752 lines
20 KiB
C
752 lines
20 KiB
C
/*
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* Entropy accumulator implementation
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*
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* Copyright The Mbed TLS Contributors
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* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
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*/
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#include "common.h"
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#if defined(MBEDTLS_ENTROPY_C)
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#if defined(MBEDTLS_TEST_NULL_ENTROPY)
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#warning "**** WARNING! MBEDTLS_TEST_NULL_ENTROPY defined! "
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#warning "**** THIS BUILD HAS NO DEFINED ENTROPY SOURCES "
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#warning "**** THIS BUILD IS *NOT* SUITABLE FOR PRODUCTION USE "
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#endif
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#include "mbedtls/entropy.h"
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#include "mbedtls/entropy_poll.h"
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#include "mbedtls/platform_util.h"
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#include "mbedtls/error.h"
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#include "mbedtls/sha256.h"
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#include "mbedtls/sha512.h"
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#include <string.h>
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#if defined(MBEDTLS_FS_IO)
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#include <stdio.h>
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#endif
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#include "mbedtls/platform.h"
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#include "mbedtls/platform.h"
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#if defined(MBEDTLS_HAVEGE_C)
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#include "mbedtls/havege.h"
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#endif
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#define ENTROPY_MAX_LOOP 256 /**< Maximum amount to loop before error */
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void mbedtls_entropy_init(mbedtls_entropy_context *ctx)
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{
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ctx->source_count = 0;
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memset(ctx->source, 0, sizeof(ctx->source));
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#if defined(MBEDTLS_THREADING_C)
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mbedtls_mutex_init(&ctx->mutex);
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#endif
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ctx->accumulator_started = 0;
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#if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR)
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mbedtls_sha512_init(&ctx->accumulator);
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#else
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mbedtls_sha256_init(&ctx->accumulator);
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#endif
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#if defined(MBEDTLS_HAVEGE_C)
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mbedtls_havege_init(&ctx->havege_data);
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#endif
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/* Reminder: Update ENTROPY_HAVE_STRONG in the test files
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* when adding more strong entropy sources here. */
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#if defined(MBEDTLS_TEST_NULL_ENTROPY)
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mbedtls_entropy_add_source(ctx, mbedtls_null_entropy_poll, NULL,
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1, MBEDTLS_ENTROPY_SOURCE_STRONG);
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#endif
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#if !defined(MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES)
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#if !defined(MBEDTLS_NO_PLATFORM_ENTROPY)
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mbedtls_entropy_add_source(ctx, mbedtls_platform_entropy_poll, NULL,
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MBEDTLS_ENTROPY_MIN_PLATFORM,
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MBEDTLS_ENTROPY_SOURCE_STRONG);
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#endif
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#if defined(MBEDTLS_TIMING_C)
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mbedtls_entropy_add_source(ctx, mbedtls_hardclock_poll, NULL,
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MBEDTLS_ENTROPY_MIN_HARDCLOCK,
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MBEDTLS_ENTROPY_SOURCE_WEAK);
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#endif
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#if defined(MBEDTLS_HAVEGE_C)
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mbedtls_entropy_add_source(ctx, mbedtls_havege_poll, &ctx->havege_data,
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MBEDTLS_ENTROPY_MIN_HAVEGE,
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MBEDTLS_ENTROPY_SOURCE_STRONG);
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#endif
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#if defined(MBEDTLS_ENTROPY_HARDWARE_ALT)
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mbedtls_entropy_add_source(ctx, mbedtls_hardware_poll, NULL,
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MBEDTLS_ENTROPY_MIN_HARDWARE,
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MBEDTLS_ENTROPY_SOURCE_STRONG);
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#endif
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#if defined(MBEDTLS_ENTROPY_NV_SEED)
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mbedtls_entropy_add_source(ctx, mbedtls_nv_seed_poll, NULL,
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MBEDTLS_ENTROPY_BLOCK_SIZE,
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MBEDTLS_ENTROPY_SOURCE_STRONG);
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ctx->initial_entropy_run = 0;
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#endif
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#endif /* MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES */
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}
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void mbedtls_entropy_free(mbedtls_entropy_context *ctx)
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{
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/* If the context was already free, don't call free() again.
