocateZeroPool (SigDBSize);
  if (Data == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  //
  // Adjust the Certificate Database parameters.
  //
  SigDBCert                      = (EFI_SIGNATURE_LIST *)Data;
  SigDBCert->SignatureListSize   = (UINT32)SigDBSize;
  SigDBCert->SignatureHeaderSize = 0;
  SigDBCert->SignatureSize       = sizeof (EFI_SIGNATURE_DATA) - 1 + (UINT32)mImageDigestSize;
  CopyGuid (&SigDBCert->SignatureType, &mCertType);

  SigDBCertData = (EFI_SIGNATURE_DATA *)((UINT8 *)SigDBCert + sizeof (EFI_SIGNATURE_LIST));
  CopyGuid (&SigDBCertData->SignatureOwner, Private->SignatureGUID);
  CopyMem (SigDBCertData->SignatureData, mImageDigest, mImageDigestSize);

  Attr = EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_RUNTIME_ACCESS
         | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS;
  Status = GetCurrentTime (&Time);
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Fail to fetch valid time data: %r", Status));
    goto ON_EXIT;
  }

  Status = CreateTimeBasedPayload (&SigDBSize, (UINT8 **)&Data, &Time);
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Fail to create time-based data payload: %r", Status));
    goto ON_EXIT;
  }

  //
  // Check if SigDB variable has been already existed.
  // If true, use EFI_VARIABLE_APPEND_WRITE attribute to append the
  // new signature data to original variable
  //
  DataSize = 0;
  Status   = gRT->GetVariable (
                    VariableName,
                    &gEfiImageSecurityDatabaseGuid,
                    NULL,
                    &DataSize,
                    NULL
                    );
  if (Status == EFI_BUFFER_TOO_SMALL) {
    Attr |= EFI_VARIABLE_APPEND_WRITE;
  } else if (Status != EFI_NOT_FOUND) {
    goto ON_EXIT;
  }

  //
  // Enroll the variable.
  //
  Status = gRT->SetVariable (
                  VariableName,
                  &gEfiImageSecurityDatabaseGuid,
                  Attr,
                  SigDBSize,
                  Data
                  );
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

ON_EXIT:

  CloseEnrolledFile (Private->FileContext);

  if (Private->SignatureGUID != NULL) {
    FreePool (Private->SignatureGUID);
    Private->SignatureGUID = NULL;
  }

  if (Data != NULL) {
    FreePool (Data);
  }

  if (mImageBase != NULL) {
    FreePool (mImageBase);
    mImageBase = NULL;
  }

  return Status;
}

/**
  Enroll signature into DB/DBX/DBT without KEK's authentication.
  The SignatureOwner GUID will be Private->SignatureGUID.

  @param[in] PrivateData     The module's private data.
  @param[in] VariableName    Variable name of signature database, must be
                             EFI_IMAGE_SECURITY_DATABASE or EFI_IMAGE_SECURITY_DATABASE1.

  @retval   EFI_SUCCESS            New signature enrolled successfully.
  @retval   EFI_INVALID_PARAMETER  The parameter is invalid.
  @retval   others                 Fail to enroll signature data.

**/
EFI_STATUS
EnrollSignatureDatabase (
  IN SECUREBOOT_CONFIG_PRIVATE_DATA  *Private,
  IN CHAR16                          *VariableName
  )
{
  UINT16      *FilePostFix;
  EFI_STATUS  Status;
  UINTN       NameLength;

  if ((Private->FileContext->FileName == NULL) || (Private->FileContext->FHandle == NULL) || (Private->SignatureGUID == NULL)) {
    return EFI_INVALID_PARAMETER;
  }

  Status = SetSecureBootMode (CUSTOM_SECURE_BOOT_MODE);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Parse the file's postfix.
  //
  NameLength = StrLen (Private->FileContext->FileName);
  if (NameLength <= 4) {
    return EFI_INVALID_PARAMETER;
  }

  FilePostFix = Private->FileContext->FileName + NameLength - 4;
  if (IsDerEncodeCertificate (FilePostFix)) {
    //
    // Supports DER-encoded X509 certificate.
    //
    return EnrollX509toSigDB (Private, VariableName);
  } else if (IsAuthentication2Format (Private->FileContext->FHandle)) {
    return EnrollAuthentication2Descriptor (Private, VariableName);
  } else {
    return EnrollImageSignatureToSigDB (Private, VariableName);
  }
}

/**
  List all signatures in specified signature database (e.g. KEK/DB/DBX/DBT)
  by GUID in the page for user to select and delete as needed.

  @param[in]    PrivateData         Module's private data.
  @param[in]    VariableName        The variable name of the vendor's signature database.
  @param[in]    VendorGuid          A unique identifier for the vendor.
  @param[in]    LabelNumber         Label number to insert opcodes.
  @param[in]    FormId              Form ID of current page.
  @param[in]    QuestionIdBase      Base question id of the signature list.

  @retval   EFI_SUCCESS             Success to update the signature list page
  @retval   EFI_OUT_OF_RESOURCES    Unable to allocate required resources.

**/
EFI_STATUS
UpdateDeletePage (
  IN SECUREBOOT_CONFIG_PRIVATE_DATA  *PrivateData,
  IN CHAR16                          *VariableName,
  IN EFI_GUID                        *VendorGuid,
  IN UINT16                          LabelNumber,
  IN EFI_FORM_ID                     FormId,
  IN EFI_QUESTION_ID                 QuestionIdBase
  )
{
  EFI_STATUS          Status;
  UINT32              Index;
  UINTN               CertCount;
  UINTN               GuidIndex;
  VOID                *StartOpCodeHandle;
  VOID                *EndOpCodeHandle;
  EFI_IFR_GUID_LABEL  *StartLabel;
  EFI_IFR_GUID_LABEL  *EndLabel;
  UINTN               DataSize;
  UINT8               *Data;
  EFI_SIGNATURE_LIST  *CertList;
  EFI_SIGNATURE_DATA  *Cert;
  UINT32              ItemDataSize;
  CHAR16              *GuidStr;
  EFI_STRING_ID       GuidID;
  EFI_STRING_ID       Help;

  Data              = NULL;
  CertList          = NULL;
  Cert              = NULL;
  GuidStr           = NULL;
  StartOpCodeHandle = NULL;
  EndOpCodeHandle   = NULL;

  //
  // Initialize the container for dynamic opcodes.
  //
  StartOpCodeHandle = HiiAllocateOpCodeHandle ();
  if (StartOpCodeHandle == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  EndOpCodeHandle = HiiAllocateOpCodeHandle ();
  if (EndOpCodeHandle == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  //
  // Create Hii Extend Label OpCode.
  //
  StartLabel = (EFI_IFR_GUID_LABEL *)HiiCreateGuidOpCode (
                                       StartOpCodeHandle,
                                       &gEfiIfrTianoGuid,
                                       NULL,
                                       sizeof (EFI_IFR_GUID_LABEL)
                                       );
  StartLabel->ExtendOpCode = EFI_IFR_EXTEND_OP_LABEL;
  StartLabel->Number       = LabelNumber;

  EndLabel = (EFI_IFR_GUID_LABEL *)HiiCreateGuidOpCode (
                                     EndOpCodeHandle,
                                     &gEfiIfrTianoGuid,
                                     NULL,
                                     sizeof (EFI_IFR_GUID_LABEL)
                                     );
  EndLabel->ExtendOpCode = EFI_IFR_EXTEND_OP_LABEL;
  EndLabel->Number       = LABEL_END;

  //
  // Read Variable.
  //
  DataSize = 0;
  Status   = gRT->GetVariable (VariableName, VendorGuid, NULL, &DataSize, Data);
  if (EFI_ERROR (Status) && (Status != EFI_BUFFER_TOO_SMALL)) {
    goto ON_EXIT;
  }

  Data = (UINT8 *)AllocateZeroPool (DataSize);
  if (Data == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  Status = gRT->GetVariable (VariableName, VendorGuid, NULL, &DataSize, Data);
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  GuidStr = AllocateZeroPool (100);
  if (GuidStr == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  //
  // Enumerate all KEK pub data.
  //
  ItemDataSize = (UINT32)DataSize;
  CertList     = (EFI_SIGNATURE_LIST *)Data;
  GuidIndex    = 0;

  while ((ItemDataSize > 0) && (ItemDataSize >= CertList->SignatureListSize)) {
    if (CompareGuid (&CertList->SignatureType, &gEfiCertRsa2048Guid) ||
        CompareGuid (&CertList->SignatureType, &gEfiCertX509Guid) ||
        CompareGuid (&CertList->SignatureType, &gEfiCertSha1Guid) ||
        CompareGuid (&CertList->SignatureType, &gEfiCertSha256Guid) ||
        CompareGuid (&CertList->SignatureType, &gEfiCertX509Sha256Guid) ||
        CompareGuid (&CertList->SignatureType, &gEfiCertX509Sha384Guid) ||
        CompareGuid (&CertList->SignatureType, &gEfiCertX509Sha512Guid)
        )
    {
      CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;
      for (Index = 0; Index < CertCount; Index++) {
        Cert = (EFI_SIGNATURE_DATA *)((UINT8 *)CertList
                                      + sizeof (EFI_SIGNATURE_LIST)
                                      + CertList->SignatureHeaderSize
                                      + Index * CertList->SignatureSize);
        //
        // Display GUID and help
        //
        GuidToString (&Cert->SignatureOwner, GuidStr, 100);
        GuidID = HiiSetString (PrivateData->HiiHandle, 0, GuidStr, NULL);

        Status = FormatHelpInfo (PrivateData, CertList, Cert, &Help);
        if (!EFI_ERROR (Status)) {
          HiiCreateCheckBoxOpCode (
            StartOpCodeHandle,
            (EFI_QUESTION_ID)(QuestionIdBase + GuidIndex++),
            0,
            0,
            GuidID,
            Help,
            EFI_IFR_FLAG_CALLBACK,
            0,
            NULL
            );
        }
      }

      ItemDataSize -= CertList->SignatureListSize;
      CertList      = (EFI_SIGNATURE_LIST *)((UINT8 *)CertList + CertList->SignatureListSize);
    }
  }

ON_EXIT:
  HiiUpdateForm (
    PrivateData->HiiHandle,
    &gSecureBootConfigFormSetGuid,
    FormId,
    StartOpCodeHandle,
    EndOpCodeHandle
    );

  if (StartOpCodeHandle != NULL) {
    HiiFreeOpCodeHandle (StartOpCodeHandle);
  }

  if (EndOpCodeHandle != NULL) {
    HiiFreeOpCodeHandle (EndOpCodeHandle);
  }

  if (Data != NULL) {
    FreePool (Data);
  }

  if (GuidStr != NULL) {
    FreePool (GuidStr);
  }

  return EFI_SUCCESS;
}

/**
  Delete a KEK entry from KEK database.

  @param[in]    PrivateData         Module's private data.
  @param[in]    QuestionId          Question id of the KEK item to delete.

  @retval   EFI_SUCCESS            Delete kek item successfully.
  @retval   EFI_OUT_OF_RESOURCES   Could not allocate needed resources.

**/
EFI_STATUS
DeleteKeyExchangeKey (
  IN SECUREBOOT_CONFIG_PRIVATE_DATA  *PrivateData,
  IN EFI_QUESTION_ID                 QuestionId
  )
{
  EFI_STATUS          Status;
  UINTN               DataSize;
  UINT8               *Data;
  UINT8               *OldData;
  UINT32              Attr;
  UINT32              Index;
  EFI_SIGNATURE_LIST  *CertList;
  EFI_SIGNATURE_LIST  *NewCertList;
  EFI_SIGNATURE_DATA  *Cert;
  UINTN               CertCount;
  UINT32              Offset;
  BOOLEAN             IsKEKItemFound;
  UINT32              KekDataSize;
  UINTN               DeleteKekIndex;
  UINTN               GuidIndex;
  EFI_TIME            Time;

  Data           = NULL;
  OldData        = NULL;
  CertList       = NULL;
  Cert           = NULL;
  Attr           = 0;
  DeleteKekIndex = QuestionId - OPTION_DEL_KEK_QUESTION_ID;

  Status = SetSecureBootMode (CUSTOM_SECURE_BOOT_MODE);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Get original KEK variable.
  //
  DataSize = 0;
  Status   = gRT->GetVariable (EFI_KEY_EXCHANGE_KEY_NAME, &gEfiGlobalVariableGuid, NULL, &DataSize, NULL);
  if (EFI_ERROR (Status) && (Status != EFI_BUFFER_TOO_SMALL)) {
    goto ON_EXIT;
  }

  OldData = (UINT8 *)AllocateZeroPool (DataSize);
  if (OldData == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  Status = gRT->GetVariable (EFI_KEY_EXCHANGE_KEY_NAME, &gEfiGlobalVariableGuid, &Attr, &DataSize, OldData);
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  //
  // Allocate space for new variable.
  //
  Data = (UINT8 *)AllocateZeroPool (DataSize);
  if (Data == NULL) {
    Status =  EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  //
  // Enumerate all KEK pub data and erasing the target item.
  //
  IsKEKItemFound = FALSE;
  KekDataSize    = (UINT32)DataSize;
  CertList       = (EFI_SIGNATURE_LIST *)OldData;
  Offset         = 0;
  GuidIndex      = 0;
  while ((KekDataSize > 0) && (KekDataSize >= CertList->SignatureListSize)) {
    if (CompareGuid (&CertList->SignatureType, &gEfiCertRsa2048Guid) ||
        CompareGuid (&CertList->SignatureType, &gEfiCertX509Guid))
    {
      CopyMem (Data + Offset, CertList, (sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize));
      NewCertList = (EFI_SIGNATURE_LIST *)(Data + Offset);
      Offset     += (sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
      Cert        = (EFI_SIGNATURE_DATA *)((UINT8 *)CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
      CertCount   = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;
      for (Index = 0; Index < CertCount; Index++) {
        if (GuidIndex == DeleteKekIndex ) {
          //
          // Find it! Skip it!
          //
          NewCertList->SignatureListSize -= CertList->SignatureSize;
          IsKEKItemFound                  = TRUE;
        } else {
          //
          // This item doesn't match. Copy it to the Data buffer.
          //
          CopyMem (Data + Offset, Cert, CertList->SignatureSize);
          Offset += CertList->SignatureSize;
        }

