bool verify_cmac128(
sample_ec_key_128bit_t mac_key,
const uint8_t *p_data_buf,
uint32_t buf_size,
const uint8_t *p_mac_buf)
{
uint8_t data_mac[SAMPLE_EC_MAC_SIZE];
sample_status_t sample_ret;
sample_ret = sample_rijndael128_cmac_msg((sample_cmac_128bit_key_t*)mac_key,
p_data_buf,
buf_size,
(sample_cmac_128bit_tag_t *)data_mac);
if(sample_ret != SAMPLE_SUCCESS)
return false;
// In real implementation, should use a time safe version of memcmp here,
// in order to avoid side channel attack.
if(!memcmp(p_mac_buf, data_mac, SAMPLE_EC_MAC_SIZE))
return true;
return false;
}
// Process remote attestation message 3
int sp_ra_proc_msg3_req(const sample_ra_msg3_t *p_msg3,
uint32_t msg3_size,
ra_samp_response_header_t **pp_att_result_msg)
{
int ret = 0;
sample_status_t sample_ret = SAMPLE_SUCCESS;
const uint8_t *p_msg3_cmaced = NULL;
sample_quote_t *p_quote = NULL;
sample_sha_state_handle_t sha_handle = NULL;
sample_report_data_t report_data = {0};
sample_ra_att_result_msg_t *p_att_result_msg = NULL;
ra_samp_response_header_t* p_att_result_msg_full = NULL;
uint32_t i;
if((!p_msg3) ||
(msg3_size < sizeof(sample_ra_msg3_t)) ||
(!pp_att_result_msg))
{
return SP_INTERNAL_ERROR;
}
// Check to see if we have registered?
if (!g_is_sp_registered)
{
return SP_UNSUPPORTED_EXTENDED_EPID_GROUP;
}
do
{
// Compare g_a in message 3 with local g_a.
ret = memcmp(&g_sp_db.g_a, &p_msg3->g_a, sizeof(sample_ec_pub_t));
if(ret)
{
fprintf(stderr, "\nError, g_a is not same [%s].", __FUNCTION__);
ret = SP_PROTOCOL_ERROR;
break;
}
//Make sure that msg3_size is bigger than sample_mac_t.
uint32_t mac_size = msg3_size - sizeof(sample_mac_t);
p_msg3_cmaced = reinterpret_cast<const uint8_t*>(p_msg3);
p_msg3_cmaced += sizeof(sample_mac_t);
// Verify the message mac using SMK
sample_cmac_128bit_tag_t mac = {0};
sample_ret = sample_rijndael128_cmac_msg(&g_sp_db.smk_key,
p_msg3_cmaced,
mac_size,
&mac);
if(SAMPLE_SUCCESS != sample_ret)
{
fprintf(stderr, "\nError, cmac fail in [%s].", __FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
// In real implementation, should use a time safe version of memcmp here,
// in order to avoid side channel attack.
ret = memcmp(&p_msg3->mac, mac, sizeof(mac));
if(ret)
{
fprintf(stderr, "\nError, verify cmac fail [%s].", __FUNCTION__);
ret = SP_INTEGRITY_FAILED;
break;
}
if(memcpy_s(&g_sp_db.ps_sec_prop, sizeof(g_sp_db.ps_sec_prop),
&p_msg3->ps_sec_prop, sizeof(p_msg3->ps_sec_prop)))
{
fprintf(stderr,"\nError, memcpy failed in [%s].", __FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
p_quote = (sample_quote_t *)p_msg3->quote;
// Check the quote version if needed. Only check the Quote.version field if the enclave
// identity fields have changed or the size of the quote has changed. The version may
// change without affecting the legacy fields or size of the quote structure.
//if(p_quote->version < ACCEPTED_QUOTE_VERSION)
//{
// fprintf(stderr,"\nError, quote version is too old.", __FUNCTION__);
// ret = SP_QUOTE_VERSION_ERROR;
// break;
//}
// Verify the report_data in the Quote matches the expected value.
// The first 32 bytes of report_data are SHA256 HASH of {ga|gb|vk}.
