| /* BEGIN_HEADER */ |
| #include "mbedtls/entropy.h" |
| #include "mbedtls/ctr_drbg.h" |
| #include "string.h" |
| |
| /* Modes for ctr_drbg_validate */ |
| enum reseed_mode { |
| RESEED_NEVER, /* never reseed */ |
| RESEED_FIRST, /* instantiate, reseed, generate, generate */ |
| RESEED_SECOND, /* instantiate, generate, reseed, generate */ |
| RESEED_ALWAYS /* prediction resistance, no explicit reseed */ |
| }; |
| |
| static size_t test_offset_idx = 0; |
| static size_t test_max_idx = 0; |
| static int mbedtls_test_entropy_func(void *data, unsigned char *buf, size_t len) |
| { |
| const unsigned char *p = (unsigned char *) data; |
| if (test_offset_idx + len > test_max_idx) { |
| return MBEDTLS_ERR_ENTROPY_SOURCE_FAILED; |
| } |
| memcpy(buf, p + test_offset_idx, len); |
| test_offset_idx += len; |
| return 0; |
| } |
| |
| static void ctr_drbg_validate_internal(int reseed_mode, data_t *nonce, |
| int entropy_len_arg, data_t *entropy, |
| data_t *reseed, |
| data_t *add1, data_t *add2, |
| data_t *result) |
| { |
| mbedtls_ctr_drbg_context ctx; |
| unsigned char buf[64]; |
| |
| size_t entropy_chunk_len = (size_t) entropy_len_arg; |
| |
| TEST_ASSERT(entropy_chunk_len <= sizeof(buf)); |
| |
| test_offset_idx = 0; |
| mbedtls_ctr_drbg_init(&ctx); |
| |
| test_max_idx = entropy->len; |
| |
| /* CTR_DRBG_Instantiate(entropy[:entropy->len], nonce, perso, <ignored>) |
| * where nonce||perso = nonce[nonce->len] */ |
| mbedtls_ctr_drbg_set_entropy_len(&ctx, entropy_chunk_len); |
| mbedtls_ctr_drbg_set_nonce_len(&ctx, 0); |
| TEST_ASSERT(mbedtls_ctr_drbg_seed( |
| &ctx, |
| mbedtls_test_entropy_func, entropy->x, |
| nonce->x, nonce->len) == 0); |
| if (reseed_mode == RESEED_ALWAYS) { |
| mbedtls_ctr_drbg_set_prediction_resistance( |
| &ctx, |
| MBEDTLS_CTR_DRBG_PR_ON); |
| } |
| |
| if (reseed_mode == RESEED_FIRST) { |
| /* CTR_DRBG_Reseed(entropy[idx:idx+entropy->len], |
| * reseed[:reseed->len]) */ |
| TEST_ASSERT(mbedtls_ctr_drbg_reseed( |
| &ctx, |
| reseed->x, reseed->len) == 0); |
| } |
| |
| /* CTR_DRBG_Generate(result->len * 8 bits, add1[:add1->len]) -> buf */ |
| /* Then reseed if prediction resistance is enabled. */ |
| TEST_ASSERT(mbedtls_ctr_drbg_random_with_add( |
| &ctx, |
| buf, result->len, |
| add1->x, add1->len) == 0); |
| |
| |
| if (reseed_mode == RESEED_SECOND) { |
| /* CTR_DRBG_Reseed(entropy[idx:idx+entropy->len], |
| * reseed[:reseed->len]) */ |
| TEST_ASSERT(mbedtls_ctr_drbg_reseed( |
| &ctx, |
| reseed->x, reseed->len) == 0); |
| } |
| |
| /* CTR_DRBG_Generate(result->len * 8 bits, add2->x[:add2->len]) -> buf */ |
| /* Then reseed if prediction resistance is enabled. */ |
| TEST_ASSERT(mbedtls_ctr_drbg_random_with_add( |
| &ctx, |
| buf, result->len, |
| add2->x, add2->len) == 0); |