        GuidIndex++;
        Cert = (EFI_SIGNATURE_DATA *)((UINT8 *)Cert + CertList->SignatureSize);
      }
    } else {
      //
      // This List doesn't match. Copy it to the Data buffer.
      //
      CopyMem (Data + Offset, CertList, CertList->SignatureListSize);
      Offset += CertList->SignatureListSize;
    }

    KekDataSize -= CertList->SignatureListSize;
    CertList     = (EFI_SIGNATURE_LIST *)((UINT8 *)CertList + CertList->SignatureListSize);
  }

  if (!IsKEKItemFound) {
    //
    // Doesn't find the Kek Item!
    //
    Status = EFI_NOT_FOUND;
    goto ON_EXIT;
  }

  //
  // Delete the Signature header if there is no signature in the list.
  //
  KekDataSize = Offset;
  CertList    = (EFI_SIGNATURE_LIST *)Data;
  Offset      = 0;
  ZeroMem (OldData, KekDataSize);
  while ((KekDataSize > 0) && (KekDataSize >= CertList->SignatureListSize)) {
    CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;
    DEBUG ((DEBUG_INFO, "       CertCount = %x\n", CertCount));
    if (CertCount != 0) {
      CopyMem (OldData + Offset, CertList, CertList->SignatureListSize);
      Offset += CertList->SignatureListSize;
    }

    KekDataSize -= CertList->SignatureListSize;
    CertList     = (EFI_SIGNATURE_LIST *)((UINT8 *)CertList + CertList->SignatureListSize);
  }

  DataSize = Offset;
  if ((Attr & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) != 0) {
    Status = GetCurrentTime (&Time);
    if (EFI_ERROR (Status)) {
      DEBUG ((DEBUG_ERROR, "Fail to fetch valid time data: %r", Status));
      goto ON_EXIT;
    }

    Status = CreateTimeBasedPayload (&DataSize, &OldData, &Time);
    if (EFI_ERROR (Status)) {
      DEBUG ((DEBUG_ERROR, "Fail to create time-based data payload: %r", Status));
      goto ON_EXIT;
    }
  }

  Status = gRT->SetVariable (
                  EFI_KEY_EXCHANGE_KEY_NAME,
                  &gEfiGlobalVariableGuid,
                  Attr,
                  DataSize,
                  OldData
                  );
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Failed to set variable, Status = %r\n", Status));
    goto ON_EXIT;
  }

ON_EXIT:
  if (Data != NULL) {
    FreePool (Data);
  }

  if (OldData != NULL) {
    FreePool (OldData);
  }

  return UpdateDeletePage (
           PrivateData,
           EFI_KEY_EXCHANGE_KEY_NAME,
           &gEfiGlobalVariableGuid,
           LABEL_KEK_DELETE,
           FORMID_DELETE_KEK_FORM,
           OPTION_DEL_KEK_QUESTION_ID
           );
}

/**
  Delete a signature entry from signature database.

  @param[in]    PrivateData         Module's private data.
  @param[in]    VariableName        The variable name of the vendor's signature database.
  @param[in]    VendorGuid          A unique identifier for the vendor.
  @param[in]    LabelNumber         Label number to insert opcodes.
  @param[in]    FormId              Form ID of current page.
  @param[in]    QuestionIdBase      Base question id of the signature list.
  @param[in]    DeleteIndex         Signature index to delete.

  @retval   EFI_SUCCESS             Delete signature successfully.
  @retval   EFI_NOT_FOUND           Can't find the signature item,
  @retval   EFI_OUT_OF_RESOURCES    Could not allocate needed resources.
**/
EFI_STATUS
DeleteSignature (
  IN SECUREBOOT_CONFIG_PRIVATE_DATA  *PrivateData,
  IN CHAR16                          *VariableName,
  IN EFI_GUID                        *VendorGuid,
  IN UINT16                          LabelNumber,
  IN EFI_FORM_ID                     FormId,
  IN EFI_QUESTION_ID                 QuestionIdBase,
  IN UINTN                           DeleteIndex
  )
{
  EFI_STATUS          Status;
  UINTN               DataSize;
  UINT8               *Data;
  UINT8               *OldData;
  UINT32              Attr;
  UINT32              Index;
  EFI_SIGNATURE_LIST  *CertList;
  EFI_SIGNATURE_LIST  *NewCertList;
  EFI_SIGNATURE_DATA  *Cert;
  UINTN               CertCount;
  UINT32              Offset;
  BOOLEAN             IsItemFound;
  UINT32              ItemDataSize;
  UINTN               GuidIndex;
  EFI_TIME            Time;

  Data     = NULL;
  OldData  = NULL;
  CertList = NULL;
  Cert     = NULL;
  Attr     = 0;

  Status = SetSecureBootMode (CUSTOM_SECURE_BOOT_MODE);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Get original signature list data.
  //
  DataSize = 0;
  Status   = gRT->GetVariable (VariableName, VendorGuid, NULL, &DataSize, NULL);
  if (EFI_ERROR (Status) && (Status != EFI_BUFFER_TOO_SMALL)) {
    goto ON_EXIT;
  }

  OldData = (UINT8 *)AllocateZeroPool (DataSize);
  if (OldData == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  Status = gRT->GetVariable (VariableName, VendorGuid, &Attr, &DataSize, OldData);
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  //
  // Allocate space for new variable.
  //
  Data = (UINT8 *)AllocateZeroPool (DataSize);
  if (Data == NULL) {
    Status =  EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  //
  // Enumerate all signature data and erasing the target item.
  //
  IsItemFound  = FALSE;
  ItemDataSize = (UINT32)DataSize;
  CertList     = (EFI_SIGNATURE_LIST *)OldData;
  Offset       = 0;
  GuidIndex    = 0;
  while ((ItemDataSize > 0) && (ItemDataSize >= CertList->SignatureListSize)) {
    if (CompareGuid (&CertList->SignatureType, &gEfiCertRsa2048Guid) ||
        CompareGuid (&CertList->SignatureType, &gEfiCertX509Guid) ||
        CompareGuid (&CertList->SignatureType, &gEfiCertSha1Guid) ||
        CompareGuid (&CertList->SignatureType, &gEfiCertSha256Guid) ||
        CompareGuid (&CertList->SignatureType, &gEfiCertX509Sha256Guid) ||
        CompareGuid (&CertList->SignatureType, &gEfiCertX509Sha384Guid) ||
        CompareGuid (&CertList->SignatureType, &gEfiCertX509Sha512Guid)
        )
    {
      //
      // Copy EFI_SIGNATURE_LIST header then calculate the signature count in this list.
      //
      CopyMem (Data + Offset, CertList, (sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize));
      NewCertList = (EFI_SIGNATURE_LIST *)(Data + Offset);
      Offset     += (sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
      Cert        = (EFI_SIGNATURE_DATA *)((UINT8 *)CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
      CertCount   = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;
      for (Index = 0; Index < CertCount; Index++) {
        if (GuidIndex == DeleteIndex) {
          //
          // Find it! Skip it!
          //
          NewCertList->SignatureListSize -= CertList->SignatureSize;
          IsItemFound                     = TRUE;
        } else {
          //
          // This item doesn't match. Copy it to the Data buffer.
          //
          CopyMem (Data + Offset, (UINT8 *)(Cert), CertList->SignatureSize);
          Offset += CertList->SignatureSize;
        }

        GuidIndex++;
        Cert = (EFI_SIGNATURE_DATA *)((UINT8 *)Cert + CertList->SignatureSize);
      }
    } else {
      //
      // This List doesn't match. Just copy it to the Data buffer.
      //
      CopyMem (Data + Offset, (UINT8 *)(CertList), CertList->SignatureListSize);
      Offset += CertList->SignatureListSize;
    }

    ItemDataSize -= CertList->SignatureListSize;
    CertList      = (EFI_SIGNATURE_LIST *)((UINT8 *)CertList + CertList->SignatureListSize);
  }

  if (!IsItemFound) {
    //
    // Doesn't find the signature Item!
    //
    Status = EFI_NOT_FOUND;
    goto ON_EXIT;
  }

  //
  // Delete the EFI_SIGNATURE_LIST header if there is no signature in the list.
  //
  ItemDataSize = Offset;
  CertList     = (EFI_SIGNATURE_LIST *)Data;
  Offset       = 0;
  ZeroMem (OldData, ItemDataSize);
  while ((ItemDataSize > 0) && (ItemDataSize >= CertList->SignatureListSize)) {
    CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;
    DEBUG ((DEBUG_INFO, "       CertCount = %x\n", CertCount));
    if (CertCount != 0) {
      CopyMem (OldData + Offset, (UINT8 *)(CertList), CertList->SignatureListSize);
      Offset += CertList->SignatureListSize;
    }

    ItemDataSize -= CertList->SignatureListSize;
    CertList      = (EFI_SIGNATURE_LIST *)((UINT8 *)CertList + CertList->SignatureListSize);
  }

  DataSize = Offset;
  if ((Attr & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) != 0) {
    Status = GetCurrentTime (&Time);
    if (EFI_ERROR (Status)) {
      DEBUG ((DEBUG_ERROR, "Fail to fetch valid time data: %r", Status));
      goto ON_EXIT;
    }

    Status = CreateTimeBasedPayload (&DataSize, &OldData, &Time);
    if (EFI_ERROR (Status)) {
      DEBUG ((DEBUG_ERROR, "Fail to create time-based data payload: %r", Status));
      goto ON_EXIT;
    }
  }

  Status = gRT->SetVariable (
                  VariableName,
                  VendorGuid,
                  Attr,
                  DataSize,
                  OldData
                  );
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Failed to set variable, Status = %r\n", Status));
    goto ON_EXIT;
  }

ON_EXIT:
  if (Data != NULL) {
    FreePool (Data);
  }

  if (OldData != NULL) {
    FreePool (OldData);
  }

  return UpdateDeletePage (
           PrivateData,
           VariableName,
           VendorGuid,
           LabelNumber,
           FormId,
           QuestionIdBase
           );
}

/**
  This function to delete signature list or data, according by DelType.

  @param[in]  PrivateData           Module's private data.
  @param[in]  DelType               Indicate delete signature list or data.
  @param[in]  CheckedCount          Indicate how many signature data have
                                    been checked in current signature list.

  @retval   EFI_SUCCESS             Success to update the signature list page
  @retval   EFI_OUT_OF_RESOURCES    Unable to allocate required resources.
**/
EFI_STATUS
DeleteSignatureEx (
  IN SECUREBOOT_CONFIG_PRIVATE_DATA  *PrivateData,
  IN SIGNATURE_DELETE_TYPE           DelType,
  IN UINT32                          CheckedCount
  )
{
  EFI_STATUS          Status;
  EFI_SIGNATURE_LIST  *ListWalker;
  EFI_SIGNATURE_LIST  *NewCertList;
  EFI_SIGNATURE_DATA  *DataWalker;
  CHAR16              VariableName[BUFFER_MAX_SIZE];
  UINT32              VariableAttr;
  UINTN               VariableDataSize;
  UINTN               RemainingSize;
  UINTN               ListIndex;
  UINTN               Index;
  UINTN               Offset;
  UINT8               *VariableData;
  UINT8               *NewVariableData;
  EFI_TIME            Time;

  Status           = EFI_SUCCESS;
  VariableAttr     = 0;
  VariableDataSize = 0;
  ListIndex        = 0;
  Offset           = 0;
  VariableData     = NULL;
  NewVariableData  = NULL;

  if (PrivateData->VariableName == Variable_DB) {
    UnicodeSPrint (VariableName, sizeof (VariableName), EFI_IMAGE_SECURITY_DATABASE);
  } else if (PrivateData->VariableName == Variable_DBX) {
    UnicodeSPrint (VariableName, sizeof (VariableName), EFI_IMAGE_SECURITY_DATABASE1);
  } else if (PrivateData->VariableName == Variable_DBT) {
    UnicodeSPrint (VariableName, sizeof (VariableName), EFI_IMAGE_SECURITY_DATABASE2);
  } else {
    goto ON_EXIT;
  }

  Status = gRT->GetVariable (
                  VariableName,
                  &gEfiImageSecurityDatabaseGuid,
                  &VariableAttr,
                  &VariableDataSize,
                  VariableData
                  );
  if (EFI_ERROR (Status) && (Status != EFI_BUFFER_TOO_SMALL)) {
    goto ON_EXIT;
  }

  VariableData = AllocateZeroPool (VariableDataSize);
  if (VariableData == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  Status = gRT->GetVariable (
                  VariableName,
                  &gEfiImageSecurityDatabaseGuid,
                  &VariableAttr,
                  &VariableDataSize,
                  VariableData
                  );
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  Status = SetSecureBootMode (CUSTOM_SECURE_BOOT_MODE);
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  NewVariableData = AllocateZeroPool (VariableDataSize);
  if (NewVariableData == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  RemainingSize = VariableDataSize;
  ListWalker    = (EFI_SIGNATURE_LIST *)(VariableData);
  if (DelType == Delete_Signature_List_All) {
    VariableDataSize = 0;
  } else {
    //
    //  Traverse to target EFI_SIGNATURE_LIST but others will be skipped.
    //
    while ((RemainingSize > 0) && (RemainingSize >= ListWalker->SignatureListSize) && ListIndex < PrivateData->ListIndex) {
      CopyMem ((UINT8 *)NewVariableData + Offset, ListWalker, ListWalker->SignatureListSize);
      Offset += ListWalker->SignatureListSize;