// The second 32 bytes of report_data are set to zero.
sample_ret = sample_sha256_init(&sha_handle);
if(sample_ret != SAMPLE_SUCCESS)
{
fprintf(stderr,"\nError, init hash failed in [%s].", __FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
sample_ret = sample_sha256_update((uint8_t *)&(g_sp_db.g_a),
sizeof(g_sp_db.g_a), sha_handle);
if(sample_ret != SAMPLE_SUCCESS)
{
fprintf(stderr,"\nError, udpate hash failed in [%s].",
__FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
sample_ret = sample_sha256_update((uint8_t *)&(g_sp_db.g_b),
sizeof(g_sp_db.g_b), sha_handle);
if(sample_ret != SAMPLE_SUCCESS)
{
fprintf(stderr,"\nError, udpate hash failed in [%s].",
__FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
sample_ret = sample_sha256_update((uint8_t *)&(g_sp_db.vk_key),
sizeof(g_sp_db.vk_key), sha_handle);
if(sample_ret != SAMPLE_SUCCESS)
{
fprintf(stderr,"\nError, udpate hash failed in [%s].",
__FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
sample_ret = sample_sha256_get_hash(sha_handle,
(sample_sha256_hash_t *)&report_data);
if(sample_ret != SAMPLE_SUCCESS)
{
fprintf(stderr,"\nError, Get hash failed in [%s].", __FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
ret = memcmp((uint8_t *)&report_data,
(uint8_t *)&(p_quote->report_body.report_data),
sizeof(report_data));
if(ret)
{
fprintf(stderr, "\nError, verify hash fail [%s].", __FUNCTION__);
ret = SP_INTEGRITY_FAILED;
break;
}
// Verify Enclave policy (an attestation server may provide an API for this if we
// registered an Enclave policy)
// Verify quote with attestation server.
// In the product, an attestation server could use a REST message and JSON formatting to request
// attestation Quote verification. The sample only simulates this interface.
ias_att_report_t attestation_report = {0};
ret = g_sp_extended_epid_group_id->verify_attestation_evidence(p_quote, NULL,
&attestation_report);
if(0 != ret)
{
ret = SP_IAS_FAILED;
break;
}
FILE* OUTPUT = stdout;
fprintf(OUTPUT, "\n\n\tAtestation Report:");
fprintf(OUTPUT, "\n\tid: 0x%0x.", attestation_report.id);
fprintf(OUTPUT, "\n\tstatus: %d.", attestation_report.status);
fprintf(OUTPUT, "\n\trevocation_reason: %u.",
attestation_report.revocation_reason);
// attestation_report.info_blob;
fprintf(OUTPUT, "\n\tpse_status: %d.", attestation_report.pse_status);
// Note: This sample always assumes the PIB is sent by attestation server. In the product
// implementation, the attestation server could only send the PIB for certain attestation
// report statuses. A product SP implementation needs to handle cases
// where the PIB is zero length.
// Respond the client with the results of the attestation.
uint32_t att_result_msg_size = sizeof(sample_ra_att_result_msg_t);
p_att_result_msg_full =
(ra_samp_response_header_t*)malloc(att_result_msg_size
+ sizeof(ra_samp_response_header_t) + sizeof(g_secret));
if(!p_att_result_msg_full)
{
fprintf(stderr, "\nError, out of memory in [%s].", __FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
memset(p_att_result_msg_full, 0, att_result_msg_size
+ sizeof(ra_samp_response_header_t) + sizeof(g_secret));
p_att_result_msg_full->type = TYPE_RA_ATT_RESULT;
p_att_result_msg_full->size = att_result_msg_size;
if(IAS_QUOTE_OK != attestation_report.status)
{
p_att_result_msg_full->status[0] = 0xFF;
}
if(IAS_PSE_OK != attestation_report.pse_status)
{
p_att_result_msg_full->status[1] = 0xFF;
}
p_att_result_msg =
(sample_ra_att_result_msg_t *)p_att_result_msg_full->body;
// In a product implementation of attestation server, the HTTP response header itself could have
// an RK based signature that the service provider needs to check here.
