Diff: mbedtls/source/timing.c

Revision:

11:cada08fc8a70

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbedtls/source/timing.c	Thu Jun 09 17:08:36 2016 +0000
@@ -0,0 +1,520 @@
+/*
+ *  Portable interface to the CPU cycle counter
+ *
+ *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *  This file is part of mbed TLS (https://tls.mbed.org)
+ */
+
+#if !defined(MBEDTLS_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)
+
+#include "mbedtls/timing.h"
+
+#if !defined(MBEDTLS_TIMING_ALT)
+
+#ifndef asm
+#define asm __asm
+#endif
+
+#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
+
+#include <windows.h>
+#include <winbase.h>
+
+struct _hr_time
+{
+    LARGE_INTEGER start;
+};
+
+#else
+
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include <signal.h>
+#include <time.h>
+
+struct _hr_time
+{
+    struct timeval start;
+};
+
+#endif /* _WIN32 && !EFIX64 && !EFI32 */
+
+#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&  \
+    ( defined(_MSC_VER) && defined(_M_IX86) ) || defined(__WATCOMC__)
+
+#define HAVE_HARDCLOCK
+
+unsigned long mbedtls_timing_hardclock( void )
+{
+    unsigned long tsc;
+    __asm   rdtsc
+    __asm   mov  [tsc], eax
+    return( tsc );
+}
+#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&
+          ( _MSC_VER && _M_IX86 ) || __WATCOMC__ */
+
+/* some versions of mingw-64 have 32-bit longs even on x84_64 */
+#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&  \
+    defined(__GNUC__) && ( defined(__i386__) || (                       \
+    ( defined(__amd64__) || defined( __x86_64__) ) && __SIZEOF_LONG__ == 4 ) )
+
+#define HAVE_HARDCLOCK
+
+unsigned long mbedtls_timing_hardclock( void )
+{
+    unsigned long lo, hi;
+    asm volatile( "rdtsc" : "=a" (lo), "=d" (hi) );
+    return( lo );
+}
+#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&
+          __GNUC__ && __i386__ */
+
+#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&  \
+    defined(__GNUC__) && ( defined(__amd64__) || defined(__x86_64__) )
+
+#define HAVE_HARDCLOCK
+
+unsigned long mbedtls_timing_hardclock( void )
+{
+    unsigned long lo, hi;
+    asm volatile( "rdtsc" : "=a" (lo), "=d" (hi) );
+    return( lo | ( hi << 32 ) );
+}
+#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&
+          __GNUC__ && ( __amd64__ || __x86_64__ ) */
+
+#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&  \
+    defined(__GNUC__) && ( defined(__powerpc__) || defined(__ppc__) )
+
+#define HAVE_HARDCLOCK
+
+unsigned long mbedtls_timing_hardclock( void )
+{
+    unsigned long tbl, tbu0, tbu1;
+
+    do
+    {
+        asm volatile( "mftbu %0" : "=r" (tbu0) );
+        asm volatile( "mftb  %0" : "=r" (tbl ) );
+        asm volatile( "mftbu %0" : "=r" (tbu1) );
+    }
+    while( tbu0 != tbu1 );
+
+    return( tbl );
+}
+#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&
+          __GNUC__ && ( __powerpc__ || __ppc__ ) */
+
+#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&  \
+    defined(__GNUC__) && defined(__sparc64__)
+
+#if defined(__OpenBSD__)
+#warning OpenBSD does not allow access to tick register using software version instead
+#else
+#define HAVE_HARDCLOCK
+
+unsigned long mbedtls_timing_hardclock( void )
+{
+    unsigned long tick;
+    asm volatile( "rdpr %%tick, %0;" : "=&r" (tick) );
+    return( tick );
+}
+#endif /* __OpenBSD__ */
+#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&
+          __GNUC__ && __sparc64__ */
+
+#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&  \
+    defined(__GNUC__) && defined(__sparc__) && !defined(__sparc64__)
+
+#define HAVE_HARDCLOCK
+