      RemainingSize -= ListWalker->SignatureListSize;
      ListWalker     = (EFI_SIGNATURE_LIST *)((UINT8 *)ListWalker + ListWalker->SignatureListSize);
      ListIndex++;
    }

    //
    //  Handle the target EFI_SIGNATURE_LIST.
    //  If CheckedCount == SIGNATURE_DATA_COUNTS (ListWalker) or DelType == Delete_Signature_List_One
    //  it means delete the whole EFI_SIGNATURE_LIST, So we just skip this EFI_SIGNATURE_LIST.
    //
    if ((CheckedCount < SIGNATURE_DATA_COUNTS (ListWalker)) && (DelType == Delete_Signature_Data)) {
      NewCertList = (EFI_SIGNATURE_LIST *)(NewVariableData + Offset);
      //
      // Copy header.
      //
      CopyMem ((UINT8 *)NewVariableData + Offset, ListWalker, sizeof (EFI_SIGNATURE_LIST) + ListWalker->SignatureHeaderSize);
      Offset += sizeof (EFI_SIGNATURE_LIST) + ListWalker->SignatureHeaderSize;

      DataWalker = (EFI_SIGNATURE_DATA *)((UINT8 *)ListWalker + sizeof (EFI_SIGNATURE_LIST) + ListWalker->SignatureHeaderSize);
      for (Index = 0; Index < SIGNATURE_DATA_COUNTS (ListWalker); Index = Index + 1) {
        if (PrivateData->CheckArray[Index]) {
          //
          // Delete checked signature data, and update the size of whole signature list.
          //
          NewCertList->SignatureListSize -= NewCertList->SignatureSize;
        } else {
          //
          // Remain the unchecked signature data.
          //
          CopyMem ((UINT8 *)NewVariableData + Offset, DataWalker, ListWalker->SignatureSize);
          Offset += ListWalker->SignatureSize;
        }

        DataWalker = (EFI_SIGNATURE_DATA *)((UINT8 *)DataWalker + ListWalker->SignatureSize);
      }
    }

    RemainingSize -= ListWalker->SignatureListSize;
    ListWalker     = (EFI_SIGNATURE_LIST *)((UINT8 *)ListWalker + ListWalker->SignatureListSize);

    //
    // Copy remaining data, maybe 0.
    //
    CopyMem ((UINT8 *)NewVariableData + Offset, ListWalker, RemainingSize);
    Offset += RemainingSize;

    VariableDataSize = Offset;
  }

  if ((VariableAttr & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) != 0) {
    Status = GetCurrentTime (&Time);
    if (EFI_ERROR (Status)) {
      DEBUG ((DEBUG_ERROR, "Fail to fetch valid time data: %r", Status));
      goto ON_EXIT;
    }

    Status = CreateTimeBasedPayload (&VariableDataSize, &NewVariableData, &Time);
    if (EFI_ERROR (Status)) {
      DEBUG ((DEBUG_ERROR, "Fail to create time-based data payload: %r", Status));
      goto ON_EXIT;
    }
  }

  Status = gRT->SetVariable (
                  VariableName,
                  &gEfiImageSecurityDatabaseGuid,
                  VariableAttr,
                  VariableDataSize,
                  NewVariableData
                  );
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Failed to set variable, Status = %r", Status));
    goto ON_EXIT;
  }

ON_EXIT:
  SECUREBOOT_FREE_NON_NULL (VariableData);
  SECUREBOOT_FREE_NON_NULL (NewVariableData);

  return Status;
}

/**

  Update SecureBoot strings based on new Secure Boot Mode State. String includes STR_SECURE_BOOT_STATE_CONTENT
 and STR_CUR_SECURE_BOOT_MODE_CONTENT.

  @param[in]    PrivateData         Module's private data.

  @return EFI_SUCCESS              Update secure boot strings successfully.
  @return other                          Fail to update secure boot strings.

**/
EFI_STATUS
UpdateSecureBootString (
  IN SECUREBOOT_CONFIG_PRIVATE_DATA  *Private
  )
{
  UINT8  *SecureBoot;

  SecureBoot = NULL;

  //
  // Get current secure boot state.
  //
  GetVariable2 (EFI_SECURE_BOOT_MODE_NAME, &gEfiGlobalVariableGuid, (VOID **)&SecureBoot, NULL);
  if (SecureBoot == NULL) {
    return EFI_NOT_FOUND;
  }

  if (*SecureBoot == SECURE_BOOT_MODE_ENABLE) {
    HiiSetString (Private->HiiHandle, STRING_TOKEN (STR_SECURE_BOOT_STATE_CONTENT), L"Enabled", NULL);
  } else {
    HiiSetString (Private->HiiHandle, STRING_TOKEN (STR_SECURE_BOOT_STATE_CONTENT), L"Disabled", NULL);
  }

  FreePool (SecureBoot);

  return EFI_SUCCESS;
}

/**
  This function extracts configuration from variable.

  @param[in]       Private      Point to SecureBoot configuration driver private data.
  @param[in, out]  ConfigData   Point to SecureBoot configuration private data.

**/
VOID
SecureBootExtractConfigFromVariable (
  IN SECUREBOOT_CONFIG_PRIVATE_DATA  *Private,
  IN OUT SECUREBOOT_CONFIGURATION    *ConfigData
  )
{
  UINT8     *SecureBootEnable;
  UINT8     *SetupMode;
  UINT8     *SecureBootMode;
  EFI_TIME  CurrTime;

  SecureBootEnable = NULL;
  SetupMode        = NULL;
  SecureBootMode   = NULL;

  //
  // Initialize the Date and Time using system time.
  //
  ConfigData->CertificateFormat = HASHALG_RAW;
  ConfigData->AlwaysRevocation  = TRUE;
  gRT->GetTime (&CurrTime, NULL);
  ConfigData->RevocationDate.Year   = CurrTime.Year;
  ConfigData->RevocationDate.Month  = CurrTime.Month;
  ConfigData->RevocationDate.Day    = CurrTime.Day;
  ConfigData->RevocationTime.Hour   = CurrTime.Hour;
  ConfigData->RevocationTime.Minute = CurrTime.Minute;
  ConfigData->RevocationTime.Second = 0;
  if (Private->FileContext->FHandle != NULL) {
    ConfigData->FileEnrollType = Private->FileContext->FileType;
  } else {
    ConfigData->FileEnrollType = UNKNOWN_FILE_TYPE;
  }

  ConfigData->ListCount = Private->ListCount;

  //
  // If it is Physical Presence User, set the PhysicalPresent to true.
  //
  if (UserPhysicalPresent ()) {
    ConfigData->PhysicalPresent = TRUE;
  } else {
    ConfigData->PhysicalPresent = FALSE;
  }

  //
  // If there is no PK then the Delete Pk button will be gray.
  //
  GetVariable2 (EFI_SETUP_MODE_NAME, &gEfiGlobalVariableGuid, (VOID **)&SetupMode, NULL);
  if ((SetupMode == NULL) || ((*SetupMode) == SETUP_MODE)) {
    ConfigData->HasPk = FALSE;
  } else {
    ConfigData->HasPk = TRUE;
  }

  //
  // Check SecureBootEnable & Pk status, fix the inconsistency.
  // If the SecureBootEnable Variable doesn't exist, hide the SecureBoot Enable/Disable
  // Checkbox.
  //
  ConfigData->AttemptSecureBoot = FALSE;
  GetVariable2 (EFI_SECURE_BOOT_ENABLE_NAME, &gEfiSecureBootEnableDisableGuid, (VOID **)&SecureBootEnable, NULL);

  //
  // Fix Pk and SecureBootEnable inconsistency
  //
  if ((SetupMode != NULL) && ((*SetupMode) == USER_MODE)) {
    ConfigData->HideSecureBoot = FALSE;
    if ((SecureBootEnable != NULL) && (*SecureBootEnable == SECURE_BOOT_ENABLE)) {
      ConfigData->AttemptSecureBoot = TRUE;
    }
  } else {
    ConfigData->HideSecureBoot = TRUE;
  }

  //
  // Get the SecureBootMode from CustomMode variable.
  //
  GetVariable2 (EFI_CUSTOM_MODE_NAME, &gEfiCustomModeEnableGuid, (VOID **)&SecureBootMode, NULL);
  if (SecureBootMode == NULL) {
    ConfigData->SecureBootMode = STANDARD_SECURE_BOOT_MODE;
  } else {
    ConfigData->SecureBootMode = *(SecureBootMode);
  }

  if (SecureBootEnable != NULL) {
    FreePool (SecureBootEnable);
  }

  if (SetupMode != NULL) {
    FreePool (SetupMode);
  }

  if (SecureBootMode != NULL) {
    FreePool (SecureBootMode);
  }
}

/**
  This function allows a caller to extract the current configuration for one
  or more named elements from the target driver.

  @param[in]   This              Points to the EFI_HII_CONFIG_ACCESS_PROTOCOL.
  @param[in]   Request           A null-terminated Unicode string in
                                 <ConfigRequest> format.
  @param[out]  Progress          On return, points to a character in the Request
                                 string. Points to the string's null terminator if
                                 request was successful. Points to the most recent
                                 '&' before the first failing name/value pair (or
                                 the beginning of the string if the failure is in
                                 the first name/value pair) if the request was not
                                 successful.
  @param[out]  Results           A null-terminated Unicode string in
                                 <ConfigAltResp> format which has all values filled
                                 in for the names in the Request string. String to
                                 be allocated by the called function.

  @retval EFI_SUCCESS            The Results is filled with the requested values.
  @retval EFI_OUT_OF_RESOURCES   Not enough memory to store the results.
  @retval EFI_INVALID_PARAMETER  Request is illegal syntax, or unknown name.
  @retval EFI_NOT_FOUND          Routing data doesn't match any storage in this
                                 driver.

**/
EFI_STATUS
EFIAPI
SecureBootExtractConfig (
  IN CONST EFI_HII_CONFIG_ACCESS_PROTOCOL  *This,
  IN CONST EFI_STRING                      Request,
  OUT EFI_STRING                           *Progress,
  OUT EFI_STRING                           *Results
  )
{
  EFI_STATUS                      Status;
  UINTN                           BufferSize;
  UINTN                           Size;
  SECUREBOOT_CONFIGURATION        Configuration;
  EFI_STRING                      ConfigRequest;
  EFI_STRING                      ConfigRequestHdr;
  SECUREBOOT_CONFIG_PRIVATE_DATA  *PrivateData;
  BOOLEAN                         AllocatedRequest;

  if ((Progress == NULL) || (Results == NULL)) {
    return EFI_INVALID_PARAMETER;
  }

  AllocatedRequest = FALSE;
  ConfigRequestHdr = NULL;
  ConfigRequest    = NULL;
  Size             = 0;

  ZeroMem (&Configuration, sizeof (Configuration));
  PrivateData = SECUREBOOT_CONFIG_PRIVATE_FROM_THIS (This);
  *Progress   = Request;

  if ((Request != NULL) && !HiiIsConfigHdrMatch (Request, &gSecureBootConfigFormSetGuid, mSecureBootStorageName)) {
    return EFI_NOT_FOUND;
  }

  ZeroMem (&Configuration, sizeof (SECUREBOOT_CONFIGURATION));

  //
  // Get Configuration from Variable.
  //
  SecureBootExtractConfigFromVariable (PrivateData, &Configuration);

  BufferSize    = sizeof (SECUREBOOT_CONFIGURATION);
  ConfigRequest = Request;
  if ((Request == NULL) || (StrStr (Request, L"OFFSET") == NULL)) {
    //
    // Request is set to NULL or OFFSET is NULL, construct full request string.
    //
    // Allocate and fill a buffer large enough to hold the <ConfigHdr> template
    // followed by "&OFFSET=0&WIDTH=WWWWWWWWWWWWWWWW" followed by a Null-terminator
    //
    ConfigRequestHdr = HiiConstructConfigHdr (&gSecureBootConfigFormSetGuid, mSecureBootStorageName, PrivateData->DriverHandle);
    Size             = (StrLen (ConfigRequestHdr) + 32 + 1) * sizeof (CHAR16);
    ConfigRequest    = AllocateZeroPool (Size);
    ASSERT (ConfigRequest != NULL);
    AllocatedRequest = TRUE;
    UnicodeSPrint (ConfigRequest, Size, L"%s&OFFSET=0&WIDTH=%016LX", ConfigRequestHdr, (UINT64)BufferSize);
    FreePool (ConfigRequestHdr);
    ConfigRequestHdr = NULL;
  }

  Status = gHiiConfigRouting->BlockToConfig (
                                gHiiConfigRouting,
                                ConfigRequest,
                                (UINT8 *)&Configuration,
                                BufferSize,
                                Results,
                                Progress
                                );

  //
  // Free the allocated config request string.
  //
  if (AllocatedRequest) {
    FreePool (ConfigRequest);
  }

  //
  // Set Progress string to the original request string.
  //
  if (Request == NULL) {
    *Progress = NULL;
  } else if (StrStr (Request, L"OFFSET") == NULL) {
    *Progress = Request + StrLen (Request);
  }

  return Status;
}

/**
  This function processes the results of changes in configuration.

  @param[in]  This               Points to the EFI_HII_CONFIG_ACCESS_PROTOCOL.
  @param[in]  Configuration      A null-terminated Unicode string in <ConfigResp>
                                 format.
  @param[out] Progress           A pointer to a string filled in with the offset of
                                 the most recent '&' before the first failing
                                 name/value pair (or the beginning of the string if
                                 the failure is in the first name/value pair) or
                                 the terminating NULL if all was successful.

