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- /*
- * Copyright (C) 2011-2017 Intel Corporation. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * * Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
- * * Neither the name of Intel Corporation nor the names of its
- * contributors may be used to endorse or promote products derived
- * from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
- #include "sgx_trts.h"
- #include "sgx_utils.h"
- #include "EnclaveMessageExchange.h"
- #include "sgx_eid.h"
- #include "error_codes.h"
- #include "sgx_ecp_types.h"
- #include "sgx_thread.h"
- #include <map>
- #include "dh_session_protocol.h"
- #include "sgx_dh.h"
- #include "sgx_tcrypto.h"
- #include "LocalAttestationCode_t.h"
- #include "sgx_tseal.h"
- #ifdef __cplusplus
- extern "C" {
- #endif
- uint32_t enclave_to_enclave_call_dispatcher(char* decrypted_data, size_t decrypted_data_length, char** resp_buffer, size_t* resp_length);
- uint32_t message_exchange_response_generator(char* decrypted_data, char** resp_buffer, size_t* resp_length);
- uint32_t verify_peer_enclave_trust(sgx_dh_session_enclave_identity_t* peer_enclave_identity);
- #ifdef __cplusplus
- }
- #endif
- #define MAX_SESSION_COUNT 16
- //number of open sessions
- // uint32_t g_session_count = 0;
- ATTESTATION_STATUS generate_session_id(uint32_t *session_id);
- ATTESTATION_STATUS end_session();
- sgx_ec256_private_t signing_priv_key;
- sgx_ecc_state_handle_t ecc_state;
- uint32_t session_ids[MAX_SESSION_COUNT];
- // Our enclave will not be doing LA with more than 1 decryptor enclave at a time.
- // We should not need this.
- //std::map<int, dh_session_t>g_dest_session_info_map;
- dh_session_t global_session_info;
- // TODO: May be we need to store all previously assigned session IDs instead of just the counter; to prevent replay attacks -
- uint32_t global_session_id=0;
- //Handle the request from Source Enclave for a session
- ATTESTATION_STATUS session_request(sgx_dh_msg1_t *dh_msg1,
- uint32_t *session_id )
- {
- // dh_session_t session_info;
- sgx_dh_session_t sgx_dh_session;
- sgx_status_t status = SGX_SUCCESS;
- if(!session_id || !dh_msg1)
- {
- return INVALID_PARAMETER_ERROR;
- }
- //Intialize the session as a session responder
- status = sgx_dh_init_session(SGX_DH_SESSION_RESPONDER, &sgx_dh_session);
- if(SGX_SUCCESS != status)
- {
- return status;
- }
- *session_id=1;
- global_session_info.status = IN_PROGRESS;
- //Generate Message1 that will be returned to Source Enclave
- status = sgx_dh_responder_gen_msg1((sgx_dh_msg1_t*)dh_msg1, &sgx_dh_session);
- if(SGX_SUCCESS != status)
- {
- global_session_id--;
- // SAFE_FREE(g_session_id_tracker[*session_id]);
- return status;
- }
- memcpy(&global_session_info.in_progress.dh_session, &sgx_dh_session, sizeof(sgx_dh_session_t));
- //return sgx_seal_data(0, NULL, 0, NULL, 0, NULL);
- //Store the session information under the correspoding source enlave id key
- // g_dest_session_info_map.insert(std::pair<sgx_enclave_id_t, dh_session_t>(src_enclave_id, session_info));
- return status;
- }
- //Verify Message 2, generate Message3 and exchange Message 3 with Source Enclave
- ATTESTATION_STATUS exchange_report(
- sgx_dh_msg2_t *dh_msg2,
- sgx_dh_msg3_t *dh_msg3,
- uint32_t* session_id)
- {
- sgx_key_128bit_t dh_aek; // Session key
- // dh_session_t session_info;
- ATTESTATION_STATUS status = SUCCESS;
- sgx_dh_session_t sgx_dh_session;
- sgx_dh_session_enclave_identity_t initiator_identity;
- if(!dh_msg2 || !dh_msg3)
- {
- return INVALID_PARAMETER_ERROR;
- }
- memset(&dh_aek,0, sizeof(sgx_key_128bit_t));
- // Why is there a do-while loop anyway? It seems like there is no successful exit ...
