build PA-TNC message only if there are PA-TNC attributes to send

3 files changed, 43 insertions, 20 deletions

diff --git a/src/libpts/plugins/imv_attestation/imv_attestation.c b/src/libpts/plugins/imv_attestation/imv_attestation.c
index 30c1832ad..4aa393678 100644
--- a/src/libpts/plugins/imv_attestation/imv_attestation.c
+++ b/src/libpts/plugins/imv_attestation/imv_attestation.c
@@ -169,30 +169,52 @@ TNC_Result TNC_IMV_NotifyConnectionChange(TNC_IMVID imv_id,
 static TNC_Result send_message(TNC_ConnectionID connection_id)
 {
 	pa_tnc_msg_t *msg;
+	pa_tnc_attr_t *attr;
 	imv_state_t *state;
 	imv_attestation_state_t *attestation_state;
 	TNC_Result result;
+	linked_list_t *attr_list;
+	enumerator_t *enumerator;
 
 	if (!imv_attestation->get_state(imv_attestation, connection_id, &state))
 	{
 		return TNC_RESULT_FATAL;
 	}
 	attestation_state = (imv_attestation_state_t*)state;
-	msg = pa_tnc_msg_create();
+	attr_list = linked_list_create();
 
-	if (imv_attestation_build(msg, attestation_state, supported_algorithms,
+	if (imv_attestation_build(attr_list, attestation_state, supported_algorithms,
 							  supported_dh_groups, pts_db))
 	{
-		msg->build(msg);
-		result = imv_attestation->send_message(imv_attestation, connection_id,
-											   FALSE, 0, TNC_IMCID_ANY,
-											   msg->get_encoding(msg));
+		if (attr_list->get_count(attr_list))
+		{
+			msg = pa_tnc_msg_create();
+
+			/* move PA-TNC attributes to PA-TNC message */
+			enumerator = attr_list->create_enumerator(attr_list);
+			while (enumerator->enumerate(enumerator, &attr))
+			{
+				msg->add_attribute(msg, attr);
+			}
+			enumerator->destroy(enumerator);
+
+			msg->build(msg);
+			result = imv_attestation->send_message(imv_attestation,
+							connection_id, FALSE, 0, TNC_IMCID_ANY,
+							msg->get_encoding(msg));
+			msg->destroy(msg);
+		}
+		else
+		{
+			result = TNC_RESULT_SUCCESS;
+		}
+		attr_list->destroy(attr_list);
 	}
 	else
 	{
+		attr_list->destroy_offset(attr_list, offsetof(pa_tnc_attr_t, destroy));
 		result = TNC_RESULT_FATAL;
 	}
-	msg->destroy(msg);
 
 	return result;
 }
@@ -310,6 +332,7 @@ static TNC_Result receive_message(TNC_IMVID imv_id,
 	{
 		pa_tnc_msg = pa_tnc_msg_create();
 
+		/* move PA-TNC attributes to PA-TNC message */
 		enumerator = attr_list->create_enumerator(attr_list);
 		while (enumerator->enumerate(enumerator, &attr))
 		{
diff --git a/src/libpts/plugins/imv_attestation/imv_attestation_build.c b/src/libpts/plugins/imv_attestation/imv_attestation_build.c
index 089ecbe9c..efcb1c695 100644
--- a/src/libpts/plugins/imv_attestation/imv_attestation_build.c
+++ b/src/libpts/plugins/imv_attestation/imv_attestation_build.c
@@ -30,7 +30,7 @@
 
 #include <debug.h>
 
-bool imv_attestation_build(pa_tnc_msg_t *msg,
+bool imv_attestation_build(linked_list_t *attr_list,
 						   imv_attestation_state_t *attestation_state,
 						   pts_meas_algorithms_t supported_algorithms,
 						   pts_dh_group_t supported_dh_groups,
@@ -90,12 +90,12 @@ bool imv_attestation_build(pa_tnc_msg_t *msg,
 			flags = pts->get_proto_caps(pts);
 			attr = tcg_pts_attr_proto_caps_create(flags, TRUE);
 			attr->set_noskip_flag(attr, TRUE);
-			msg->add_attribute(msg, attr);
+			attr_list->insert_last(attr_list, attr);
 