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* This is important for mutexes which don't allow double-free. */
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if (ctx->accumulator_started == -1) {
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return;
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}
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#if defined(MBEDTLS_HAVEGE_C)
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mbedtls_havege_free(&ctx->havege_data);
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#endif
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#if defined(MBEDTLS_THREADING_C)
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mbedtls_mutex_free(&ctx->mutex);
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#endif
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#if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR)
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mbedtls_sha512_free(&ctx->accumulator);
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#else
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mbedtls_sha256_free(&ctx->accumulator);
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#endif
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#if defined(MBEDTLS_ENTROPY_NV_SEED)
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ctx->initial_entropy_run = 0;
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#endif
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ctx->source_count = 0;
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mbedtls_platform_zeroize(ctx->source, sizeof(ctx->source));
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ctx->accumulator_started = -1;
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}
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int mbedtls_entropy_add_source(mbedtls_entropy_context *ctx,
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mbedtls_entropy_f_source_ptr f_source, void *p_source,
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size_t threshold, int strong)
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{
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int idx, ret = 0;
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#if defined(MBEDTLS_THREADING_C)
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if ((ret = mbedtls_mutex_lock(&ctx->mutex)) != 0) {
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return ret;
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}
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#endif
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idx = ctx->source_count;
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if (idx >= MBEDTLS_ENTROPY_MAX_SOURCES) {
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ret = MBEDTLS_ERR_ENTROPY_MAX_SOURCES;
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goto exit;
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}
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ctx->source[idx].f_source = f_source;
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ctx->source[idx].p_source = p_source;
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ctx->source[idx].threshold = threshold;
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ctx->source[idx].strong = strong;
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ctx->source_count++;
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exit:
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#if defined(MBEDTLS_THREADING_C)
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if (mbedtls_mutex_unlock(&ctx->mutex) != 0) {
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return MBEDTLS_ERR_THREADING_MUTEX_ERROR;
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}
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#endif
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return ret;
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}
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/*
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* Entropy accumulator update
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*/
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static int entropy_update(mbedtls_entropy_context *ctx, unsigned char source_id,
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const unsigned char *data, size_t len)
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{
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unsigned char header[2];
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unsigned char tmp[MBEDTLS_ENTROPY_BLOCK_SIZE];
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size_t use_len = len;
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const unsigned char *p = data;
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int ret = 0;
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if (use_len > MBEDTLS_ENTROPY_BLOCK_SIZE) {
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#if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR)
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if ((ret = mbedtls_sha512_ret(data, len, tmp, 0)) != 0) {
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goto cleanup;
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}
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#else
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if ((ret = mbedtls_sha256_ret(data, len, tmp, 0)) != 0) {
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goto cleanup;
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}
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#endif
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p = tmp;
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use_len = MBEDTLS_ENTROPY_BLOCK_SIZE;
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}
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header[0] = source_id;
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header[1] = use_len & 0xFF;
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/*
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* Start the accumulator if this has not already happened. Note that
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* it is sufficient to start the accumulator here only because all calls to
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* gather entropy eventually execute this code.
