1. Remove the code path which use X509 cert in KEK to validate PKCS7 signed image.

2. Remove the code path to validate UEFI image signed by RSA2048 key.
3. Disable the ALLOW_EXECUTE/DEFER_EXECUTE/QUERY_USER policy PCD.

Signed-off-by: Fu Siyuan <siyuan.fu@intel.com>
Reviewed-by: Ye Ting  <ting.ye@intel.com>
Reviewed-by: Dong Guo <guo.dong@intel.com>

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@13636 6f19259b-4bc3-4df7-8a09-765794883524

1 files changed, 56 insertions, 277 deletions

diff --git a/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c b/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c
index f83e530c5c..402540eb1b 100644
--- a/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c
+++ b/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c
@@ -783,60 +783,6 @@ AddImageExeInfo (
 }

 

 /**

-  Discover if the UEFI image is authorized by user's policy setting.

-

-  @param[in]    Policy            Specify platform's policy setting.

-

-  @retval EFI_ACCESS_DENIED       Image is not allowed to run.

-  @retval EFI_SECURITY_VIOLATION  Image is deferred.

-  @retval EFI_SUCCESS             Image is authorized to run.

-

-**/

-EFI_STATUS

-ImageAuthorization (

-  IN UINT32     Policy

-  )

-{

-  EFI_STATUS    Status;

-  EFI_INPUT_KEY Key;

-

-  Status = EFI_ACCESS_DENIED;

-

-  switch (Policy) {

-

-  case QUERY_USER_ON_SECURITY_VIOLATION:

-    do {

-      CreatePopUp (EFI_LIGHTGRAY | EFI_BACKGROUND_BLUE, &Key, mNotifyString1, mNotifyString2, NULL);

-      if (Key.UnicodeChar == L'Y' || Key.UnicodeChar == L'y') {

-        Status = EFI_SUCCESS;

-        break;

-      } else if (Key.UnicodeChar == L'N' || Key.UnicodeChar == L'n') {

-        Status = EFI_ACCESS_DENIED;

-        break;

-      } else if (Key.UnicodeChar == L'D' || Key.UnicodeChar == L'd') {

-        Status = EFI_SECURITY_VIOLATION;

-        break;

-      }

-    } while (TRUE);

-    break;

-

-  case ALLOW_EXECUTE_ON_SECURITY_VIOLATION:

-    Status = EFI_SUCCESS;

-    break;

-

-  case DEFER_EXECUTE_ON_SECURITY_VIOLATION:

-    Status = EFI_SECURITY_VIOLATION;

-    break;

-

-  case DENY_EXECUTE_ON_SECURITY_VIOLATION:

-    Status = EFI_ACCESS_DENIED;

-    break;

-  }

-

-  return Status;

-}

-

-/**

   Check whether signature is in specified database.

 

   @param[in]  VariableName        Name of database variable that is searched in.

@@ -1040,14 +986,7 @@ VerifyCertPkcsSignedData (
   }

 

   //

-  // 2: Find certificate from KEK database and try to verify authenticode struct.

-  //

-  if (IsPkcsSignedDataVerifiedBySignatureList (EFI_KEY_EXCHANGE_KEY_NAME, &gEfiGlobalVariableGuid)) {

-    return EFI_SUCCESS;

-  }

-

-  //

-  // 3: Find certificate from DB database and try to verify authenticode struct.

+  // 2: Find certificate from DB database and try to verify authenticode struct.

   //

   if (IsPkcsSignedDataVerifiedBySignatureList (EFI_IMAGE_SECURITY_DATABASE, &gEfiImageSecurityDatabaseGuid)) {

     return EFI_SUCCESS;

@@ -1057,139 +996,6 @@ VerifyCertPkcsSignedData (
 }

 

 /**

-  Verify certificate in WIN_CERTIFICATE_UEFI_GUID format.

-

-  @retval EFI_SUCCESS                 Image pass verification.

-  @retval EFI_SECURITY_VIOLATION      Image fail verification.