  @retval EFI_SUCCESS            The Results is processed successfully.
  @retval EFI_INVALID_PARAMETER  Configuration is NULL.
  @retval EFI_NOT_FOUND          Routing data doesn't match any storage in this
                                 driver.

**/
EFI_STATUS
EFIAPI
SecureBootRouteConfig (
  IN CONST EFI_HII_CONFIG_ACCESS_PROTOCOL  *This,
  IN CONST EFI_STRING                      Configuration,
  OUT EFI_STRING                           *Progress
  )
{
  SECUREBOOT_CONFIGURATION        IfrNvData;
  UINTN                           BufferSize;
  SECUREBOOT_CONFIG_PRIVATE_DATA  *PrivateData;
  EFI_STATUS                      Status;

  if ((Configuration == NULL) || (Progress == NULL)) {
    return EFI_INVALID_PARAMETER;
  }

  *Progress = Configuration;
  if (!HiiIsConfigHdrMatch (Configuration, &gSecureBootConfigFormSetGuid, mSecureBootStorageName)) {
    return EFI_NOT_FOUND;
  }

  PrivateData = SECUREBOOT_CONFIG_PRIVATE_FROM_THIS (This);

  //
  // Get Configuration from Variable.
  //
  SecureBootExtractConfigFromVariable (PrivateData, &IfrNvData);

  //
  // Map the Configuration to the configuration block.
  //
  BufferSize = sizeof (SECUREBOOT_CONFIGURATION);
  Status     = gHiiConfigRouting->ConfigToBlock (
                                    gHiiConfigRouting,
                                    Configuration,
                                    (UINT8 *)&IfrNvData,
                                    &BufferSize,
                                    Progress
                                    );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Store Buffer Storage back to EFI variable if needed
  //
  if (!IfrNvData.HideSecureBoot) {
    Status = SaveSecureBootVariable (IfrNvData.AttemptSecureBoot);
    if (EFI_ERROR (Status)) {
      return Status;
    }
  }

  *Progress = Configuration + StrLen (Configuration);
  return EFI_SUCCESS;
}

/**
  This function to load signature list, the update the menu page.

  @param[in]  PrivateData         Module's private data.
  @param[in]  LabelId             Label number to insert opcodes.
  @param[in]  FormId              Form ID of current page.
  @param[in]  QuestionIdBase      Base question id of the signature list.

  @retval   EFI_SUCCESS           Success to update the signature list page
  @retval   EFI_OUT_OF_RESOURCES  Unable to allocate required resources.
**/
EFI_STATUS
LoadSignatureList (
  IN SECUREBOOT_CONFIG_PRIVATE_DATA  *PrivateData,
  IN UINT16                          LabelId,
  IN EFI_FORM_ID                     FormId,
  IN EFI_QUESTION_ID                 QuestionIdBase
  )
{
  EFI_STATUS          Status;
  EFI_STRING_ID       ListType;
  EFI_STRING          FormatNameString;
  EFI_STRING          FormatHelpString;
  EFI_STRING          FormatTypeString;
  EFI_SIGNATURE_LIST  *ListWalker;
  EFI_IFR_GUID_LABEL  *StartLabel;
  EFI_IFR_GUID_LABEL  *EndLabel;
  EFI_IFR_GUID_LABEL  *StartGoto;
  EFI_IFR_GUID_LABEL  *EndGoto;
  EFI_FORM_ID         DstFormId;
  VOID                *StartOpCodeHandle;
  VOID                *EndOpCodeHandle;
  VOID                *StartGotoHandle;
  VOID                *EndGotoHandle;
  UINTN               DataSize;
  UINTN               RemainingSize;
  UINT16              Index;
  UINT8               *VariableData;
  CHAR16              VariableName[BUFFER_MAX_SIZE];
  CHAR16              NameBuffer[BUFFER_MAX_SIZE];
  CHAR16              HelpBuffer[BUFFER_MAX_SIZE];

  Status            = EFI_SUCCESS;
  FormatNameString  = NULL;
  FormatHelpString  = NULL;
  StartOpCodeHandle = NULL;
  EndOpCodeHandle   = NULL;
  StartGotoHandle   = NULL;
  EndGotoHandle     = NULL;
  Index             = 0;
  VariableData      = NULL;

  //
  // Initialize the container for dynamic opcodes.
  //
  StartOpCodeHandle = HiiAllocateOpCodeHandle ();
  if (StartOpCodeHandle == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  EndOpCodeHandle = HiiAllocateOpCodeHandle ();
  if (EndOpCodeHandle == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  StartGotoHandle = HiiAllocateOpCodeHandle ();
  if (StartGotoHandle == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  EndGotoHandle = HiiAllocateOpCodeHandle ();
  if (EndGotoHandle == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  //
  // Create Hii Extend Label OpCode.
  //
  StartLabel = (EFI_IFR_GUID_LABEL *)HiiCreateGuidOpCode (
                                       StartOpCodeHandle,
                                       &gEfiIfrTianoGuid,
                                       NULL,
                                       sizeof (EFI_IFR_GUID_LABEL)
                                       );
  StartLabel->ExtendOpCode = EFI_IFR_EXTEND_OP_LABEL;
  StartLabel->Number       = LabelId;

  EndLabel = (EFI_IFR_GUID_LABEL *)HiiCreateGuidOpCode (
                                     EndOpCodeHandle,
                                     &gEfiIfrTianoGuid,
                                     NULL,
                                     sizeof (EFI_IFR_GUID_LABEL)
                                     );
  EndLabel->ExtendOpCode = EFI_IFR_EXTEND_OP_LABEL;
  EndLabel->Number       = LABEL_END;

  StartGoto = (EFI_IFR_GUID_LABEL *)HiiCreateGuidOpCode (
                                      StartGotoHandle,
                                      &gEfiIfrTianoGuid,
                                      NULL,
                                      sizeof (EFI_IFR_GUID_LABEL)
                                      );
  StartGoto->ExtendOpCode = EFI_IFR_EXTEND_OP_LABEL;
  StartGoto->Number       = LABEL_DELETE_ALL_LIST_BUTTON;

  EndGoto = (EFI_IFR_GUID_LABEL *)HiiCreateGuidOpCode (
                                    EndGotoHandle,
                                    &gEfiIfrTianoGuid,
                                    NULL,
                                    sizeof (EFI_IFR_GUID_LABEL)
                                    );
  EndGoto->ExtendOpCode = EFI_IFR_EXTEND_OP_LABEL;
  EndGoto->Number       = LABEL_END;

  if (PrivateData->VariableName == Variable_DB) {
    UnicodeSPrint (VariableName, sizeof (VariableName), EFI_IMAGE_SECURITY_DATABASE);
    DstFormId = FORMID_SECURE_BOOT_DB_OPTION_FORM;
  } else if (PrivateData->VariableName == Variable_DBX) {
    UnicodeSPrint (VariableName, sizeof (VariableName), EFI_IMAGE_SECURITY_DATABASE1);
    DstFormId = FORMID_SECURE_BOOT_DBX_OPTION_FORM;
  } else if (PrivateData->VariableName == Variable_DBT) {
    UnicodeSPrint (VariableName, sizeof (VariableName), EFI_IMAGE_SECURITY_DATABASE2);
    DstFormId = FORMID_SECURE_BOOT_DBT_OPTION_FORM;
  } else {
    goto ON_EXIT;
  }

  HiiCreateGotoOpCode (
    StartGotoHandle,
    DstFormId,
    STRING_TOKEN (STR_SECURE_BOOT_DELETE_ALL_LIST),
    STRING_TOKEN (STR_SECURE_BOOT_DELETE_ALL_LIST),
    EFI_IFR_FLAG_CALLBACK,
    KEY_SECURE_BOOT_DELETE_ALL_LIST
    );

  //
  // Read Variable, the variable name save in the PrivateData->VariableName.
  //
  DataSize = 0;
  Status   = gRT->GetVariable (VariableName, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, VariableData);
  if (EFI_ERROR (Status) && (Status != EFI_BUFFER_TOO_SMALL)) {
    goto ON_EXIT;
  }

  VariableData = AllocateZeroPool (DataSize);
  if (VariableData == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  Status = gRT->GetVariable (VariableName, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, VariableData);
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  FormatNameString = HiiGetString (PrivateData->HiiHandle, STRING_TOKEN (STR_SIGNATURE_LIST_NAME_FORMAT), NULL);
  FormatHelpString = HiiGetString (PrivateData->HiiHandle, STRING_TOKEN (STR_SIGNATURE_LIST_HELP_FORMAT), NULL);
  if ((FormatNameString == NULL) || (FormatHelpString == NULL)) {
    goto ON_EXIT;
  }

  RemainingSize = DataSize;
  ListWalker    = (EFI_SIGNATURE_LIST *)VariableData;
  while ((RemainingSize > 0) && (RemainingSize >= ListWalker->SignatureListSize)) {
    if (CompareGuid (&ListWalker->SignatureType, &gEfiCertRsa2048Guid)) {
      ListType = STRING_TOKEN (STR_LIST_TYPE_RSA2048_SHA256);
    } else if (CompareGuid (&ListWalker->SignatureType, &gEfiCertX509Guid)) {
      ListType = STRING_TOKEN (STR_LIST_TYPE_X509);
    } else if (CompareGuid (&ListWalker->SignatureType, &gEfiCertSha1Guid)) {
      ListType = STRING_TOKEN (STR_LIST_TYPE_SHA1);
    } else if (CompareGuid (&ListWalker->SignatureType, &gEfiCertSha256Guid)) {
      ListType = STRING_TOKEN (STR_LIST_TYPE_SHA256);
    } else if (CompareGuid (&ListWalker->SignatureType, &gEfiCertSha384Guid)) {
      ListType = STRING_TOKEN (STR_LIST_TYPE_SHA384);
    } else if (CompareGuid (&ListWalker->SignatureType, &gEfiCertSha512Guid)) {
      ListType = STRING_TOKEN (STR_LIST_TYPE_SHA512);
    } else if (CompareGuid (&ListWalker->SignatureType, &gEfiCertX509Sha256Guid)) {
      ListType = STRING_TOKEN (STR_LIST_TYPE_X509_SHA256);
    } else if (CompareGuid (&ListWalker->SignatureType, &gEfiCertX509Sha384Guid)) {
      ListType = STRING_TOKEN (STR_LIST_TYPE_X509_SHA384);
    } else if (CompareGuid (&ListWalker->SignatureType, &gEfiCertX509Sha512Guid)) {
      ListType = STRING_TOKEN (STR_LIST_TYPE_X509_SHA512);
    } else {
      ListType = STRING_TOKEN (STR_LIST_TYPE_UNKNOWN);
    }

    FormatTypeString = HiiGetString (PrivateData->HiiHandle, ListType, NULL);
    if (FormatTypeString == NULL) {
      goto ON_EXIT;
    }

    ZeroMem (NameBuffer, sizeof (NameBuffer));
    UnicodeSPrint (NameBuffer, sizeof (NameBuffer), FormatNameString, Index + 1);

    ZeroMem (HelpBuffer, sizeof (HelpBuffer));
    UnicodeSPrint (
      HelpBuffer,
      sizeof (HelpBuffer),
      FormatHelpString,
      FormatTypeString,
      SIGNATURE_DATA_COUNTS (ListWalker)
      );
    SECUREBOOT_FREE_NON_NULL (FormatTypeString);
    FormatTypeString = NULL;

    HiiCreateGotoOpCode (
      StartOpCodeHandle,
      SECUREBOOT_DELETE_SIGNATURE_DATA_FORM,
      HiiSetString (PrivateData->HiiHandle, 0, NameBuffer, NULL),
      HiiSetString (PrivateData->HiiHandle, 0, HelpBuffer, NULL),
      EFI_IFR_FLAG_CALLBACK,
      QuestionIdBase + Index++
      );

    RemainingSize -= ListWalker->SignatureListSize;
    ListWalker     = (EFI_SIGNATURE_LIST *)((UINT8 *)ListWalker + ListWalker->SignatureListSize);
  }

ON_EXIT:
  HiiUpdateForm (
    PrivateData->HiiHandle,
    &gSecureBootConfigFormSetGuid,
    FormId,
    StartOpCodeHandle,
    EndOpCodeHandle
    );

  HiiUpdateForm (
    PrivateData->HiiHandle,
    &gSecureBootConfigFormSetGuid,
    FormId,
    StartGotoHandle,
    EndGotoHandle
    );

  SECUREBOOT_FREE_NON_OPCODE (StartOpCodeHandle);
  SECUREBOOT_FREE_NON_OPCODE (EndOpCodeHandle);
  SECUREBOOT_FREE_NON_OPCODE (StartGotoHandle);
  SECUREBOOT_FREE_NON_OPCODE (EndGotoHandle);

  SECUREBOOT_FREE_NON_NULL (VariableData);
  SECUREBOOT_FREE_NON_NULL (FormatNameString);
  SECUREBOOT_FREE_NON_NULL (FormatHelpString);

  PrivateData->ListCount = Index;

  return Status;
}

/**
  Parse hash value from EFI_SIGNATURE_DATA, and save in the CHAR16 type array.
  The buffer is callee allocated and should be freed by the caller.

  @param[in]    ListEntry                 The pointer point to the signature list.
  @param[in]    DataEntry                 The signature data we are processing.
  @param[out]   BufferToReturn            Buffer to save the hash value.

