//Function to decode ProvMsg4 and generate epid data blob
uint32_t CPVEClass::proc_prov_msg4(
bool use_ek2_in_input,
const uint8_t ek2[SK_SIZE],
const uint8_t* msg4,
uint32_t msg4_size,
uint8_t* data_blob,
uint32_t blob_size)
{
ae_error_t ret = AE_SUCCESS;
uint8_t local_ek2[SK_SIZE];
uint8_t *decoded_msg4 = NULL;
const provision_response_header_t *msg4_header = reinterpret_cast<const provision_response_header_t *>(msg4);
if(msg4_size < PROVISION_RESPONSE_HEADER_SIZE){
AESM_DBG_ERROR("invalid msg4 size");
return PVE_MSG_ERROR;
}
if(blob_size != HARD_CODED_EPID_BLOB_SIZE){
AESM_DBG_FATAL("invalid input epid blob size");
return PVE_PARAMETER_ERROR;
}
ret = check_prov_msg4_header(msg4_header, msg4_size);
if( AE_SUCCESS != ret){
AESM_DBG_ERROR("Invalid ProvMsg4 Header:%d",ret);
return ret;
}
ret = check_epid_pve_pg_status_before_mac_verification(msg4_header);
if( AE_SUCCESS != ret){
AESM_DBG_ERROR("Backend return failure in ProvMsg4 Header:%d",ret);
return ret;
}
do{
TLVsMsg tlvs_msg4;
tlv_status_t tlv_status;
tlv_status = tlvs_msg4.init_from_buffer(msg4+static_cast<uint32_t>(PROVISION_RESPONSE_HEADER_SIZE), msg4_size - static_cast<uint32_t>(PROVISION_RESPONSE_HEADER_SIZE));
ret = tlv_error_2_pve_error(tlv_status);
if(AE_SUCCESS!=ret){
AESM_DBG_ERROR("fail to decode ProvMsg4:%d",tlv_status);
break;
}
ret = msg4_integrity_checking(tlvs_msg4);
if(AE_SUCCESS != ret){
AESM_DBG_ERROR("ProvMsg4 integrity checking error:%d",ret);
break;
}
AESM_DBG_TRACE("ProvMsg4 decoded");
if(!use_ek2_in_input){ //we need generate ek2
prov_get_ek2_input_t ek2_input;
if(memcpy_s(ek2_input.nonce, NONCE_SIZE, MSG4_TOP_FIELD_NONCE.payload, NONCE_SIZE)!=0){
AESM_DBG_ERROR("fail in memcpy");
ret = PVE_UNEXPECTED_ERROR;
break;
}
if(memcpy_s(ek2_input.xid, XID_SIZE, msg4_header->xid, XID_SIZE)!=0){
AESM_DBG_ERROR("fail in memcpy");
ret = PVE_UNEXPECTED_ERROR;
break;
}
//call PvE to get EK2
se_static_assert(SK_SIZE == sizeof(prov_get_ek2_output_t));
ret = (ae_error_t)get_ek2(&ek2_input, reinterpret_cast<prov_get_ek2_output_t *>(local_ek2));
if(AE_SUCCESS != ret){
AESM_DBG_ERROR("fail to get EK2:%d",ret);
break;
}
}else{//reuse ek2 generated in processing ProvMsg2
if(0!=memcpy_s(local_ek2, sizeof(local_ek2), ek2, SK_SIZE)){
AESM_DBG_ERROR("fail in memcpy");
ret = PVE_UNEXPECTED_ERROR;
break;
}
}
se_static_assert(SK_SIZE==sizeof(sgx_aes_gcm_128bit_key_t));
tlv_msg_t field1 = block_cipher_tlv_get_encrypted_text(MSG4_TOP_FIELD_DATA);
decoded_msg4 = reinterpret_cast<uint8_t *>(malloc(field1.msg_size));
if(NULL == decoded_msg4){
AESM_DBG_ERROR("malloc error");
ret = AE_OUT_OF_MEMORY_ERROR;
break;
}
sgx_status_t sgx_status = sgx_rijndael128GCM_decrypt(reinterpret_cast<const sgx_aes_gcm_128bit_key_t *>(local_ek2),
field1.msg_buf, field1.msg_size, decoded_msg4,
reinterpret_cast<uint8_t *>(block_cipher_tlv_get_iv(MSG4_TOP_FIELD_DATA)), IV_SIZE,