-  @retval other error value

-

-**/

-EFI_STATUS

-VerifyCertUefiGuid (

-  VOID

-  )

-{

-  BOOLEAN                         Status;

-  WIN_CERTIFICATE_UEFI_GUID       *EfiCert;

-  EFI_SIGNATURE_LIST              *KekList;

-  EFI_SIGNATURE_DATA              *KekItem;

-  EFI_CERT_BLOCK_RSA_2048_SHA256  *CertBlock;

-  VOID                            *Rsa;

-  UINTN                           KekCount;

-  UINTN                           Index;

-  UINTN                           KekDataSize;

-  BOOLEAN                         IsFound;

-  EFI_STATUS                      Result;

-

-  EfiCert   = NULL;

-  KekList   = NULL;

-  KekItem   = NULL;

-  CertBlock = NULL;

-  Rsa       = NULL;

-  Status    = FALSE;

-  IsFound   = FALSE;

-  KekDataSize = 0;

-

-  EfiCert   = (WIN_CERTIFICATE_UEFI_GUID *) (mImageBase + mSecDataDir->VirtualAddress);

-  CertBlock = (EFI_CERT_BLOCK_RSA_2048_SHA256 *) EfiCert->CertData;

-  if (!CompareGuid (&EfiCert->CertType, &gEfiCertTypeRsa2048Sha256Guid)) {

-    //

-    // Invalid Certificate Data Type.

-    //

-    return EFI_SECURITY_VIOLATION;

-  }

-

-  //

-  // Get KEK database variable data size

-  //

-  Result = gRT->GetVariable (EFI_KEY_EXCHANGE_KEY_NAME, &gEfiGlobalVariableGuid, NULL, &KekDataSize, NULL);

-  if (Result != EFI_BUFFER_TOO_SMALL) {

-    return EFI_SECURITY_VIOLATION;

-  }

-

-  //

-  // Get KEK database variable.

-  //

-  GetEfiGlobalVariable2 (EFI_KEY_EXCHANGE_KEY_NAME, (VOID**)&KekList, NULL);

-  if (KekList == NULL) {

-    return EFI_SECURITY_VIOLATION;

-  }

-

-  //

-  // Enumerate all Kek items in this list to verify the variable certificate data.

-  // If anyone is authenticated successfully, it means the variable is correct!

-  //

-  while ((KekDataSize > 0) && (KekDataSize >= KekList->SignatureListSize)) {

-    if (CompareGuid (&KekList->SignatureType, &gEfiCertRsa2048Guid)) {

-      KekItem   = (EFI_SIGNATURE_DATA *) ((UINT8 *) KekList + sizeof (EFI_SIGNATURE_LIST) + KekList->SignatureHeaderSize);

-      KekCount  = (KekList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - KekList->SignatureHeaderSize) / KekList->SignatureSize;

-      for (Index = 0; Index < KekCount; Index++) {

-        if (CompareMem (KekItem->SignatureData, CertBlock->PublicKey, EFI_CERT_TYPE_RSA2048_SIZE) == 0) {

-          IsFound = TRUE;

-          break;

-        }

-        KekItem = (EFI_SIGNATURE_DATA *) ((UINT8 *) KekItem + KekList->SignatureSize);

-      }

-    }

-    KekDataSize -= KekList->SignatureListSize;

-    KekList = (EFI_SIGNATURE_LIST *) ((UINT8 *) KekList + KekList->SignatureListSize);

-  }

-

-  if (!IsFound) {

-    //

-    // Signed key is not a trust one.

-    //

-    goto Done;

-  }

-

-  //

-  // Now, we found the corresponding security policy.

-  // Verify the data payload.

-  //

-  Rsa = RsaNew ();

-  if (Rsa == NULL) {

-    Status = FALSE;

-    goto Done;

-  }

-

-  //

-  // Set RSA Key Components.

-  // NOTE: Only N and E are needed to be set as RSA public key for signature verification.

