text: /* mbedTLS Elliptic Curve functionality tests
   *
   * Focus on testing functionality where we use ESP32 hardware
   * accelerated crypto features.
   *
   * SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
   *
   * SPDX-License-Identifier: Apache-2.0
   */
  #include <string.h>
  #include <stdio.h>
  #include <stdbool.h>
  #include <esp_random.h>
  
  /* ToDo - Remove this once appropriate solution is available.
  We need to define this for the file as ssl_misc.h uses private structures from mbedtls,
  which are undefined if the following flag is not defined */
  /* Many APIs in the file make use of this flag instead of `MBEDTLS_PRIVATE` */
  /* ToDo - Replace them with proper getter-setter once they are added */
  #define MBEDTLS_ALLOW_PRIVATE_ACCESS
  
  #include <mbedtls/entropy.h>
  #include <mbedtls/ctr_drbg.h>
  #include <mbedtls/ecdh.h>
  #include <mbedtls/ecdsa.h>
  #include <mbedtls/error.h>
  
  #include "unity.h"
  
  /* Note: negative value here so that assert message prints a grep-able
     error hex value (mbedTLS uses -N for error codes) */
  #define TEST_ASSERT_MBEDTLS_OK(X) TEST_ASSERT_EQUAL_HEX32(0, -(X))
  
  TEST_CASE("mbedtls ECDH Generate Key", "[mbedtls]")
  {
      mbedtls_ecdh_context ctx;
      mbedtls_entropy_context entropy;
      mbedtls_ctr_drbg_context ctr_drbg;
  
      mbedtls_ecdh_init(&ctx);
      mbedtls_ctr_drbg_init(&ctr_drbg);
  
      mbedtls_entropy_init(&entropy);
      TEST_ASSERT_MBEDTLS_OK( mbedtls_ctr_drbg_seed(&ctr_drbg, mbedtls_entropy_func, &entropy, NULL, 0) );
  
      TEST_ASSERT_MBEDTLS_OK( mbedtls_ecp_group_load(&ctx.ctx.mbed_ecdh.grp, MBEDTLS_ECP_DP_CURVE25519) );
  
      TEST_ASSERT_MBEDTLS_OK( mbedtls_ecdh_gen_public(&ctx.ctx.mbed_ecdh.grp, &ctx.ctx.mbed_ecdh.d, &ctx.ctx.mbed_ecdh.Q,
                                                      mbedtls_ctr_drbg_random, &ctr_drbg ) );
  
      mbedtls_ecdh_free(&ctx);
      mbedtls_ctr_drbg_free(&ctr_drbg);
      mbedtls_entropy_free(&entropy);
  }
  
  TEST_CASE("mbedtls ECP self-tests", "[mbedtls]")
  {
      TEST_ASSERT_EQUAL(0, mbedtls_ecp_self_test(1));
  }
  
  TEST_CASE("mbedtls ECP mul w/ koblitz", "[mbedtls]")
  {
      /* Test case code via https://github.com/espressif/esp-idf/issues/1556 */
      mbedtls_entropy_context ctxEntropy;
      mbedtls_ctr_drbg_context ctxRandom;
      mbedtls_ecdsa_context ctxECDSA;
      const char* pers = "myecdsa";
  
      mbedtls_entropy_init(&ctxEntropy);
      mbedtls_ctr_drbg_init(&ctxRandom);
      TEST_ASSERT_MBEDTLS_OK( mbedtls_ctr_drbg_seed(&ctxRandom, mbedtls_entropy_func, &ctxEntropy,
                                                    (const unsigned char*) pers, strlen(pers)) );
  
      mbedtls_ecdsa_init(&ctxECDSA);
  
      TEST_ASSERT_MBEDTLS_OK( mbedtls_ecdsa_genkey(&ctxECDSA, MBEDTLS_ECP_DP_SECP256K1,
                                                   mbedtls_ctr_drbg_random, &ctxRandom) );
  
  
      TEST_ASSERT_MBEDTLS_OK(mbedtls_ecp_mul(&ctxECDSA.grp, &ctxECDSA.Q, &ctxECDSA.d, &ctxECDSA.grp.G,
                                             mbedtls_ctr_drbg_random, &ctxRandom) );
  
      mbedtls_ecdsa_free(&ctxECDSA);
      mbedtls_ctr_drbg_free(&ctxRandom);
      mbedtls_entropy_free(&ctxEntropy);
  }
  
