将char数组传递给函数以获得更新char数组的值。

Question

int get_alpha()
{
    std::string sealed_alpha_file = "/home/roshan/thesis/osn_server/sealed_alpha";

    long fsize;
    ocall_get_textsize(sealed_alpha_file.c_str(), &fsize, 0);
    unsigned char sealed_data[fsize];
    size_t ocall_return;
    ocall_load_file(&ocall_return, sealed_alpha_file.c_str(), fsize, sealed_data, 0);

      char resecret[12];
      uint64_t resecret_size = sizeof(resecret);
      sgx_status_t ret;
      ret = sgx_unseal_data(
              (sgx_sealed_data_t*)sealed_data,
              NULL,
              NULL,
              (uint8_t*)&resecret,
              (uint32_t*)&resecret_size);

      if(ret != SGX_SUCCESS)
      {
          mbedtls_printf("Enclave: Unsealing sealed_alpha failed %#x\n", ret);
          return -1;
      }

    mbedtls_printf("Enclave: Unsealing sealed_alpha success");
    mbedtls_printf("Enclave: After unsealing alpha number: %llu\n", *(char *)resecret);
    return 0;
}

我想从另一个函数调用get_alpha()函数，并从resecret数组中获取值。我尝试将get_alpha()更改为get_alpha(char *resecret)，并在get_alpha函数中注释char resecret12，并使uint64_t resecret_size = sizeof(resecret)；uint64_t resecret_size = (12)；。

然后从其他函数中这样称呼它

char resecret[12];
get_alpha(resecret);

mbedtls_printf("Enclave: After unsealing alpha number: %llu\n", *(char *)resecret);

但我没有得到正确的答案。看来sgx_unseal_data失败了。

Sgx_unseal_data的签名：

sgx_status_t SGXAPI sgx_unseal_data(const sgx_sealed_data_t *p_sealed_data,
    uint8_t *p_additional_MACtext,
    uint32_t *p_additional_MACtext_length,
    uint8_t *p_decrypted_text,
    uint32_t *p_decrypted_text_length);

Answer 1

这条标线似乎很奇怪：

ret = sgx_unseal_data(
              (sgx_sealed_data_t*)sealed_data,
              NULL,
              NULL,
              (uint8_t*)&resecret,    // Probably shouldn't use address-of (&) here?
              (uint32_t*)&resecret_size);

我相信这个呼吁应该是：

ret = sgx_unseal_data(
              (sgx_sealed_data_t*)sealed_data,
              NULL,
              NULL,
              (uint8_t*)resecret,                  
              (uint32_t*)&resecret_size);