-  //

-  Status = RsaSetKey (Rsa, RsaKeyN, CertBlock->PublicKey, EFI_CERT_TYPE_RSA2048_SIZE);

-  if (!Status) {

-    goto Done;

-  }

-  Status = RsaSetKey (Rsa, RsaKeyE, mRsaE, sizeof (mRsaE));

-  if (!Status) {

-    goto Done;

-  }

-  //

-  // Verify the signature.

-  //

-  Status = RsaPkcs1Verify (

-             Rsa,

-             mImageDigest,

-             mImageDigestSize,

-             CertBlock->Signature,

-             EFI_CERT_TYPE_RSA2048_SHA256_SIZE

-             );

-

-Done:

-  if (KekList != NULL) {

-    FreePool (KekList);

-  }

-  if (Rsa != NULL ) {

-    RsaFree (Rsa);

-  }

-  if (Status) {

-    return EFI_SUCCESS;

-  } else {

-    return EFI_SECURITY_VIOLATION;

-  }

-}

-

-/**

   Provide verification service for signed images, which include both signature validation

   and platform policy control. For signature types, both UEFI WIN_CERTIFICATE_UEFI_GUID and

   MSFT Authenticode type signatures are supported.

@@ -1198,22 +1004,24 @@ Done:
   Executables from FV is bypass, so pass in AuthenticationStatus is ignored.

 

   The image verification process is:

-    Is the Image signed?

-      If yes,

-        Does the image verify against a certificate (root or intermediate) in the allowed db?

-          Run it

-        Image verification fail

-          Is the Image's Hash not in forbidden database and the Image's Hash in allowed db?

-            Run it

-      If no,

-        Is the Image's Hash in the forbidden database (DBX)?

-          if yes,

-            Error out

-        Is the Image's Hash in the allowed database (DB)?

-          If yes,

-            Run it

-          If no,

-            Error out

+    If the image is signed,

+      If the image's certificate verifies against a certificate (root or intermediate) in the allowed 

+      database (DB) and not in the forbidden database (DBX), the certificate verification is passed.

+        If the image's hash digest is in DBX,

+          deny execution.

+        If not,

+          run it.

+      If the Image's certificate verification failed.

+        If the Image's Hash is in DB and not in DBX,

+          run it.

+        Otherwise,

+          deny execution.

+    Otherwise, the image is not signed,

+      Is the Image's Hash in DBX?

+        If yes, deny execution.

+        If not, is the Image's Hash in DB?

+          If yes, run it.

+          If not, deny execution.

 

   Caution: This function may receive untrusted input.

   PE/COFF image is external input, so this function will validate its data structure

@@ -1445,25 +1253,7 @@ DxeImageVerificationHandler (
     goto Done;

   }

 

-  switch (WinCertificate->wCertificateType) {

-

-  case WIN_CERT_TYPE_EFI_GUID:

-    CertSize = sizeof (WIN_CERTIFICATE_UEFI_GUID) + sizeof (EFI_CERT_BLOCK_RSA_2048_SHA256) - sizeof (UINT8);

-    if (WinCertificate->dwLength < CertSize) {

-      goto Done;

-    }

-

-    //

-    // Verify UEFI GUID type.

-    //

-    if (!HashPeImage (HASHALG_SHA256)) {

-      goto Done;

-    }

-

-    VerifyStatus = VerifyCertUefiGuid ();

-    break;

-

-  case WIN_CERT_TYPE_PKCS_SIGNED_DATA:

+  if (WinCertificate->wCertificateType == WIN_CERT_TYPE_PKCS_SIGNED_DATA) {

     //

     // Verify Pkcs signed data type.

     //

@@ -1471,42 +1261,31 @@ DxeImageVerificationHandler (
     if (EFI_ERROR (Status)) {

       goto Done;

     }

-

+    

     VerifyStatus = VerifyCertPkcsSignedData ();

+  } else {

+    goto Done;

+  }

 

+  if (!EFI_ERROR (VerifyStatus)) {

     //

-    // For image verification against enrolled certificate(root or intermediate),

-    // no need to check image's hash in the allowed database.