| TEST_ASSERT(memcmp(buf, result->x, result->len) == 0); |
| |
| exit: |
| mbedtls_ctr_drbg_free(&ctx); |
| } |
| |
| /* END_HEADER */ |
| |
| /* BEGIN_DEPENDENCIES |
| * depends_on:MBEDTLS_CTR_DRBG_C |
| * END_DEPENDENCIES |
| */ |
| |
| /* BEGIN_CASE */ |
| void ctr_drbg_special_behaviours() |
| { |
| mbedtls_ctr_drbg_context ctx; |
| unsigned char output[512]; |
| unsigned char additional[512]; |
| |
| mbedtls_ctr_drbg_init(&ctx); |
| memset(output, 0, sizeof(output)); |
| memset(additional, 0, sizeof(additional)); |
| |
| TEST_ASSERT(mbedtls_ctr_drbg_random_with_add(&ctx, |
| output, MBEDTLS_CTR_DRBG_MAX_REQUEST + 1, |
| additional, 16) == |
| MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG); |
| TEST_ASSERT(mbedtls_ctr_drbg_random_with_add(&ctx, |
| output, 16, |
| additional, MBEDTLS_CTR_DRBG_MAX_INPUT + 1) == |
| MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG); |
| |
| TEST_ASSERT(mbedtls_ctr_drbg_reseed(&ctx, additional, |
| MBEDTLS_CTR_DRBG_MAX_SEED_INPUT + 1) == |
| MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG); |
| |
| mbedtls_ctr_drbg_set_entropy_len(&ctx, ~0); |
| TEST_ASSERT(mbedtls_ctr_drbg_reseed(&ctx, additional, |
| MBEDTLS_CTR_DRBG_MAX_SEED_INPUT) == |
| MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG); |
| exit: |
| mbedtls_ctr_drbg_free(&ctx); |
| } |
| /* END_CASE */ |
| |
| |
| /* BEGIN_CASE */ |
| void ctr_drbg_validate_no_reseed(data_t *add_init, data_t *entropy, |
| data_t *add1, data_t *add2, |
| data_t *result_string) |
| { |
| data_t empty = { 0, 0 }; |
| ctr_drbg_validate_internal(RESEED_NEVER, add_init, |
| entropy->len, entropy, |
| &empty, add1, add2, |
| result_string); |
| goto exit; // goto is needed to avoid warning ( no test assertions in func) |
| } |
| /* END_CASE */ |
| |
| /* BEGIN_CASE */ |
| void ctr_drbg_validate_pr(data_t *add_init, data_t *entropy, |
| data_t *add1, data_t *add2, |
| data_t *result_string) |
| { |
| data_t empty = { 0, 0 }; |
| ctr_drbg_validate_internal(RESEED_ALWAYS, add_init, |
| entropy->len / 3, entropy, |
| &empty, add1, add2, |
| result_string); |
| goto exit; // goto is needed to avoid warning ( no test assertions in func) |
| } |
| /* END_CASE */ |
| |
| /* BEGIN_CASE */ |
| void ctr_drbg_validate_reseed_between(data_t *add_init, data_t *entropy, |
| data_t *add1, data_t *add_reseed, |
| data_t *add2, data_t *result_string) |
| { |
| ctr_drbg_validate_internal(RESEED_SECOND, add_init, |
| entropy->len / 2, entropy, |
| add_reseed, add1, add2, |
| result_string); |
| goto exit; // goto is needed to avoid warning ( no test assertions in func) |
| } |
| /* END_CASE */ |
| |
| /* BEGIN_CASE */ |
| void ctr_drbg_validate_reseed_first(data_t *add_init, data_t *entropy, |
| data_t *add1, data_t *add_reseed, |
