Decryptor/LocalAttestationCode/LocalAttestationTrusted.cpp

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#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 "dh_session_protocol.h"
#include "sgx_dh.h"
#include "sgx_tcrypto.h"
#include "LocalAttestationCode_t.h"
#include "sgx_tseal.h"

static class LocalAttestationTrusted{
  dh_session_t global_session_info;
  uint32_t global_session_id=0;
  uint32_t one_successful_la_done;
  sgx_ecc_state_handle_t ecc_state;
  uint8_t verifier_mr_enclave[32];
  SymmetricEncryptionBox symmetricEncryptionBoxApache;
  SymmetricEncryptionBox symmetricEncryptionBoxVerifier;

  extern "C" uint32_t verify_peer_enclave_trust(sgx_dh_session_enclave_identity_t* peer_enclave_identity)
  {
  	uint32_t count; sgx_measurement_t given_mr_signer ;
  	if(!peer_enclave_identity)
  	{
  		return INVALID_PARAMETER_ERROR;
  	}
  	if(one_successful_la_done==0)
  	{
  		// TODO: Set this attribute in the decryptor object.
  		verifier_mr_enclave = peer_enclave_identity->mr_enclave;
  		memset(&(apache_mr_signer.m),0x0,SGX_HASH_SIZE); // "initialization"
  		one_successful_la_done=1;
  	}
  	else // apache enclave
  	{
  		given_mr_signer = peer_enclave_identity->mr_signer;
  		int count;
  		for(count=0; count<SGX_HASH_SIZE; count++)
  		{
  			if( given_mr_signer.m[count] != apache_mr_signer.m[count] )
  				return ENCLAVE_TRUST_ERROR;
  		}
      one_successful_la_done ++;
  	}
  	return SGX_SUCCESS;
  }

  public:
    //Handle the request from Source Enclave for a session
    ATTESTATION_STATUS session_request(sgx_dh_msg1_t *dh_msg1, uint32_t *session_id)
    {
        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)
          return status;

        memcpy(&global_session_info.in_progress.dh_session, &sgx_dh_session, sizeof(sgx_dh_session_t));

        return 0;
    }

    // TODO: Hope to edit the sgx_dh_responder_proc_msg2 call to return 32 byte key.
    //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;
        sgx_status_t status = SUCCESS;
        sgx_dh_session_t sgx_dh_session;
        sgx_dh_session_enclave_identity_t initiator_identity;
        uint32_t verify_return;
        memset(&dh_aek,0, sizeof(sgx_key_128bit_t));

        if(!dh_msg2 || !dh_msg3)
          return INVALID_PARAMETER_ERROR;

        if(global_session_info.status != IN_PROGRESS)
          return INVALID_SESSION; // end_session(); // TODO: DA FUQ RETURN STH HERE.

        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
        status = sgx_dh_responder_proc_msg2(dh_msg2, dh_msg3, &sgx_dh_session, &dh_aek, &initiator_identity);
        if(SGX_SUCCESS != status)
          return status;

        //Verify source enclave's trust
    	  verify_return = verify_peer_enclave_trust(&initiator_identity);
        if(verify_return != 0)
         return verify_return;

    	  if(one_successful_la_done == 1)
          symmetricEncryptionBoxVerifier.set_symmetric_key(dh_aek);
      	else
          symmetricEncryptionBoxApache.set_symmetric_key(dh_aek);
        /*
        //save the session ID, status and initialize the session nonce
        global_session_info.session_id = *session_id;
        global_session_info.status = ACTIVE; // This means that you can't keep calling exchange_report over and over again.
        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));
        */
        return status;
    }

  public:
    LocalAttestationTrusted(): symmetricEncryptionBoxApache(), symmetricEncryptionBoxVerifier();
};