+unsigned long mbedtls_timing_hardclock( void )
+{
+    unsigned long tick;
+    asm volatile( ".byte 0x83, 0x41, 0x00, 0x00" );
+    asm volatile( "mov   %%g1, %0" : "=r" (tick) );
+    return( tick );
+}
+#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&
+          __GNUC__ && __sparc__ && !__sparc64__ */
+
+#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&      \
+    defined(__GNUC__) && defined(__alpha__)
+
+#define HAVE_HARDCLOCK
+
+unsigned long mbedtls_timing_hardclock( void )
+{
+    unsigned long cc;
+    asm volatile( "rpcc %0" : "=r" (cc) );
+    return( cc & 0xFFFFFFFF );
+}
+#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&
+          __GNUC__ && __alpha__ */
+
+#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&      \
+    defined(__GNUC__) && defined(__ia64__)
+
+#define HAVE_HARDCLOCK
+
+unsigned long mbedtls_timing_hardclock( void )
+{
+    unsigned long itc;
+    asm volatile( "mov %0 = ar.itc" : "=r" (itc) );
+    return( itc );
+}
+#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&
+          __GNUC__ && __ia64__ */
+
+#if !defined(HAVE_HARDCLOCK) && defined(_MSC_VER) && \
+    !defined(EFIX64) && !defined(EFI32)
+
+#define HAVE_HARDCLOCK
+
+unsigned long mbedtls_timing_hardclock( void )
+{
+    LARGE_INTEGER offset;
+
+    QueryPerformanceCounter( &offset );
+
+    return( (unsigned long)( offset.QuadPart ) );
+}
+#endif /* !HAVE_HARDCLOCK && _MSC_VER && !EFIX64 && !EFI32 */
+
+#if !defined(HAVE_HARDCLOCK)
+
+#define HAVE_HARDCLOCK
+
+static int hardclock_init = 0;
+static struct timeval tv_init;
+
+unsigned long mbedtls_timing_hardclock( void )
+{
+    struct timeval tv_cur;
+
+    if( hardclock_init == 0 )
+    {
+        gettimeofday( &tv_init, NULL );
+        hardclock_init = 1;
+    }
+
+    gettimeofday( &tv_cur, NULL );
+    return( ( tv_cur.tv_sec  - tv_init.tv_sec  ) * 1000000
+          + ( tv_cur.tv_usec - tv_init.tv_usec ) );
+}
+#endif /* !HAVE_HARDCLOCK */
+
+volatile int mbedtls_timing_alarmed = 0;
+
+#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
+
+unsigned long mbedtls_timing_get_timer( struct mbedtls_timing_hr_time *val, int reset )
+{
+    unsigned long delta;
+    LARGE_INTEGER offset, hfreq;
+    struct _hr_time *t = (struct _hr_time *) val;
+
+    QueryPerformanceCounter(  &offset );
+    QueryPerformanceFrequency( &hfreq );
+
+    delta = (unsigned long)( ( 1000 *
+        ( offset.QuadPart - t->start.QuadPart ) ) /
+           hfreq.QuadPart );
+
+    if( reset )
+        QueryPerformanceCounter( &t->start );
+
+    return( delta );
+}
+
+/* It's OK to use a global because alarm() is supposed to be global anyway */
+static DWORD alarmMs;
+
+static DWORD WINAPI TimerProc( LPVOID TimerContext )
+{
+    ((void) TimerContext);
+    Sleep( alarmMs );
+    mbedtls_timing_alarmed = 1;
+    return( TRUE );
+}
+
+void mbedtls_set_alarm( int seconds )
+{
+    DWORD ThreadId;
+
+    mbedtls_timing_alarmed = 0;
+    alarmMs = seconds * 1000;
+    CloseHandle( CreateThread( NULL, 0, TimerProc, NULL, 0, &ThreadId ) );
+}
+
+#else /* _WIN32 && !EFIX64 && !EFI32 */
+
+unsigned long mbedtls_timing_get_timer( struct mbedtls_timing_hr_time *val, int reset )
+{
+    unsigned long delta;
+    struct timeval offset;
+    struct _hr_time *t = (struct _hr_time *) val;
+
+    gettimeofday( &offset, NULL );
+
+    if( reset )
+    {
+        t->start.tv_sec  = offset.tv_sec;
+        t->start.tv_usec = offset.tv_usec;
+        return( 0 );
+    }
+
+    delta = ( offset.tv_sec  - t->start.tv_sec  ) * 1000
+          + ( offset.tv_usec - t->start.tv_usec ) / 1000;
+
+    return( delta );
