github.com/ebceco/ebc@v1.8.19-0.20190309150932-8cb0b9e06484/crypto/secp256k1/libsecp256k1/src/modules/ecdh/tests_impl.h (about)

     1  /**********************************************************************
     2   * Copyright (c) 2015 Andrew Poelstra                                 *
     3   * Distributed under the MIT software license, see the accompanying   *
     4   * file COPYING or http://www.opensource.org/licenses/mit-license.php.*
     5   **********************************************************************/
     6  
     7  #ifndef _SECP256K1_MODULE_ECDH_TESTS_
     8  #define _SECP256K1_MODULE_ECDH_TESTS_
     9  
    10  void test_ecdh_api(void) {
    11      /* Setup context that just counts errors */
    12      secp256k1_context *tctx = secp256k1_context_create(SECP256K1_CONTEXT_SIGN);
    13      secp256k1_pubkey point;
    14      unsigned char res[32];
    15      unsigned char s_one[32] = { 0 };
    16      int32_t ecount = 0;
    17      s_one[31] = 1;
    18  
    19      secp256k1_context_set_error_callback(tctx, counting_illegal_callback_fn, &ecount);
    20      secp256k1_context_set_illegal_callback(tctx, counting_illegal_callback_fn, &ecount);
    21      CHECK(secp256k1_ec_pubkey_create(tctx, &point, s_one) == 1);
    22  
    23      /* Check all NULLs are detected */
    24      CHECK(secp256k1_ecdh(tctx, res, &point, s_one) == 1);
    25      CHECK(ecount == 0);
    26      CHECK(secp256k1_ecdh(tctx, NULL, &point, s_one) == 0);
    27      CHECK(ecount == 1);
    28      CHECK(secp256k1_ecdh(tctx, res, NULL, s_one) == 0);
    29      CHECK(ecount == 2);
    30      CHECK(secp256k1_ecdh(tctx, res, &point, NULL) == 0);
    31      CHECK(ecount == 3);
    32      CHECK(secp256k1_ecdh(tctx, res, &point, s_one) == 1);
    33      CHECK(ecount == 3);
    34  
    35      /* Cleanup */
    36      secp256k1_context_destroy(tctx);
    37  }
    38  
    39  void test_ecdh_generator_basepoint(void) {
    40      unsigned char s_one[32] = { 0 };
    41      secp256k1_pubkey point[2];
    42      int i;
    43  
    44      s_one[31] = 1;
    45      /* Check against pubkey creation when the basepoint is the generator */
    46      for (i = 0; i < 100; ++i) {
    47          secp256k1_sha256_t sha;
    48          unsigned char s_b32[32];
    49          unsigned char output_ecdh[32];
    50          unsigned char output_ser[32];
    51          unsigned char point_ser[33];
    52          size_t point_ser_len = sizeof(point_ser);
    53          secp256k1_scalar s;
    54  
    55          random_scalar_order(&s);
    56          secp256k1_scalar_get_b32(s_b32, &s);
    57  
    58          /* compute using ECDH function */
    59          CHECK(secp256k1_ec_pubkey_create(ctx, &point[0], s_one) == 1);
    60          CHECK(secp256k1_ecdh(ctx, output_ecdh, &point[0], s_b32) == 1);
    61          /* compute "explicitly" */
    62          CHECK(secp256k1_ec_pubkey_create(ctx, &point[1], s_b32) == 1);
    63          CHECK(secp256k1_ec_pubkey_serialize(ctx, point_ser, &point_ser_len, &point[1], SECP256K1_EC_COMPRESSED) == 1);
    64          CHECK(point_ser_len == sizeof(point_ser));
    65          secp256k1_sha256_initialize(&sha);
    66          secp256k1_sha256_write(&sha, point_ser, point_ser_len);
    67          secp256k1_sha256_finalize(&sha, output_ser);
    68          /* compare */
    69          CHECK(memcmp(output_ecdh, output_ser, sizeof(output_ser)) == 0);
    70      }
    71  }
    72  
    73  void test_bad_scalar(void) {
    74      unsigned char s_zero[32] = { 0 };
    75      unsigned char s_overflow[32] = {
    76          0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    77          0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe,
    78          0xba, 0xae, 0xdc, 0xe6, 0xaf, 0x48, 0xa0, 0x3b,
    79          0xbf, 0xd2, 0x5e, 0x8c, 0xd0, 0x36, 0x41, 0x41
    80      };
    81      unsigned char s_rand[32] = { 0 };
    82      unsigned char output[32];
    83      secp256k1_scalar rand;
    84      secp256k1_pubkey point;
    85  
    86      /* Create random point */
    87      random_scalar_order(&rand);
    88      secp256k1_scalar_get_b32(s_rand, &rand);
    89      CHECK(secp256k1_ec_pubkey_create(ctx, &point, s_rand) == 1);
    90  
    91      /* Try to multiply it by bad values */
    92      CHECK(secp256k1_ecdh(ctx, output, &point, s_zero) == 0);
    93      CHECK(secp256k1_ecdh(ctx, output, &point, s_overflow) == 0);
    94      /* ...and a good one */
    95      s_overflow[31] -= 1;
    96      CHECK(secp256k1_ecdh(ctx, output, &point, s_overflow) == 1);
    97  }
    98  
    99  void run_ecdh_tests(void) {
   100      test_ecdh_api();
   101      test_ecdh_generator_basepoint();
   102      test_bad_scalar();
   103  }
   104  
   105  #endif