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*/
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#if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR)
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if (ctx->accumulator_started == 0 &&
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(ret = mbedtls_sha512_starts_ret(&ctx->accumulator, 0)) != 0) {
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goto cleanup;
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} else {
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ctx->accumulator_started = 1;
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}
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if ((ret = mbedtls_sha512_update_ret(&ctx->accumulator, header, 2)) != 0) {
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goto cleanup;
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}
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ret = mbedtls_sha512_update_ret(&ctx->accumulator, p, use_len);
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#else
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if (ctx->accumulator_started == 0 &&
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(ret = mbedtls_sha256_starts_ret(&ctx->accumulator, 0)) != 0) {
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goto cleanup;
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} else {
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ctx->accumulator_started = 1;
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}
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if ((ret = mbedtls_sha256_update_ret(&ctx->accumulator, header, 2)) != 0) {
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goto cleanup;
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}
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ret = mbedtls_sha256_update_ret(&ctx->accumulator, p, use_len);
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#endif
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cleanup:
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mbedtls_platform_zeroize(tmp, sizeof(tmp));
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return ret;
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}
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int mbedtls_entropy_update_manual(mbedtls_entropy_context *ctx,
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const unsigned char *data, size_t len)
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{
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int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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#if defined(MBEDTLS_THREADING_C)
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if ((ret = mbedtls_mutex_lock(&ctx->mutex)) != 0) {
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return ret;
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}
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#endif
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ret = entropy_update(ctx, MBEDTLS_ENTROPY_SOURCE_MANUAL, data, len);
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#if defined(MBEDTLS_THREADING_C)
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if (mbedtls_mutex_unlock(&ctx->mutex) != 0) {
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return MBEDTLS_ERR_THREADING_MUTEX_ERROR;
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}
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#endif
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return ret;
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}
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/*
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* Run through the different sources to add entropy to our accumulator
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*/
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static int entropy_gather_internal(mbedtls_entropy_context *ctx)
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{
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int ret = MBEDTLS_ERR_ENTROPY_SOURCE_FAILED;
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int i;
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int have_one_strong = 0;
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unsigned char buf[MBEDTLS_ENTROPY_MAX_GATHER];
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size_t olen;
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if (ctx->source_count == 0) {
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return MBEDTLS_ERR_ENTROPY_NO_SOURCES_DEFINED;
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}
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/*
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* Run through our entropy sources
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*/
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for (i = 0; i < ctx->source_count; i++) {
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if (ctx->source[i].strong == MBEDTLS_ENTROPY_SOURCE_STRONG) {
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have_one_strong = 1;
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}
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olen = 0;
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if ((ret = ctx->source[i].f_source(ctx->source[i].p_source,
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buf, MBEDTLS_ENTROPY_MAX_GATHER, &olen)) != 0) {
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goto cleanup;
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}
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/*
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* Add if we actually gathered something
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*/
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if (olen > 0) {
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if ((ret = entropy_update(ctx, (unsigned char) i,
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buf, olen)) != 0) {
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return ret;
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}
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ctx->source[i].size += olen;
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}
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}
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if (have_one_strong == 0) {
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ret = MBEDTLS_ERR_ENTROPY_NO_STRONG_SOURCE;
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}
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cleanup:
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mbedtls_platform_zeroize(buf, sizeof(buf));
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return ret;
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}
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/*
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* Thread-safe wrapper for entropy_gather_internal()
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*/
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int mbedtls_entropy_gather(mbedtls_entropy_context *ctx)
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{
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int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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#if defined(MBEDTLS_THREADING_C)
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if ((ret = mbedtls_mutex_lock(&ctx->mutex)) != 0) {
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return ret;
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}
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#endif
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ret = entropy_gather_internal(ctx);
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#if defined(MBEDTLS_THREADING_C)
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if (mbedtls_mutex_unlock(&ctx->mutex) != 0) {
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return MBEDTLS_ERR_THREADING_MUTEX_ERROR;
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}
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#endif
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return ret;
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}
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int mbedtls_entropy_func(void *data, unsigned char *output, size_t len)
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{
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int ret, count = 0, i, thresholds_reached;
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size_t strong_size;
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mbedtls_entropy_context *ctx = (mbedtls_entropy_context *) data;
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unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
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if (len > MBEDTLS_ENTROPY_BLOCK_SIZE) {
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return MBEDTLS_ERR_ENTROPY_SOURCE_FAILED;
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}
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#if defined(MBEDTLS_ENTROPY_NV_SEED)
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/* Update the NV entropy seed before generating any entropy for outside
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* use.