  @retval       EFI_INVALID_PARAMETER     Invalid List or Data or Buffer.
  @retval       EFI_OUT_OF_RESOURCES      A memory allocation failed.
  @retval       EFI_SUCCESS               Operation success.
**/
EFI_STATUS
ParseHashValue (
  IN     EFI_SIGNATURE_LIST  *ListEntry,
  IN     EFI_SIGNATURE_DATA  *DataEntry,
  OUT CHAR16                 **BufferToReturn
  )
{
  UINTN  Index;
  UINTN  BufferIndex;
  UINTN  TotalSize;
  UINTN  DataSize;
  UINTN  Line;
  UINTN  OneLineBytes;

  //
  //  Assume that, display 8 bytes in one line.
  //
  OneLineBytes = 8;

  if ((ListEntry == NULL) || (DataEntry == NULL) || (BufferToReturn == NULL)) {
    return EFI_INVALID_PARAMETER;
  }

  DataSize = ListEntry->SignatureSize - sizeof (EFI_GUID);
  Line     = (DataSize + OneLineBytes - 1) / OneLineBytes;

  //
  // Each byte will split two Hex-number, and each line need additional memory to save '\r\n'.
  //
  TotalSize = ((DataSize + Line) * 2 * sizeof (CHAR16));

  *BufferToReturn = AllocateZeroPool (TotalSize);
  if (*BufferToReturn == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  for (Index = 0, BufferIndex = 0; Index < DataSize; Index = Index + 1) {
    if ((Index > 0) && (Index % OneLineBytes == 0)) {
      BufferIndex += UnicodeSPrint (&(*BufferToReturn)[BufferIndex], TotalSize - sizeof (CHAR16) * BufferIndex, L"\n");
    }

    BufferIndex += UnicodeSPrint (&(*BufferToReturn)[BufferIndex], TotalSize - sizeof (CHAR16) * BufferIndex, L"%02x", DataEntry->SignatureData[Index]);
  }

  BufferIndex += UnicodeSPrint (&(*BufferToReturn)[BufferIndex], TotalSize - sizeof (CHAR16) * BufferIndex, L"\n");

  return EFI_SUCCESS;
}

/**
  Function to get the common name from the X509 format certificate.
  The buffer is callee allocated and should be freed by the caller.

  @param[in]    ListEntry                 The pointer point to the signature list.
  @param[in]    DataEntry                 The signature data we are processing.
  @param[out]   BufferToReturn            Buffer to save the CN of X509 certificate.

  @retval       EFI_INVALID_PARAMETER     Invalid List or Data or Buffer.
  @retval       EFI_OUT_OF_RESOURCES      A memory allocation failed.
  @retval       EFI_SUCCESS               Operation success.
  @retval       EFI_NOT_FOUND             Not found CN field in the X509 certificate.
**/
EFI_STATUS
GetCommonNameFromX509 (
  IN     EFI_SIGNATURE_LIST  *ListEntry,
  IN     EFI_SIGNATURE_DATA  *DataEntry,
  OUT CHAR16                 **BufferToReturn
  )
{
  EFI_STATUS  Status;
  CHAR8       *CNBuffer;
  UINTN       CNBufferSize;

  Status   = EFI_SUCCESS;
  CNBuffer = NULL;

  CNBuffer = AllocateZeroPool (256);
  if (CNBuffer == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  CNBufferSize = 256;
  X509GetCommonName (
    (UINT8 *)DataEntry + sizeof (EFI_GUID),
    ListEntry->SignatureSize - sizeof (EFI_GUID),
    CNBuffer,
    &CNBufferSize
    );

  *BufferToReturn = AllocateZeroPool (256 * sizeof (CHAR16));
  if (*BufferToReturn == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  AsciiStrToUnicodeStrS (CNBuffer, *BufferToReturn, 256);

ON_EXIT:
  SECUREBOOT_FREE_NON_NULL (CNBuffer);

  return Status;
}

/**
  Format the help info for the signature data, each help info contain 3 parts.
  1. Onwer Guid.
  2. Content, depends on the type of the signature list.
  3. Revocation time.

  @param[in]      PrivateData             Module's private data.
  @param[in]      ListEntry               Point to the signature list.
  @param[in]      DataEntry               Point to the signature data we are processing.
  @param[out]     StringId                Save the string id of help info.

  @retval         EFI_SUCCESS             Operation success.
  @retval         EFI_OUT_OF_RESOURCES    Unable to allocate required resources.
**/
EFI_STATUS
FormatHelpInfo (
  IN     SECUREBOOT_CONFIG_PRIVATE_DATA  *PrivateData,
  IN     EFI_SIGNATURE_LIST              *ListEntry,
  IN     EFI_SIGNATURE_DATA              *DataEntry,
  OUT EFI_STRING_ID                      *StringId
  )
{
  EFI_STATUS     Status;
  EFI_TIME       *Time;
  EFI_STRING_ID  ListTypeId;
  EFI_STRING     FormatHelpString;
  EFI_STRING     FormatTypeString;
  UINTN          DataSize;
  UINTN          HelpInfoIndex;
  UINTN          TotalSize;
  CHAR16         GuidString[BUFFER_MAX_SIZE];
  CHAR16         TimeString[BUFFER_MAX_SIZE];
  CHAR16         *DataString;
  CHAR16         *HelpInfoString;
  BOOLEAN        IsCert;

  Status           = EFI_SUCCESS;
  Time             = NULL;
  FormatTypeString = NULL;
  HelpInfoIndex    = 0;
  DataString       = NULL;
  HelpInfoString   = NULL;
  IsCert           = FALSE;

  if (CompareGuid (&ListEntry->SignatureType, &gEfiCertRsa2048Guid)) {
    ListTypeId = STRING_TOKEN (STR_LIST_TYPE_RSA2048_SHA256);
    DataSize   = ListEntry->SignatureSize - sizeof (EFI_GUID);
    IsCert     = TRUE;
  } else if (CompareGuid (&ListEntry->SignatureType, &gEfiCertX509Guid)) {
    ListTypeId = STRING_TOKEN (STR_LIST_TYPE_X509);
    DataSize   = ListEntry->SignatureSize - sizeof (EFI_GUID);
    IsCert     = TRUE;
  } else if (CompareGuid (&ListEntry->SignatureType, &gEfiCertSha1Guid)) {
    ListTypeId = STRING_TOKEN (STR_LIST_TYPE_SHA1);
    DataSize   = 20;
  } else if (CompareGuid (&ListEntry->SignatureType, &gEfiCertSha256Guid)) {
    ListTypeId = STRING_TOKEN (STR_LIST_TYPE_SHA256);
    DataSize   = 32;
  } else if (CompareGuid (&ListEntry->SignatureType, &gEfiCertSha384Guid)) {
    ListTypeId = STRING_TOKEN (STR_LIST_TYPE_SHA384);
    DataSize   = 48;
  } else if (CompareGuid (&ListEntry->SignatureType, &gEfiCertSha512Guid)) {
    ListTypeId = STRING_TOKEN (STR_LIST_TYPE_SHA512);
    DataSize   = 64;
  } else if (CompareGuid (&ListEntry->SignatureType, &gEfiCertX509Sha256Guid)) {
    ListTypeId = STRING_TOKEN (STR_LIST_TYPE_X509_SHA256);
    DataSize   = 32;
    Time       = (EFI_TIME *)(DataEntry->SignatureData + DataSize);
  } else if (CompareGuid (&ListEntry->SignatureType, &gEfiCertX509Sha384Guid)) {
    ListTypeId = STRING_TOKEN (STR_LIST_TYPE_X509_SHA384);
    DataSize   = 48;
    Time       = (EFI_TIME *)(DataEntry->SignatureData + DataSize);
  } else if (CompareGuid (&ListEntry->SignatureType, &gEfiCertX509Sha512Guid)) {
    ListTypeId = STRING_TOKEN (STR_LIST_TYPE_X509_SHA512);
    DataSize   = 64;
    Time       = (EFI_TIME *)(DataEntry->SignatureData + DataSize);
  } else {
    Status = EFI_UNSUPPORTED;
    goto ON_EXIT;
  }

  FormatTypeString = HiiGetString (PrivateData->HiiHandle, ListTypeId, NULL);
  if (FormatTypeString == NULL) {
    goto ON_EXIT;
  }

  TotalSize      = 1024;
  HelpInfoString = AllocateZeroPool (TotalSize);
  if (HelpInfoString == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  //
  // Format GUID part.
  //
  ZeroMem (GuidString, sizeof (GuidString));
  GuidToString (&DataEntry->SignatureOwner, GuidString, BUFFER_MAX_SIZE);
  FormatHelpString = HiiGetString (PrivateData->HiiHandle, STRING_TOKEN (STR_SIGNATURE_DATA_HELP_FORMAT_GUID), NULL);
  if (FormatHelpString == NULL) {
    goto ON_EXIT;
  }

  HelpInfoIndex += UnicodeSPrint (
                     &HelpInfoString[HelpInfoIndex],
                     TotalSize - sizeof (CHAR16) * HelpInfoIndex,
                     FormatHelpString,
                     GuidString
                     );
  SECUREBOOT_FREE_NON_NULL (FormatHelpString);
  FormatHelpString = NULL;

  //
  // Format content part, it depends on the type of signature list, hash value or CN.
  //
  if (IsCert) {
    GetCommonNameFromX509 (ListEntry, DataEntry, &DataString);
    FormatHelpString = HiiGetString (PrivateData->HiiHandle, STRING_TOKEN (STR_SIGNATURE_DATA_HELP_FORMAT_CN), NULL);
  } else {
    //
    //  Format hash value for each signature data entry.
    //
    ParseHashValue (ListEntry, DataEntry, &DataString);
    FormatHelpString = HiiGetString (PrivateData->HiiHandle, STRING_TOKEN (STR_SIGNATURE_DATA_HELP_FORMAT_HASH), NULL);
  }

  if (FormatHelpString == NULL) {
    goto ON_EXIT;
  }

  HelpInfoIndex += UnicodeSPrint (
                     &HelpInfoString[HelpInfoIndex],
                     TotalSize - sizeof (CHAR16) * HelpInfoIndex,
                     FormatHelpString,
                     FormatTypeString,
                     DataSize,
                     DataString
                     );
  SECUREBOOT_FREE_NON_NULL (FormatHelpString);
  FormatHelpString = NULL;

  //
  // Format revocation time part.
  //
  if (Time != NULL) {
    ZeroMem (TimeString, sizeof (TimeString));
    UnicodeSPrint (
      TimeString,
      sizeof (TimeString),
      L"%d-%d-%d %d:%d:%d",
      Time->Year,
      Time->Month,
      Time->Day,
      Time->Hour,
      Time->Minute,
      Time->Second
      );
    FormatHelpString = HiiGetString (PrivateData->HiiHandle, STRING_TOKEN (STR_SIGNATURE_DATA_HELP_FORMAT_TIME), NULL);
    if (FormatHelpString == NULL) {
      goto ON_EXIT;
    }

    UnicodeSPrint (
      &HelpInfoString[HelpInfoIndex],
      TotalSize - sizeof (CHAR16) * HelpInfoIndex,
      FormatHelpString,
      TimeString
      );
    SECUREBOOT_FREE_NON_NULL (FormatHelpString);
    FormatHelpString = NULL;
  }

  *StringId = HiiSetString (PrivateData->HiiHandle, 0, HelpInfoString, NULL);
ON_EXIT:
  SECUREBOOT_FREE_NON_NULL (DataString);
  SECUREBOOT_FREE_NON_NULL (HelpInfoString);

  SECUREBOOT_FREE_NON_NULL (FormatTypeString);

  return Status;
}

/**
  This function to load signature data under the signature list.

  @param[in]  PrivateData         Module's private data.
  @param[in]  LabelId             Label number to insert opcodes.
  @param[in]  FormId              Form ID of current page.
  @param[in]  QuestionIdBase      Base question id of the signature list.
  @param[in]  ListIndex           Indicate to load which signature list.

  @retval   EFI_SUCCESS           Success to update the signature list page
  @retval   EFI_OUT_OF_RESOURCES  Unable to allocate required resources.
**/
EFI_STATUS
LoadSignatureData (
  IN SECUREBOOT_CONFIG_PRIVATE_DATA  *PrivateData,
  IN UINT16                          LabelId,
  IN EFI_FORM_ID                     FormId,
  IN EFI_QUESTION_ID                 QuestionIdBase,
  IN UINT16                          ListIndex
  )
{
  EFI_STATUS          Status;
  EFI_SIGNATURE_LIST  *ListWalker;
  EFI_SIGNATURE_DATA  *DataWalker;
  EFI_IFR_GUID_LABEL  *StartLabel;
  EFI_IFR_GUID_LABEL  *EndLabel;
  EFI_STRING_ID       HelpStringId;
  EFI_STRING          FormatNameString;
  VOID                *StartOpCodeHandle;
  VOID                *EndOpCodeHandle;
  UINTN               DataSize;
  UINTN               RemainingSize;
  UINT16              Index;
  UINT8               *VariableData;
  CHAR16              VariableName[BUFFER_MAX_SIZE];
  CHAR16              NameBuffer[BUFFER_MAX_SIZE];

  Status            = EFI_SUCCESS;
  FormatNameString  = NULL;
  StartOpCodeHandle = NULL;
  EndOpCodeHandle   = NULL;
  Index             = 0;
  VariableData      = NULL;

  //
  // Initialize the container for dynamic opcodes.
  //
  StartOpCodeHandle = HiiAllocateOpCodeHandle ();
  if (StartOpCodeHandle == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  EndOpCodeHandle = HiiAllocateOpCodeHandle ();
  if (EndOpCodeHandle == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  //
  // Create Hii Extend Label OpCode.
  //
  StartLabel = (EFI_IFR_GUID_LABEL *)HiiCreateGuidOpCode (
                                       StartOpCodeHandle,
                                       &gEfiIfrTianoGuid,
                                       NULL,
                                       sizeof (EFI_IFR_GUID_LABEL)
                                       );
  StartLabel->ExtendOpCode = EFI_IFR_EXTEND_OP_LABEL;
  StartLabel->Number       = LabelId;

