/* * Portable interface to the CPU cycle counter * * Copyright The Mbed TLS Contributors * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */ #include #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 /* *INDENT-OFF* */ #ifndef asm #define asm __asm #endif /* *INDENT-ON* */ #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) * 1000000U + (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; if (reset) { QueryPerformanceCounter(&t.start); memcpy(val, &t, sizeof(struct _hr_time)); return 0; } else { unsigned long delta; LARGE_INTEGER now, hfreq; /* We can't safely cast val because it may not be aligned, so use memcpy */ memcpy(&t, val, sizeof(struct _hr_time)); 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; if (reset) { gettimeofday(&t.start, NULL); memcpy(val, &t, sizeof(struct _hr_time)); return 0; } else { unsigned long delta; struct timeval now; /* We can't safely cast val because it may not be aligned, so use memcpy */ memcpy(&t, val, sizeof(struct _hr_time)); 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 status(ctx)=%d\n", \ mbedtls_timing_get_timer(&hires, 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; memset(&ctx, 0, sizeof(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 */