- // do
- // {
- // TODO: Make sure that this works - pointers
- // session_info = global_session_info;
- if(global_session_info.status != IN_PROGRESS)
- {
- status = INVALID_SESSION;
- end_session();
- }
- memcpy(&sgx_dh_session, &global_session_info.in_progress.dh_session, sizeof(sgx_dh_session_t));
- dh_msg3->msg3_body.additional_prop_length = 0;
- //Process message 2 from source enclave and obtain message 3
- sgx_status_t se_ret = sgx_dh_responder_proc_msg2(dh_msg2,
- dh_msg3,
- &sgx_dh_session,
- &dh_aek,
- &initiator_identity);
- if(SGX_SUCCESS != se_ret)
- {
- status = se_ret;
- end_session();
- }
- // THIS IS WHERE THE DECRYPTOR VERIFIES THE APACHE'S MRSIGNER IS THE PUBLIC KEY GIVEN AFTER THE LOCAL ATTESTATION WITH THE VERIFIER.
- //Verify source enclave's trust
- uint32_t ret = verify_peer_enclave_trust(&initiator_identity);
- if(ret != SUCCESS)
- {
- return ret; //INVALID_SESSION;
- }
-
- // TODO: Verify that these changes will be lost on update.
- //save the session ID, status and initialize the session nonce
- global_session_info.session_id = *session_id;
- global_session_info.status = ACTIVE;
- global_session_info.active.counter = 0;
- memcpy(&global_session_info.active.AEK, &dh_aek, sizeof(sgx_key_128bit_t));
- memset(&dh_aek,0, sizeof(sgx_key_128bit_t));
- //g_session_count++;*/
- // }while(0);
- return status;
- }
- uint32_t create_ecdsa_key_pair(sgx_ec256_public_t* pub_key, sgx_ec256_private_t* priv_key)
- {
- sgx_status_t se_ret; sgx_status_t se_ret2;
- //create ECC context
- ecc_state = NULL;
- se_ret = sgx_ecc256_open_context(&ecc_state);
- if(SGX_SUCCESS != se_ret)
- return se_ret;
- // generate private key and public key
- se_ret = sgx_ecc256_create_key_pair(priv_key, pub_key, ecc_state);
- se_ret2 = sgx_ecc256_close_context(ecc_state);
- if(SGX_SUCCESS != se_ret && se_ret2!= SGX_SUCCESS) // something weird has happened - couldn't shut it down.
- return 0xFFFFFFFF;
- return SGX_SUCCESS;
- }
- // todo: set to private
- // todo: assumes that the length of the keystring is at least 3*SGX_ECP256_KEY_SIZE
- void serialize_signing_key_pair_to_string(sgx_ec256_public_t* pub_key, sgx_ec256_private_t* signing_priv_key, uint8_t* private_public_key_string)
- {
- if(private_public_key_string != NULL) // nowhere to serialize to
- {
- uint32_t counter;
- if(pub_key != NULL) // public key to serialize
- {
- for(counter=0;counter<SGX_ECP256_KEY_SIZE; counter++)
- *(private_public_key_string+counter)=pub_key->gx[counter];
- for(counter=SGX_ECP256_KEY_SIZE;counter<2*SGX_ECP256_KEY_SIZE; counter++)
- *(private_public_key_string+counter)=pub_key->gy[counter-SGX_ECP256_KEY_SIZE];
- }
- if(signing_priv_key != NULL) // private key to serialize
- {
- for(counter=2*SGX_ECP256_KEY_SIZE;counter<3*SGX_ECP256_KEY_SIZE; counter++)
- *(private_public_key_string+counter)=signing_priv_key->r[counter - 2*SGX_ECP256_KEY_SIZE];
- }
- /*
- if(pub_key != NULL) // public key to serialize
- {
- for(counter=SGX_ECP256_KEY_SIZE;counter<2*SGX_ECP256_KEY_SIZE; counter++)
- *(private_public_key_string+counter)=pub_key->gx[counter-SGX_ECP256_KEY_SIZE];
