| /* |
| * Entropy accumulator implementation |
| * |
| * 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" |
| |
| #if defined(MBEDTLS_ENTROPY_C) |
| |
| #include "mbedtls/entropy.h" |
| #include "entropy_poll.h" |
| #include "mbedtls/platform_util.h" |
| #include "mbedtls/error.h" |
| |
| #include <string.h> |
| |
| #if defined(MBEDTLS_FS_IO) |
| #include <stdio.h> |
| #endif |
| |
| #include "mbedtls/platform.h" |
| |
| #include "mbedtls/platform.h" |
| |
| |
| #define ENTROPY_MAX_LOOP 256 /**< Maximum amount to loop before error */ |
| |
| void mbedtls_entropy_init(mbedtls_entropy_context *ctx) |
| { |
| ctx->source_count = 0; |
| memset(ctx->source, 0, sizeof(ctx->source)); |
| |
| #if defined(MBEDTLS_THREADING_C) |
| mbedtls_mutex_init(&ctx->mutex); |
| #endif |
| |
| ctx->accumulator_started = 0; |
| #if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR) |
| mbedtls_sha512_init(&ctx->accumulator); |
| #else |
| mbedtls_sha256_init(&ctx->accumulator); |
| #endif |
| |
| /* Reminder: Update ENTROPY_HAVE_STRONG in the test files |
| * when adding more strong entropy sources here. */ |
| |
| #if !defined(MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES) |
| #if !defined(MBEDTLS_NO_PLATFORM_ENTROPY) |
| mbedtls_entropy_add_source(ctx, mbedtls_platform_entropy_poll, NULL, |
| MBEDTLS_ENTROPY_MIN_PLATFORM, |
| MBEDTLS_ENTROPY_SOURCE_STRONG); |
| #endif |
| #if defined(MBEDTLS_ENTROPY_HARDWARE_ALT) |
| mbedtls_entropy_add_source(ctx, mbedtls_hardware_poll, NULL, |
| MBEDTLS_ENTROPY_MIN_HARDWARE, |
| MBEDTLS_ENTROPY_SOURCE_STRONG); |
| #endif |
| #if defined(MBEDTLS_ENTROPY_NV_SEED) |
| mbedtls_entropy_add_source(ctx, mbedtls_nv_seed_poll, NULL, |
| MBEDTLS_ENTROPY_BLOCK_SIZE, |
| MBEDTLS_ENTROPY_SOURCE_STRONG); |
| ctx->initial_entropy_run = 0; |
| #endif |
| #endif /* MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES */ |
| } |
| |
| void mbedtls_entropy_free(mbedtls_entropy_context *ctx) |
| { |
| /* If the context was already free, don't call free() again. |
| * This is important for mutexes which don't allow double-free. */ |
| if (ctx->accumulator_started == -1) { |
| return; |
| } |
| |
| #if defined(MBEDTLS_THREADING_C) |
| mbedtls_mutex_free(&ctx->mutex); |
| #endif |
| #if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR) |
| mbedtls_sha512_free(&ctx->accumulator); |
| #else |
| mbedtls_sha256_free(&ctx->accumulator); |
| #endif |
| #if defined(MBEDTLS_ENTROPY_NV_SEED) |
| ctx->initial_entropy_run = 0; |
| #endif |
| ctx->source_count = 0; |
| mbedtls_platform_zeroize(ctx->source, sizeof(ctx->source)); |
| ctx->accumulator_started = -1; |
| } |
| |
| int mbedtls_entropy_add_source(mbedtls_entropy_context *ctx, |
| mbedtls_entropy_f_source_ptr f_source, void *p_source, |
| size_t threshold, int strong) |
| { |
| int idx, ret = 0; |
| |
| #if defined(MBEDTLS_THREADING_C) |
| if ((ret = mbedtls_mutex_lock(&ctx->mutex)) != 0) { |
| return ret; |
| } |
| #endif |
| |
| idx = ctx->source_count; |
| if (idx >= MBEDTLS_ENTROPY_MAX_SOURCES) { |
| ret = MBEDTLS_ERR_ENTROPY_MAX_SOURCES; |
| goto exit; |
| } |
| |
| ctx->source[idx].f_source = f_source; |
| ctx->source[idx].p_source = p_source; |
| ctx->source[idx].threshold = threshold; |
| ctx->source[idx].strong = strong; |
| |
| ctx->source_count++; |
| |
| exit: |
| #if defined(MBEDTLS_THREADING_C) |
| if (mbedtls_mutex_unlock(&ctx->mutex) != 0) { |
