Add mbed-based timing module (for the K64F)

include/mbedtls/config.h

@@ -1049,7 +1049,7 @@
  *
  * Comment this macro to disable support for DTLS
  */
-//#define MBEDTLS_SSL_PROTO_DTLS
+#define MBEDTLS_SSL_PROTO_DTLS
 
 /**
  * \def MBEDTLS_SSL_ALPN
@@ -1073,7 +1073,7 @@
  *
  * Comment this to disable anti-replay in DTLS.
  */
-//#define MBEDTLS_SSL_DTLS_ANTI_REPLAY
+#define MBEDTLS_SSL_DTLS_ANTI_REPLAY
 
 /**
  * \def MBEDTLS_SSL_DTLS_HELLO_VERIFY
@@ -1092,7 +1092,7 @@
  *
  * Comment this to disable support for HelloVerifyRequest.
  */
-//#define MBEDTLS_SSL_DTLS_HELLO_VERIFY
+#define MBEDTLS_SSL_DTLS_HELLO_VERIFY
 
 /**
  * \def MBEDTLS_SSL_DTLS_BADMAC_LIMIT
@@ -1103,7 +1103,7 @@
  *
  * Requires: MBEDTLS_SSL_PROTO_DTLS
  */
-//#define MBEDTLS_SSL_DTLS_BADMAC_LIMIT
+#define MBEDTLS_SSL_DTLS_BADMAC_LIMIT
 
 /**
  * \def MBEDTLS_SSL_SESSION_TICKETS
@@ -2087,7 +2087,7 @@
  *
  * Requires: MBEDTLS_SSL_DTLS_HELLO_VERIFY
  */
-//#define MBEDTLS_SSL_COOKIE_C
+#define MBEDTLS_SSL_COOKIE_C
 
 /**
  * \def MBEDTLS_SSL_CLI_C
@@ -2164,7 +2164,7 @@
  *
  * This module is used by the HAVEGE random number generator.
  */
-//#define MBEDTLS_TIMING_C
+#define MBEDTLS_TIMING_C
 
 /**
  * \def MBEDTLS_VERSION_C

library/CMakeLists.txt

@@ -60,7 +60,8 @@ set(src
      ssl_srv.c
      ssl_tls.c
      threading.c
-     timing.c
+     #timing.c
+     timing.cpp
      version.c
      version_features.c
      x509.c