- for(counter=2*SGX_ECP256_KEY_SIZE;counter<3*SGX_ECP256_KEY_SIZE; counter++)
- *(private_public_key_string+counter)=pub_key->gy[counter-2*SGX_ECP256_KEY_SIZE];
- }*/
- }
- }
- // todo: set to private
- void deserialize_string_to_public_private_key_pair(uint8_t* private_public_key_string, sgx_ec256_public_t* pub_key, sgx_ec256_private_t* signing_priv_key)
- {
- if(private_public_key_string != NULL) // nowhere to deserialize from
- {
- uint32_t counter;
- if(signing_priv_key != NULL)
- {
- for(counter=2*SGX_ECP256_KEY_SIZE;counter<3*SGX_ECP256_KEY_SIZE; counter++)
- signing_priv_key->r[counter-2*SGX_ECP256_KEY_SIZE]=*(private_public_key_string+counter);
- }
- if(pub_key != NULL)
- {
- for(counter=0;counter<SGX_ECP256_KEY_SIZE; counter++)
- pub_key->gx[counter]=*(private_public_key_string+counter);
- for(counter=SGX_ECP256_KEY_SIZE;counter<2*SGX_ECP256_KEY_SIZE; counter++)
- pub_key->gy[counter-SGX_ECP256_KEY_SIZE]=*(private_public_key_string+counter);
- }
- }
- }
- uint32_t create_and_seal_ecdsa_signing_key_pair(__attribute__((unused)) sgx_ec256_public_t* pub_key, __attribute__((unused)) uint32_t* sealed_data_length, __attribute__((unused)) uint8_t* sealed_data)
- {
- uint32_t ret_status; sgx_ec256_private_t private_key; uint32_t counter;
- ret_status=create_ecdsa_key_pair(pub_key, &private_key);
- if(ret_status!=SGX_SUCCESS)
- return ret_status;
- for(counter=0;counter<SGX_ECP256_KEY_SIZE; counter++)
- signing_priv_key.r[counter]=private_key.r[counter];
- // generating the entire string as there is no SGX function to generate the public key from the private one.
- uint8_t* private_public_key_string = (uint8_t*) malloc(3*SGX_ECP256_KEY_SIZE);
- uint8_t* sealed_data2 = (uint8_t*) malloc(*sealed_data_length);
- // serializing keypair to string
- serialize_signing_key_pair_to_string(pub_key, &private_key, private_public_key_string);
- uint8_t* private_key_string = (uint8_t*) malloc(SGX_ECP256_KEY_SIZE);
- for(counter=0;counter<SGX_ECP256_KEY_SIZE;counter++)
- *(private_key_string+counter)=private_key.r[counter];
- // return *sealed_data_length;
- ret_status = sgx_seal_data(0, NULL, 3*SGX_ECP256_KEY_SIZE, private_public_key_string, *sealed_data_length, (sgx_sealed_data_t*) sealed_data2);
- for(counter=0;counter<*sealed_data_length;counter++)
- *(sealed_data+counter)=*(sealed_data2+counter);
- free(sealed_data2);
- free(private_key_string); //free(private_key);
- free(private_public_key_string);
- return ret_status; // SGX_SUCCESS;
- }
- /*
- uint32_t unseal_and_restore_sealed_signing_key_pair(__attribute__((unused)) sgx_ec256_public_t* pub_key, __attribute__((unused)) uint8_t* sealed_data, __attribute__((unused)) uint32_t* sgx_sealed_data_length)
- {
- return SGX_SUCCESS;
- }*/
- uint32_t unseal_and_restore_sealed_signing_key_pair(__attribute__((unused)) sgx_ec256_public_t* pub_key, uint8_t* sealed_data, size_t* sgx_sealed_data_length)
- {
- uint32_t expected_plaintext_msg_length; uint8_t* temp_plaintext; uint32_t counter; uint32_t ret_status;
- expected_plaintext_msg_length = sgx_get_encrypt_txt_len((sgx_sealed_data_t*)sealed_data);