// The platform_info_blob signature will be verified by the client
// when sent. No need to have the Service Provider to check it. The SP
// should pass it down to the application for further analysis.
fprintf(OUTPUT, "\n\n\tEnclave Report:");
fprintf(OUTPUT, "\n\tSignature Type: 0x%x", p_quote->sign_type);
fprintf(OUTPUT, "\n\tSignature Basename: ");
for(i=0; i<sizeof(p_quote->basename.name) && p_quote->basename.name[i];
i++)
{
fprintf(OUTPUT, "%c", p_quote->basename.name[i]);
}
#ifdef __x86_64__
fprintf(OUTPUT, "\n\tattributes.flags: 0x%0lx",
p_quote->report_body.attributes.flags);
fprintf(OUTPUT, "\n\tattributes.xfrm: 0x%0lx",
p_quote->report_body.attributes.xfrm);
#else
fprintf(OUTPUT, "\n\tattributes.flags: 0x%0llx",
p_quote->report_body.attributes.flags);
fprintf(OUTPUT, "\n\tattributes.xfrm: 0x%0llx",
p_quote->report_body.attributes.xfrm);
#endif
fprintf(OUTPUT, "\n\tmr_enclave: ");
for(i=0;i<sizeof(sample_measurement_t);i++)
{
fprintf(OUTPUT, "%02x",p_quote->report_body.mr_enclave[i]);
//fprintf(stderr, "%02x",p_quote->report_body.mr_enclave.m[i]);
}
fprintf(OUTPUT, "\n\tmr_signer: ");
for(i=0;i<sizeof(sample_measurement_t);i++)
{
fprintf(OUTPUT, "%02x",p_quote->report_body.mr_signer[i]);
//fprintf(stderr, "%02x",p_quote->report_body.mr_signer.m[i]);
}
fprintf(OUTPUT, "\n\tisv_prod_id: 0x%0x",
p_quote->report_body.isv_prod_id);
fprintf(OUTPUT, "\n\tisv_svn: 0x%0x",p_quote->report_body.isv_svn);
fprintf(OUTPUT, "\n");
// A product service provider needs to verify that its enclave properties
// match what is expected. The SP needs to check these values before
// trusting the enclave. For the sample, we always pass the policy check.
// Attestation server only verifies the quote structure and signature. It does not
// check the identity of the enclave.
bool isv_policy_passed = true;
// Assemble Attestation Result Message
// Note, this is a structure copy. We don't copy the policy reports
// right now.
p_att_result_msg->platform_info_blob = attestation_report.info_blob;
// Generate mac based on the mk key.
mac_size = sizeof(ias_platform_info_blob_t);
sample_ret = sample_rijndael128_cmac_msg(&g_sp_db.mk_key,
(const uint8_t*)&p_att_result_msg->platform_info_blob,
mac_size,
&p_att_result_msg->mac);
if(SAMPLE_SUCCESS != sample_ret)
{
fprintf(stderr, "\nError, cmac fail in [%s].", __FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
// Generate shared secret and encrypt it with SK, if attestation passed.
uint8_t aes_gcm_iv[SAMPLE_SP_IV_SIZE] = {0};
p_att_result_msg->secret.payload_size = 8;
if((IAS_QUOTE_OK == attestation_report.status) &&
(IAS_PSE_OK == attestation_report.pse_status) &&
(isv_policy_passed == true))
{
ret = sample_rijndael128GCM_encrypt(&g_sp_db.sk_key,
&g_secret[0],
p_att_result_msg->secret.payload_size,
p_att_result_msg->secret.payload,
&aes_gcm_iv[0],
SAMPLE_SP_IV_SIZE,
NULL,
0,
&p_att_result_msg->secret.payload_tag);
}
}while(0);
if(ret)
{
*pp_att_result_msg = NULL;
SAFE_FREE(p_att_result_msg_full);
}
else
{
// Freed by the network simulator in ra_free_network_response_buffer
*pp_att_result_msg = p_att_result_msg_full;
}
return ret;
}
// Verify message 1 then generate and return message 2 to isv.
