From cd4f4b384857f4295d336d66fc8693348ef08a33 Mon Sep 17 00:00:00 2001
From: Laszlo Ersek <lersek@redhat.com>
Date: Fri, 31 Jan 2020 12:42:38 +0100
Subject: [PATCH 02/12] SecurityPkg/DxeImageVerificationHandler: simplify
 "VerifyStatus"
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RH-Author: Laszlo Ersek <lersek@redhat.com>
Message-id: <20200131124248.22369-3-lersek@redhat.com>
Patchwork-id: 93611
O-Subject: [RHEL-8.2.0 edk2 PATCH 02/12] SecurityPkg/DxeImageVerificationHandler: simplify "VerifyStatus"
Bugzilla: 1751993
RH-Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>
RH-Acked-by: Vitaly Kuznetsov <vkuznets@redhat.com>

In the DxeImageVerificationHandler() function, the "VerifyStatus" variable
can only contain one of two values: EFI_SUCCESS and EFI_ACCESS_DENIED.
Furthermore, the variable is only consumed with EFI_ERROR().

Therefore, using the EFI_STATUS type for the variable is unnecessary.
Worse, given the complex meanings of the function's return values, using
EFI_STATUS for "VerifyStatus" is actively confusing.

Rename the variable to "IsVerified", and make it a simple BOOLEAN.

This patch is a no-op, regarding behavior.

Cc: Chao Zhang <chao.b.zhang@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2129
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20200116190705.18816-2-lersek@redhat.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>
[lersek@redhat.com: push with Mike's R-b due to Chinese New Year
 Holiday: <https://edk2.groups.io/g/devel/message/53429>; msgid
 <d3fbb76dabed4e1987c512c328c82810@intel.com>]
(cherry picked from commit 1e0f973b65c34841288c25fd441a37eec8a30ac7)

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 .../DxeImageVerificationLib.c                        | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c b/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c
index a0a12b5..5afd723 100644
--- a/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c
+++ b/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c
@@ -1563,7 +1563,7 @@ DxeImageVerificationHandler (
 {
   EFI_STATUS                           Status;
   EFI_IMAGE_DOS_HEADER                 *DosHdr;
-  EFI_STATUS                           VerifyStatus;
+  BOOLEAN                              IsVerified;
   EFI_SIGNATURE_LIST                   *SignatureList;
   UINTN                                SignatureListSize;
   EFI_SIGNATURE_DATA                   *Signature;
@@ -1588,7 +1588,7 @@ DxeImageVerificationHandler (
   PkcsCertData      = NULL;
   Action            = EFI_IMAGE_EXECUTION_AUTH_UNTESTED;
   Status            = EFI_ACCESS_DENIED;
-  VerifyStatus      = EFI_ACCESS_DENIED;
+  IsVerified        = FALSE;
 
 
   //
@@ -1812,16 +1812,16 @@ DxeImageVerificationHandler (
     //
     if (IsForbiddenByDbx (AuthData, AuthDataSize)) {
       Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED;
-      VerifyStatus = EFI_ACCESS_DENIED;
+      IsVerified = FALSE;
       break;
     }
 
     //
     // Check the digital signature against the valid certificate in allowed database (db).
     //
-    if (EFI_ERROR (VerifyStatus)) {
+    if (!IsVerified) {
       if (IsAllowedByDb (AuthData, AuthDataSize)) {
-        VerifyStatus = EFI_SUCCESS;
+        IsVerified = TRUE;
       }
     }
 
@@ -1831,11 +1831,11 @@ DxeImageVerificationHandler (
     if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, mImageDigest, &mCertType, mImageDigestSize)) {
       Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FOUND;
       DEBUG ((DEBUG_INFO, "DxeImageVerificationLib: Image is signed but %s hash of image is found in DBX.\n", mHashTypeStr));
-      VerifyStatus = EFI_ACCESS_DENIED;
+      IsVerified = FALSE;
       break;
-    } else if (EFI_ERROR (VerifyStatus)) {
+    } else if (!IsVerified) {
       if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE, mImageDigest, &mCertType, mImageDigestSize)) {
-        VerifyStatus = EFI_SUCCESS;
+        IsVerified = TRUE;
       } else {
         DEBUG ((DEBUG_INFO, "DxeImageVerificationLib: Image is signed but signature is not allowed by DB and %s hash of image is not found in DB/DBX.\n", mHashTypeStr));
       }
@@ -1846,10 +1846,10 @@ DxeImageVerificationHandler (
     //
     // The Size in Certificate Table or the attribute certificate table is corrupted.
     //
-    VerifyStatus = EFI_ACCESS_DENIED;
+    IsVerified = FALSE;
   }
 
-  if (!EFI_ERROR (VerifyStatus)) {
+  if (IsVerified) {
     return EFI_SUCCESS;
   } else {
     Status = EFI_ACCESS_DENIED;
-- 
1.8.3.1