  EndLabel = (EFI_IFR_GUID_LABEL *)HiiCreateGuidOpCode (
                                     EndOpCodeHandle,
                                     &gEfiIfrTianoGuid,
                                     NULL,
                                     sizeof (EFI_IFR_GUID_LABEL)
                                     );
  EndLabel->ExtendOpCode = EFI_IFR_EXTEND_OP_LABEL;
  EndLabel->Number       = LABEL_END;

  if (PrivateData->VariableName == Variable_DB) {
    UnicodeSPrint (VariableName, sizeof (VariableName), EFI_IMAGE_SECURITY_DATABASE);
  } else if (PrivateData->VariableName == Variable_DBX) {
    UnicodeSPrint (VariableName, sizeof (VariableName), EFI_IMAGE_SECURITY_DATABASE1);
  } else if (PrivateData->VariableName == Variable_DBT) {
    UnicodeSPrint (VariableName, sizeof (VariableName), EFI_IMAGE_SECURITY_DATABASE2);
  } else {
    goto ON_EXIT;
  }

  //
  // Read Variable, the variable name save in the PrivateData->VariableName.
  //
  DataSize = 0;
  Status   = gRT->GetVariable (VariableName, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, VariableData);
  if (EFI_ERROR (Status) && (Status != EFI_BUFFER_TOO_SMALL)) {
    goto ON_EXIT;
  }

  VariableData = AllocateZeroPool (DataSize);
  if (VariableData == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }

  Status = gRT->GetVariable (VariableName, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, VariableData);
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  RemainingSize = DataSize;
  ListWalker    = (EFI_SIGNATURE_LIST *)VariableData;

  //
  // Skip signature list.
  //
  while ((RemainingSize > 0) && (RemainingSize >= ListWalker->SignatureListSize) && ListIndex-- > 0) {
    RemainingSize -= ListWalker->SignatureListSize;
    ListWalker     = (EFI_SIGNATURE_LIST *)((UINT8 *)ListWalker + ListWalker->SignatureListSize);
  }

  FormatNameString = HiiGetString (PrivateData->HiiHandle, STRING_TOKEN (STR_SIGNATURE_DATA_NAME_FORMAT), NULL);
  if (FormatNameString == NULL) {
    goto ON_EXIT;
  }

  DataWalker = (EFI_SIGNATURE_DATA *)((UINT8 *)ListWalker + sizeof (EFI_SIGNATURE_LIST) + ListWalker->SignatureHeaderSize);
  for (Index = 0; Index < SIGNATURE_DATA_COUNTS (ListWalker); Index = Index + 1) {
    //
    // Format name buffer.
    //
    ZeroMem (NameBuffer, sizeof (NameBuffer));
    UnicodeSPrint (NameBuffer, sizeof (NameBuffer), FormatNameString, Index + 1);

    //
    // Format help info buffer.
    //
    Status = FormatHelpInfo (PrivateData, ListWalker, DataWalker, &HelpStringId);
    if (EFI_ERROR (Status)) {
      goto ON_EXIT;
    }

    HiiCreateCheckBoxOpCode (
      StartOpCodeHandle,
      (EFI_QUESTION_ID)(QuestionIdBase + Index),
      0,
      0,
      HiiSetString (PrivateData->HiiHandle, 0, NameBuffer, NULL),
      HelpStringId,
      EFI_IFR_FLAG_CALLBACK,
      0,
      NULL
      );

    ZeroMem (NameBuffer, 100);
    DataWalker = (EFI_SIGNATURE_DATA *)((UINT8 *)DataWalker + ListWalker->SignatureSize);
  }

  //
  // Allocate a buffer to record which signature data will be checked.
  // This memory buffer will be freed when exit from the SECUREBOOT_DELETE_SIGNATURE_DATA_FORM form.
  //
  PrivateData->CheckArray = AllocateZeroPool (SIGNATURE_DATA_COUNTS (ListWalker) * sizeof (BOOLEAN));
ON_EXIT:
  HiiUpdateForm (
    PrivateData->HiiHandle,
    &gSecureBootConfigFormSetGuid,
    FormId,
    StartOpCodeHandle,
    EndOpCodeHandle
    );

  SECUREBOOT_FREE_NON_OPCODE (StartOpCodeHandle);
  SECUREBOOT_FREE_NON_OPCODE (EndOpCodeHandle);

  SECUREBOOT_FREE_NON_NULL (VariableData);
  SECUREBOOT_FREE_NON_NULL (FormatNameString);

  return Status;
}

/**
  This function reinitializes Secure Boot variables with default values.

  @retval   EFI_SUCCESS           Success to update the signature list page
  @retval   others                Fail to delete or enroll signature data.
**/
STATIC EFI_STATUS
EFIAPI
KeyEnrollReset (
  VOID
  )
{
  EFI_STATUS  Status;
  UINT8       SetupMode;

  Status = EFI_SUCCESS;

  Status = SetSecureBootMode (CUSTOM_SECURE_BOOT_MODE);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  // Clear all the keys and databases
  Status = DeleteDb ();
  if (EFI_ERROR (Status) && (Status != EFI_NOT_FOUND)) {
    DEBUG ((DEBUG_ERROR, "Fail to clear DB: %r\n", Status));
    return Status;
  }

  Status = DeleteDbx ();
  if (EFI_ERROR (Status) && (Status != EFI_NOT_FOUND)) {
    DEBUG ((DEBUG_ERROR, "Fail to clear DBX: %r\n", Status));
    return Status;
  }

  Status = DeleteDbt ();
  if (EFI_ERROR (Status) && (Status != EFI_NOT_FOUND)) {
    DEBUG ((DEBUG_ERROR, "Fail to clear DBT: %r\n", Status));
    return Status;
  }

  Status = DeleteKEK ();
  if (EFI_ERROR (Status) && (Status != EFI_NOT_FOUND)) {
    DEBUG ((DEBUG_ERROR, "Fail to clear KEK: %r\n", Status));
    return Status;
  }

  Status = DeletePlatformKey ();
  if (EFI_ERROR (Status) && (Status != EFI_NOT_FOUND)) {
    DEBUG ((DEBUG_ERROR, "Fail to clear PK: %r\n", Status));
    return Status;
  }

  // After PK clear, Setup Mode shall be enabled
  Status = GetSetupMode (&SetupMode);
  if (EFI_ERROR (Status)) {
    DEBUG ((
      DEBUG_ERROR,
      "Cannot get SetupMode variable: %r\n",
      Status
      ));
    return Status;
  }

  if (SetupMode == USER_MODE) {
    DEBUG ((DEBUG_INFO, "Skipped - USER_MODE\n"));
    return EFI_SUCCESS;
  }

  Status = SetSecureBootMode (CUSTOM_SECURE_BOOT_MODE);
  if (EFI_ERROR (Status)) {
    DEBUG ((
      DEBUG_ERROR,
      "Cannot set CUSTOM_SECURE_BOOT_MODE: %r\n",
      Status
      ));
    return EFI_SUCCESS;
  }

  // Enroll all the keys from default variables
  Status = EnrollDbFromDefault ();
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Cannot enroll db: %r\n", Status));
    goto error;
  }

  Status = EnrollDbxFromDefault ();
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Cannot enroll dbx: %r\n", Status));
  }

  Status = EnrollDbtFromDefault ();
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Cannot enroll dbt: %r\n", Status));
  }

  Status = EnrollKEKFromDefault ();
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Cannot enroll KEK: %r\n", Status));
    goto cleardbs;
  }

  Status = EnrollPKFromDefault ();
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Cannot enroll PK: %r\n", Status));
    goto clearKEK;
  }

  Status = SetSecureBootMode (STANDARD_SECURE_BOOT_MODE);
  if (EFI_ERROR (Status)) {
    DEBUG ((
      DEBUG_ERROR,
      "Cannot set CustomMode to STANDARD_SECURE_BOOT_MODE\n"
      "Please do it manually, otherwise system can be easily compromised\n"
      ));
  }

  return Status;

clearKEK:
  DeleteKEK ();

cleardbs:
  DeleteDbt ();
  DeleteDbx ();
  DeleteDb ();

error:
  if (SetSecureBootMode (STANDARD_SECURE_BOOT_MODE) != EFI_SUCCESS) {
    DEBUG ((DEBUG_ERROR, "Cannot set mode to Secure: %r\n", Status));
  }

  return Status;
}

/**
  This function is called to provide results data to the driver.

  @param[in]  This               Points to the EFI_HII_CONFIG_ACCESS_PROTOCOL.
  @param[in]  Action             Specifies the type of action taken by the browser.
  @param[in]  QuestionId         A unique value which is sent to the original
                                 exporting driver so that it can identify the type
                                 of data to expect.
  @param[in]  Type               The type of value for the question.
  @param[in]  Value              A pointer to the data being sent to the original
                                 exporting driver.
  @param[out] ActionRequest      On return, points to the action requested by the
                                 callback function.

  @retval EFI_SUCCESS            The callback successfully handled the action.
  @retval EFI_OUT_OF_RESOURCES   Not enough storage is available to hold the
                                 variable and its data.
  @retval EFI_DEVICE_ERROR       The variable could not be saved.
  @retval EFI_UNSUPPORTED        The specified Action is not supported by the
                                 callback.

**/
EFI_STATUS
EFIAPI
SecureBootCallback (
  IN CONST EFI_HII_CONFIG_ACCESS_PROTOCOL  *This,
  IN     EFI_BROWSER_ACTION                Action,
  IN     EFI_QUESTION_ID                   QuestionId,
  IN     UINT8                             Type,
  IN     EFI_IFR_TYPE_VALUE                *Value,
  OUT EFI_BROWSER_ACTION_REQUEST           *ActionRequest
  )
{
  EFI_INPUT_KEY                   Key;
  EFI_STATUS                      Status;
  RETURN_STATUS                   RStatus;
  SECUREBOOT_CONFIG_PRIVATE_DATA  *Private;
  UINTN                           BufferSize;
  SECUREBOOT_CONFIGURATION        *IfrNvData;
  UINT16                          LabelId;
  UINT8                           *SecureBootEnable;
  UINT8                           *Pk;
  UINT8                           *SecureBootMode;
  UINT8                           *SetupMode;
  CHAR16                          PromptString[100];
  EFI_DEVICE_PATH_PROTOCOL        *File;
  UINTN                           NameLength;
  UINT16                          *FilePostFix;
  SECUREBOOT_CONFIG_PRIVATE_DATA  *PrivateData;
  BOOLEAN                         GetBrowserDataResult;
  ENROLL_KEY_ERROR                EnrollKeyErrorCode;
  EFI_HII_POPUP_PROTOCOL          *HiiPopup;
  EFI_HII_POPUP_SELECTION         UserSelection;

  Status               = EFI_SUCCESS;
  SecureBootEnable     = NULL;
  SecureBootMode       = NULL;
  SetupMode            = NULL;
  File                 = NULL;
  EnrollKeyErrorCode   = None_Error;
  GetBrowserDataResult = FALSE;

  if ((This == NULL) || (Value == NULL) || (ActionRequest == NULL)) {
    return EFI_INVALID_PARAMETER;
  }

  Private = SECUREBOOT_CONFIG_PRIVATE_FROM_THIS (This);

  gSecureBootPrivateData = Private;

  //
  // Retrieve uncommitted data from Browser
  //
  BufferSize = sizeof (SECUREBOOT_CONFIGURATION);
  IfrNvData  = AllocateZeroPool (BufferSize);
  if (IfrNvData == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  if (Action == EFI_BROWSER_ACTION_FORM_OPEN) {
    if (QuestionId == KEY_SECURE_BOOT_MODE) {
      //
      // Update secure boot strings when opening this form
      //
      Status                 = UpdateSecureBootString (Private);
      mIsEnterSecureBootForm = TRUE;
    } else {
      //
      // When entering SecureBoot OPTION Form
      // always close opened file & free resource
      //
      if ((QuestionId == KEY_SECURE_BOOT_PK_OPTION) ||
          (QuestionId == KEY_SECURE_BOOT_KEK_OPTION) ||
          (QuestionId == KEY_SECURE_BOOT_DB_OPTION) ||
          (QuestionId == KEY_SECURE_BOOT_DBX_OPTION) ||
          (QuestionId == KEY_SECURE_BOOT_DBT_OPTION))
      {
        CloseEnrolledFile (Private->FileContext);
      }
    }

    goto EXIT;
  }

  GetBrowserDataResult = HiiGetBrowserData (&gSecureBootConfigFormSetGuid, mSecureBootStorageName, BufferSize, (UINT8 *)IfrNvData);

  if (Action == EFI_BROWSER_ACTION_RETRIEVE) {
    Status = EFI_UNSUPPORTED;
    if (QuestionId == KEY_SECURE_BOOT_MODE) {
      if (mIsEnterSecureBootForm) {
        if (GetBrowserDataResult) {
          SecureBootExtractConfigFromVariable (Private, IfrNvData);
        }