int sp_ra_proc_msg1_req(const sample_ra_msg1_t *p_msg1,
uint32_t msg1_size,
ra_samp_response_header_t **pp_msg2)
{
int ret = 0;
ra_samp_response_header_t* p_msg2_full = NULL;
sample_ra_msg2_t *p_msg2 = NULL;
sample_ecc_state_handle_t ecc_state = NULL;
sample_status_t sample_ret = SAMPLE_SUCCESS;
bool derive_ret = false;
if(!p_msg1 ||
!pp_msg2 ||
(msg1_size != sizeof(sample_ra_msg1_t)))
{
return -1;
}
// Check to see if we have registered?
if (!g_is_sp_registered)
{
return SP_UNSUPPORTED_EXTENDED_EPID_GROUP;
}
do
{
// Get the sig_rl from attestation server using GID.
// GID is Base-16 encoded of EPID GID in little-endian format.
// In the product, the SP and attesation server uses an established channel for
// communication.
uint8_t* sig_rl;
uint32_t sig_rl_size = 0;
// The product interface uses a REST based message to get the SigRL.
ret = g_sp_extended_epid_group_id->get_sigrl(p_msg1->gid, &sig_rl_size, &sig_rl);
if(0 != ret)
{
fprintf(stderr, "\nError, ias_get_sigrl [%s].", __FUNCTION__);
ret = SP_IAS_FAILED;
break;
}
// Need to save the client's public ECCDH key to local storage
if (memcpy_s(&g_sp_db.g_a, sizeof(g_sp_db.g_a), &p_msg1->g_a,
sizeof(p_msg1->g_a)))
{
fprintf(stderr, "\nError, cannot do memcpy in [%s].", __FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
// Generate the Service providers ECCDH key pair.
sample_ret = sample_ecc256_open_context(&ecc_state);
if(SAMPLE_SUCCESS != sample_ret)
{
fprintf(stderr, "\nError, cannot get ECC context in [%s].",
__FUNCTION__);
ret = -1;
break;
}
sample_ec256_public_t pub_key = {{0},{0}};
sample_ec256_private_t priv_key = {{0}};
sample_ret = sample_ecc256_create_key_pair(&priv_key, &pub_key,
ecc_state);
if(SAMPLE_SUCCESS != sample_ret)
{
fprintf(stderr, "\nError, cannot generate key pair in [%s].",
__FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
// Need to save the SP ECCDH key pair to local storage.
if(memcpy_s(&g_sp_db.b, sizeof(g_sp_db.b), &priv_key,sizeof(priv_key))
|| memcpy_s(&g_sp_db.g_b, sizeof(g_sp_db.g_b),
&pub_key,sizeof(pub_key)))
{
fprintf(stderr, "\nError, cannot do memcpy in [%s].", __FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
// Generate the client/SP shared secret
sample_ec_dh_shared_t dh_key = {{0}};
sample_ret = sample_ecc256_compute_shared_dhkey(&priv_key,
(sample_ec256_public_t *)&p_msg1->g_a,
(sample_ec256_dh_shared_t *)&dh_key,
ecc_state);
if(SAMPLE_SUCCESS != sample_ret)
{
fprintf(stderr, "\nError, compute share key fail in [%s].",
__FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
#ifdef SUPPLIED_KEY_DERIVATION
// smk is only needed for msg2 generation.
derive_ret = derive_key(&dh_key, SAMPLE_DERIVE_KEY_SMK_SK,
&g_sp_db.smk_key, &g_sp_db.sk_key);
if(derive_ret != true)
{
fprintf(stderr, "\nError, derive key fail in [%s].", __FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
// The rest of the keys are the shared secrets for future communication.
derive_ret = derive_key(&dh_key, SAMPLE_DERIVE_KEY_MK_VK,
&g_sp_db.mk_key, &g_sp_db.vk_key);
if(derive_ret != true)
{
fprintf(stderr, "\nError, derive key fail in [%s].", __FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
#else
// smk is only needed for msg2 generation.
derive_ret = derive_key(&dh_key, SAMPLE_DERIVE_KEY_SMK,
&g_sp_db.smk_key);
if(derive_ret != true)
{
fprintf(stderr, "\nError, derive key fail in [%s].", __FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
// The rest of the keys are the shared secrets for future communication.
