1/* BEGIN_HEADER */ 2/** \file test_suite_constant_time.function 3 * 4 * Functional testing of functions in the constant_time module. 5 * 6 * The tests are instrumented with #TEST_CF_SECRET and #TEST_CF_PUBLIC 7 * (see tests/include/test/constant_flow.h) so that running the tests 8 * under MSan or Valgrind will detect a non-constant-time implementation. 9 */ 10 11#include <mbedtls/constant_time.h> 12#include <constant_time_internal.h> 13#include <constant_time_invasive.h> 14 15#include <test/constant_flow.h> 16/* END_HEADER */ 17 18/* BEGIN_CASE */ 19void mbedtls_ct_memcmp_null() 20{ 21 uint32_t x = 0; 22 TEST_ASSERT(mbedtls_ct_memcmp(&x, NULL, 0) == 0); 23 TEST_ASSERT(mbedtls_ct_memcmp(NULL, &x, 0) == 0); 24 TEST_ASSERT(mbedtls_ct_memcmp(NULL, NULL, 0) == 0); 25} 26/* END_CASE */ 27 28/* BEGIN_CASE */ 29void mbedtls_ct_memcmp(int same, int size, int offset) 30{ 31 uint8_t *a = NULL, *b = NULL; 32 ASSERT_ALLOC(a, size + offset); 33 ASSERT_ALLOC(b, size + offset); 34 35 TEST_CF_SECRET(a + offset, size); 36 TEST_CF_SECRET(b + offset, size); 37 38 /* Construct data that matches, if same == -1, otherwise 39 * same gives the number of bytes (after the initial offset) 40 * that will match; after that it will differ. 41 */ 42 for (int i = 0; i < size + offset; i++) { 43 a[i] = i & 0xff; 44 if (same == -1 || (i - offset) < same) { 45 b[i] = a[i]; 46 } else { 47 b[i] = (i + 1) & 0xff; 48 } 49 } 50 51 int reference = memcmp(a + offset, b + offset, size); 52 int actual = mbedtls_ct_memcmp(a + offset, b + offset, size); 53 TEST_CF_PUBLIC(a + offset, size); 54 TEST_CF_PUBLIC(b + offset, size); 55 56 if (same == -1 || same >= size) { 57 TEST_ASSERT(reference == 0); 58 TEST_ASSERT(actual == 0); 59 } else { 60 TEST_ASSERT(reference != 0); 61 TEST_ASSERT(actual != 0); 62 } 63exit: 64 mbedtls_free(a); 65 mbedtls_free(b); 66} 67/* END_CASE */ 68 69/* BEGIN_CASE depends_on:MBEDTLS_SSL_SOME_SUITES_USE_MAC */ 70void mbedtls_ct_memcpy_if_eq(int eq, int size, int offset) 71{ 72 uint8_t *src = NULL, *result = NULL, *expected = NULL; 73 ASSERT_ALLOC(src, size + offset); 74 ASSERT_ALLOC(result, size + offset); 75 ASSERT_ALLOC(expected, size + offset); 76 77 for (int i = 0; i < size + offset; i++) { 78 src[i] = 1; 79 result[i] = 0xff; 80 expected[i] = eq ? 1 : 0xff; 81 } 82 83 int one, secret_eq; 84 TEST_CF_SECRET(&one, sizeof(one)); 85 TEST_CF_SECRET(&secret_eq, sizeof(secret_eq)); 86 one = 1; 87 secret_eq = eq; 88 89 mbedtls_ct_memcpy_if_eq(result + offset, src, size, secret_eq, one); 90 91 TEST_CF_PUBLIC(&one, sizeof(one)); 92 TEST_CF_PUBLIC(&secret_eq, sizeof(secret_eq)); 93 94 ASSERT_COMPARE(expected, size, result + offset, size); 95 96 for (int i = 0; i < size + offset; i++) { 97 src[i] = 1; 98 result[i] = 0xff; 99 expected[i] = eq ? 1 : 0xff; 100 } 101 102 TEST_CF_SECRET(&one, sizeof(one)); 103 TEST_CF_SECRET(&secret_eq, sizeof(secret_eq)); 104 one = 1; 105 secret_eq = eq; 106 107 mbedtls_ct_memcpy_if_eq(result, src + offset, size, secret_eq, one); 108 109 TEST_CF_PUBLIC(&one, sizeof(one)); 110 TEST_CF_PUBLIC(&secret_eq, sizeof(secret_eq)); 111 112 ASSERT_COMPARE(expected, size, result, size); 113exit: 114 mbedtls_free(src); 115 mbedtls_free(result); 116 mbedtls_free(expected); 117} 118/* END_CASE */ 119 120/* BEGIN_CASE depends_on:MBEDTLS_SSL_SOME_SUITES_USE_TLS_CBC:MBEDTLS_TEST_HOOKS */ 121void ssl_cf_memcpy_offset(int offset_min, int offset_max, int len) 122{ 123 unsigned char *dst = NULL; 124 unsigned char *src = NULL; 125 size_t src_len = offset_max + len; 126 size_t secret; 127 128 ASSERT_ALLOC(dst, len); 129 ASSERT_ALLOC(src, src_len); 130 131 /* Fill src in a way that we can detect if we copied the right bytes */ 132 mbedtls_test_rnd_std_rand(NULL, src, src_len); 133 134 for (secret = offset_min; secret <= (size_t) offset_max; secret++) { 135 mbedtls_test_set_step((int) secret); 136 137 TEST_CF_SECRET(&secret, sizeof(secret)); 138 mbedtls_ct_memcpy_offset(dst, src, secret, 139 offset_min, offset_max, len); 140 TEST_CF_PUBLIC(&secret, sizeof(secret)); 141 TEST_CF_PUBLIC(dst, len); 142 143 ASSERT_COMPARE(dst, len, src + secret, len); 144 } 145 146exit: 147 mbedtls_free(dst); 148 mbedtls_free(src); 149} 150/* END_CASE */ 151