Ability to provide alternate timing implementation

ChangeLog

@@ -10,6 +10,7 @@ Features
    * Support for RSASSA-PSS keys and signatures in certificates, CSRs
      and CRLs
    * Single Platform compatilibity layer (for memory / printf / fprintf)
+   * Ability to provide alternate timing implementation
 
 Changes
    * Deprecated the Memory layer

include/polarssl/config.h

@@ -159,6 +159,19 @@
  * \{
  */
 
+/**
+ * \def POLARSSL_TIMING_ALT
+ *
+ * Uncomment to provide your own alternate implementation for hardclock(),
+ * get_timer(), set_alarm() and m_sleep().
+ *
+ * Only works if you have POLARSSL_TIMING_C enabled.
+ *
+ * You will need to provide a header "timing_alt.h" and an implementation at
+ * compile time.
+ */
+//#define POLARSSL_TIMING_ALT
+
 /**
  * \def POLARSSL_XXX_ALT
  *

include/polarssl/timing.h

@@ -3,7 +3,7 @@
  *
  * \brief Portable interface to the CPU cycle counter
  *
- *  Copyright (C) 2006-2013, Brainspark B.V.
+ *  Copyright (C) 2006-2014, Brainspark B.V.
  *
  *  This file is part of PolarSSL (http://www.polarssl.org)
  *  Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
@@ -27,6 +27,12 @@
 #ifndef POLARSSL_TIMING_H
 #define POLARSSL_TIMING_H
 
+#include "config.h"
+
+#if !defined(POLARSSL_TIMING_ALT)
+// Regular implementation
+//
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -72,4 +78,8 @@ void m_sleep( int milliseconds );
 }
 #endif
 
+#else  /* POLARSSL_TIMING_ALT */
+#include "timing_alt.h"
+#endif /* POLARSSL_TIMING_ALT */
+
 #endif /* timing.h */

library/timing.c

 /*
  *  Portable interface to the CPU cycle counter
  *
- *  Copyright (C) 2006-2010, Brainspark B.V.
+ *  Copyright (C) 2006-2014, Brainspark B.V.
  *
  *  This file is part of PolarSSL (http://www.polarssl.org)
  *  Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
@@ -25,7 +25,7 @@
 
 #include "polarssl/config.h"
 
-#if defined(POLARSSL_TIMING_C)
+#if defined(POLARSSL_TIMING_C) && !defined(POLARSSL_TIMING_ALT)
 
 #include "polarssl/timing.h"