reinterpret_cast<const uint8_t *>(msg4_header), PROVISION_RESPONSE_HEADER_SIZE,
reinterpret_cast<const sgx_aes_gcm_128bit_tag_t *>(MSG4_TOP_FIELD_MAC.payload));
if(SGX_ERROR_MAC_MISMATCH == sgx_status){
AESM_DBG_ERROR("fail to decrypt ProvMsg4 by EK2");
ret = PVE_INTEGRITY_CHECK_ERROR;
break;
}
if( AE_SUCCESS != (ret = sgx_error_to_ae_error(sgx_status))){
AESM_DBG_ERROR("error in decrypting ProvMsg4:%d",sgx_status);
break;
}
AESM_DBG_TRACE("ProvMsg4 decrypted by EK2 successfully");
ret = check_epid_pve_pg_status_after_mac_verification(msg4_header);
if(AE_SUCCESS != ret){
AESM_DBG_ERROR("Backend reported error passed MAC verification:%d",ret);
break;
}
TLVsMsg tlvs_field1;
tlv_status = tlvs_field1.init_from_buffer(decoded_msg4, field1.msg_size);
ret = tlv_error_2_pve_error(tlv_status);
if(AE_SUCCESS != ret){
AESM_DBG_ERROR("ProvMsg4 Field2.1 decoding failed:%d",tlv_status);
break;
}
ret = msg4_field1_msg_checking(tlvs_field1);
if( AE_SUCCESS != ret){
AESM_DBG_ERROR("ProvMsg4 Field2.1 invalid:%d",ret);
break;
}
proc_prov_msg4_input_t msg4_input;
if(sizeof(proc_prov_msg4_output_t)!=SGX_TRUSTED_EPID_BLOB_SIZE){
AESM_DBG_FATAL("Trusted ProvMsg4 output buffer size error");
ret = PVE_UNEXPECTED_ERROR;
break;
}
tlv_msg_t tcb_data = block_cipher_tlv_get_encrypted_text(MSG4_FIELD1_ENC_TCB);
tlv_msg_t Axf_data = block_cipher_tlv_get_encrypted_text(MSG4_FIELD1_ENC_Axf);
if(0!=memcpy_s(&msg4_input.group_cert, sizeof(msg4_input.group_cert), MSG4_FIELD1_GROUP_CERT.payload, MSG4_FIELD1_GROUP_CERT.size)||
0!=memcpy_s(&msg4_input.equivalent_psvn, sizeof(psvn_t), device_id_tlv_get_psvn(MSG4_FIELD1_DEVICE_ID), sizeof(psvn_t))||
0!=memcpy_s(&msg4_input.fmsp, sizeof(fmsp_t), device_id_tlv_get_fmsp(MSG4_FIELD1_DEVICE_ID), sizeof(fmsp_t))||
0!=memcpy_s(&msg4_input.tcb_iv, IV_SIZE, block_cipher_tlv_get_iv(MSG4_FIELD1_ENC_TCB), IV_SIZE)||
0!=memcpy_s(&msg4_input.encrypted_tcb, SK_SIZE, tcb_data.msg_buf, tcb_data.msg_size)||
0!=memcpy_s(&msg4_input.tcb_mac, MAC_SIZE, MSG4_FIELD1_MAC_TCB.payload, MSG4_FIELD1_MAC_TCB.size)||
0!=memcpy_s(&msg4_input.member_credential_iv, IV_SIZE, block_cipher_tlv_get_iv(MSG4_FIELD1_ENC_Axf), IV_SIZE)||
0!=memcpy_s(&msg4_input.encrypted_member_credential, HARD_CODED_EPID_MEMBER_WITH_ESCROW_TLV_SIZE, Axf_data.msg_buf, Axf_data.msg_size)||
0!=memcpy_s(&msg4_input.member_credential_mac, MAC_SIZE, MSG4_FIELD1_MAC_Axf.payload, MSG4_FIELD1_MAC_Axf.size)){
AESM_DBG_ERROR("memcpy error");
ret = PVE_UNEXPECTED_ERROR;
break;
}
ret = (ae_error_t)proc_prov_msg4_data(&msg4_input, reinterpret_cast<proc_prov_msg4_output_t *>(data_blob));
AESM_DBG_TRACE("PvE return %d in Process ProvMsg4",ret);
}while(0);
if(decoded_msg4)free(decoded_msg4);
return ret;
}
//Function to decode ProvMsg4 and generate epid data blob
uint32_t CPVEClass::proc_prov_msg4(