| return MBEDTLS_ERR_THREADING_MUTEX_ERROR; |
| } |
| #endif |
| |
| return ret; |
| } |
| |
| /* |
| * Entropy accumulator update |
| */ |
| static int entropy_update(mbedtls_entropy_context *ctx, unsigned char source_id, |
| const unsigned char *data, size_t len) |
| { |
| unsigned char header[2]; |
| unsigned char tmp[MBEDTLS_ENTROPY_BLOCK_SIZE]; |
| size_t use_len = len; |
| const unsigned char *p = data; |
| int ret = 0; |
| |
| if (use_len > MBEDTLS_ENTROPY_BLOCK_SIZE) { |
| #if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR) |
| if ((ret = mbedtls_sha512(data, len, tmp, 0)) != 0) { |
| goto cleanup; |
| } |
| #else |
| if ((ret = mbedtls_sha256(data, len, tmp, 0)) != 0) { |
| goto cleanup; |
| } |
| #endif |
| p = tmp; |
| use_len = MBEDTLS_ENTROPY_BLOCK_SIZE; |
| } |
| |
| header[0] = source_id; |
| header[1] = use_len & 0xFF; |
| |
| /* |
| * Start the accumulator if this has not already happened. Note that |
| * it is sufficient to start the accumulator here only because all calls to |
| * gather entropy eventually execute this code. |
| */ |
| #if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR) |
| if (ctx->accumulator_started == 0 && |
| (ret = mbedtls_sha512_starts(&ctx->accumulator, 0)) != 0) { |
| goto cleanup; |
| } else { |
| ctx->accumulator_started = 1; |
| } |
| if ((ret = mbedtls_sha512_update(&ctx->accumulator, header, 2)) != 0) { |
| goto cleanup; |
| } |
| ret = mbedtls_sha512_update(&ctx->accumulator, p, use_len); |
| #else |
| if (ctx->accumulator_started == 0 && |
| (ret = mbedtls_sha256_starts(&ctx->accumulator, 0)) != 0) { |
| goto cleanup; |
| } else { |
| ctx->accumulator_started = 1; |
| } |
| if ((ret = mbedtls_sha256_update(&ctx->accumulator, header, 2)) != 0) { |
| goto cleanup; |
| } |
| ret = mbedtls_sha256_update(&ctx->accumulator, p, use_len); |
| #endif |
| |
| cleanup: |
| mbedtls_platform_zeroize(tmp, sizeof(tmp)); |
| |
| return ret; |
| } |
| |
| int mbedtls_entropy_update_manual(mbedtls_entropy_context *ctx, |
| const unsigned char *data, size_t len) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| |
| #if defined(MBEDTLS_THREADING_C) |
| if ((ret = mbedtls_mutex_lock(&ctx->mutex)) != 0) { |
| return ret; |
| } |
| #endif |
| |
| ret = entropy_update(ctx, MBEDTLS_ENTROPY_SOURCE_MANUAL, data, len); |
| |
| #if defined(MBEDTLS_THREADING_C) |
| if (mbedtls_mutex_unlock(&ctx->mutex) != 0) { |
| return MBEDTLS_ERR_THREADING_MUTEX_ERROR; |
| } |
| #endif |
| |
| return ret; |
| } |
| |
| /* |
| * Run through the different sources to add entropy to our accumulator |
| */ |
| static int entropy_gather_internal(mbedtls_entropy_context *ctx) |
| { |
| int ret = MBEDTLS_ERR_ENTROPY_SOURCE_FAILED; |
| int i; |
| int have_one_strong = 0; |
| unsigned char buf[MBEDTLS_ENTROPY_MAX_GATHER]; |
| size_t olen; |
| |
| if (ctx->source_count == 0) { |
| return MBEDTLS_ERR_ENTROPY_NO_SOURCES_DEFINED; |
| } |
| |
| /* |
| * Run through our entropy sources |
| */ |
| for (i = 0; i < ctx->source_count; i++) { |
| if (ctx->source[i].strong == MBEDTLS_ENTROPY_SOURCE_STRONG) { |
| have_one_strong = 1; |
| } |
| |
| olen = 0; |
| if ((ret = ctx->source[i].f_source(ctx->source[i].p_source, |
| buf, MBEDTLS_ENTROPY_MAX_GATHER, &olen)) != 0) { |
| goto cleanup; |
| } |
| |
| /* |
| * Add if we actually gathered something |
| */ |
| if (olen > 0) { |
| if ((ret = entropy_update(ctx, (unsigned char) i, |
| buf, olen)) != 0) { |