  #if CONFIG_MBEDTLS_HARDWARE_ECC
  /*
   * Coordinates and integers stored in big endian format
   */
  const uint8_t ecc_p192_point_x[] = {
      0x18, 0x8D, 0xA8, 0x0E, 0xB0, 0x30, 0x90, 0xF6,
      0x7C, 0xBF, 0x20, 0xEB, 0x43, 0xA1, 0x88, 0x00,
      0xF4, 0xFF, 0x0A, 0xFD, 0x82, 0xFF, 0x10, 0x12
  };
  
  const uint8_t ecc_p192_point_y[] = {
      0x07, 0x19, 0x2B, 0x95, 0xFF, 0xC8, 0xDA, 0x78,
      0x63, 0x10, 0x11, 0xED, 0x6B, 0x24, 0xCD, 0xD5,
      0x73, 0xF9, 0x77, 0xA1, 0x1E, 0x79, 0x48, 0x11
  };
  
  const uint8_t ecc_p192_scalar[] = {
      0x6f, 0x18, 0x34, 0xeb, 0x16, 0xb7, 0xac, 0x9f,
      0x3c, 0x77, 0x71, 0xb3, 0x02, 0x30, 0x70, 0x48,
      0x75, 0x87, 0xbb, 0x6f, 0x80, 0x34, 0x8d, 0x5e
  };
  
  const uint8_t ecc_p192_mul_res_x[] = {
      0x3F, 0xEE, 0x6F, 0x1F, 0x99, 0xDC, 0xCB, 0x78,
      0xB7, 0x47, 0x1C, 0x2A, 0xF5, 0xA0, 0xAC, 0xE6,
      0xEC, 0x24, 0x82, 0x37, 0x6C, 0xC0, 0x27, 0xC5,
  };
  
  const uint8_t ecc_p192_mul_res_y[] = {
      0xDF, 0xF3, 0x9E, 0x76, 0x24, 0xF4, 0xF6, 0xB4,
      0xF0, 0x0A, 0x18, 0xE1, 0x0B, 0xD2, 0xD9, 0x83,
      0xE8, 0x29, 0x5E, 0xD9, 0x46, 0x54, 0xC3, 0xE1
  };
  
  const uint8_t ecc_p256_point_x[] = {
      0x6B, 0x17, 0xD1, 0xF2, 0xE1, 0x2C, 0x42, 0x47,
      0xF8, 0xBC, 0xE6, 0xE5, 0x63, 0xA4, 0x40, 0xF2,
      0x77, 0x03, 0x7D, 0x81, 0x2D, 0xEB, 0x33, 0xA0,
      0xF4, 0xA1, 0x39, 0x45, 0xD8, 0x98, 0xC2, 0x96
  };
  
  const uint8_t ecc_p256_point_y[] = {
      0x4F, 0xE3, 0x42, 0xE2, 0xFE, 0x1A, 0x7F, 0x9B,
      0x8E, 0xE7, 0xEB, 0x4A, 0x7C, 0x0F, 0x9E, 0x16,
      0x2B, 0xCE, 0x33, 0x57, 0x6B, 0x31, 0x5E, 0xCE,
      0xCB, 0xB6, 0x40, 0x68, 0x37, 0xBF, 0x51, 0xF5
  };
  
  const uint8_t ecc_p256_scalar[] = {
     0xB2, 0xC5, 0x9E, 0x92, 0x64, 0xCD, 0x5F, 0x66,
     0x9E, 0xC8, 0x83, 0x6D, 0x99, 0x61, 0x18, 0x72,
     0xC8, 0x60, 0x83, 0x1E, 0xE5, 0x79, 0xCC, 0x73,
     0xA9, 0xB4, 0x74, 0x85, 0x70, 0x11, 0x2D, 0xA2,
  };
  
  const uint8_t ecc_p256_mul_res_x[] = {
      0x26, 0x1A, 0x0F, 0xBD, 0xA5, 0xE5, 0x1E, 0xE7,
      0xB3, 0xC3, 0xB7, 0x09, 0xD1, 0x4A, 0x7A, 0x2A,
      0x16, 0x69, 0x4B, 0xAF, 0x76, 0x5C, 0xD4, 0x0E,
      0x93, 0x57, 0xB8, 0x67, 0xF9, 0xA1, 0xE5, 0xE8
  };
  
  const uint8_t ecc_p256_mul_res_y[] = {
      0xA0, 0xF4, 0x2E, 0x62, 0x36, 0x25, 0x9F, 0xE0,
      0xF2, 0xA0, 0x41, 0x42, 0xD2, 0x95, 0x89, 0x41,
      0x38, 0xF0, 0xEB, 0x6E, 0xA7, 0x96, 0x29, 0x24,
      0xC7, 0xD4, 0x0C, 0x90, 0xA1, 0xC9, 0xD3, 0x3A
  };
  
