topic Hi Yudao. in Intel® Software Guard Extensions (Intel® SGX)

Facing MAC_MISMATCH during unseal data

Yan__Yudao — Wed, 28 Nov 2018 15:17:30 GMT

We try to seal a private key in encalve for future use:

sealed_len = sgx_calc_sealed_data_size(0,sizeof(priv_key));

sgx_status_t ret_priKey = sgx_seal_data(0, NULL, sizeof(priv_key), (uint8_t*)&priv_key, sealed_len, &tmpbuf); // tmpbuf will send out the sealed data

In the future, we do unseal in encalve as following:

uint32_t decLen = sgx_get_encrypt_txt_len(&fix_data->enc_ec256_private_key); // fix_data contained sealed data

uint8_t *priv_tmp = (uint8_t*)malloc(decLen);

memset(&sealed_data_tmp, 0, sizeof(tmpbuf));

memcpy(&sealed_data_tmp, &fix_data->enc_ec256_private_key, sizeof(tmpbuf));

sgx_status_t retUnseal = sgx_unseal_data(&sealed_data_tmp, NULL, 0, priv_tmp, &decLen);

But it shows MAC_MISMATCH during the unsealing.

Can anyone help on this?

Scott_R_Intel — Thu, 29 Nov 2018 14:04:46 GMT

Hi Yudao.

You didn't show how tmpbuf nor sealed_data_tmp are allocated... Are you sure they are large enough to hold the data?

Regards.

Scott

Tom__Jimmy — Mon, 18 May 2020 07:06:17 GMT

Hi,YuDao.Yan, your problem is solve?

I also encountered this problem, ask how to solve it.

Tom__Jimmy — Mon, 18 May 2020 07:18:36 GMT

Hi,Have you solved this problem, I also encountered this problem, ask how to solve it.