| return ret; |
| } |
| ctx->source[i].size += olen; |
| } |
| } |
| |
| if (have_one_strong == 0) { |
| ret = MBEDTLS_ERR_ENTROPY_NO_STRONG_SOURCE; |
| } |
| |
| cleanup: |
| mbedtls_platform_zeroize(buf, sizeof(buf)); |
| |
| return ret; |
| } |
| |
| /* |
| * Thread-safe wrapper for entropy_gather_internal() |
| */ |
| int mbedtls_entropy_gather(mbedtls_entropy_context *ctx) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| |
| #if defined(MBEDTLS_THREADING_C) |
| if ((ret = mbedtls_mutex_lock(&ctx->mutex)) != 0) { |
| return ret; |
| } |
| #endif |
| |
| ret = entropy_gather_internal(ctx); |
| |
| #if defined(MBEDTLS_THREADING_C) |
| if (mbedtls_mutex_unlock(&ctx->mutex) != 0) { |
| return MBEDTLS_ERR_THREADING_MUTEX_ERROR; |
| } |
| #endif |
| |
| return ret; |
| } |
| |
| int mbedtls_entropy_func(void *data, unsigned char *output, size_t len) |
| { |
| int ret, count = 0, i, thresholds_reached; |
| size_t strong_size; |
| mbedtls_entropy_context *ctx = (mbedtls_entropy_context *) data; |
| unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE]; |
| |
| if (len > MBEDTLS_ENTROPY_BLOCK_SIZE) { |
| return MBEDTLS_ERR_ENTROPY_SOURCE_FAILED; |
| } |
| |
| #if defined(MBEDTLS_ENTROPY_NV_SEED) |
| /* Update the NV entropy seed before generating any entropy for outside |
| * use. |
| */ |
| if (ctx->initial_entropy_run == 0) { |
| ctx->initial_entropy_run = 1; |
| if ((ret = mbedtls_entropy_update_nv_seed(ctx)) != 0) { |
| return ret; |
| } |
| } |
| #endif |
| |
| #if defined(MBEDTLS_THREADING_C) |
| if ((ret = mbedtls_mutex_lock(&ctx->mutex)) != 0) { |
| return ret; |
| } |
| #endif |
| |
| /* |
| * Always gather extra entropy before a call |
| */ |
| do { |
| if (count++ > ENTROPY_MAX_LOOP) { |
| ret = MBEDTLS_ERR_ENTROPY_SOURCE_FAILED; |
| goto exit; |
| } |
| |
| if ((ret = entropy_gather_internal(ctx)) != 0) { |
| goto exit; |
| } |
| |
| thresholds_reached = 1; |
| strong_size = 0; |
| for (i = 0; i < ctx->source_count; i++) { |
| if (ctx->source[i].size < ctx->source[i].threshold) { |
| thresholds_reached = 0; |
| } |
| if (ctx->source[i].strong == MBEDTLS_ENTROPY_SOURCE_STRONG) { |
| strong_size += ctx->source[i].size; |
| } |
| } |
| } while (!thresholds_reached || strong_size < MBEDTLS_ENTROPY_BLOCK_SIZE); |
| |
| memset(buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE); |
| |
| #if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR) |
| /* |
| * Note that at this stage it is assumed that the accumulator was started |
| * in a previous call to entropy_update(). If this is not guaranteed, the |
| * code below will fail. |
| */ |
| if ((ret = mbedtls_sha512_finish(&ctx->accumulator, buf)) != 0) { |
| goto exit; |
| } |
| |
| /* |
| * Reset accumulator and counters and recycle existing entropy |
| */ |
| mbedtls_sha512_free(&ctx->accumulator); |
| mbedtls_sha512_init(&ctx->accumulator); |
| if ((ret = mbedtls_sha512_starts(&ctx->accumulator, 0)) != 0) { |
| goto exit; |
| } |
| if ((ret = mbedtls_sha512_update(&ctx->accumulator, buf, |
| MBEDTLS_ENTROPY_BLOCK_SIZE)) != 0) { |
| goto exit; |
| } |
| |
| /* |
| * Perform second SHA-512 on entropy |
| */ |
| if ((ret = mbedtls_sha512(buf, MBEDTLS_ENTROPY_BLOCK_SIZE, |
| buf, 0)) != 0) { |
| goto exit; |
| } |
| #else /* MBEDTLS_ENTROPY_SHA512_ACCUMULATOR */ |
| if ((ret = mbedtls_sha256_finish(&ctx->accumulator, buf)) != 0) { |
| goto exit; |
| } |
| |
| /* |