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*/
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if (ctx->initial_entropy_run == 0) {
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ctx->initial_entropy_run = 1;
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if ((ret = mbedtls_entropy_update_nv_seed(ctx)) != 0) {
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return ret;
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}
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}
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#endif
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#if defined(MBEDTLS_THREADING_C)
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if ((ret = mbedtls_mutex_lock(&ctx->mutex)) != 0) {
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return ret;
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}
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#endif
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/*
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* Always gather extra entropy before a call
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*/
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do {
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if (count++ > ENTROPY_MAX_LOOP) {
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ret = MBEDTLS_ERR_ENTROPY_SOURCE_FAILED;
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goto exit;
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}
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if ((ret = entropy_gather_internal(ctx)) != 0) {
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goto exit;
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}
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thresholds_reached = 1;
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strong_size = 0;
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for (i = 0; i < ctx->source_count; i++) {
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if (ctx->source[i].size < ctx->source[i].threshold) {
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thresholds_reached = 0;
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}
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if (ctx->source[i].strong == MBEDTLS_ENTROPY_SOURCE_STRONG) {
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strong_size += ctx->source[i].size;
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}
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}
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} while (!thresholds_reached || strong_size < MBEDTLS_ENTROPY_BLOCK_SIZE);
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memset(buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE);
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#if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR)
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/*
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* Note that at this stage it is assumed that the accumulator was started
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* in a previous call to entropy_update(). If this is not guaranteed, the
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* code below will fail.
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*/
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if ((ret = mbedtls_sha512_finish_ret(&ctx->accumulator, buf)) != 0) {
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goto exit;
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}
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/*
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* Reset accumulator and counters and recycle existing entropy
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*/
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mbedtls_sha512_free(&ctx->accumulator);
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mbedtls_sha512_init(&ctx->accumulator);
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if ((ret = mbedtls_sha512_starts_ret(&ctx->accumulator, 0)) != 0) {
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goto exit;
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}
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if ((ret = mbedtls_sha512_update_ret(&ctx->accumulator, buf,
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MBEDTLS_ENTROPY_BLOCK_SIZE)) != 0) {
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goto exit;
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}
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/*
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* Perform second SHA-512 on entropy
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*/
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if ((ret = mbedtls_sha512_ret(buf, MBEDTLS_ENTROPY_BLOCK_SIZE,
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buf, 0)) != 0) {
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goto exit;
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}
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#else /* MBEDTLS_ENTROPY_SHA512_ACCUMULATOR */
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if ((ret = mbedtls_sha256_finish_ret(&ctx->accumulator, buf)) != 0) {
