crypto/constant_time_test.c

   1 /* crypto/constant_time_test.c */
   2 /*
   3  * Utilities for constant-time cryptography.
   4  *
   5  * Author: Emilia Kasper (emilia@openssl.org)
   6  * Based on previous work by Bodo Moeller, Emilia Kasper, Adam Langley
   7  * (Google).
   8  * ====================================================================
   9  * Copyright (c) 2014 The OpenSSL Project.  All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. All advertising materials mentioning features or use of this software
  20  *    must display the following acknowledgement:
  21  *    "This product includes cryptographic software written by
  22  *     Eric Young (eay@cryptsoft.com)"
  23  *    The word 'cryptographic' can be left out if the rouines from the library
  24  *    being used are not cryptographic related :-).
  25  * 4. If you include any Windows specific code (or a derivative thereof) from
  26  *    the apps directory (application code) you must include an acknowledgement:
  27  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  30  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  31  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  32  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  33  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  34  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  35  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  36  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  37  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  38  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  39  * SUCH DAMAGE.
  40  *
  41  * The licence and distribution terms for any publically available version or
  42  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  43  * copied and put under another distribution licence
  44  * [including the GNU Public Licence.]
  45  */
  46
  47 #include "../crypto/constant_time_locl.h"
  48
  49 #include <limits.h>
  50 #include <stdio.h>
  51 #include <stdlib.h>
  52
  53 static const unsigned int CONSTTIME_TRUE = (unsigned)(~0);
  54 static const unsigned int CONSTTIME_FALSE = 0;
  55 static const unsigned char CONSTTIME_TRUE_8 = 0xff;
  56 static const unsigned char CONSTTIME_FALSE_8 = 0;
  57
  58 static int test_binary_op(unsigned int (*op)(unsigned int a, unsigned int b),
  59         const char* op_name, unsigned int a, unsigned int b, int is_true)
  60         {
  61         unsigned c = op(a, b);
  62         if (is_true && c != CONSTTIME_TRUE)
  63                 {
  64                 fprintf(stderr, "Test failed for %s(%du, %du): expected %du "
  65                         "(TRUE), got %du\n", op_name, a, b, CONSTTIME_TRUE, c);
  66                 return 1;
  67                 }
  68         else if (!is_true && c != CONSTTIME_FALSE)
  69                 {
  70                 fprintf(stderr, "Test failed for  %s(%du, %du): expected %du "
  71                         "(FALSE), got %du\n", op_name, a, b, CONSTTIME_FALSE,
  72                         c);
  73                 return 1;
  74                 }
  75         return 0;
  76         }
  77
  78 static int test_binary_op_8(unsigned char (*op)(unsigned int a, unsigned int b),
  79         const char* op_name, unsigned int a, unsigned int b, int is_true)
  80         {
  81         unsigned char c = op(a, b);
  82         if (is_true && c != CONSTTIME_TRUE_8)
  83                 {
  84                 fprintf(stderr, "Test failed for %s(%du, %du): expected %u "
  85                         "(TRUE), got %u\n", op_name, a, b, CONSTTIME_TRUE_8, c);
  86                 return 1;
  87                 }
  88         else if (!is_true && c != CONSTTIME_FALSE_8)
  89                 {
  90                 fprintf(stderr, "Test failed for  %s(%du, %du): expected %u "
  91                         "(FALSE), got %u\n", op_name, a, b, CONSTTIME_FALSE_8,
  92                         c);
  93                 return 1;
  94                 }
  95         return 0;
  96         }
  97
  98 static int test_is_zero(unsigned int a)
  99         {
 100         unsigned int c = constant_time_is_zero(a);
 101         if (a == 0 && c != CONSTTIME_TRUE)
 102                 {
 103                 fprintf(stderr, "Test failed for constant_time_is_zero(%du): "