- if(expected_plaintext_msg_length == 0xffffffff)
- return 0xFFFFFFFF;
- // uint32_t return_status;
- uint8_t* sealed_data2 = (uint8_t*) malloc(*sgx_sealed_data_length);
- for(counter=0;counter<*sgx_sealed_data_length;counter++)
- {
- *(sealed_data2+counter)=*(sealed_data+counter);
- }
- temp_plaintext = (uint8_t*)malloc( expected_plaintext_msg_length );
- ret_status = sgx_unseal_data((sgx_sealed_data_t*)sealed_data2, NULL, 0, temp_plaintext, &expected_plaintext_msg_length);
- if(ret_status != SGX_SUCCESS)
- {
- free(temp_plaintext);free(sealed_data2);
- switch(ret_status)
- {
- case SGX_ERROR_MAC_MISMATCH:
- // MAC of the sealed data is incorrect. The sealed data has been tampered.
- break;
- case SGX_ERROR_INVALID_ATTRIBUTE:
- // Indicates attribute field of the sealed data is incorrect.
- break;
- case SGX_ERROR_INVALID_ISVSVN:
- // Indicates isv_svn field of the sealed data is greater than the enclave�s ISVSVN. This is a downgraded enclave.
- break;
- case SGX_ERROR_INVALID_CPUSVN:
- // Indicates cpu_svn field of the sealed data is greater than the platform�s cpu_svn. enclave is on a downgraded platform.
- break;
- case SGX_ERROR_INVALID_KEYNAME:
- // Indicates key_name field of the sealed data is incorrect.
- break;
- default:
- // other errors
- break;
- }
- return ret_status;
- }
-
- deserialize_string_to_public_private_key_pair(temp_plaintext, pub_key, &signing_priv_key);
- free(temp_plaintext); free(sealed_data2);
- return SGX_SUCCESS;
- }
- uint32_t calculate_sealed_data_size( uint32_t input_size)
- {
- // *op_size=sgx_calc_sealed_data_size(0, input_size);
- return sgx_calc_sealed_data_size(0, input_size);
- }
- /*
- uint32_t create_ecdsa_key_pair( sgx_ec256_public_t* pub_key )
- {
- //sgx_ec256_public_t pub_key;
- sgx_status_t se_ret;
- //create ECC context
- ecc_state = NULL;
- se_ret = sgx_ecc256_open_context(&ecc_state);
- if(SGX_SUCCESS != se_ret)
- {
- return se_ret;
- }
- // generate private key and public key
- se_ret = sgx_ecc256_create_key_pair(&signing_priv_key, pub_key, ecc_state);
- if(SGX_SUCCESS != se_ret)
- return se_ret;
- se_ret = sgx_ecc256_close_context(ecc_state);
- // if(SGX_SUCCESS != se_ret)
- // return se_ret;
- return se_ret;
- }
- */
- /*
- uint32_t generate_and_seal_signing_private_key(uint8_t* pub_key, )
- {
- uint32_t ret_status;
- ret_status=create_ecdsa_key_pair(pub_key);
- if(ret_status!=SGX_SUCCESS)
- return ret_status;
- uint8_t* public_key_string = (uint8_t*) malloc(2*SGX_ECP256_KEY_SIZE);
- uint32_t counter;
- for(counter=0;counter<SGX_ECP256_KEY_SIZE; counter++)
- {
- *(public_key_string+counter)=pub_key->gx[counter];
- }
- for(counter=SGX_ECP256_KEY_SIZE;counter<2*SGX_ECP256_KEY_SIZE; counter++)
- {
- *(public_key_string+counter)=pub_key->gy[counter];
- }
- // sgx_seal_data() call
- uint32_t expected_sealed_data_length=sgx_calc_sealed_data_size(0,2*ECP256_KEY_SIZE);
- if(expected_sealed_data_length == 0xFFFFFFFF)
- return 0xFFFFFFFF;
- uint8_t* sealed_data=(uint8_t*) malloc(expected_sealed_data_length);
- sgx_sealed_data_t sealed_data;
- sgx_seal_data(0, NULL, public_key_string, 2*ECP256_KEY_SIZE, );
