[PATCH 3/3] MdeModulePkg: Variable: Update PCR[7] measure for new TCG spec

["Zhang, Chao B" <chao.b.zhang@intel.com>]

Measure DBX into PCR[7] when it is updated between initial measure and
ExitBootService. Measure "SecureBoot" change after PK update.
Spec version : TCG PC Client PFP 00.37. http://www.trustedcomputinggroup.org/wp-content/uploads/PC-ClientSpecific_Platform_Profile_for_TPM_2p0_Systems_v21.pdf

Cc: Star Zeng <star.zeng@intel.com>
Cc: Yao Jiewen <jiewen.yao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Chao Zhang <chao.b.zhang@intel.com>
---
 .../Universal/Variable/RuntimeDxe/Measurement.c    | 88 +++++++++++++++++++++-
 .../Universal/Variable/RuntimeDxe/VariableDxe.c    | 17 +++++
 .../Variable/RuntimeDxe/VariableSmmRuntimeDxe.c    | 17 +++++
 3 files changed, 121 insertions(+), 1 deletion(-)

diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/Measurement.c b/MdeModulePkg/Universal/Variable/RuntimeDxe/Measurement.c
index 2f92fae..707f988 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/Measurement.c
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/Measurement.c
@@ -1,7 +1,7 @@
 /** @file
   Measure TrEE required variable.
 
-Copyright (c) 2013 - 2014, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2013 - 2017, Intel Corporation. All rights reserved.<BR>
 This program and the accompanying materials
 are licensed and made available under the terms and conditions of the BSD License
 which accompanies this distribution.  The full text of the license may be found at
@@ -36,6 +36,24 @@ VARIABLE_TYPE  mVariableType[] = {
   {EFI_KEY_EXCHANGE_KEY_NAME,    &gEfiGlobalVariableGuid},
   {EFI_IMAGE_SECURITY_DATABASE,  &gEfiImageSecurityDatabaseGuid},
   {EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid},
+  {EFI_IMAGE_SECURITY_DATABASE2, &gEfiImageSecurityDatabaseGuid},
+};
+
+typedef struct {
+  CHAR16                                 *VariableName;
+  EFI_GUID                               *VendorGuid;
+  UINT8                                  *VarData;
+  UINTN                                  VarDataSize;
+} VARIABLE_FOLLOW_TYPE;
+
+//
+// "SecureBoot" may update following PK Del/Add
+//
+static VARIABLE_FOLLOW_TYPE  SecureBootFollowUpdate = {
+   EFI_SECURE_BOOT_MODE_NAME,
+   &gEfiGlobalVariableGuid,
+   NULL,
+   0,
 };
 
 /**
@@ -251,5 +269,73 @@ SecureBootHook (
     FreePool (VariableData);
   }
 
+  //
+  // "SecureBoot" is 8bit & read-only. It can only be changed according to PK update
+  //
+  if ((StrCmp (VariableName, EFI_PLATFORM_KEY_NAME) == 0) &&
+       CompareGuid (VendorGuid, &gEfiGlobalVariableGuid)) {
+     Status = InternalGetVariable (
+                SecureBootFollowUpdate.VariableName,
+                SecureBootFollowUpdate.VendorGuid,
+                &VariableData,
+                &VariableDataSize
+                );
+     if (EFI_ERROR (Status)) {
+       return;
+     }
+
+     if ((SecureBootFollowUpdate.VarData != NULL) &&
+         (CompareMem(SecureBootFollowUpdate.VarData, VariableData, VariableDataSize) != 0)) {
+       FreePool(SecureBootFollowUpdate.VarData);
+       SecureBootFollowUpdate.VarData = VariableData;
+       SecureBootFollowUpdate.VarDataSize = VariableDataSize;
+
+       DEBUG((DEBUG_INFO, "%s variable updated according to PK change. Remeasure the value!\n", SecureBootFollowUpdate.VariableName));
+       Status = MeasureVariable (
+                  SecureBootFollowUpdate.VariableName,
+                  SecureBootFollowUpdate.VendorGuid,
+                  SecureBootFollowUpdate.VarData,
+                  SecureBootFollowUpdate.VarDataSize
+                  );
+       DEBUG ((DEBUG_INFO, "MeasureBootPolicyVariable - %r\n", Status));
+     } else {
+       //
+       // "SecureBoot" variable is not changed
+       //
+       FreePool(VariableData);
+     }
+  }
+
   return ;
 }
+
+/**
+  Some Secure Boot Policy Variable may update following other variable changes(SecureBoot follows PK change, etc).
+  Record their initial State when variable write service is ready.
+
+**/
+VOID
+EFIAPI
+RecordSecureBootPolicyVarFollow(
+  VOID
+  )
+{
+  EFI_STATUS Status;
+
+  //
+  // Record initial "SecureBoot" variable value.
+  // It is used to detect SecureBoot variable change in SecureBootHook.
+  //
+  Status = InternalGetVariable (
+             SecureBootFollowUpdate.VariableName,
+             SecureBootFollowUpdate.VendorGuid,
+             (VOID **)&SecureBootFollowUpdate.VarData,
+             &SecureBootFollowUpdate.VarDataSize
+             );
+  if (EFI_ERROR(Status)) {
+    //
+    // Read could fail when Auth Variable solution is not supported
+    //
+    DEBUG((DEBUG_INFO, "RecordSecureBootPolicyVarFollow GetVariable %s Status %x\n", SecureBootFollowUpdate.VariableName, Status));
+  }
+}
diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableDxe.c b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableDxe.c
index 3d3cd24..5d81f87 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableDxe.c
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableDxe.c
@@ -32,6 +32,17 @@ EDKII_VAR_CHECK_PROTOCOL            mVarCheck                  = { VarCheckRegis
                                                                     VarCheckVariablePropertyGet };
 
 /**
+  Some Secure Boot Policy Variable may update following other variable changes(SecureBoot follows PK change, etc).
+  Record their initial State when variable write service is ready.
+
+**/
+VOID
+EFIAPI
+RecordSecureBootPolicyVarFollow(
+  VOID
+  );
+
+/**
   Return TRUE if ExitBootServices () has been called.
 
   @retval TRUE If ExitBootServices () has been called.
@@ -415,6 +426,12 @@ FtwNotificationEvent (
   }
 
   //
+  // Some Secure Boot Policy Var (SecureBoot, etc) updates following other
+  // Secure Boot Policy Variable change. Record their initial value.
+  //
+  RecordSecureBootPolicyVarFollow();
+
+  //
   // Install the Variable Write Architectural protocol.
   //
   Status = gBS->InstallProtocolInterface (
diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.c b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.c
index 0a076ae..3d0925d 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.c
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.c
@@ -71,6 +71,17 @@ SecureBootHook (
   );
 
 /**
+  Some Secure Boot Policy Variable may update following other variable changes(SecureBoot follows PK change, etc).
+  Record their initial State when variable write service is ready.
+
+**/
+VOID
+EFIAPI
+RecordSecureBootPolicyVarFollow(
+  VOID
+  );
+
+/**
   Acquires lock only at boot time. Simply returns at runtime.
 
   This is a temperary function that will be removed when
@@ -1079,6 +1090,12 @@ SmmVariableWriteReady (
     return;
   }
 
+  //
+  // Some Secure Boot Policy Var (SecureBoot, etc) updates following other
+  // Secure Boot Policy Variable change.  Record their initial value.
+  //
+  RecordSecureBootPolicyVarFollow();
+
   Status = gBS->InstallProtocolInterface (
                   &mHandle,
                   &gEfiVariableWriteArchProtocolGuid,
-- 
1.9.5.msysgit.1