 104                         "expected %du (TRUE), got %du\n", a, CONSTTIME_TRUE, c);
 105                 return 1;
 106                 }
 107         else if (a != 0 && c != CONSTTIME_FALSE)
 108                 {
 109                 fprintf(stderr, "Test failed for constant_time_is_zero(%du): "
 110                         "expected %du (FALSE), got %du\n", a, CONSTTIME_FALSE,
 111                         c);
 112                 return 1;
 113                 }
 114         return 0;
 115         }
 116
 117 static int test_is_zero_8(unsigned int a)
 118         {
 119         unsigned char c = constant_time_is_zero_8(a);
 120         if (a == 0 && c != CONSTTIME_TRUE_8)
 121                 {
 122                 fprintf(stderr, "Test failed for constant_time_is_zero(%du): "
 123                         "expected %u (TRUE), got %u\n", a, CONSTTIME_TRUE_8, c);
 124                 return 1;
 125                 }
 126         else if (a != 0 && c != CONSTTIME_FALSE)
 127                 {
 128                 fprintf(stderr, "Test failed for constant_time_is_zero(%du): "
 129                         "expected %u (FALSE), got %u\n", a, CONSTTIME_FALSE_8,
 130                         c);
 131                 return 1;
 132                 }
 133         return 0;
 134         }
 135
 136 static int test_select(unsigned int a, unsigned int b)
 137         {
 138         unsigned int selected = constant_time_select(CONSTTIME_TRUE, a, b);
 139         if (selected != a)
 140                 {
 141                 fprintf(stderr, "Test failed for constant_time_select(%du, %du,"
 142                         "%du): expected %du(first value), got %du\n",
 143                         CONSTTIME_TRUE, a, b, a, selected);
 144                 return 1;
 145                 }
 146         selected = constant_time_select(CONSTTIME_FALSE, a, b);
 147         if (selected != b)
 148                 {
 149                 fprintf(stderr, "Test failed for constant_time_select(%du, %du,"
 150                         "%du): expected %du(second value), got %du\n",
 151                         CONSTTIME_FALSE, a, b, b, selected);
 152                 return 1;
 153                 }
 154         return 0;
 155         }
 156
 157 static int test_select_8(unsigned char a, unsigned char b)
 158         {
 159         unsigned char selected = constant_time_select_8(CONSTTIME_TRUE_8, a, b);
 160         if (selected != a)
 161                 {
 162                 fprintf(stderr, "Test failed for constant_time_select(%u, %u,"
 163                         "%u): expected %u(first value), got %u\n",
 164                         CONSTTIME_TRUE, a, b, a, selected);
 165                 return 1;
 166                 }
 167         selected = constant_time_select_8(CONSTTIME_FALSE_8, a, b);
 168         if (selected != b)
 169                 {
 170                 fprintf(stderr, "Test failed for constant_time_select(%u, %u,"
 171                         "%u): expected %u(second value), got %u\n",
 172                         CONSTTIME_FALSE, a, b, b, selected);
 173                 return 1;
 174                 }
 175         return 0;
 176         }
 177
 178 static int test_select_int(int a, int b)
 179         {
 180         int selected = constant_time_select_int(CONSTTIME_TRUE, a, b);
 181         if (selected != a)
 182                 {
 183                 fprintf(stderr, "Test failed for constant_time_select(%du, %d,"
 184                         "%d): expected %d(first value), got %d\n",
 185                         CONSTTIME_TRUE, a, b, a, selected);
 186                 return 1;
 187                 }
 188         selected = constant_time_select_int(CONSTTIME_FALSE, a, b);
 189         if (selected != b)
 190                 {
 191                 fprintf(stderr, "Test failed for constant_time_select(%du, %d,"
 192                         "%d): expected %d(second value), got %d\n",
 193                         CONSTTIME_FALSE, a, b, b, selected);
 194                 return 1;
 195                 }
 196         return 0;
 197         }
 198
 199
 200 static unsigned int test_values[] = {0, 1, 1024, 12345, 32000, UINT_MAX/2-1,
 201                                      UINT_MAX/2, UINT_MAX/2+1, UINT_MAX-1,
 202                                      UINT_MAX};