| * Reset accumulator and counters and recycle existing entropy |
| */ |
| mbedtls_sha256_free(&ctx->accumulator); |
| mbedtls_sha256_init(&ctx->accumulator); |
| if ((ret = mbedtls_sha256_starts(&ctx->accumulator, 0)) != 0) { |
| goto exit; |
| } |
| if ((ret = mbedtls_sha256_update(&ctx->accumulator, buf, |
| MBEDTLS_ENTROPY_BLOCK_SIZE)) != 0) { |
| goto exit; |
| } |
| |
| /* |
| * Perform second SHA-256 on entropy |
| */ |
| if ((ret = mbedtls_sha256(buf, MBEDTLS_ENTROPY_BLOCK_SIZE, |
| buf, 0)) != 0) { |
| goto exit; |
| } |
| #endif /* MBEDTLS_ENTROPY_SHA512_ACCUMULATOR */ |
| |
| for (i = 0; i < ctx->source_count; i++) { |
| ctx->source[i].size = 0; |
| } |
| |
| memcpy(output, buf, len); |
| |
| ret = 0; |
| |
| exit: |
| mbedtls_platform_zeroize(buf, sizeof(buf)); |
| |
| #if defined(MBEDTLS_THREADING_C) |
| if (mbedtls_mutex_unlock(&ctx->mutex) != 0) { |
| return MBEDTLS_ERR_THREADING_MUTEX_ERROR; |
| } |
| #endif |
| |
| return ret; |
| } |
| |
| #if defined(MBEDTLS_ENTROPY_NV_SEED) |
| int mbedtls_entropy_update_nv_seed(mbedtls_entropy_context *ctx) |
| { |
| int ret = MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR; |
| unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE]; |
| |
| /* Read new seed and write it to NV */ |
| if ((ret = mbedtls_entropy_func(ctx, buf, MBEDTLS_ENTROPY_BLOCK_SIZE)) != 0) { |
| return ret; |
| } |
| |
| if (mbedtls_nv_seed_write(buf, MBEDTLS_ENTROPY_BLOCK_SIZE) < 0) { |
| return MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR; |
| } |
| |
| /* Manually update the remaining stream with a separator value to diverge */ |
| memset(buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE); |
| ret = mbedtls_entropy_update_manual(ctx, buf, MBEDTLS_ENTROPY_BLOCK_SIZE); |
| |
| return ret; |
| } |
| #endif /* MBEDTLS_ENTROPY_NV_SEED */ |
| |
| #if defined(MBEDTLS_FS_IO) |
| int mbedtls_entropy_write_seed_file(mbedtls_entropy_context *ctx, const char *path) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| FILE *f = NULL; |
| unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE]; |
| |
| if ((ret = mbedtls_entropy_func(ctx, buf, MBEDTLS_ENTROPY_BLOCK_SIZE)) != 0) { |
| ret = MBEDTLS_ERR_ENTROPY_SOURCE_FAILED; |
| goto exit; |
| } |
| |
| if ((f = fopen(path, "wb")) == NULL) { |
| ret = MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR; |
| goto exit; |
| } |
| |
| /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */ |
| mbedtls_setbuf(f, NULL); |
| |
| if (fwrite(buf, 1, MBEDTLS_ENTROPY_BLOCK_SIZE, f) != MBEDTLS_ENTROPY_BLOCK_SIZE) { |
| ret = MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR; |
| goto exit; |
| } |
| |
| ret = 0; |
| |
| exit: |
| 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; |
| } |
| |
| /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */ |
| mbedtls_setbuf(f, NULL); |
| |
| 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) |
| /* |
| * 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; |
| } |
| |
| #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; |
| mbedtls_entropy_context ctx; |
| unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE] = { 0 }; |
| unsigned char acc[MBEDTLS_ENTROPY_BLOCK_SIZE] = { 0 }; |
| size_t i, j; |
| |
| if (verbose != 0) { |
| mbedtls_printf(" ENTROPY test: "); |
| } |
| |
| 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); |
| |
| 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 */ |