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goto exit;
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}
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/*
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* Reset accumulator and counters and recycle existing entropy
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*/
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mbedtls_sha256_free(&ctx->accumulator);
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mbedtls_sha256_init(&ctx->accumulator);
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if ((ret = mbedtls_sha256_starts_ret(&ctx->accumulator, 0)) != 0) {
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goto exit;
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}
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if ((ret = mbedtls_sha256_update_ret(&ctx->accumulator, buf,
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MBEDTLS_ENTROPY_BLOCK_SIZE)) != 0) {
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goto exit;
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}
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/*
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* Perform second SHA-256 on entropy
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*/
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if ((ret = mbedtls_sha256_ret(buf, MBEDTLS_ENTROPY_BLOCK_SIZE,
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buf, 0)) != 0) {
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goto exit;
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}
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#endif /* MBEDTLS_ENTROPY_SHA512_ACCUMULATOR */
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for (i = 0; i < ctx->source_count; i++) {
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ctx->source[i].size = 0;
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}
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memcpy(output, buf, len);
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ret = 0;
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exit:
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mbedtls_platform_zeroize(buf, sizeof(buf));
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#if defined(MBEDTLS_THREADING_C)
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if (mbedtls_mutex_unlock(&ctx->mutex) != 0) {
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return MBEDTLS_ERR_THREADING_MUTEX_ERROR;
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}
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#endif
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return ret;
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}
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#if defined(MBEDTLS_ENTROPY_NV_SEED)
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int mbedtls_entropy_update_nv_seed(mbedtls_entropy_context *ctx)
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{
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int ret = MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR;
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unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
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/* Read new seed and write it to NV */
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if ((ret = mbedtls_entropy_func(ctx, buf, MBEDTLS_ENTROPY_BLOCK_SIZE)) != 0) {
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return ret;
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}
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if (mbedtls_nv_seed_write(buf, MBEDTLS_ENTROPY_BLOCK_SIZE) < 0) {
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return MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR;
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}
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/* Manually update the remaining stream with a separator value to diverge */
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memset(buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE);
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ret = mbedtls_entropy_update_manual(ctx, buf, MBEDTLS_ENTROPY_BLOCK_SIZE);
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return ret;
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}
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#endif /* MBEDTLS_ENTROPY_NV_SEED */
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#if defined(MBEDTLS_FS_IO)
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int mbedtls_entropy_write_seed_file(mbedtls_entropy_context *ctx, const char *path)
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{
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int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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FILE *f = NULL;
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unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
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if ((ret = mbedtls_entropy_func(ctx, buf, MBEDTLS_ENTROPY_BLOCK_SIZE)) != 0) {
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ret = MBEDTLS_ERR_ENTROPY_SOURCE_FAILED;
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goto exit;