        Value->u8 = SECURE_BOOT_MODE_STANDARD;
        Status    = EFI_SUCCESS;
      }
    }

    goto EXIT;
  }

  if ((Action != EFI_BROWSER_ACTION_CHANGED) &&
      (Action != EFI_BROWSER_ACTION_CHANGING) &&
      (Action != EFI_BROWSER_ACTION_FORM_CLOSE) &&
      (Action != EFI_BROWSER_ACTION_DEFAULT_STANDARD))
  {
    Status = EFI_UNSUPPORTED;
    goto EXIT;
  }

  if (Action == EFI_BROWSER_ACTION_CHANGING) {
    switch (QuestionId) {
      case KEY_SECURE_BOOT_ENABLE:
        GetVariable2 (EFI_SECURE_BOOT_ENABLE_NAME, &gEfiSecureBootEnableDisableGuid, (VOID **)&SecureBootEnable, NULL);
        if (NULL != SecureBootEnable) {
          FreePool (SecureBootEnable);
          if (EFI_ERROR (SaveSecureBootVariable (Value->u8))) {
            CreatePopUp (
              EFI_LIGHTGRAY | EFI_BACKGROUND_BLUE,
              &Key,
              L"Only Physical Presence User could disable secure boot!",
              NULL
              );
            Status = EFI_UNSUPPORTED;
          } else {
            CreatePopUp (
              EFI_LIGHTGRAY | EFI_BACKGROUND_BLUE,
              &Key,
              L"Configuration changed, please reset the platform to take effect!",
              NULL
              );
          }
        }

        break;

      case KEY_SECURE_BOOT_KEK_OPTION:
      case KEY_SECURE_BOOT_DB_OPTION:
      case KEY_SECURE_BOOT_DBX_OPTION:
      case KEY_SECURE_BOOT_DBT_OPTION:
        PrivateData = SECUREBOOT_CONFIG_PRIVATE_FROM_THIS (This);
        //
        // Clear Signature GUID.
        //
        ZeroMem (IfrNvData->SignatureGuid, sizeof (IfrNvData->SignatureGuid));
        if (Private->SignatureGUID == NULL) {
          Private->SignatureGUID = (EFI_GUID *)AllocateZeroPool (sizeof (EFI_GUID));
          if (Private->SignatureGUID == NULL) {
            return EFI_OUT_OF_RESOURCES;
          }
        }

        //
        // Cleanup VFRData once leaving PK/KEK/DB/DBX/DBT enroll/delete page
        //
        SecureBootExtractConfigFromVariable (PrivateData, IfrNvData);

        if (QuestionId == KEY_SECURE_BOOT_DB_OPTION) {
          LabelId = SECUREBOOT_ENROLL_SIGNATURE_TO_DB;
        } else if (QuestionId == KEY_SECURE_BOOT_DBX_OPTION) {
          LabelId = SECUREBOOT_ENROLL_SIGNATURE_TO_DBX;
        } else if (QuestionId == KEY_SECURE_BOOT_DBT_OPTION) {
          LabelId = SECUREBOOT_ENROLL_SIGNATURE_TO_DBT;
        } else {
          LabelId = FORMID_ENROLL_KEK_FORM;
        }

        //
        // Refresh selected file.
        //
        CleanUpPage (LabelId, Private);
        break;
      case KEY_SECURE_BOOT_PK_OPTION:
        LabelId = FORMID_ENROLL_PK_FORM;
        //
        // Refresh selected file.
        //
        CleanUpPage (LabelId, Private);
        break;

      case FORMID_ENROLL_PK_FORM:
        ChooseFile (NULL, NULL, UpdatePKFromFile, &File);
        break;

      case FORMID_ENROLL_KEK_FORM:
        ChooseFile (NULL, NULL, UpdateKEKFromFile, &File);
        break;

      case SECUREBOOT_ENROLL_SIGNATURE_TO_DB:
        ChooseFile (NULL, NULL, UpdateDBFromFile, &File);
        break;

      case SECUREBOOT_ENROLL_SIGNATURE_TO_DBX:
        ChooseFile (NULL, NULL, UpdateDBXFromFile, &File);

        if (Private->FileContext->FHandle != NULL) {
          //
          // Parse the file's postfix.
          //
          NameLength = StrLen (Private->FileContext->FileName);
          if (NameLength <= 4) {
            return FALSE;
          }

          FilePostFix = Private->FileContext->FileName + NameLength - 4;

          if (IsDerEncodeCertificate (FilePostFix)) {
            //
            // Supports DER-encoded X509 certificate.
            //
            IfrNvData->FileEnrollType = X509_CERT_FILE_TYPE;
          } else if (IsAuthentication2Format (Private->FileContext->FHandle)) {
            IfrNvData->FileEnrollType = AUTHENTICATION_2_FILE_TYPE;
          } else {
            IfrNvData->FileEnrollType = PE_IMAGE_FILE_TYPE;
          }

          Private->FileContext->FileType = IfrNvData->FileEnrollType;

          //
          // Clean up Certificate Format if File type is not X509 DER
          //
          if (IfrNvData->FileEnrollType != X509_CERT_FILE_TYPE) {
            IfrNvData->CertificateFormat = HASHALG_RAW;
          }

          DEBUG ((DEBUG_ERROR, "IfrNvData->FileEnrollType %d\n", Private->FileContext->FileType));
        }

        break;

      case SECUREBOOT_ENROLL_SIGNATURE_TO_DBT:
        ChooseFile (NULL, NULL, UpdateDBTFromFile, &File);
        break;

      case KEY_SECURE_BOOT_DELETE_PK:
        if (Value->u8) {
          CreatePopUp (
            EFI_LIGHTGRAY | EFI_BACKGROUND_BLUE,
            &Key,
            L"Are you sure you want to delete PK? Secure boot will be disabled!",
            L"Press 'Y' to delete PK and exit, 'N' to discard change and return",
            NULL
            );
          if ((Key.UnicodeChar == 'y') || (Key.UnicodeChar == 'Y')) {
            Status = DeletePlatformKey ();
            if (EFI_ERROR (Status)) {
              CreatePopUp (
                EFI_LIGHTGRAY | EFI_BACKGROUND_BLUE,
                &Key,
                L"Only Physical Presence User could delete PK in custom mode!",
                NULL
                );
            } else {
              SecureBootExtractConfigFromVariable (Private, IfrNvData);
            }
          }
        }

        break;

      case KEY_DELETE_KEK:
        UpdateDeletePage (
          Private,
          EFI_KEY_EXCHANGE_KEY_NAME,
          &gEfiGlobalVariableGuid,
          LABEL_KEK_DELETE,
          FORMID_DELETE_KEK_FORM,
          OPTION_DEL_KEK_QUESTION_ID
          );
        break;

      case SECUREBOOT_DELETE_SIGNATURE_FROM_DB:
        UpdateDeletePage (
          Private,
          EFI_IMAGE_SECURITY_DATABASE,
          &gEfiImageSecurityDatabaseGuid,
          LABEL_DB_DELETE,
          SECUREBOOT_DELETE_SIGNATURE_FROM_DB,
          OPTION_DEL_DB_QUESTION_ID
          );
        break;

      //
      // From DBX option to the level-1 form, display signature list.
      //
      case KEY_VALUE_FROM_DBX_TO_LIST_FORM:
        Private->VariableName = Variable_DBX;
        LoadSignatureList (
          Private,
          LABEL_SIGNATURE_LIST_START,
          SECUREBOOT_DELETE_SIGNATURE_LIST_FORM,
          OPTION_SIGNATURE_LIST_QUESTION_ID
          );
        break;

      //
      // Delete all signature list and reload.
      //
      case KEY_SECURE_BOOT_DELETE_ALL_LIST:
        CreatePopUp (
          EFI_LIGHTGRAY | EFI_BACKGROUND_BLUE,
          &Key,
          L"Press 'Y' to delete signature list.",
          L"Press other key to cancel and exit.",
          NULL
          );

        if ((Key.UnicodeChar == L'Y') || (Key.UnicodeChar == L'y')) {
          DeleteSignatureEx (Private, Delete_Signature_List_All, IfrNvData->CheckedDataCount);
        }

        LoadSignatureList (
          Private,
          LABEL_SIGNATURE_LIST_START,
          SECUREBOOT_DELETE_SIGNATURE_LIST_FORM,
          OPTION_SIGNATURE_LIST_QUESTION_ID
          );
        IfrNvData->ListCount = Private->ListCount;
        break;

      //
      // Delete one signature list and reload.
      //
      case KEY_SECURE_BOOT_DELETE_ALL_DATA:
        CreatePopUp (
          EFI_LIGHTGRAY | EFI_BACKGROUND_BLUE,
          &Key,
          L"Press 'Y' to delete signature data.",
          L"Press other key to cancel and exit.",
          NULL
          );

        if ((Key.UnicodeChar == L'Y') || (Key.UnicodeChar == L'y')) {
          DeleteSignatureEx (Private, Delete_Signature_List_One, IfrNvData->CheckedDataCount);
        }

        LoadSignatureList (
          Private,
          LABEL_SIGNATURE_LIST_START,
          SECUREBOOT_DELETE_SIGNATURE_LIST_FORM,
          OPTION_SIGNATURE_LIST_QUESTION_ID
          );
        IfrNvData->ListCount = Private->ListCount;
        break;

      //
      // Delete checked signature data and reload.
      //
      case KEY_SECURE_BOOT_DELETE_CHECK_DATA:
        CreatePopUp (
          EFI_LIGHTGRAY | EFI_BACKGROUND_BLUE,
          &Key,
          L"Press 'Y' to delete signature data.",
          L"Press other key to cancel and exit.",
          NULL
          );

        if ((Key.UnicodeChar == L'Y') || (Key.UnicodeChar == L'y')) {
          DeleteSignatureEx (Private, Delete_Signature_Data, IfrNvData->CheckedDataCount);
        }

        LoadSignatureList (
          Private,
          LABEL_SIGNATURE_LIST_START,
          SECUREBOOT_DELETE_SIGNATURE_LIST_FORM,
          OPTION_SIGNATURE_LIST_QUESTION_ID
          );
        IfrNvData->ListCount = Private->ListCount;
        break;

      case SECUREBOOT_DELETE_SIGNATURE_FROM_DBT:
        UpdateDeletePage (
          Private,
          EFI_IMAGE_SECURITY_DATABASE2,
          &gEfiImageSecurityDatabaseGuid,
          LABEL_DBT_DELETE,
          SECUREBOOT_DELETE_SIGNATURE_FROM_DBT,
          OPTION_DEL_DBT_QUESTION_ID
          );

        break;

      case KEY_VALUE_SAVE_AND_EXIT_KEK:
        Status = EnrollKeyExchangeKey (Private);
        if (EFI_ERROR (Status)) {
          CreatePopUp (
            EFI_LIGHTGRAY | EFI_BACKGROUND_BLUE,
            &Key,
            L"ERROR: Unsupported file type!",
            L"Only supports DER-encoded X509 certificate",
            NULL
            );
        }

        break;

      case KEY_VALUE_SAVE_AND_EXIT_DB:
        Status = EnrollSignatureDatabase (Private, EFI_IMAGE_SECURITY_DATABASE);
        if (EFI_ERROR (Status)) {
          CreatePopUp (
            EFI_LIGHTGRAY | EFI_BACKGROUND_BLUE,
            &Key,
            L"ERROR: Unsupported file type!",
            L"Only supports DER-encoded X509 certificate and executable EFI image",
            NULL
            );
        }

        break;

      case KEY_VALUE_SAVE_AND_EXIT_DBX:
        if (IsX509CertInDbx (Private, EFI_IMAGE_SECURITY_DATABASE1)) {
          CreatePopUp (
            EFI_LIGHTGRAY | EFI_BACKGROUND_BLUE,
            &Key,
            L"Enrollment failed! Same certificate had already been in the dbx!",
            NULL
            );

          //
          // Cert already exists in DBX. Close opened file before exit.
          //
          CloseEnrolledFile (Private->FileContext);
          break;
        }

        if ((IfrNvData != NULL) && (IfrNvData->CertificateFormat < HASHALG_MAX)) {
          Status = EnrollX509HashtoSigDB (
                     Private,
                     IfrNvData->CertificateFormat,
                     &IfrNvData->RevocationDate,
                     &IfrNvData->RevocationTime,
                     IfrNvData->AlwaysRevocation
                     );
          IfrNvData->CertificateFormat = HASHALG_RAW;
        } else {
          Status = EnrollSignatureDatabase (Private, EFI_IMAGE_SECURITY_DATABASE1);
        }

        if (EFI_ERROR (Status)) {
          CreatePopUp (
            EFI_LIGHTGRAY | EFI_BACKGROUND_BLUE,
            &Key,
            L"ERROR: Unsupported file type!",
            L"Only supports DER-encoded X509 certificate, AUTH_2 format data & executable EFI image",
            NULL
            );
        } else {
          IfrNvData->ListCount = Private->ListCount;
        }

        break;

      case KEY_VALUE_SAVE_AND_EXIT_DBT:
        Status = EnrollSignatureDatabase (Private, EFI_IMAGE_SECURITY_DATABASE2);
        if (EFI_ERROR (Status)) {
          CreatePopUp (
            EFI_LIGHTGRAY | EFI_BACKGROUND_BLUE,
            &Key,
            L"ERROR: Unsupported file type!",
            L"Only supports DER-encoded X509 certificate.",
            NULL
            );
        }

        break;
      case KEY_VALUE_SAVE_AND_EXIT_PK:
        //
        // Check the suffix, encode type and the key strength of PK certificate.
        //
        Status = CheckX509Certificate (Private->FileContext, &EnrollKeyErrorCode);
        if (EFI_ERROR (Status)) {
          if ((EnrollKeyErrorCode != None_Error) && (EnrollKeyErrorCode < Enroll_Error_Max)) {
            CreatePopUp (
              EFI_LIGHTGRAY | EFI_BACKGROUND_BLUE,
              &Key,
              mX509EnrollPromptTitle[EnrollKeyErrorCode],
              mX509EnrollPromptString[EnrollKeyErrorCode],
              NULL
              );
            break;
          }
        } else {
          Status = EnrollPlatformKey (Private);
        }

        if (EFI_ERROR (Status)) {
          UnicodeSPrint (
            PromptString,
            sizeof (PromptString),
            L"Error status: %x.",
            Status
            );
          CreatePopUp (
            EFI_LIGHTGRAY | EFI_BACKGROUND_BLUE,
            &Key,
            L"ERROR: Enrollment failed!",
            PromptString,
            NULL
            );
        } else {
          SecureBootExtractConfigFromVariable (Private, IfrNvData);
        }