+    // Verification is passed.

+    // Continue to check the image digest in signature database.

     //

-    if (!EFI_ERROR (VerifyStatus)) {

-      if (!IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, mImageDigest, &mCertType, mImageDigestSize)) {

-        return EFI_SUCCESS;

-      }

+    if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, mImageDigest, &mCertType, mImageDigestSize)) {

+      //

+      // Executable signature verification passes, but is found in forbidden signature database.

+      //

+      Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FOUND;

+      Status = EFI_ACCESS_DENIED;

+    } else {

+      //

+      // For image verification against enrolled X.509 certificate(root or intermediate),

+      // no need to check image's hash in the allowed database.

+      //

+      return EFI_SUCCESS;

     }

-    break;

-

-  default:

-    goto Done;

-  }

-  //

-  // Get image hash value as executable's signature.

-  //

-  SignatureListSize = sizeof (EFI_SIGNATURE_LIST) + sizeof (EFI_SIGNATURE_DATA) - 1 + mImageDigestSize;

-  SignatureList     = (EFI_SIGNATURE_LIST *) AllocateZeroPool (SignatureListSize);

-  if (SignatureList == NULL) {

-    Status = EFI_OUT_OF_RESOURCES;

-    goto Done;

-  }

-  SignatureList->SignatureHeaderSize  = 0;

-  SignatureList->SignatureListSize    = (UINT32) SignatureListSize;

-  SignatureList->SignatureSize        = (UINT32) mImageDigestSize;

-  CopyMem (&SignatureList->SignatureType, &mCertType, sizeof (EFI_GUID));

-  Signature = (EFI_SIGNATURE_DATA *) ((UINT8 *) SignatureList + sizeof (EFI_SIGNATURE_LIST));

-  CopyMem (Signature->SignatureData, mImageDigest, mImageDigestSize);

-  //

-  // Signature database check after verification.

-  //

-  if (EFI_ERROR (VerifyStatus)) {

+  } else {

     //

     // Verification failure.

     //

@@ -1521,24 +1300,24 @@ DxeImageVerificationHandler (
       Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED;

       Status = EFI_ACCESS_DENIED;

     }

-  } else if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, Signature->SignatureData, &mCertType, mImageDigestSize)) {

-    //

-    // Executable signature verification passes, but is found in forbidden signature database.

-    //

-    Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FOUND;

-    Status = EFI_ACCESS_DENIED;

-  } else if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE, Signature->SignatureData, &mCertType, mImageDigestSize)) {

-    //

-    // Executable signature is found in authorized signature database.

-    //

-    Status = EFI_SUCCESS;

-  } else {

+  }

+

+  if (EFI_ERROR (Status)) {

     //

-    // Executable signature verification passes, but cannot be found in authorized signature database.

-    // Get platform policy to determine the action.

+    // Get image hash value as executable's signature.

     //

-    Action = EFI_IMAGE_EXECUTION_AUTH_SIG_PASSED;

-    Status = ImageAuthorization (Policy);

+    SignatureListSize = sizeof (EFI_SIGNATURE_LIST) + sizeof (EFI_SIGNATURE_DATA) - 1 + mImageDigestSize;

+    SignatureList     = (EFI_SIGNATURE_LIST *) AllocateZeroPool (SignatureListSize);

+    if (SignatureList == NULL) {

+      Status = EFI_OUT_OF_RESOURCES;

+      goto Done;

+    }

+    SignatureList->SignatureHeaderSize  = 0;

+    SignatureList->SignatureListSize    = (UINT32) SignatureListSize;

+    SignatureList->SignatureSize        = (UINT32) mImageDigestSize;

+    CopyMem (&SignatureList->SignatureType, &mCertType, sizeof (EFI_GUID));

+    Signature = (EFI_SIGNATURE_DATA *) ((UINT8 *) SignatureList + sizeof (EFI_SIGNATURE_LIST));

+    CopyMem (Signature->SignatureData, mImageDigest, mImageDigestSize);

   }

 

 Done: