Add method to get random bytes from the TPM.

tpm_init.h

 // 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.
 
 // TpmInit - public interface class for initializing the TPM
 
 #include <base/scoped_ptr.h>
 #include <base/platform_thread.h>
 #include <chromeos/utility.h>
 
 #ifndef TPM_INIT_TPM_INIT_H_
 #define TPM_INIT_TPM_INIT_H_
 
 namespace tpm_init {
 
 class TpmInitTask;
 
 class TpmInit {
  public:
 
   // Default constructor
   TpmInit();
 
   virtual ~TpmInit();
 
+  // Gets random data from the TPM
+  //
+  // Parameters
+  //   length - The number of bytes to get
+  //   data (OUT) - Receives the random bytes
+  virtual bool GetRandomData(int length, chromeos::Blob* data);
+
   // Starts asynchronous initialization of the TPM
   virtual bool StartInitializeTpm();
 
   // Returns true if the TPM is initialized and ready for use
   virtual bool IsTpmReady();
 
   // Returns true if the TPM is enabled
   virtual bool IsTpmEnabled();
 
   // Gets the TPM password if the TPM initialization took ownership
   //
   // Parameters
   //   password (OUT) - The owner password used for the TPM
   virtual bool GetTpmPassword(chromeos::Blob* password);
 
   // Returns the number of milliseconds it took to initialize the TPM
   virtual long GetInitializationMillis();
 
  private:
   // The background task for initializing the TPM, implemented as a
   // PlatformThread::Delegate
   scoped_ptr<TpmInitTask> tpm_init_;
 
   DISALLOW_COPY_AND_ASSIGN(TpmInit);
 };
 
 }  // namespace tpm_init
 
 #endif  // TPM_INIT_TPM_INIT_H_