        break;
      default:
        if ((QuestionId >= OPTION_DEL_KEK_QUESTION_ID) &&
            (QuestionId < (OPTION_DEL_KEK_QUESTION_ID + OPTION_CONFIG_RANGE)))
        {
          DeleteKeyExchangeKey (Private, QuestionId);
        } else if ((QuestionId >= OPTION_DEL_DB_QUESTION_ID) &&
                   (QuestionId < (OPTION_DEL_DB_QUESTION_ID + OPTION_CONFIG_RANGE)))
        {
          DeleteSignature (
            Private,
            EFI_IMAGE_SECURITY_DATABASE,
            &gEfiImageSecurityDatabaseGuid,
            LABEL_DB_DELETE,
            SECUREBOOT_DELETE_SIGNATURE_FROM_DB,
            OPTION_DEL_DB_QUESTION_ID,
            QuestionId - OPTION_DEL_DB_QUESTION_ID
            );
        } else if ((QuestionId >= OPTION_SIGNATURE_LIST_QUESTION_ID) &&
                   (QuestionId < (OPTION_SIGNATURE_LIST_QUESTION_ID + OPTION_CONFIG_RANGE)))
        {
          LoadSignatureData (
            Private,
            LABEL_SIGNATURE_DATA_START,
            SECUREBOOT_DELETE_SIGNATURE_DATA_FORM,
            OPTION_SIGNATURE_DATA_QUESTION_ID,
            QuestionId - OPTION_SIGNATURE_LIST_QUESTION_ID
            );
          Private->ListIndex = QuestionId - OPTION_SIGNATURE_LIST_QUESTION_ID;
        } else if ((QuestionId >= OPTION_SIGNATURE_DATA_QUESTION_ID) &&
                   (QuestionId < (OPTION_SIGNATURE_DATA_QUESTION_ID + OPTION_CONFIG_RANGE)))
        {
          if (Private->CheckArray[QuestionId - OPTION_SIGNATURE_DATA_QUESTION_ID]) {
            IfrNvData->CheckedDataCount--;
            Private->CheckArray[QuestionId - OPTION_SIGNATURE_DATA_QUESTION_ID] = FALSE;
          } else {
            IfrNvData->CheckedDataCount++;
            Private->CheckArray[QuestionId - OPTION_SIGNATURE_DATA_QUESTION_ID] = TRUE;
          }
        } else if ((QuestionId >= OPTION_DEL_DBT_QUESTION_ID) &&
                   (QuestionId < (OPTION_DEL_DBT_QUESTION_ID + OPTION_CONFIG_RANGE)))
        {
          DeleteSignature (
            Private,
            EFI_IMAGE_SECURITY_DATABASE2,
            &gEfiImageSecurityDatabaseGuid,
            LABEL_DBT_DELETE,
            SECUREBOOT_DELETE_SIGNATURE_FROM_DBT,
            OPTION_DEL_DBT_QUESTION_ID,
            QuestionId - OPTION_DEL_DBT_QUESTION_ID
            );
        }

        break;

      case KEY_VALUE_NO_SAVE_AND_EXIT_PK:
      case KEY_VALUE_NO_SAVE_AND_EXIT_KEK:
      case KEY_VALUE_NO_SAVE_AND_EXIT_DB:
      case KEY_VALUE_NO_SAVE_AND_EXIT_DBX:
      case KEY_VALUE_NO_SAVE_AND_EXIT_DBT:
        CloseEnrolledFile (Private->FileContext);

        if (Private->SignatureGUID != NULL) {
          FreePool (Private->SignatureGUID);
          Private->SignatureGUID = NULL;
        }

        break;
    }
  } else if (Action == EFI_BROWSER_ACTION_CHANGED) {
    switch (QuestionId) {
      case KEY_SECURE_BOOT_ENABLE:
        *ActionRequest = EFI_BROWSER_ACTION_REQUEST_FORM_APPLY;
        break;
      case KEY_SECURE_BOOT_MODE:
        mIsEnterSecureBootForm = FALSE;
        break;
      case KEY_SECURE_BOOT_KEK_GUID:
      case KEY_SECURE_BOOT_SIGNATURE_GUID_DB:
      case KEY_SECURE_BOOT_SIGNATURE_GUID_DBX:
      case KEY_SECURE_BOOT_SIGNATURE_GUID_DBT:
        ASSERT (Private->SignatureGUID != NULL);
        RStatus = StrToGuid (IfrNvData->SignatureGuid, Private->SignatureGUID);
        if (RETURN_ERROR (RStatus) || (IfrNvData->SignatureGuid[GUID_STRING_LENGTH] != L'\0')) {
          Status = EFI_INVALID_PARAMETER;
          break;
        }

        *ActionRequest = EFI_BROWSER_ACTION_REQUEST_FORM_APPLY;
        break;
      case KEY_SECURE_BOOT_DELETE_PK:
        GetVariable2 (EFI_SETUP_MODE_NAME, &gEfiGlobalVariableGuid, (VOID **)&SetupMode, NULL);
        if ((SetupMode == NULL) || ((*SetupMode) == SETUP_MODE)) {
          IfrNvData->DeletePk = TRUE;
          IfrNvData->HasPk    = FALSE;
          *ActionRequest      = EFI_BROWSER_ACTION_REQUEST_SUBMIT;
        } else {
          IfrNvData->DeletePk = FALSE;
          IfrNvData->HasPk    = TRUE;
          *ActionRequest      = EFI_BROWSER_ACTION_REQUEST_FORM_APPLY;
        }

        if (SetupMode != NULL) {
          FreePool (SetupMode);
        }

        break;
      case KEY_SECURE_BOOT_RESET_TO_DEFAULT:
      {
        Status = gBS->LocateProtocol (&gEfiHiiPopupProtocolGuid, NULL, (VOID **)&HiiPopup);
        if (EFI_ERROR (Status)) {
          return Status;
        }

        Status = HiiPopup->CreatePopup (
                             HiiPopup,
                             EfiHiiPopupStyleInfo,
                             EfiHiiPopupTypeYesNo,
                             Private->HiiHandle,
                             STRING_TOKEN (STR_RESET_TO_DEFAULTS_POPUP),
                             &UserSelection
                             );
        if (UserSelection == EfiHiiPopupSelectionYes) {
          Status = KeyEnrollReset ();
        }

        //
        // Update secure boot strings after key reset
        //
        if (Status == EFI_SUCCESS) {
          Status = UpdateSecureBootString (Private);
          SecureBootExtractConfigFromVariable (Private, IfrNvData);
        }
      }
      default:
        break;
    }
  } else if (Action == EFI_BROWSER_ACTION_DEFAULT_STANDARD) {
    if (QuestionId == KEY_HIDE_SECURE_BOOT) {
      GetVariable2 (EFI_PLATFORM_KEY_NAME, &gEfiGlobalVariableGuid, (VOID **)&Pk, NULL);
      if (Pk == NULL) {
        IfrNvData->HideSecureBoot = TRUE;
      } else {
        FreePool (Pk);
        IfrNvData->HideSecureBoot = FALSE;
      }

      Value->b = IfrNvData->HideSecureBoot;
    }
  } else if (Action == EFI_BROWSER_ACTION_FORM_CLOSE) {
    //
    // Force the platform back to Standard Mode once user leave the setup screen.
    //
    GetVariable2 (EFI_CUSTOM_MODE_NAME, &gEfiCustomModeEnableGuid, (VOID **)&SecureBootMode, NULL);
    if ((NULL != SecureBootMode) && (*SecureBootMode == CUSTOM_SECURE_BOOT_MODE)) {
      IfrNvData->SecureBootMode = STANDARD_SECURE_BOOT_MODE;
      SetSecureBootMode (STANDARD_SECURE_BOOT_MODE);
    }

    if (SecureBootMode != NULL) {
      FreePool (SecureBootMode);
    }

    if (QuestionId == KEY_SECURE_BOOT_DELETE_ALL_DATA) {
      //
      // Free memory when exit from the SECUREBOOT_DELETE_SIGNATURE_DATA_FORM form.
      //
      SECUREBOOT_FREE_NON_NULL (Private->CheckArray);
      IfrNvData->CheckedDataCount = 0;
    }
  }

EXIT:

  if (!EFI_ERROR (Status) && GetBrowserDataResult) {
    BufferSize = sizeof (SECUREBOOT_CONFIGURATION);
    HiiSetBrowserData (&gSecureBootConfigFormSetGuid, mSecureBootStorageName, BufferSize, (UINT8 *)IfrNvData, NULL);
  }

  FreePool (IfrNvData);

  if (File != NULL) {
    FreePool (File);
    File = NULL;
  }

  return EFI_SUCCESS;
}

/**
  This function publish the SecureBoot configuration Form.

  @param[in, out]  PrivateData   Points to SecureBoot configuration private data.

  @retval EFI_SUCCESS            HII Form is installed successfully.
  @retval EFI_OUT_OF_RESOURCES   Not enough resource for HII Form installation.
  @retval Others                 Other errors as indicated.

**/
EFI_STATUS
InstallSecureBootConfigForm (
  IN OUT SECUREBOOT_CONFIG_PRIVATE_DATA  *PrivateData
  )
{
  EFI_STATUS                      Status;
  EFI_HII_HANDLE                  HiiHandle;
  EFI_HANDLE                      DriverHandle;
  EFI_HII_CONFIG_ACCESS_PROTOCOL  *ConfigAccess;

  DriverHandle = NULL;
  ConfigAccess = &PrivateData->ConfigAccess;
  Status       = gBS->InstallMultipleProtocolInterfaces (
                        &DriverHandle,
                        &gEfiDevicePathProtocolGuid,
                        &mSecureBootHiiVendorDevicePath,
                        &gEfiHiiConfigAccessProtocolGuid,
                        ConfigAccess,
                        NULL
                        );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  PrivateData->DriverHandle = DriverHandle;

  //
  // Publish the HII package list
  //
  HiiHandle = HiiAddPackages (
                &gSecureBootConfigFormSetGuid,
                DriverHandle,
                SecureBootConfigDxeStrings,
                SecureBootConfigBin,
                NULL
                );
  if (HiiHandle == NULL) {
    gBS->UninstallMultipleProtocolInterfaces (
           DriverHandle,
           &gEfiDevicePathProtocolGuid,
           &mSecureBootHiiVendorDevicePath,
           &gEfiHiiConfigAccessProtocolGuid,
           ConfigAccess,
           NULL
           );
    return EFI_OUT_OF_RESOURCES;
  }

  PrivateData->HiiHandle = HiiHandle;

  PrivateData->FileContext = AllocateZeroPool (sizeof (SECUREBOOT_FILE_CONTEXT));

  if (PrivateData->FileContext == NULL) {
    UninstallSecureBootConfigForm (PrivateData);
    return EFI_OUT_OF_RESOURCES;
  }

  //
  // Init OpCode Handle and Allocate space for creation of Buffer
  //
  mStartOpCodeHandle = HiiAllocateOpCodeHandle ();
  if (mStartOpCodeHandle == NULL) {
    UninstallSecureBootConfigForm (PrivateData);
    return EFI_OUT_OF_RESOURCES;
  }

  mEndOpCodeHandle = HiiAllocateOpCodeHandle ();
  if (mEndOpCodeHandle == NULL) {
    UninstallSecureBootConfigForm (PrivateData);
    return EFI_OUT_OF_RESOURCES;
  }

  //
  // Create Hii Extend Label OpCode as the start opcode
  //
  mStartLabel = (EFI_IFR_GUID_LABEL *)HiiCreateGuidOpCode (
                                        mStartOpCodeHandle,
                                        &gEfiIfrTianoGuid,
                                        NULL,
                                        sizeof (EFI_IFR_GUID_LABEL)
                                        );
  mStartLabel->ExtendOpCode = EFI_IFR_EXTEND_OP_LABEL;

  //
  // Create Hii Extend Label OpCode as the end opcode
  //
  mEndLabel = (EFI_IFR_GUID_LABEL *)HiiCreateGuidOpCode (
                                      mEndOpCodeHandle,
                                      &gEfiIfrTianoGuid,
                                      NULL,
                                      sizeof (EFI_IFR_GUID_LABEL)
                                      );
  mEndLabel->ExtendOpCode = EFI_IFR_EXTEND_OP_LABEL;
  mEndLabel->Number       = LABEL_END;

  return EFI_SUCCESS;
}

/**
  This function removes SecureBoot configuration Form.

  @param[in, out]  PrivateData   Points to SecureBoot configuration private data.

**/
VOID
UninstallSecureBootConfigForm (
  IN OUT SECUREBOOT_CONFIG_PRIVATE_DATA  *PrivateData
  )
{
  //
  // Uninstall HII package list
  //
  if (PrivateData->HiiHandle != NULL) {
    HiiRemovePackages (PrivateData->HiiHandle);
    PrivateData->HiiHandle = NULL;
  }

  //
  // Uninstall HII Config Access Protocol
  //
  if (PrivateData->DriverHandle != NULL) {
    gBS->UninstallMultipleProtocolInterfaces (
           PrivateData->DriverHandle,
           &gEfiDevicePathProtocolGuid,
           &mSecureBootHiiVendorDevicePath,
           &gEfiHiiConfigAccessProtocolGuid,
           &PrivateData->ConfigAccess,
           NULL
           );
    PrivateData->DriverHandle = NULL;
  }

  if (PrivateData->SignatureGUID != NULL) {
    FreePool (PrivateData->SignatureGUID);
  }

  if (PrivateData->FileContext != NULL) {
    FreePool (PrivateData->FileContext);
  }

  FreePool (PrivateData);

  if (mStartOpCodeHandle != NULL) {
    HiiFreeOpCodeHandle (mStartOpCodeHandle);
  }

  if (mEndOpCodeHandle != NULL) {
    HiiFreeOpCodeHandle (mEndOpCodeHandle);
  }
}