- free(public_key_string);
- }
- */
- /*
- uint32_t sign_with_signing_private_key(uint8_t* data, uint8_t* length)
- {
- }
- */
- // uint32_t create_
- /*
- //Request for the response size, send the request message to the destination enclave and receive the response message back
- ATTESTATION_STATUS send_request_receive_response(
- sgx_enclave_id_t dest_enclave_id,
- dh_session_t *session_info,
- char *inp_buff,
- size_t inp_buff_len,
- size_t max_out_buff_size,
- char **out_buff,
- size_t* out_buff_len)
- {
- const uint8_t* plaintext;
- uint32_t plaintext_length;
- sgx_status_t status;
- uint32_t retstatus;
- secure_message_t* req_message;
- secure_message_t* resp_message;
- uint8_t *decrypted_data;
- uint32_t decrypted_data_length;
- uint32_t plain_text_offset;
- uint8_t l_tag[TAG_SIZE];
- size_t max_resp_message_length;
- plaintext = (const uint8_t*)(" ");
- plaintext_length = 0;
- if(!session_info || !inp_buff)
- {
- return INVALID_PARAMETER_ERROR;
- }
- // TODO: Figure out what this was supposed to be for.
- //Check if the nonce for the session has not exceeded 2^32-2 if so end session and start a new session
- if(session_info->active.counter == ((uint32_t) - 2))
- {
- close_session(src_enclave_id, dest_enclave_id);
- create_session(src_enclave_id, dest_enclave_id, session_info);
- }
- //Allocate memory for the AES-GCM request message
- req_message = (secure_message_t*)malloc(sizeof(secure_message_t)+ inp_buff_len);
- if(!req_message)
- {
- return MALLOC_ERROR;
- }
- memset(req_message,0,sizeof(secure_message_t)+ inp_buff_len);
- const uint32_t data2encrypt_length = (uint32_t)inp_buff_len;
- //Set the payload size to data to encrypt length
- req_message->message_aes_gcm_data.payload_size = data2encrypt_length;
- //Use the session nonce as the payload IV
- memcpy(req_message->message_aes_gcm_data.reserved,&session_info->active.counter,sizeof(session_info->active.counter));
- //Set the session ID of the message to the current session id
- req_message->session_id = session_info->session_id;
- //Prepare the request message with the encrypted payload
- status = sgx_rijndael128GCM_encrypt(&session_info->active.AEK, (uint8_t*)inp_buff, data2encrypt_length,
- reinterpret_cast<uint8_t *>(&(req_message->message_aes_gcm_data.payload)),
- reinterpret_cast<uint8_t *>(&(req_message->message_aes_gcm_data.reserved)),
- sizeof(req_message->message_aes_gcm_data.reserved), plaintext, plaintext_length,
- &(req_message->message_aes_gcm_data.payload_tag));
- if(SGX_SUCCESS != status)
- {
- SAFE_FREE(req_message);
- return status;
- }
- //Allocate memory for the response payload to be copied
- *out_buff = (char*)malloc(max_out_buff_size);
- if(!*out_buff)
- {
- SAFE_FREE(req_message);
- return MALLOC_ERROR;
- }
- memset(*out_buff, 0, max_out_buff_size);
- //Allocate memory for the response message
- resp_message = (secure_message_t*)malloc(sizeof(secure_message_t)+ max_out_buff_size);
- if(!resp_message)
- {
- SAFE_FREE(req_message);
- return MALLOC_ERROR;
- }
- memset(resp_message, 0, sizeof(secure_message_t)+ max_out_buff_size);
- // TODO: This should not exist.
