text: /*
   *  Portable interface to the CPU cycle counter
   *
   *  Copyright The Mbed TLS Contributors
   *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
   *
   *  This file is provided under the Apache License 2.0, or the
   *  GNU General Public License v2.0 or later.
   *
   *  **********
   *  Apache License 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.
   *
   *  **********
   *
   *  **********
   *  GNU General Public License v2.0 or later:
   *
   *  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(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)
  
  #if !defined(unix) && !defined(__unix__) && !defined(__unix) && \
      !defined(__APPLE__) && !defined(_WIN32) && !defined(__QNXNTO__) && \
      !defined(__HAIKU__)
  //#error "This module only works on Unix and Windows, see MBEDTLS_TIMING_C in config.h"
  #endif
  
  #ifndef asm
  #define asm __asm
  #endif
  
  #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
  
  #include <windows.h>
  #include <process.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 )
  {
      struct _hr_time *t = (struct _hr_time *) val;
  
      if( reset )
      {
          QueryPerformanceCounter( &t->start );
          return( 0 );
      }
      else
      {
          unsigned long delta;
          LARGE_INTEGER now, hfreq;
          QueryPerformanceCounter(  &now );
          QueryPerformanceFrequency( &hfreq );
          delta = (unsigned long)( ( now.QuadPart - t->start.QuadPart ) * 1000ul
                                   / hfreq.QuadPart );
          return( delta );
      }
  }
  
  /* It's OK to use a global because alarm() is supposed to be global anyway */
  static DWORD alarmMs;
  
  static void TimerProc( void *TimerContext )
  {
      (void) TimerContext;
      Sleep( alarmMs );
      mbedtls_timing_alarmed = 1;
      /* _endthread will be called implicitly on return
       * That ensures execution of thread funcition's epilogue */
  }
  
  void mbedtls_set_alarm( int seconds )
  {
      if( seconds == 0 )
      {
          /* No need to create a thread for this simple case.
           * Also, this shorcut is more reliable at least on MinGW32 */
          mbedtls_timing_alarmed = 1;
          return;
      }
  
      mbedtls_timing_alarmed = 0;
      alarmMs = seconds * 1000;
      (void) _beginthread( TimerProc, 0, NULL );
  }
  
  #else /* _WIN32 && !EFIX64 && !EFI32 */
  
  unsigned long mbedtls_timing_get_timer( struct mbedtls_timing_hr_time *val, int reset )
  {
      struct _hr_time *t = (struct _hr_time *) val;
  
      if( reset )
      {
          gettimeofday( &t->start, NULL );
          return( 0 );
      }
      else
      {
          unsigned long delta;
          struct timeval now;
          gettimeofday( &now, NULL );
          delta = ( now.tv_sec  - t->start.tv_sec  ) * 1000ul
                + ( now.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 );
      if( seconds == 0 )
      {
          /* alarm(0) cancelled any previous pending alarm, but the
             handler won't fire, so raise the flag straight away. */
          mbedtls_timing_alarmed = 1;
      }
  }
  
  #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 at line %d\n", __LINE__ );          \
              mbedtls_printf( " cycles=%lu ratio=%lu millisecs=%lu secs=%lu hardfail=%d a=%lu b=%lu\n", \
                              cycles, ratio, millisecs, secs, hardfail,   \
                              (unsigned long) a, (unsigned long) b );     \
              mbedtls_printf( " elapsed(hires)=%lu elapsed(ctx)=%lu status(ctx)=%d\n", \
                              mbedtls_timing_get_timer( &hires, 0 ),      \
                              mbedtls_timing_get_timer( &ctx.timer, 0 ),  \
                              mbedtls_timing_get_delay( &ctx ) );         \
          }                                                               \
          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 = 0, ratio = 0;
      unsigned long millisecs = 0, secs = 0;
      int hardfail = 0;
      struct mbedtls_timing_hr_time hires;
      uint32_t a = 0, b = 0;
      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): " );
  
      {
          secs = 1;
  
          (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 )
              FAIL;
      }
  
      if( verbose != 0 )
          mbedtls_printf( "passed\n" );
  
      if( verbose != 0 )
          mbedtls_printf( "  TIMING test #2 (set/get_delay        ): " );
  
      {
          a = 800;
          b = 400;
          mbedtls_timing_set_delay( &ctx, a, a + b );          /* T = 0 */
  
          busy_msleep( a - a / 4 );                      /* T = a - a/4 */
          if( mbedtls_timing_get_delay( &ctx ) != 0 )
              FAIL;
  
          busy_msleep( a / 4 + b / 4 );                  /* T = a + b/4 */
          if( mbedtls_timing_get_delay( &ctx ) != 1 )
              FAIL;
  
          busy_msleep( b );                          /* T = a + b + 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.
       */
  
  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 */
  