Proceed with attestation only if Attestation IMC returns a discovery response

src/libpts/plugins/imv_attestation/imv_attestation_agent.c

@@ -440,9 +440,8 @@ METHOD(imv_agent_if_t, batch_ending, TNC_Result,
 	}
 
 	/* check the IMV state for the next PA-TNC attributes to send */
-	if (!imv_attestation_build(out_msg, attestation_state,
-							  this->supported_algorithms,
-							  this->supported_dh_groups, this->pts_db))
+	if (!imv_attestation_build(out_msg, state, this->supported_algorithms,
+							   this->supported_dh_groups, this->pts_db))
 	{
 		state->set_recommendation(state,
 								TNC_IMV_ACTION_RECOMMENDATION_NO_RECOMMENDATION,

src/libpts/plugins/imv_attestation/imv_attestation_build.c

@@ -28,18 +28,29 @@
 #include <utils/debug.h>
 
 bool imv_attestation_build(imv_msg_t *out_msg,
-						   imv_attestation_state_t *attestation_state,
+						   imv_state_t *state,
 						   pts_meas_algorithms_t supported_algorithms,
 						   pts_dh_group_t supported_dh_groups,
 						   pts_database_t *pts_db)
 {
+	imv_attestation_state_t *attestation_state;
 	imv_attestation_handshake_state_t handshake_state;
 	pts_t *pts;
 	pa_tnc_attr_t *attr = NULL;
 
+	attestation_state = (imv_attestation_state_t*)state;
 	handshake_state = attestation_state->get_handshake_state(attestation_state);
 	pts = attestation_state->get_pts(attestation_state);
 
+	/**
+	 * Received a response form the Attestation IMC so we can proceeed
+	 */
+	if (handshake_state == IMV_ATTESTATION_STATE_DISCOVERY &&
+	   (state->get_action_flags(state) & IMV_ATTESTATION_FLAG_ALGO))
+	{
+		handshake_state = IMV_ATTESTATION_STATE_NONCE_REQ;
+	}
+
 	/**
 	 * Skip DH Nonce Parameters Request attribute when
 	 *   DH Nonce Exchange is not selected by PTS-IMC side
@@ -80,9 +91,11 @@ bool imv_attestation_build(imv_msg_t *out_msg,
 			out_msg->add_attribute(out_msg, attr);
 
 			attestation_state->set_handshake_state(attestation_state,
-										IMV_ATTESTATION_STATE_NONCE_REQ);
+										IMV_ATTESTATION_STATE_DISCOVERY);
 			break;
 		}
+		case IMV_ATTESTATION_STATE_DISCOVERY:
+			break;
 		case IMV_ATTESTATION_STATE_NONCE_REQ:
 		{
 			int min_nonce_len;

src/libpts/plugins/imv_attestation/imv_attestation_build.h

@@ -34,14 +34,14 @@
  * Process a TCG PTS attribute
  *
  * @param out_msg				outbound PA-TNC message to be built
- * @param attestation_state		attestation state of a given connection
+ * @param _state				state of a given connection
  * @param supported_algorithms	supported PTS measurement algorithms
  * @param supported_dh_groups	supported DH groups
  * @param pts_db				PTS configuration database
  * @return						TRUE if successful
  */
 bool imv_attestation_build(imv_msg_t *out_msg,
-						   imv_attestation_state_t *attestation_state,
+						   imv_state_t *state,
 						   pts_meas_algorithms_t supported_algorithms,
 						   pts_dh_group_t supported_dh_groups,
 						   pts_database_t *pts_db);

src/libpts/plugins/imv_attestation/imv_attestation_state.h

@@ -50,6 +50,7 @@ enum imv_attestation_flag_t {
  */
 enum imv_attestation_handshake_state_t {
 	IMV_ATTESTATION_STATE_INIT,
+	IMV_ATTESTATION_STATE_DISCOVERY,
 	IMV_ATTESTATION_STATE_NONCE_REQ,
 	IMV_ATTESTATION_STATE_TPM_INIT,
 	IMV_ATTESTATION_STATE_COMP_EVID,