/* * Portable interface to the CPU cycle counter * * Copyright The Mbed TLS Contributors * 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. */ #include "common.h" #include "mbedtls/platform.h" #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__) && !defined(__midipix__) #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 #include struct _hr_time { LARGE_INTEGER start; }; #else #include #include #include /* time.h should be included independently of MBEDTLS_HAVE_TIME. If the * platform matches the ifdefs above, it will be used. */ #include #include 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__ */ // -- GODOT start -- #if !defined(HAVE_HARDCLOCK) && defined(_WIN32) && \ !defined(EFIX64) && !defined(EFI32) // -- GODOT end -- #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 function'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 ); } #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_ALT */ #endif /* MBEDTLS_TIMING_C */