security/nss/fuzz/mpi_add_target.cc

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 /*
   6  * This target fuzzes NSS mpi against openssl bignum.
   7  * It therefore requires openssl to be installed.
   8  */
   9
  10 #include "mpi_helper.h"
  11
  12 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
  13   // We require at least size 3 to get two integers from Data.
  14   if (size < 3) {
  15     return 0;
  16   }
  17   INIT_FOUR_NUMBERS
  18
  19   // Compare with OpenSSL addition
  20   assert(mp_add(&a, &b, &c) == MP_OKAY);
  21   (void)BN_add(C, A, B);
  22   check_equal(C, &c, max_size);
  23
  24   // Check a + b == a - -b
  25   mp_neg(&b, &b);
  26   assert(mp_sub(&a, &b, &r) == MP_OKAY);
  27   bool eq = mp_cmp(&r, &c) == 0;
  28   if (!eq) {
  29     char rC[max_size], cC[max_size], aC[max_size], bC[max_size];
  30     mp_tohex(&r, rC);
  31     mp_tohex(&c, cC);
  32     mp_tohex(&a, aC);
  33     mp_tohex(&b, bC);
  34     std::cout << "a = " << std::hex << aC << std::endl;
  35     std::cout << "-b = " << std::hex << bC << std::endl;
  36     std::cout << "a + b = " << std::hex << cC << std::endl;
  37     std::cout << "a - -b = " << std::hex << rC << std::endl;
  38   }
  39   assert(eq);
  40
  41   CLEANUP_AND_RETURN
  42 }