| data_t *add2, data_t *result_string) |
| { |
| ctr_drbg_validate_internal(RESEED_FIRST, add_init, |
| entropy->len / 2, entropy, |
| add_reseed, add1, add2, |
| result_string); |
| goto exit; // goto is needed to avoid warning ( no test assertions in func) |
| } |
| /* END_CASE */ |
| |
| /* BEGIN_CASE */ |
| void ctr_drbg_entropy_strength(int expected_bit_strength) |
| { |
| unsigned char entropy[/*initial entropy*/ MBEDTLS_CTR_DRBG_ENTROPY_LEN + |
| /*nonce*/ MBEDTLS_CTR_DRBG_ENTROPY_NONCE_LEN + |
| /*reseed*/ MBEDTLS_CTR_DRBG_ENTROPY_LEN]; |
| mbedtls_ctr_drbg_context ctx; |
| size_t last_idx; |
| size_t byte_strength = expected_bit_strength / 8; |
| |
| mbedtls_ctr_drbg_init(&ctx); |
| test_offset_idx = 0; |
| test_max_idx = sizeof(entropy); |
| memset(entropy, 0, sizeof(entropy)); |
| |
| /* The initial seeding must grab at least byte_strength bytes of entropy |
| * for the entropy input and byte_strength/2 bytes for a nonce. */ |
| TEST_ASSERT(mbedtls_ctr_drbg_seed(&ctx, |
| mbedtls_test_entropy_func, entropy, |
| NULL, 0) == 0); |
| TEST_ASSERT(test_offset_idx >= (byte_strength * 3 + 1) / 2); |
| last_idx = test_offset_idx; |
| |
| /* A reseed must grab at least byte_strength bytes of entropy. */ |
| TEST_ASSERT(mbedtls_ctr_drbg_reseed(&ctx, NULL, 0) == 0); |
| TEST_ASSERT(test_offset_idx - last_idx >= byte_strength); |
| |
| exit: |
| mbedtls_ctr_drbg_free(&ctx); |
| } |
| /* END_CASE */ |
| |
| /* BEGIN_CASE */ |
| void ctr_drbg_entropy_usage(int entropy_nonce_len) |
| { |
| unsigned char out[16]; |
| unsigned char add[16]; |
| unsigned char entropy[1024]; |
| mbedtls_ctr_drbg_context ctx; |
| size_t i, reps = 10; |
| size_t expected_idx = 0; |
| |
| mbedtls_ctr_drbg_init(&ctx); |
| test_offset_idx = 0; |
| test_max_idx = sizeof(entropy); |
| memset(entropy, 0, sizeof(entropy)); |
| memset(out, 0, sizeof(out)); |
| memset(add, 0, sizeof(add)); |
| |
| if (entropy_nonce_len >= 0) { |
| TEST_ASSERT(mbedtls_ctr_drbg_set_nonce_len(&ctx, entropy_nonce_len) == 0); |
| } |
| |
| /* Set reseed interval before seed */ |
| mbedtls_ctr_drbg_set_reseed_interval(&ctx, 2 * reps); |
| |
| /* Init must use entropy */ |
| TEST_ASSERT(mbedtls_ctr_drbg_seed(&ctx, mbedtls_test_entropy_func, entropy, NULL, 0) == 0); |
| expected_idx += MBEDTLS_CTR_DRBG_ENTROPY_LEN; |
| if (entropy_nonce_len >= 0) { |
| expected_idx += entropy_nonce_len; |
| } else { |
| expected_idx += MBEDTLS_CTR_DRBG_ENTROPY_NONCE_LEN; |
| } |
| TEST_EQUAL(test_offset_idx, expected_idx); |
| |
| /* By default, PR is off, and reseed interval was set to |
| * 2 * reps so the next few calls should not use entropy */ |
| for (i = 0; i < reps; i++) { |
| TEST_ASSERT(mbedtls_ctr_drbg_random(&ctx, out, sizeof(out) - 4) == 0); |
| TEST_ASSERT(mbedtls_ctr_drbg_random_with_add(&ctx, out, sizeof(out) - 4, |