derive_ret = derive_key(&dh_key, SAMPLE_DERIVE_KEY_MK,
&g_sp_db.mk_key);
if(derive_ret != true)
{
fprintf(stderr, "\nError, derive key fail in [%s].", __FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
derive_ret = derive_key(&dh_key, SAMPLE_DERIVE_KEY_SK,
&g_sp_db.sk_key);
if(derive_ret != true)
{
fprintf(stderr, "\nError, derive key fail in [%s].", __FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
derive_ret = derive_key(&dh_key, SAMPLE_DERIVE_KEY_VK,
&g_sp_db.vk_key);
if(derive_ret != true)
{
fprintf(stderr, "\nError, derive key fail in [%s].", __FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
#endif
uint32_t msg2_size = sizeof(sample_ra_msg2_t) + sig_rl_size;
p_msg2_full = (ra_samp_response_header_t*)malloc(msg2_size
+ sizeof(ra_samp_response_header_t));
if(!p_msg2_full)
{
fprintf(stderr, "\nError, out of memory in [%s].", __FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
memset(p_msg2_full, 0, msg2_size + sizeof(ra_samp_response_header_t));
p_msg2_full->type = TYPE_RA_MSG2;
p_msg2_full->size = msg2_size;
// The simulated message2 always passes. This would need to be set
// accordingly in a real service provider implementation.
p_msg2_full->status[0] = 0;
p_msg2_full->status[1] = 0;
p_msg2 = (sample_ra_msg2_t *)p_msg2_full->body;
// Assemble MSG2
if(memcpy_s(&p_msg2->g_b, sizeof(p_msg2->g_b), &g_sp_db.g_b,
sizeof(g_sp_db.g_b)) ||
memcpy_s(&p_msg2->spid, sizeof(sample_spid_t),
&g_spid, sizeof(g_spid)))
{
fprintf(stderr,"\nError, memcpy failed in [%s].", __FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
// The service provider is responsible for selecting the proper EPID
// signature type and to understand the implications of the choice!
p_msg2->quote_type = SAMPLE_QUOTE_LINKABLE_SIGNATURE;
#ifdef SUPPLIED_KEY_DERIVATION
//isv defined key derivation function id
#define ISV_KDF_ID 2
p_msg2->kdf_id = ISV_KDF_ID;
#else
p_msg2->kdf_id = SAMPLE_AES_CMAC_KDF_ID;
#endif
// Create gb_ga
sample_ec_pub_t gb_ga[2];
if(memcpy_s(&gb_ga[0], sizeof(gb_ga[0]), &g_sp_db.g_b,
sizeof(g_sp_db.g_b))
|| memcpy_s(&gb_ga[1], sizeof(gb_ga[1]), &g_sp_db.g_a,
sizeof(g_sp_db.g_a)))
{
fprintf(stderr,"\nError, memcpy failed in [%s].", __FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
// Sign gb_ga
sample_ret = sample_ecdsa_sign((uint8_t *)&gb_ga, sizeof(gb_ga),
(sample_ec256_private_t *)&g_sp_priv_key,
(sample_ec256_signature_t *)&p_msg2->sign_gb_ga,
ecc_state);
if(SAMPLE_SUCCESS != sample_ret)
{
fprintf(stderr, "\nError, sign ga_gb fail in [%s].", __FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
// Generate the CMACsmk for gb||SPID||TYPE||KDF_ID||Sigsp(gb,ga)
uint8_t mac[SAMPLE_EC_MAC_SIZE] = {0};
uint32_t cmac_size = offsetof(sample_ra_msg2_t, mac);
sample_ret = sample_rijndael128_cmac_msg(&g_sp_db.smk_key,
(uint8_t *)&p_msg2->g_b, cmac_size, &mac);
if(SAMPLE_SUCCESS != sample_ret)
{
fprintf(stderr, "\nError, cmac fail in [%s].", __FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
if(memcpy_s(&p_msg2->mac, sizeof(p_msg2->mac), mac, sizeof(mac)))
{
fprintf(stderr,"\nError, memcpy failed in [%s].", __FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
if(memcpy_s(&p_msg2->sig_rl[0], sig_rl_size, sig_rl, sig_rl_size))
{
fprintf(stderr,"\nError, memcpy failed in [%s].", __FUNCTION__);
ret = SP_INTERNAL_ERROR;
break;
}
p_msg2->sig_rl_size = sig_rl_size;
}while(0);
if(ret)
{
*pp_msg2 = NULL;
SAFE_FREE(p_msg2_full);
}
else
{
// Freed by the network simulator in ra_free_network_response_buffer
*pp_msg2 = p_msg2_full;
}
if(ecc_state)
{
sample_ecc256_close_context(ecc_state);
}
return ret;
}
// Derive key from shared key and key id.