  static int rng_wrapper(void *ctx, unsigned char *buf, size_t len)
  {
      esp_fill_random(buf, len);
  	return 0;
  }
  
  static void test_ecp_mul(mbedtls_ecp_group_id id, const uint8_t *x_coord, const uint8_t *y_coord, const uint8_t *scalar,
                          const uint8_t *result_x_coord, const uint8_t *result_y_coord)
  {
      uint8_t x[32];
      uint8_t y[32];
      int size;
      int ret;
  
      mbedtls_ecp_group grp;
      mbedtls_ecp_point R;
      mbedtls_ecp_point P;
      mbedtls_mpi m;
  
      mbedtls_ecp_group_init(&grp);
      mbedtls_ecp_point_init(&R);
      mbedtls_ecp_point_init(&P);
      mbedtls_mpi_init(&m);
  
      mbedtls_ecp_group_load(&grp, id);
  
      size = grp.pbits / 8;
  
      mbedtls_mpi_read_binary(&m, scalar, size);
  
      mbedtls_mpi_read_binary(&P.X, x_coord, size);
      mbedtls_mpi_read_binary(&P.Y, y_coord, size);
  
      mbedtls_mpi_lset(&P.Z, 1);
  
      ret = mbedtls_ecp_mul(&grp, &R, &m, &P, rng_wrapper, NULL);
  
      TEST_ASSERT_EQUAL(0, ret);
  
      mbedtls_mpi_write_binary(&R.X, x, mbedtls_mpi_size(&R.X));
      mbedtls_mpi_write_binary(&R.Y, y, mbedtls_mpi_size(&R.Y));
  
      TEST_ASSERT_EQUAL(0, memcmp(x, result_x_coord, mbedtls_mpi_size(&R.X)));
      TEST_ASSERT_EQUAL(0, memcmp(y, result_y_coord, mbedtls_mpi_size(&R.Y)));
  
      mbedtls_ecp_point_free(&R);
      mbedtls_ecp_point_free(&P);
      mbedtls_mpi_free(&m);
      mbedtls_ecp_group_free(&grp);
  }
  
  TEST_CASE("mbedtls ECP point multiply with SECP192R1", "[mbedtls]")
  {
      test_ecp_mul(MBEDTLS_ECP_DP_SECP192R1, ecc_p192_point_x, ecc_p192_point_y, ecc_p192_scalar,
                   ecc_p192_mul_res_x, ecc_p192_mul_res_y);
  }
  
  TEST_CASE("mbedtls ECP point multiply with SECP256R1", "[mbedtls]")
  {
      test_ecp_mul(MBEDTLS_ECP_DP_SECP256R1, ecc_p256_point_x, ecc_p256_point_y, ecc_p256_scalar,
                   ecc_p256_mul_res_x, ecc_p256_mul_res_y);
  }
  
  static void test_ecp_verify(mbedtls_ecp_group_id id, const uint8_t *x_coord, const uint8_t *y_coord)
  {
      int size;
      int ret;
  
      mbedtls_ecp_group grp;
      mbedtls_ecp_point P;
  
      mbedtls_ecp_group_init(&grp);
      mbedtls_ecp_point_init(&P);
  
      mbedtls_ecp_group_load(&grp, id);
  
      size = grp.pbits / 8;
  
      mbedtls_mpi_read_binary(&P.X, x_coord, size);
      mbedtls_mpi_read_binary(&P.Y, y_coord, size);
      mbedtls_mpi_lset(&P.Z, 1);
  
      ret = mbedtls_ecp_check_pubkey(&grp, &P);
  
      TEST_ASSERT_EQUAL(0, ret);
  
      mbedtls_ecp_point_free(&P);
      mbedtls_ecp_group_free(&grp);
  }
  
  TEST_CASE("mbedtls ECP point verify with SECP192R1", "[mbedtls]")
  {
      test_ecp_verify(MBEDTLS_ECP_DP_SECP192R1, ecc_p192_mul_res_x, ecc_p192_mul_res_y);
  }
  
  TEST_CASE("mbedtls ECP point verify with SECP256R1", "[mbedtls]")
  {
      test_ecp_verify(MBEDTLS_ECP_DP_SECP256R1, ecc_p256_mul_res_x, ecc_p256_mul_res_y);
  }
  #endif /* CONFIG_MBEDTLS_HARDWARE_ECC */
  