aboutsummaryrefslogtreecommitdiffstats
path: root/src/libimcv/plugins/imv_swid/imv_swid_agent.c
blob: 724611de8ce0dfda22466a631a62b85878fb318c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
/*
 * Copyright (C) 2013-2014 Andreas Steffen
 * HSR Hochschule fuer Technik Rapperswil
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 */

#define _GNU_SOURCE
#include <stdio.h>

#include "imv_swid_agent.h"
#include "imv_swid_state.h"
#include "imv_swid_rest.h"

#include <imcv.h>
#include <imv/imv_agent.h>
#include <imv/imv_msg.h>
#include <ietf/ietf_attr_pa_tnc_error.h>
#include <ita/ita_attr.h>
#include <ita/ita_attr_angel.h>
#include "tcg/seg/tcg_seg_attr_max_size.h"
#include "tcg/seg/tcg_seg_attr_seg_env.h"
#include "tcg/swid/tcg_swid_attr_req.h"
#include "tcg/swid/tcg_swid_attr_tag_inv.h"
#include "tcg/swid/tcg_swid_attr_tag_id_inv.h"
#include "swid/swid_error.h"
#include "swid/swid_inventory.h"

#include <tncif_names.h>
#include <tncif_pa_subtypes.h>

#include <pen/pen.h>
#include <utils/debug.h>
#include <bio/bio_reader.h>

typedef struct private_imv_swid_agent_t private_imv_swid_agent_t;

#define SWID_MAX_ATTR_SIZE	1000000000

/* Subscribed PA-TNC message subtypes */
static pen_type_t msg_types[] = {
	{ PEN_TCG, PA_SUBTYPE_TCG_SWID }
};

/**
 * Flag set when corresponding attribute has been received
 */
enum imv_swid_attr_t {
	IMV_SWID_ATTR_TAG_INV =    (1<<0),
	IMV_SWID_ATTR_TAG_ID_INV = (1<<1)
};

/**
 * Private data of an imv_swid_agent_t object.
 */
struct private_imv_swid_agent_t {

	/**
	 * Public members of imv_swid_agent_t
	 */
	imv_agent_if_t public;

	/**
	 * IMV agent responsible for generic functions
	 */
	imv_agent_t *agent;

	/**
	 * REST API to strongTNC manager
	 */
	imv_swid_rest_t *rest_api;

};

METHOD(imv_agent_if_t, bind_functions, TNC_Result,
	private_imv_swid_agent_t *this, TNC_TNCS_BindFunctionPointer bind_function)
{
	return this->agent->bind_functions(this->agent, bind_function);
}

METHOD(imv_agent_if_t, notify_connection_change, TNC_Result,
	private_imv_swid_agent_t *this, TNC_ConnectionID id,
	TNC_ConnectionState new_state)
{
	imv_state_t *state;

	switch (new_state)
	{
		case TNC_CONNECTION_STATE_CREATE:
			state = imv_swid_state_create(id);
			return this->agent->create_state(this->agent, state);
		case TNC_CONNECTION_STATE_DELETE:
			return this->agent->delete_state(this->agent, id);
		default:
			return this->agent->change_state(this->agent, id, new_state, NULL);
	}
}

/**
 * Process a received message
 */
static TNC_Result receive_msg(private_imv_swid_agent_t *this,
							  imv_state_t *state, imv_msg_t *in_msg)
{
	imv_swid_state_t *swid_state;
	imv_msg_t *out_msg;
	enumerator_t *enumerator;
	pa_tnc_attr_t *attr;
	TNC_Result result;
	bool fatal_error = FALSE;

	/* generate an outgoing PA-TNC message - we might need it */
	out_msg = imv_msg_create_as_reply(in_msg);

	/* parse received PA-TNC message and handle local and remote errors */
	result = in_msg->receive(in_msg, out_msg, &fatal_error);
	if (result != TNC_RESULT_SUCCESS)
	{
		out_msg->destroy(out_msg);
		return result;
	}

	swid_state = (imv_swid_state_t*)state;

	/* analyze PA-TNC attributes */
	enumerator = in_msg->create_attribute_enumerator(in_msg);
	while (enumerator->enumerate(enumerator, &attr))
	{
		uint32_t request_id = 0, last_eid, eid_epoch;
		swid_inventory_t *inventory;
		pen_type_t type;

		type = attr->get_type(attr);

		if (type.vendor_id == PEN_IETF && type.type == IETF_ATTR_PA_TNC_ERROR)
		{
			ietf_attr_pa_tnc_error_t *error_attr;
			pen_type_t error_code;
			chunk_t msg_info, description;
			bio_reader_t *reader;
			uint32_t max_attr_size;
			bool success;

			error_attr = (ietf_attr_pa_tnc_error_t*)attr;
			error_code = error_attr->get_error_code(error_attr);

			if (error_code.vendor_id == PEN_TCG)
			{
				fatal_error = TRUE;
				msg_info = error_attr->get_msg_info(error_attr);
				reader = bio_reader_create(msg_info);
				success = reader->read_uint32(reader, &request_id);