const pve_data_t &data,
const uint8_t *msg4,
uint32_t msg4_size,
uint8_t *data_blob,
uint32_t blob_size)
{
ae_error_t ret = AE_SUCCESS;
uint8_t local_ek2[SK_SIZE];
uint8_t *decoded_msg4 = NULL;
uint8_t temp[XID_SIZE+NONCE_SIZE];
sgx_status_t sgx_status;
const provision_response_header_t *msg4_header = reinterpret_cast<const provision_response_header_t *>(msg4);
if(msg4_size < PROVISION_RESPONSE_HEADER_SIZE) {
AESM_DBG_ERROR("invalid msg4 size");
return PVE_MSG_ERROR;
}
if (blob_size != SGX_TRUSTED_EPID_BLOB_SIZE_PAK) {
AESM_DBG_FATAL("invalid input epid blob size");
return PVE_PARAMETER_ERROR;
}
ret = check_prov_msg4_header(msg4_header, msg4_size);
if( AE_SUCCESS != ret) {
AESM_DBG_ERROR("Invalid ProvMsg4 Header:(ae%d)",ret);
return ret;
}
if(0!=memcmp(msg4_header->xid, data.xid, XID_SIZE)) {
AESM_DBG_ERROR("Invalid XID in msg4 header");
return PVE_MSG_ERROR;
}
ret = check_epid_pve_pg_status_before_mac_verification(msg4_header);
if( AE_SUCCESS != ret) {
AESM_DBG_ERROR("Backend return failure in ProvMsg4 Header:(ae%d)",ret);
return ret;
}
do {
TLVsMsg tlvs_msg4;
uint8_t aad[PROVISION_RESPONSE_HEADER_SIZE+NONCE_SIZE];
tlv_status_t tlv_status;
tlv_status = tlvs_msg4.init_from_buffer(msg4+static_cast<uint32_t>(PROVISION_RESPONSE_HEADER_SIZE), msg4_size - static_cast<uint32_t>(PROVISION_RESPONSE_HEADER_SIZE));
ret = tlv_error_2_pve_error(tlv_status);
if(AE_SUCCESS!=ret) {
AESM_DBG_ERROR("fail to decode ProvMsg4:(ae%d)",ret);
break;
}
ret = msg4_integrity_checking(tlvs_msg4);
if(AE_SUCCESS != ret) {
AESM_DBG_ERROR("ProvMsg4 integrity checking error:(ae%d)",ret);
break;
}
AESM_DBG_TRACE("ProvMsg4 decoded");
se_static_assert(sizeof(sgx_cmac_128bit_key_t)==SK_SIZE);
if(0!=memcpy_s(temp,sizeof(temp), data.xid, XID_SIZE)||
0!=memcpy_s(temp+XID_SIZE, sizeof(temp)-XID_SIZE, MSG4_TOP_FIELD_NONCE.payload, NONCE_SIZE)) {
AESM_DBG_ERROR("Fail in memcpy");
ret = AE_FAILURE;
break;
}
if((sgx_status=sgx_rijndael128_cmac_msg(reinterpret_cast<const sgx_cmac_128bit_key_t *>(data.sk),
temp, XID_SIZE+NONCE_SIZE, reinterpret_cast<sgx_cmac_128bit_tag_t *>(local_ek2)))!=SGX_SUCCESS) {
AESM_DBG_ERROR("Fail to generate ek2:(sgx0x%x)",sgx_status);
ret = AE_FAILURE;
break;
}
se_static_assert(SK_SIZE==sizeof(sgx_aes_gcm_128bit_key_t));
tlv_msg_t field1 = block_cipher_tlv_get_encrypted_text(MSG4_TOP_FIELD_DATA);
decoded_msg4 = reinterpret_cast<uint8_t *>(malloc(field1.msg_size));
if(NULL == decoded_msg4) {
AESM_DBG_ERROR("malloc error");
ret = AE_OUT_OF_MEMORY_ERROR;
break;
}
if (memcpy_s(aad, sizeof(aad), msg4_header, PROVISION_RESPONSE_HEADER_SIZE) != 0 ||
memcpy_s(aad + PROVISION_RESPONSE_HEADER_SIZE, sizeof(aad)-PROVISION_RESPONSE_HEADER_SIZE,
MSG4_TOP_FIELD_NONCE.payload, MSG4_TOP_FIELD_NONCE.size) != 0) {
AESM_DBG_ERROR("memcpy failure");
ret = AE_FAILURE;
break;
}