| add, sizeof(add)) == 0); |
| } |
| TEST_EQUAL(test_offset_idx, expected_idx); |
| |
| /* While at it, make sure we didn't write past the requested length */ |
| TEST_ASSERT(out[sizeof(out) - 4] == 0); |
| TEST_ASSERT(out[sizeof(out) - 3] == 0); |
| TEST_ASSERT(out[sizeof(out) - 2] == 0); |
| TEST_ASSERT(out[sizeof(out) - 1] == 0); |
| |
| /* There have been 2 * reps calls to random. The next call should reseed */ |
| TEST_ASSERT(mbedtls_ctr_drbg_random(&ctx, out, sizeof(out)) == 0); |
| expected_idx += MBEDTLS_CTR_DRBG_ENTROPY_LEN; |
| TEST_EQUAL(test_offset_idx, expected_idx); |
| |
| /* Set reseed interval after seed */ |
| mbedtls_ctr_drbg_set_reseed_interval(&ctx, 4 * reps + 1); |
| |
| /* The next few calls should not reseed */ |
| for (i = 0; i < (2 * reps); i++) { |
| TEST_ASSERT(mbedtls_ctr_drbg_random(&ctx, out, sizeof(out)) == 0); |
| TEST_ASSERT(mbedtls_ctr_drbg_random_with_add(&ctx, out, sizeof(out), |
| add, sizeof(add)) == 0); |
| } |
| TEST_EQUAL(test_offset_idx, expected_idx); |
| |
| /* Call update with too much data (sizeof(entropy) > MAX(_SEED)_INPUT). |
| * Make sure it's detected as an error and doesn't cause memory |
| * corruption. */ |
| TEST_ASSERT(mbedtls_ctr_drbg_update( |
| &ctx, entropy, sizeof(entropy)) != 0); |
| |
| /* Now enable PR, so the next few calls should all reseed */ |
| mbedtls_ctr_drbg_set_prediction_resistance(&ctx, MBEDTLS_CTR_DRBG_PR_ON); |
| TEST_ASSERT(mbedtls_ctr_drbg_random(&ctx, out, sizeof(out)) == 0); |
| expected_idx += MBEDTLS_CTR_DRBG_ENTROPY_LEN; |
| TEST_EQUAL(test_offset_idx, expected_idx); |
| |
| /* Finally, check setting entropy_len */ |
| mbedtls_ctr_drbg_set_entropy_len(&ctx, 42); |
| TEST_ASSERT(mbedtls_ctr_drbg_random(&ctx, out, sizeof(out)) == 0); |
| expected_idx += 42; |
| TEST_EQUAL(test_offset_idx, expected_idx); |
| |
| mbedtls_ctr_drbg_set_entropy_len(&ctx, 13); |
| TEST_ASSERT(mbedtls_ctr_drbg_random(&ctx, out, sizeof(out)) == 0); |
| expected_idx += 13; |
| TEST_EQUAL(test_offset_idx, expected_idx); |
| |
| exit: |
| mbedtls_ctr_drbg_free(&ctx); |
| } |
| /* END_CASE */ |
| |
| /* BEGIN_CASE depends_on:MBEDTLS_FS_IO */ |
| void ctr_drbg_seed_file(char *path, int ret) |
| { |
| mbedtls_ctr_drbg_context ctx; |
| |
| mbedtls_ctr_drbg_init(&ctx); |
| |
| TEST_ASSERT(mbedtls_ctr_drbg_seed(&ctx, mbedtls_test_rnd_std_rand, |
| NULL, NULL, 0) == 0); |
| TEST_ASSERT(mbedtls_ctr_drbg_write_seed_file(&ctx, path) == ret); |
| TEST_ASSERT(mbedtls_ctr_drbg_update_seed_file(&ctx, path) == ret); |
| |
| exit: |
| mbedtls_ctr_drbg_free(&ctx); |
| } |
| /* END_CASE */ |
| |
| /* BEGIN_CASE depends_on:MBEDTLS_SELF_TEST */ |
| void ctr_drbg_selftest() |
| { |
| TEST_ASSERT(mbedtls_ctr_drbg_self_test(1) == 0); |
| } |
| /* END_CASE */ |