library/timing.cpp

@@ -0,0 +1,276 @@
+/*
+ *  Timing functions for mbed TLS on top of mbed OS
+ *
+ *  Copyright (C) 2014, ARM Limited, All Rights Reserved
+ *
+ *  This file is part of mbed TLS (https://tls.mbed.org)
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#if !defined(POLARSSL_CONFIG_FILE)
+#include "mbedtls/config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
+#if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_PLATFORM_C)
+#include "mbedtls/platform.h"
+#else
+#include <stdio.h>
+#define mbedtls_printf     printf
+#endif
+
+#if defined(MBEDTLS_TIMING_C) && !defined(MBEDTLS_TIMING_ALT)
+
+#include "mbedtls/timing.h"
+
+#include "mbed.h"
+
+#if defined(TARGET_LIKE_CORTEX_M4)
+
+#include "core_cm4.h"
+
+unsigned long mbedtls_timing_hardclock( void )
+{
+    static int dwt_started = 0;
+
+    if( dwt_started == 0 )
+    {
+        CoreDebug->DEMCR |= CoreDebug_DEMCR_TRCENA_Msk;
+        DWT->CTRL |= DWT_CTRL_CYCCNTENA_Msk;
+    }
+
+    return( DWT->CYCCNT );
+}
+
+#else
+unsigned long mbedtls_timing_hardclock( void )
+{
+    /* dummy implementation that fails in a visible way */
+    return( 0 );
+}
+#endif
+
+unsigned long mbedtls_timing_get_timer( struct mbedtls_timing_hr_time *val, int reset )
+{
+    Timer *t = reinterpret_cast<Timer *>( val );
+
+    if( sizeof( struct mbedtls_timing_hr_time ) < sizeof( Timer ) )
+    {
+        mbedtls_printf( "You got bitten by your dirty hack.\r\n" );
+        while( 1 )
+            ;
+    }
+
+    if( reset )
+    {
+        t->reset();
+        t->start();
+        return( 0 );
+    }
+
+    return( t->read_ms() );
+}
+
+void mbedtls_timing_m_sleep( int milliseconds )
+{
+    wait_ms( milliseconds );
+}
+
+volatile int mbedtls_timing_alarmed = 0;
+
+static void alarm_handler( void )
+{
+    mbedtls_timing_alarmed = 1;
+}
+
+static Timeout alarm_setter;
+
+void mbedtls_set_alarm( int seconds )
+{
+    mbedtls_timing_alarmed = 0;
+    alarm_setter.attach( alarm_handler, seconds );
+}
+
+#if defined(MBEDTLS_SELF_TEST)
+
+/* To test mbedtls_net_usleep against our functions */
+#if defined(MBEDTLS_NET_C) && defined(MBEDTLS_HAVE_TIME)
+#include "mbedtls/net.h"
+#endif
+
+/*
+ * Busy-waits for the given number of milliseconds.
+ * Used for testing mbedtls_timing_hardclock.
+ */
+static void busy_msleep( unsigned long msec )
+{
+    struct mbedtls_timing_hr_time hires;
+    unsigned long i = 0; /* for busy-waiting */
+    volatile unsigned long j; /* to prevent optimisation */
+
+    (void) mbedtls_timing_get_timer( &hires, 1 );
+
+    while( mbedtls_timing_get_timer( &hires, 0 ) < msec )
+        i++;
+
+    j = i;
+    (void) j;
+}
+
+/*
+ * Checkup routine
+ *
+ * Warning: this is work in progress, some tests may not be reliable enough
+ * yet! False positives may happen.
+ */
+int mbedtls_timing_self_test( int verbose )
+{
+    unsigned long cycles, ratio;
+    unsigned long millisecs, secs;
+    int hardfail;
+    struct mbedtls_timing_hr_time hires;
+
+    if( verbose != 0 )
+        mbedtls_printf( "  TIMING tests note: will take some time!\r\n" );
+
+    if( verbose != 0 )
+        mbedtls_printf( "  TIMING test #1 (m_sleep   / get_timer): " );
+
+    for( secs = 1; secs <= 3; secs++ )
+    {
+        (void) mbedtls_timing_get_timer( &hires, 1 );
+
+        mbedtls_timing_m_sleep( (int)( 500 * secs ) );
+
+        millisecs = mbedtls_timing_get_timer( &hires, 0 );
+
+        if( millisecs < 450 * secs || millisecs > 550 * secs )
+        {
+            if( verbose != 0 )
+                mbedtls_printf( "failed\r\n" );
+
+            return( 1 );
+        }
+    }
+
+    if( verbose != 0 )
+        mbedtls_printf( "passed\r\n" );
+
+    if( verbose != 0 )
+        mbedtls_printf( "  TIMING test #2 (set_alarm / get_timer): " );
+
+    for( secs = 1; secs <= 3; secs++ )
+    {
+        (void) mbedtls_timing_get_timer( &hires, 1 );
+
+        mbedtls_set_alarm( (int) secs );
+        while( !mbedtls_timing_alarmed )
+            ;
+
+        millisecs = mbedtls_timing_get_timer( &hires, 0 );
+
+        if( millisecs < 900 * secs || millisecs > 1100 * secs )
+        {
+            if( verbose != 0 )
+                mbedtls_printf( "failed\r\n" );
+
+            return( 1 );
+        }
+    }
+
+    if( verbose != 0 )
+        mbedtls_printf( "passed\r\n" );
+
+    if( verbose != 0 )
+        mbedtls_printf( "  TIMING test #3 (hardclock / get_timer): " );
+
+    /*
+     * Allow one failure for possible counter wrapping.
+     * On a 4Ghz 32-bit machine the cycle counter wraps about once per second;
+     * since the whole test is about 10ms, it shouldn't happen twice in a row.
+     */
+    hardfail = 0;
+
+hard_test:
+    if( hardfail > 1 )
+    {
+        if( verbose != 0 )
+            mbedtls_printf( "failed\r\n" );
+
+        return( 1 );
+    }
+
+    /* Get a reference ratio cycles/ms */
+    millisecs = 1;
+    cycles = mbedtls_timing_hardclock();
+    busy_msleep( millisecs );
+    cycles = mbedtls_timing_hardclock() - cycles;
+    ratio = cycles / millisecs;
+
+    /* Check that the ratio is mostly constant */
+    for( millisecs = 2; millisecs <= 4; millisecs++ )
+    {
+        cycles = mbedtls_timing_hardclock();
+        busy_msleep( millisecs );
+        cycles = mbedtls_timing_hardclock() - cycles;
+
+        /* Allow variation up to 20% */
+        if( cycles / millisecs < ratio - ratio / 5 ||
+            cycles / millisecs > ratio + ratio / 5 )
+        {
+            hardfail++;
+            goto hard_test;
+        }
+    }
+
+    if( verbose != 0 )
+        mbedtls_printf( "passed (%lu MHz)\r\n", ratio / 1000 );
+
+#if defined(MBEDTLS_NET_C) && defined(MBEDTLS_HAVE_TIME)
+    if( verbose != 0 )
+        mbedtls_printf( "  TIMING test #4 (net_usleep/ get_timer): " );
+
+    for( secs = 1; secs <= 3; secs++ )
+    {
+        (void) mbedtls_timing_get_timer( &hires, 1 );
+
+        mbedtls_net_usleep( 500000 * secs );
+
+        millisecs = mbedtls_timing_get_timer( &hires, 0 );
+
+        if( millisecs < 450 * secs || millisecs > 550 * secs )
+        {
+            if( verbose != 0 )
+                mbedtls_printf( "failed\r\n" );
+
+            return( 1 );
+        }
+    }
+
+    if( verbose != 0 )
+        mbedtls_printf( "passed\r\n" );
+#endif /* MBEDTLS_NET_C */
+
+    if( verbose != 0 )
+        mbedtls_printf( "\r\n" );
+
+    return( 0 );
+}
+
+#endif /* MBEDTLS_SELF_TEST */
+
+#endif /* MBEDTLS_TIMING_C && !MBEDTLS_TIMING_ALT */