- //Ocall to send the request to the Destination Enclave and get the response message back
- status = send_request_ocall(&retstatus, src_enclave_id, dest_enclave_id, req_message,
- (sizeof(secure_message_t)+ inp_buff_len), max_out_buff_size,
- resp_message, (sizeof(secure_message_t)+ max_out_buff_size));
- if (status == SGX_SUCCESS)
- {
- if ((ATTESTATION_STATUS)retstatus != SUCCESS)
- {
- SAFE_FREE(req_message);
- SAFE_FREE(resp_message);
- return ((ATTESTATION_STATUS)retstatus);
- }
- }
- else
- {
- SAFE_FREE(req_message);
- SAFE_FREE(resp_message);
- return ATTESTATION_SE_ERROR;
- }
- max_resp_message_length = sizeof(secure_message_t)+ max_out_buff_size;
- if(sizeof(resp_message) > max_resp_message_length)
- {
- SAFE_FREE(req_message);
- SAFE_FREE(resp_message);
- return INVALID_PARAMETER_ERROR;
- }
- //Code to process the response message from the Destination Enclave
- decrypted_data_length = resp_message->message_aes_gcm_data.payload_size;
- plain_text_offset = decrypted_data_length;
- decrypted_data = (uint8_t*)malloc(decrypted_data_length);
- if(!decrypted_data)
- {
- SAFE_FREE(req_message);
- SAFE_FREE(resp_message);
- return MALLOC_ERROR;
- }
- memset(&l_tag, 0, 16);
- memset(decrypted_data, 0, decrypted_data_length);
- //Decrypt the response message payload
- status = sgx_rijndael128GCM_decrypt(&session_info->active.AEK, resp_message->message_aes_gcm_data.payload,
- decrypted_data_length, decrypted_data,
- reinterpret_cast<uint8_t *>(&(resp_message->message_aes_gcm_data.reserved)),
- sizeof(resp_message->message_aes_gcm_data.reserved), &(resp_message->message_aes_gcm_data.payload[plain_text_offset]), plaintext_length,
- &resp_message->message_aes_gcm_data.payload_tag);
- if(SGX_SUCCESS != status)
- {
- SAFE_FREE(req_message);
- SAFE_FREE(decrypted_data);
- SAFE_FREE(resp_message);
- return status;
- }
- // Verify if the nonce obtained in the response is equal to the session nonce + 1 (Prevents replay attacks)
- if(*(resp_message->message_aes_gcm_data.reserved) != (session_info->active.counter + 1 ))
- {
- SAFE_FREE(req_message);
- SAFE_FREE(resp_message);
- SAFE_FREE(decrypted_data);
- return INVALID_PARAMETER_ERROR;
- }
- //Update the value of the session nonce in the source enclave
- session_info->active.counter = session_info->active.counter + 1;
- memcpy(out_buff_len, &decrypted_data_length, sizeof(decrypted_data_length));
- memcpy(*out_buff, decrypted_data, decrypted_data_length);
- SAFE_FREE(decrypted_data);
- SAFE_FREE(req_message);
- SAFE_FREE(resp_message);
- return SUCCESS;
- }
- */
- /*
- //Process the request from the Source enclave and send the response message back to the Source enclave
- ATTESTATION_STATUS generate_response(sgx_enclave_id_t src_enclave_id,
- secure_message_t* req_message,
- size_t req_message_size,
- size_t max_payload_size,
- secure_message_t* resp_message,
- size_t resp_message_size)
- {
- const uint8_t* plaintext;
- uint32_t plaintext_length;
- uint8_t *decrypted_data;
- uint32_t decrypted_data_length;
- uint32_t plain_text_offset;
- ms_in_msg_exchange_t * ms;
- size_t resp_data_length;
- size_t resp_message_calc_size;
- char* resp_data;
- uint8_t l_tag[TAG_SIZE];
- size_t header_size, expected_payload_size;
- dh_session_t *session_info;
- secure_message_t* temp_resp_message;
- uint32_t ret;
- sgx_status_t status;
- plaintext = (const uint8_t*)(" ");
- plaintext_length = 0;
- if(!req_message || !resp_message)
- {
- return INVALID_PARAMETER_ERROR;
- }
- // TODO: Set session_info from somewhere.