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}
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if ((f = fopen(path, "wb")) == NULL) {
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ret = MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR;
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goto exit;
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}
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if (fwrite(buf, 1, MBEDTLS_ENTROPY_BLOCK_SIZE, f) != MBEDTLS_ENTROPY_BLOCK_SIZE) {
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ret = MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR;
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goto exit;
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}
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ret = 0;
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exit:
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mbedtls_platform_zeroize(buf, sizeof(buf));
|
|
|
|
if (f != NULL) {
|
|
fclose(f);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
int mbedtls_entropy_update_seed_file(mbedtls_entropy_context *ctx, const char *path)
|
|
{
|
|
int ret = 0;
|
|
FILE *f;
|
|
size_t n;
|
|
unsigned char buf[MBEDTLS_ENTROPY_MAX_SEED_SIZE];
|
|
|
|
if ((f = fopen(path, "rb")) == NULL) {
|
|
return MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR;
|
|
}
|
|
|
|
fseek(f, 0, SEEK_END);
|
|
n = (size_t) ftell(f);
|
|
fseek(f, 0, SEEK_SET);
|
|
|
|
if (n > MBEDTLS_ENTROPY_MAX_SEED_SIZE) {
|
|
n = MBEDTLS_ENTROPY_MAX_SEED_SIZE;
|
|
}
|
|
|
|
if (fread(buf, 1, n, f) != n) {
|
|
ret = MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR;
|
|
} else {
|
|
ret = mbedtls_entropy_update_manual(ctx, buf, n);
|
|
}
|
|
|
|
fclose(f);
|
|
|
|
mbedtls_platform_zeroize(buf, sizeof(buf));
|
|
|
|
if (ret != 0) {
|
|
return ret;
|
|
}
|
|
|
|
return mbedtls_entropy_write_seed_file(ctx, path);
|
|
}
|
|
#endif /* MBEDTLS_FS_IO */
|
|
|
|
#if defined(MBEDTLS_SELF_TEST)
|
|
#if !defined(MBEDTLS_TEST_NULL_ENTROPY)
|
|
/*
|
|
* Dummy source function
|
|
*/
|
|
static int entropy_dummy_source(void *data, unsigned char *output,
|
|
size_t len, size_t *olen)
|
|
{
|
|
((void) data);
|
|
|
|
memset(output, 0x2a, len);
|
|
*olen = len;
|
|
|
|
return 0;
|
|
}
|
|
#endif /* !MBEDTLS_TEST_NULL_ENTROPY */
|
|
|
|
#if defined(MBEDTLS_ENTROPY_HARDWARE_ALT)
|
|
|
|
static int mbedtls_entropy_source_self_test_gather(unsigned char *buf, size_t buf_len)
|
|
{
|
|
int ret = 0;
|
|
size_t entropy_len = 0;
|
|
size_t olen = 0;
|
|
size_t attempts = buf_len;
|
|
|
|
while (attempts > 0 && entropy_len < buf_len) {
|
|
if ((ret = mbedtls_hardware_poll(NULL, buf + entropy_len,
|
|
buf_len - entropy_len, &olen)) != 0) {
|
|
return ret;
|
|
}
|
|
|
|
entropy_len += olen;
|
|
attempts--;
|
|
}
|
|
|
|
if (entropy_len < buf_len) {
|
|
ret = 1;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
|
|
static int mbedtls_entropy_source_self_test_check_bits(const unsigned char *buf,
|
|
size_t buf_len)
|
|
{
|
|
unsigned char set = 0xFF;
|
|
unsigned char unset = 0x00;
|
|
size_t i;
|
|
|
|
for (i = 0; i < buf_len; i++) {
|
|
set &= buf[i];
|
|
unset |= buf[i];
|
|
}
|
|
|
|
return set == 0xFF || unset == 0x00;
|
|
}
|
|
|
|
/*
|
|
* A test to ensure that the entropy sources are functioning correctly
|
|
* and there is no obvious failure. The test performs the following checks:
|
|
* - The entropy source is not providing only 0s (all bits unset) or 1s (all
|
|
* bits set).
|
|
* - The entropy source is not providing values in a pattern. Because the
|
|
* hardware could be providing data in an arbitrary length, this check polls
|
|
* the hardware entropy source twice and compares the result to ensure they
|
|
* are not equal.
|
|
* - The error code returned by the entropy source is not an error.
|
|
*/
|
|
int mbedtls_entropy_source_self_test(int verbose)
|
|
{
|
|
int ret = 0;
|
|
unsigned char buf0[2 * sizeof(unsigned long long int)];
|
|
unsigned char buf1[2 * sizeof(unsigned long long int)];
|
|
|
|
if (verbose != 0) {
|
|
mbedtls_printf(" ENTROPY_BIAS test: ");
|
|
}
|
|
|
|
memset(buf0, 0x00, sizeof(buf0));
|
|
memset(buf1, 0x00, sizeof(buf1));
|
|
|
|
if ((ret = mbedtls_entropy_source_self_test_gather(buf0, sizeof(buf0))) != 0) {
|
|
goto cleanup;
|
|
}
|
|
if ((ret = mbedtls_entropy_source_self_test_gather(buf1, sizeof(buf1))) != 0) {
|
|
goto cleanup;
|
|
}
|
|
|
|
/* Make sure that the returned values are not all 0 or 1 */
|
|
if ((ret = mbedtls_entropy_source_self_test_check_bits(buf0, sizeof(buf0))) != 0) {
|
|
goto cleanup;
|
|
}
|
|
if ((ret = mbedtls_entropy_source_self_test_check_bits(buf1, sizeof(buf1))) != 0) {
|
|
goto cleanup;
|
|
}
|
|
|
|
/* Make sure that the entropy source is not returning values in a
|
|
* pattern */
|
|
ret = memcmp(buf0, buf1, sizeof(buf0)) == 0;
|
|
|
|
cleanup:
|
|
if (verbose != 0) {
|
|
if (ret != 0) {
|
|
mbedtls_printf("failed\n");
|
|
} else {
|
|
mbedtls_printf("passed\n");
|
|
}
|
|
|
|
mbedtls_printf("\n");
|
|
}
|
|
|
|
return ret != 0;
|
|
}
|
|
|
|
#endif /* MBEDTLS_ENTROPY_HARDWARE_ALT */
|
|
|
|
/*
|
|
* The actual entropy quality is hard to test, but we can at least
|
|
* test that the functions don't cause errors and write the correct
|
|
* amount of data to buffers.