 			/* Send Measurement Algorithms attribute */
 			attr = tcg_pts_attr_meas_algo_create(supported_algorithms, FALSE);
 			attr->set_noskip_flag(attr, TRUE);
-			msg->add_attribute(msg, attr);
+			attr_list->insert_last(attr_list, attr);
 
 			attestation_state->set_handshake_state(attestation_state,
 										IMV_ATTESTATION_STATE_NONCE_REQ);
@@ -111,7 +111,7 @@ bool imv_attestation_build(pa_tnc_msg_t *msg,
 			attr = tcg_pts_attr_dh_nonce_params_req_create(min_nonce_len,
 													 supported_dh_groups);
 			attr->set_noskip_flag(attr, TRUE);
-			msg->add_attribute(msg, attr);
+			attr_list->insert_last(attr_list, attr);
 
 			attestation_state->set_handshake_state(attestation_state,
 										IMV_ATTESTATION_STATE_TPM_INIT);
@@ -130,18 +130,18 @@ bool imv_attestation_build(pa_tnc_msg_t *msg,
 				attr = tcg_pts_attr_dh_nonce_finish_create(selected_algorithm,
 											initiator_value, initiator_nonce);
 				attr->set_noskip_flag(attr, TRUE);
-				msg->add_attribute(msg, attr);
+			attr_list->insert_last(attr_list, attr);
 			}
 
 			/* Send Get TPM Version attribute */
 			attr = tcg_pts_attr_get_tpm_version_info_create();
 			attr->set_noskip_flag(attr, TRUE);
-			msg->add_attribute(msg, attr);
+			attr_list->insert_last(attr_list, attr);
 
 			/* Send Get AIK attribute */
 			attr = tcg_pts_attr_get_aik_create();
 			attr->set_noskip_flag(attr, TRUE);
-			msg->add_attribute(msg, attr);
+			attr_list->insert_last(attr_list, attr);
 
 			attestation_state->set_handshake_state(attestation_state,
 										IMV_ATTESTATION_STATE_MEAS);
@@ -187,7 +187,7 @@ bool imv_attestation_build(pa_tnc_msg_t *msg,
 				attr = tcg_pts_attr_req_file_meta_create(is_dir, delimiter,
 														 pathname);
 				attr->set_noskip_flag(attr, TRUE);
-				msg->add_attribute(msg, attr);
+				attr_list->insert_last(attr_list, attr);
 			}
 			enumerator->destroy(enumerator);
 			
@@ -208,7 +208,7 @@ bool imv_attestation_build(pa_tnc_msg_t *msg,
 				attr = tcg_pts_attr_req_file_meas_create(is_dir, request_id,
 													 delimiter, pathname);
 				attr->set_noskip_flag(attr, TRUE);
-				msg->add_attribute(msg, attr);
+				attr_list->insert_last(attr_list, attr);
 			}
 			enumerator->destroy(enumerator);
 			break;
@@ -275,12 +275,12 @@ bool imv_attestation_build(pa_tnc_msg_t *msg,
 			if (attr)
 			{
 				/* Send Request Functional Component Evidence attribute */
-				msg->add_attribute(msg, attr);
+				attr_list->insert_last(attr_list, attr);
 
 				/* Send Generate Attestation Evidence attribute */
 				attr = tcg_pts_attr_gen_attest_evid_create();
 				attr->set_noskip_flag(attr, TRUE);
-				msg->add_attribute(msg, attr);
+				attr_list->insert_last(attr_list, attr);
 			}
 			break;
 		}
diff --git a/src/libpts/plugins/imv_attestation/imv_attestation_build.h b/src/libpts/plugins/imv_attestation/imv_attestation_build.h
index e397e8458..7f934fd09 100644
--- a/src/libpts/plugins/imv_attestation/imv_attestation_build.h
+++ b/src/libpts/plugins/imv_attestation/imv_attestation_build.h
@@ -34,14 +34,14 @@
 /**
  * Process a TCG PTS attribute
  *
- * @param msg					PA-TNC message to be built
+ * @param attr_list				list of PA-TNC attriubutes to be built
  * @param attestation_state		attestation 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(pa_tnc_msg_t *msg,
+bool imv_attestation_build(linked_list_t *attr_list,
 						   imv_attestation_state_t *attestation_state,
 						   pts_meas_algorithms_t supported_algorithms,
 						   pts_dh_group_t supported_dh_groups,