 203
 204 static unsigned char test_values_8[] = {0, 1, 2, 20, 32, 127, 128, 129, 255};
 205
 206 static int signed_test_values[] = {0, 1, -1, 1024, -1024, 12345, -12345,
 207                                    32000, -32000, INT_MAX, INT_MIN, INT_MAX-1,
 208                                    INT_MIN+1};
 209
 210
 211 int main(int argc, char *argv[])
 212         {
 213         unsigned int a, b, i, j;
 214         int c, d;
 215         unsigned char e, f;
 216         int num_failed = 0, num_all = 0;
 217         fprintf(stdout, "Testing constant time operations...\n");
 218
 219         for (i = 0; i < sizeof(test_values)/sizeof(int); ++i)
 220                 {
 221                 a = test_values[i];
 222                 num_failed += test_is_zero(a);
 223                 num_failed += test_is_zero_8(a);
 224                 num_all += 2;
 225                 for (j = 0; j < sizeof(test_values)/sizeof(int); ++j)
 226                         {
 227                         b = test_values[j];
 228                         num_failed += test_binary_op(&constant_time_lt,
 229                                 "constant_time_lt", a, b, a < b);
 230                         num_failed += test_binary_op_8(&constant_time_lt_8,
 231                                 "constant_time_lt_8", a, b, a < b);
 232                         num_failed += test_binary_op(&constant_time_lt,
 233                                 "constant_time_lt_8", b, a, b < a);
 234                         num_failed += test_binary_op_8(&constant_time_lt_8,
 235                                 "constant_time_lt_8", b, a, b < a);
 236                         num_failed += test_binary_op(&constant_time_ge,
 237                                 "constant_time_ge", a, b, a >= b);
 238                         num_failed += test_binary_op_8(&constant_time_ge_8,
 239                                 "constant_time_ge_8", a, b, a >= b);
 240                         num_failed += test_binary_op(&constant_time_ge,
 241                                 "constant_time_ge", b, a, b >= a);
 242                         num_failed += test_binary_op_8(&constant_time_ge_8,
 243                                 "constant_time_ge_8", b, a, b >= a);
 244                         num_failed += test_binary_op(&constant_time_eq,
 245                                 "constant_time_eq", a, b, a == b);
 246                         num_failed += test_binary_op_8(&constant_time_eq_8,
 247                                 "constant_time_eq_8", a, b, a == b);
 248                         num_failed += test_binary_op(&constant_time_eq,
 249                                 "constant_time_eq", b, a, b == a);
 250                         num_failed += test_binary_op_8(&constant_time_eq_8,
 251                                 "constant_time_eq_8", b, a, b == a);
 252                         num_failed += test_select(a, b);
 253                         num_all += 13;
 254                         }
 255                 }
 256
 257         for (i = 0; i < sizeof(signed_test_values)/sizeof(int); ++i)
 258                 {
 259                 c = signed_test_values[i];
 260                 for (j = 0; j < sizeof(signed_test_values)/sizeof(int); ++j)
 261                         {
 262                         d = signed_test_values[j];
 263                         num_failed += test_select_int(c, d);
 264                         num_all += 1;
 265                         }
 266                 }
 267
 268         for (i = 0; i < sizeof(test_values_8); ++i)
 269                 {
 270                 e = test_values_8[i];
 271                 for (j = 0; j < sizeof(test_values_8); ++j)
 272                         {
 273                         f = test_values_8[j];
 274                         num_failed += test_select_8(e, f);
 275                         num_all += 1;
 276                         }
 277                 }
 278
 279         if (!num_failed)
 280                 {
 281                 fprintf(stdout, "ok (ran %d tests)\n", num_all);
 282                 return EXIT_SUCCESS;
 283                 }
 284         else
 285                 {
 286                 fprintf(stdout, "%d of %d tests failed!\n", num_failed, num_all);
 287                 return EXIT_FAILURE;
 288                 }
 289         }