|
|
*/
|
|
int mbedtls_entropy_self_test(int verbose)
|
|
{
|
|
int ret = 1;
|
|
#if !defined(MBEDTLS_TEST_NULL_ENTROPY)
|
|
mbedtls_entropy_context ctx;
|
|
unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE] = { 0 };
|
|
unsigned char acc[MBEDTLS_ENTROPY_BLOCK_SIZE] = { 0 };
|
|
size_t i, j;
|
|
#endif /* !MBEDTLS_TEST_NULL_ENTROPY */
|
|
|
|
if (verbose != 0) {
|
|
mbedtls_printf(" ENTROPY test: ");
|
|
}
|
|
|
|
#if !defined(MBEDTLS_TEST_NULL_ENTROPY)
|
|
mbedtls_entropy_init(&ctx);
|
|
|
|
/* First do a gather to make sure we have default sources */
|
|
if ((ret = mbedtls_entropy_gather(&ctx)) != 0) {
|
|
goto cleanup;
|
|
}
|
|
|
|
ret = mbedtls_entropy_add_source(&ctx, entropy_dummy_source, NULL, 16,
|
|
MBEDTLS_ENTROPY_SOURCE_WEAK);
|
|
if (ret != 0) {
|
|
goto cleanup;
|
|
}
|
|
|
|
if ((ret = mbedtls_entropy_update_manual(&ctx, buf, sizeof(buf))) != 0) {
|
|
goto cleanup;
|
|
}
|
|
|
|
/*
|
|
* To test that mbedtls_entropy_func writes correct number of bytes:
|
|
* - use the whole buffer and rely on ASan to detect overruns
|
|
* - collect entropy 8 times and OR the result in an accumulator:
|
|
* any byte should then be 0 with probably 2^(-64), so requiring
|
|
* each of the 32 or 64 bytes to be non-zero has a false failure rate
|
|
* of at most 2^(-58) which is acceptable.
|
|
*/
|
|
for (i = 0; i < 8; i++) {
|
|
if ((ret = mbedtls_entropy_func(&ctx, buf, sizeof(buf))) != 0) {
|
|
goto cleanup;
|
|
}
|
|
|
|
for (j = 0; j < sizeof(buf); j++) {
|
|
acc[j] |= buf[j];
|
|
}
|
|
}
|
|
|
|
for (j = 0; j < sizeof(buf); j++) {
|
|
if (acc[j] == 0) {
|
|
ret = 1;
|
|
goto cleanup;
|
|
}
|
|
}
|
|
|
|
#if defined(MBEDTLS_ENTROPY_HARDWARE_ALT)
|
|
if ((ret = mbedtls_entropy_source_self_test(0)) != 0) {
|
|
goto cleanup;
|
|
}
|
|
#endif
|
|
|
|
cleanup:
|
|
mbedtls_entropy_free(&ctx);
|
|
#endif /* !MBEDTLS_TEST_NULL_ENTROPY */
|
|
|
|
if (verbose != 0) {
|
|
if (ret != 0) {
|
|
mbedtls_printf("failed\n");
|
|
} else {
|
|
mbedtls_printf("passed\n");
|
|
}
|
|
|
|
mbedtls_printf("\n");
|
|
}
|
|
|
|
return ret != 0;
|
|
}
|
|
#endif /* MBEDTLS_SELF_TEST */
|
|
|
|
#endif /* MBEDTLS_ENTROPY_C */
|