Add better handling of a TPM clear.

tpm.cc

 // Copyright (c) 2009-2010 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Contains the implementation of class Tpm
 
 #include "tpm.h"
 
 #include <base/file_util.h>
 #include <base/platform_thread.h>
@@ skipping 478 matching lines @@
   if (password_sync_lock_.Try()) {
     if (owner_password_.size() != 0) {
       owner_password->assign(owner_password_.begin(), owner_password_.end());
       result = true;
     }
     password_sync_lock_.Release();
   }
   return result;
 }
 
-bool Tpm::InitializeTpm() {
+bool Tpm::InitializeTpm(bool* OUT_took_ownership) {
+  if (OUT_took_ownership) {
+    *OUT_took_ownership = false;
+  }
+
   if (!IsConnected()) {
     Connect();
   }
 
   if (!IsConnected()) {
     LOG(ERROR) << "Failed to connect to TPM";
     return false;
   }
 
   if (is_disabled_) {
@@ skipping 28 matching lines @@
                        default_owner_password)) {
       LOG(ERROR) << "Take Ownership failed";
       is_being_owned_ = false;
       return false;
     }
 
     is_owned_ = true;
     took_ownership = true;
   }
 
+  if (OUT_took_ownership) {
+    *OUT_took_ownership = took_ownership;
+  }
+
   // Ensure the SRK is available
   TSS_RESULT result;
   TSS_HKEY srk_handle;
   TSS_UUID SRK_UUID = TSS_UUID_SRK;
   if ((result = Tspi_Context_LoadKeyByUUID(context_handle_, TSS_PS_TYPE_SYSTEM,
                                            SRK_UUID, &srk_handle))) {
     is_srk_available_ = false;
   } else {
     Tspi_Context_CloseObject(context_handle_, srk_handle);
     is_srk_available_ = true;
@@ skipping 27 matching lines @@
 
     password_sync_lock_.Acquire();
     owner_password_.assign(owner_password.begin(), owner_password.end());
     password_sync_lock_.Release();
 
     file_util::WriteFile(FilePath(kTpmOwnedFile), NULL, 0);
   }
 
   is_being_owned_ = false;
 
-  return took_ownership;
+  return true;
 }
 
 bool Tpm::GetRandomData(size_t length, chromeos::Blob* data) {
   TSS_HCONTEXT context_handle;
   if (!OpenAndConnectTpm(&context_handle)) {
     LOG(ERROR) << "Could not open the TPM";
     return false;
   }
 
   TSS_HTPM tpm_handle;
@@ skipping 13 matching lines @@
   }
   memcpy(random.data(), tpm_data, random.size());
   Tspi_Context_FreeMemory(context_handle, tpm_data);
   chromeos::SecureMemset(tpm_data, 0, random.size());
   Tspi_Context_Close(context_handle);
   data->swap(random);
   return true;
 }
 
 } // namespace tpm_init