- //Get the session information from the map corresponding to the source enclave id
- std::map<sgx_enclave_id_t, dh_session_t>::iterator it = g_dest_session_info_map.find(src_enclave_id);
- if(it != g_dest_session_info_map.end())
- {
- session_info = &it->second;
- }
- else
- {
- return INVALID_SESSION;
- }
- if(session_info->status != ACTIVE)
- {
- return INVALID_SESSION;
- }
- //Set the decrypted data length to the payload size obtained from the message
- decrypted_data_length = req_message->message_aes_gcm_data.payload_size;
- header_size = sizeof(secure_message_t);
- expected_payload_size = req_message_size - header_size;
- //Verify the size of the payload
- if(expected_payload_size != decrypted_data_length)
- return INVALID_PARAMETER_ERROR;
- memset(&l_tag, 0, 16);
- plain_text_offset = decrypted_data_length;
- decrypted_data = (uint8_t*)malloc(decrypted_data_length);
- if(!decrypted_data)
- {
- return MALLOC_ERROR;
- }
- memset(decrypted_data, 0, decrypted_data_length);
- //Decrypt the request message payload from source enclave
- status = sgx_rijndael128GCM_decrypt(&session_info->active.AEK, req_message->message_aes_gcm_data.payload,
- decrypted_data_length, decrypted_data,
- reinterpret_cast<uint8_t *>(&(req_message->message_aes_gcm_data.reserved)),
- sizeof(req_message->message_aes_gcm_data.reserved), &(req_message->message_aes_gcm_data.payload[plain_text_offset]), plaintext_length,
- &req_message->message_aes_gcm_data.payload_tag);
- if(SGX_SUCCESS != status)
- {
- SAFE_FREE(decrypted_data);
- return status;
- }
- //Casting the decrypted data to the marshaling structure type to obtain type of request (generic message exchange/enclave to enclave call)
- ms = (ms_in_msg_exchange_t *)decrypted_data;
- // Verify if the nonce obtained in the request is equal to the session nonce
- if((uint32_t)*(req_message->message_aes_gcm_data.reserved) != session_info->active.counter || *(req_message->message_aes_gcm_data.reserved) > ((2^32)-2))
- {
- SAFE_FREE(decrypted_data);
- return INVALID_PARAMETER_ERROR;
- }
- if(ms->msg_type == MESSAGE_EXCHANGE)
- {
- //Call the generic secret response generator for message exchange
- ret = message_exchange_response_generator((char*)decrypted_data, &resp_data, &resp_data_length);
- if(ret !=0)
- {
- SAFE_FREE(decrypted_data);
- SAFE_FREE(resp_data);
- return INVALID_SESSION;
- }
- }
- else if(ms->msg_type == ENCLAVE_TO_ENCLAVE_CALL)
- {
- //Call the destination enclave's dispatcher to call the appropriate function in the destination enclave
- ret = enclave_to_enclave_call_dispatcher((char*)decrypted_data, decrypted_data_length, &resp_data, &resp_data_length);
- if(ret !=0)
- {
- SAFE_FREE(decrypted_data);
- SAFE_FREE(resp_data);
- return INVALID_SESSION;
- }
- }
- else
- {
- SAFE_FREE(decrypted_data);
- return INVALID_REQUEST_TYPE_ERROR;
- }
- if(resp_data_length > max_payload_size)
- {
- SAFE_FREE(resp_data);
- SAFE_FREE(decrypted_data);
- return OUT_BUFFER_LENGTH_ERROR;
- }
- resp_message_calc_size = sizeof(secure_message_t)+ resp_data_length;
- if(resp_message_calc_size > resp_message_size)
- {
- SAFE_FREE(resp_data);
- SAFE_FREE(decrypted_data);
- return OUT_BUFFER_LENGTH_ERROR;
- }
- //Code to build the response back to the Source Enclave