+}
+
+static void sighandler( int signum )
+{
+    mbedtls_timing_alarmed = 1;
+    signal( signum, sighandler );
+}
+
+void mbedtls_set_alarm( int seconds )
+{
+    mbedtls_timing_alarmed = 0;
+    signal( SIGALRM, sighandler );
+    alarm( seconds );
+}
+
+#endif /* _WIN32 && !EFIX64 && !EFI32 */
+
+/*
+ * Set delays to watch
+ */
+void mbedtls_timing_set_delay( void *data, uint32_t int_ms, uint32_t fin_ms )
+{
+    mbedtls_timing_delay_context *ctx = (mbedtls_timing_delay_context *) data;
+
+    ctx->int_ms = int_ms;
+    ctx->fin_ms = fin_ms;
+
+    if( fin_ms != 0 )
+        (void) mbedtls_timing_get_timer( &ctx->timer, 1 );
+}
+
+/*
+ * Get number of delays expired
+ */
+int mbedtls_timing_get_delay( void *data )
+{
+    mbedtls_timing_delay_context *ctx = (mbedtls_timing_delay_context *) data;
+    unsigned long elapsed_ms;
+
+    if( ctx->fin_ms == 0 )
+        return( -1 );
+
+    elapsed_ms = mbedtls_timing_get_timer( &ctx->timer, 0 );
+
+    if( elapsed_ms >= ctx->fin_ms )
+        return( 2 );
+
+    if( elapsed_ms >= ctx->int_ms )
+        return( 1 );
+
+    return( 0 );
+}
+
+#endif /* !MBEDTLS_TIMING_ALT */
+
+#if defined(MBEDTLS_SELF_TEST)
+
+/*
+ * 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;
+}
+
+#define FAIL    do                      \
+{                                       \
+    if( verbose != 0 )                  \
+        mbedtls_printf( "failed\n" );   \
+                                        \
+    return( 1 );                        \
+} while( 0 )
+
+/*
+ * 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;
+    uint32_t a, b;
+    mbedtls_timing_delay_context ctx;
+
+    if( verbose != 0 )
+        mbedtls_printf( "  TIMING tests note: will take some time!\n" );
+
+
+    if( verbose != 0 )
+        mbedtls_printf( "  TIMING test #1 (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 );
+
+        /* For some reason on Windows it looks like alarm has an extra delay
+         * (maybe related to creating a new thread). Allow some room here. */
+        if( millisecs < 800 * secs || millisecs > 1200 * secs + 300 )
+        {
+            if( verbose != 0 )
+                mbedtls_printf( "failed\n" );
+
+            return( 1 );
+        }
+    }
+
+    if( verbose != 0 )
+        mbedtls_printf( "passed\n" );
+
+    if( verbose != 0 )
+        mbedtls_printf( "  TIMING test #2 (set/get_delay        ): " );
+
+    for( a = 200; a <= 400; a += 200 )
+    {
+        for( b = 200; b <= 400; b += 200 )
+        {
+            mbedtls_timing_set_delay( &ctx, a, a + b );
+
+            busy_msleep( a - a / 8 );
+            if( mbedtls_timing_get_delay( &ctx ) != 0 )
+                FAIL;
+
+            busy_msleep( a / 4 );
+            if( mbedtls_timing_get_delay( &ctx ) != 1 )
+                FAIL;
+
+            busy_msleep( b - a / 8 - b / 8 );
+            if( mbedtls_timing_get_delay( &ctx ) != 1 )
+                FAIL;
+
+            busy_msleep( b / 4 );
+            if( mbedtls_timing_get_delay( &ctx ) != 2 )
+                FAIL;
+        }
+    }
+
+    mbedtls_timing_set_delay( &ctx, 0, 0 );
+    busy_msleep( 200 );
+    if( mbedtls_timing_get_delay( &ctx ) != -1 )
+        FAIL;
+
+    if( verbose != 0 )
+        mbedtls_printf( "passed\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 (ignored)\n" );
+
+        goto hard_test_done;
+    }
+
+    /* 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\n" );
+
+hard_test_done:
+
+    if( verbose != 0 )
+        mbedtls_printf( "\n" );
+
+    return( 0 );
+}
+
+#endif /* MBEDTLS_SELF_TEST */
+
+#endif /* MBEDTLS_TIMING_C */