// key id should be sample_derive_key_type_t.
bool derive_key(
const sample_ec_dh_shared_t *p_shared_key,
uint8_t key_id,
sample_ec_key_128bit_t* derived_key)
{
sample_status_t sample_ret = SAMPLE_SUCCESS;
uint8_t cmac_key[MAC_KEY_SIZE];
sample_ec_key_128bit_t key_derive_key;
memset(&cmac_key, 0, MAC_KEY_SIZE);
sample_ret = sample_rijndael128_cmac_msg(
(sample_cmac_128bit_key_t *)&cmac_key,
(uint8_t*)p_shared_key,
sizeof(sample_ec_dh_shared_t),
(sample_cmac_128bit_tag_t *)&key_derive_key);
if (sample_ret != SAMPLE_SUCCESS)
{
// memset here can be optimized away by compiler, so please use memset_s on
// windows for production code and similar functions on other OSes.
memset(&key_derive_key, 0, sizeof(key_derive_key));
return false;
}
const char *label = NULL;
uint32_t label_length = 0;
switch (key_id)
{
case SAMPLE_DERIVE_KEY_SMK:
label = str_SMK;
label_length = sizeof(str_SMK) -1;
break;
case SAMPLE_DERIVE_KEY_SK:
label = str_SK;
label_length = sizeof(str_SK) -1;
break;
case SAMPLE_DERIVE_KEY_MK:
label = str_MK;
label_length = sizeof(str_MK) -1;
break;
case SAMPLE_DERIVE_KEY_VK:
label = str_VK;
label_length = sizeof(str_VK) -1;
break;
default:
// memset here can be optimized away by compiler, so please use memset_s on
// windows for production code and similar functions on other OSes.
memset(&key_derive_key, 0, sizeof(key_derive_key));
return false;
break;
}
/* derivation_buffer = counter(0x01) || label || 0x00 || output_key_len(0x0080) */
uint32_t derivation_buffer_length = EC_DERIVATION_BUFFER_SIZE(label_length);
uint8_t *p_derivation_buffer = (uint8_t *)malloc(derivation_buffer_length);
if (p_derivation_buffer == NULL)
{
// memset here can be optimized away by compiler, so please use memset_s on
// windows for production code and similar functions on other OSes.
memset(&key_derive_key, 0, sizeof(key_derive_key));
return false;
}
memset(p_derivation_buffer, 0, derivation_buffer_length);
/*counter = 0x01 */
p_derivation_buffer[0] = 0x01;
/*label*/
memcpy(&p_derivation_buffer[1], label, label_length);
/*output_key_len=0x0080*/
uint16_t *key_len = (uint16_t *)(&(p_derivation_buffer[derivation_buffer_length - 2]));
*key_len = 0x0080;
sample_ret = sample_rijndael128_cmac_msg(
(sample_cmac_128bit_key_t *)&key_derive_key,
p_derivation_buffer,
derivation_buffer_length,
(sample_cmac_128bit_tag_t *)derived_key);
free(p_derivation_buffer);
// memset here can be optimized away by compiler, so please use memset_s on
// windows for production code and similar functions on other OSes.
memset(&key_derive_key, 0, sizeof(key_derive_key));
if (sample_ret != SAMPLE_SUCCESS)
{
return false;
}
return true;
}