- temp_resp_message = (secure_message_t*)malloc(resp_message_calc_size);
- if(!temp_resp_message)
- {
- SAFE_FREE(resp_data);
- SAFE_FREE(decrypted_data);
- return MALLOC_ERROR;
- }
- memset(temp_resp_message,0,sizeof(secure_message_t)+ resp_data_length);
- const uint32_t data2encrypt_length = (uint32_t)resp_data_length;
- temp_resp_message->session_id = session_info->session_id;
- temp_resp_message->message_aes_gcm_data.payload_size = data2encrypt_length;
- //Increment the Session Nonce (Replay Protection)
- session_info->active.counter = session_info->active.counter + 1;
- //Set the response nonce as the session nonce
- memcpy(&temp_resp_message->message_aes_gcm_data.reserved,&session_info->active.counter,sizeof(session_info->active.counter));
- //Prepare the response message with the encrypted payload
- status = sgx_rijndael128GCM_encrypt(&session_info->active.AEK, (uint8_t*)resp_data, data2encrypt_length,
- reinterpret_cast<uint8_t *>(&(temp_resp_message->message_aes_gcm_data.payload)),
- reinterpret_cast<uint8_t *>(&(temp_resp_message->message_aes_gcm_data.reserved)),
- sizeof(temp_resp_message->message_aes_gcm_data.reserved), plaintext, plaintext_length,
- &(temp_resp_message->message_aes_gcm_data.payload_tag));
- if(SGX_SUCCESS != status)
- {
- SAFE_FREE(resp_data);
- SAFE_FREE(decrypted_data);
- SAFE_FREE(temp_resp_message);
- return status;
- }
- memset(resp_message, 0, sizeof(secure_message_t)+ resp_data_length);
- memcpy(resp_message, temp_resp_message, sizeof(secure_message_t)+ resp_data_length);
- SAFE_FREE(decrypted_data);
- SAFE_FREE(resp_data);
- SAFE_FREE(temp_resp_message);
- return SUCCESS;
- }
- */
- /*
- //Close a current session
- ATTESTATION_STATUS close_session(sgx_enclave_id_t src_enclave_id,
- sgx_enclave_id_t dest_enclave_id)
- {
- sgx_status_t status;
- uint32_t retstatus;
- //Ocall to ask the destination enclave to end the session
- status = end_session_ocall(&retstatus, src_enclave_id, dest_enclave_id);
- if (status == SGX_SUCCESS)
- {
- if ((ATTESTATION_STATUS)retstatus != SUCCESS)
- return ((ATTESTATION_STATUS)retstatus);
- }
- else
- {
- return ATTESTATION_SE_ERROR;
- }
- return SUCCESS;
- }
- */
- // TODO: Fix this.
- //Respond to the request from the Source Enclave to close the session
- ATTESTATION_STATUS end_session(/**/)
- {
- return SUCCESS;
- }
- /*
- // Session_id is set to the first index of the pointer array that is non-null.(Not sure how it is ensured that all of them point to NULL at the start)
- // Why can't it just keep a counter that is incremented? What are the values of g_session_id_tracker array?
- //Returns a new sessionID for the source destination session
- ATTESTATION_STATUS generate_session_id(uint32_t *session_id)
- {
- ATTESTATION_STATUS status = SUCCESS;
- if(!session_id)
- {
- return INVALID_PARAMETER_ERROR;
- }
- //if the session structure is untintialized, set that as the next session ID
- for (int i = 0; i < MAX_SESSION_COUNT; i++)
- {
- if (g_session_id_tracker[i] == NULL)
- {
- *session_id = i;
- return status;
- }
- }
- status = NO_AVAILABLE_SESSION_ERROR;
- return status;
- */
- // *session_id=++global_session_id;
- //}
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