sgx_status_t sgx_status = sgx_rijndael128GCM_decrypt(reinterpret_cast<const sgx_aes_gcm_128bit_key_t *>(local_ek2),
field1.msg_buf, field1.msg_size, decoded_msg4,
reinterpret_cast<uint8_t *>(block_cipher_tlv_get_iv(MSG4_TOP_FIELD_DATA)), IV_SIZE,
aad, sizeof(aad),
reinterpret_cast<const sgx_aes_gcm_128bit_tag_t *>(MSG4_TOP_FIELD_MAC.payload));
if(SGX_ERROR_MAC_MISMATCH == sgx_status) {
AESM_DBG_ERROR("fail to decrypt ProvMsg4 by EK2 (sgx0x%x)",sgx_status);
ret = PVE_INTEGRITY_CHECK_ERROR;
break;
}
if( AE_SUCCESS != (ret = sgx_error_to_ae_error(sgx_status))) {
AESM_DBG_ERROR("error in decrypting ProvMsg4:(sgx0x%x)",sgx_status);
break;
}
AESM_DBG_TRACE("ProvMsg4 decrypted by EK2 successfully");
ret = check_epid_pve_pg_status_after_mac_verification(msg4_header);
if(AE_SUCCESS != ret) {
AESM_DBG_ERROR("Backend reported error passed MAC verification:(ae%d)",ret);
break;
}
TLVsMsg tlvs_field1;
tlv_status = tlvs_field1.init_from_buffer(decoded_msg4, field1.msg_size);
ret = tlv_error_2_pve_error(tlv_status);
if(AE_SUCCESS != ret) {
AESM_DBG_ERROR("ProvMsg4 Field2.1 decoding failed:(ae%d)",ret);
break;
}
ret = msg4_field1_msg_checking(tlvs_field1);
if( AE_SUCCESS != ret) {
AESM_DBG_ERROR("ProvMsg4 Field2.1 invalid:(ae%d)",ret);
break;
}
proc_prov_msg4_input_t msg4_input;
tlv_msg_t Axf_data = block_cipher_tlv_get_encrypted_text(MSG4_FIELD1_ENC_Axf);
if(0!=memcpy_s(&msg4_input.group_cert, sizeof(msg4_input.group_cert), MSG4_FIELD1_GROUP_CERT.payload, MSG4_FIELD1_GROUP_CERT.size)||
0!=memcpy_s(&msg4_input.n2, NONCE_2_SIZE, MSG4_FIELD1_Nonce2.payload, MSG4_FIELD1_Nonce2.size) ||
0!=memcpy_s(&msg4_input.equivalent_psvn, sizeof(psvn_t), platform_info_tlv_get_psvn(MSG4_FIELD1_PLATFORM_INFO), sizeof(psvn_t))||
0!=memcpy_s(&msg4_input.fmsp, sizeof(fmsp_t), platform_info_tlv_get_fmsp(MSG4_FIELD1_PLATFORM_INFO), sizeof(fmsp_t))||
0!=memcpy_s(&msg4_input.member_credential_iv, IV_SIZE, block_cipher_tlv_get_iv(MSG4_FIELD1_ENC_Axf), IV_SIZE)||
0!=memcpy_s(&msg4_input.encrypted_member_credential, HARD_CODED_EPID_MEMBER_WITH_ESCROW_TLV_SIZE, Axf_data.msg_buf, Axf_data.msg_size)||
0!=memcpy_s(&msg4_input.member_credential_mac, MAC_SIZE, MSG4_FIELD1_MAC_Axf.payload, MSG4_FIELD1_MAC_Axf.size)) {
AESM_DBG_ERROR("memcpy error");
ret = PVE_UNEXPECTED_ERROR;
break;
}
if (AE_SUCCESS != (ret =XEGDBlob::instance().read(msg4_input.xegb))) {
AESM_DBG_ERROR("Fail to read extend epid blob info (ae%d)",ret);
return ret;
}
ret = CPVEClass::instance().load_enclave();//Load PvE enclave now
if( ret != AE_SUCCESS) {
AESM_DBG_ERROR("Fail to load PvE enclave:(ae%d)\n",ret);
break;
}
ret = (ae_error_t)proc_prov_msg4_data(&msg4_input, reinterpret_cast<proc_prov_msg4_output_t *>(data_blob));
AESM_DBG_TRACE("PvE return (ae%d) in Process ProvMsg4",ret);
} while(0);
if(decoded_msg4)free(decoded_msg4);
return ret;
}