				DBG1(DBG_IMV, "received TCG error '%N' for request %d",
					 swid_error_code_names, error_code.type, request_id);
				if (!success)
				{
					reader->destroy(reader);
					continue;
				}
				if (error_code.type == TCG_SWID_RESPONSE_TOO_LARGE)
				{
					if (!reader->read_uint32(reader, &max_attr_size))
					{
						reader->destroy(reader);
						continue;
					}
					DBG1(DBG_IMV, "  maximum PA-TNC attribute size is %u bytes",
						max_attr_size);
				}
				description = reader->peek(reader);
				if (description.len)
				{ 
					DBG1(DBG_IMV, "  description: %.*s", description.len,
														 description.ptr);
				}
				reader->destroy(reader);
			}
		}
		else if (type.vendor_id == PEN_ITA)
		{
			switch (type.type)
			{
				case ITA_ATTR_START_ANGEL:
					swid_state->set_angel_count(swid_state, TRUE);
					continue;
				case ITA_ATTR_STOP_ANGEL:
					swid_state->set_angel_count(swid_state, FALSE);
					continue;
				default:
					continue;
			}
		}
		else if (type.vendor_id != PEN_TCG)
		{
			continue;
		}

		switch (type.type)
		{
			case TCG_SWID_TAG_ID_INVENTORY:
			{
				tcg_swid_attr_tag_id_inv_t *attr_cast;
				int tag_id_count;

				state->set_action_flags(state, IMV_SWID_ATTR_TAG_ID_INV);

				attr_cast = (tcg_swid_attr_tag_id_inv_t*)attr;
				request_id = attr_cast->get_request_id(attr_cast);
				last_eid = attr_cast->get_last_eid(attr_cast, &eid_epoch);
				inventory = attr_cast->get_inventory(attr_cast);
				tag_id_count = inventory->get_count(inventory);

				DBG2(DBG_IMV, "received SWID tag ID inventory with %d item%s "
							  "for request %d at eid %d of epoch 0x%08x",
							   tag_id_count, (tag_id_count == 1) ? "" : "s",
							   request_id, last_eid, eid_epoch);

				if (request_id == swid_state->get_request_id(swid_state))
				{
					swid_state->set_swid_inventory(swid_state, inventory);
					swid_state->set_count(swid_state, tag_id_count, 0);
				}
				else
				{
					DBG1(DBG_IMV, "no workitem found for SWID tag ID inventory "
								  "with request ID %d", request_id);
				}
				break;
			 }
			case TCG_SWID_TAG_INVENTORY:
			{
				tcg_swid_attr_tag_inv_t *attr_cast;
				swid_tag_t *tag;
				chunk_t tag_encoding;
				json_object *jobj, *jarray, *jstring;
				char *tag_str;
				int tag_count;
				enumerator_t *e;

				state->set_action_flags(state, IMV_SWID_ATTR_TAG_INV);

				attr_cast = (tcg_swid_attr_tag_inv_t*)attr;
				request_id = attr_cast->get_request_id(attr_cast);
				last_eid = attr_cast->get_last_eid(attr_cast, &eid_epoch);
				inventory = attr_cast->get_inventory(attr_cast);
				tag_count = inventory->get_count(inventory);

				DBG2(DBG_IMV, "received SWID tag inventory with %d item%s for "
							  "request %d at eid %d of epoch 0x%08x",
							   tag_count, (tag_count == 1) ? "" : "s",
							   request_id, last_eid, eid_epoch);


				if (request_id == swid_state->get_request_id(swid_state))
				{
					swid_state->set_count(swid_state, 0, tag_count);

					if (this->rest_api)
					{
						jobj = json_object_new_object();
						jarray = json_object_new_array();
						json_object_object_add(jobj, "data", jarray);

						e = inventory->create_enumerator(inventory);
						while (e->enumerate(e, &tag))
						{
							tag_encoding = tag->get_encoding(tag);
							tag_str = strndup(tag_encoding.ptr, tag_encoding.len);
							DBG3(DBG_IMV, "%s", tag_str);
							jstring = json_object_new_string(tag_str);
							json_object_array_add(jarray, jstring);
							free(tag_str);
						}
						e->destroy(e);

						if (this->rest_api->post(this->rest_api,
								"swid/add-tags/", jobj, NULL) != SUCCESS)
						{
							DBG1(DBG_IMV, "error in REST API add-tags request");
						}
						json_object_put(jobj);
					}
				}
				else
				{
					DBG1(DBG_IMV, "no workitem found for SWID tag inventory "
								  "with request ID %d", request_id);
				}
			}
			default:
				continue;
		 }
	}
	enumerator->destroy(enumerator);

	if (fatal_error)
	{
		state->set_recommendation(state,
								TNC_IMV_ACTION_RECOMMENDATION_NO_RECOMMENDATION,
								TNC_IMV_EVALUATION_RESULT_ERROR);
		result = out_msg->send_assessment(out_msg);
		if (result == TNC_RESULT_SUCCESS)
		{
			result = this->agent->provide_recommendation(this->agent, state);
		}
	}
	else
	{
		/* send PA-TNC message with the EXCL flag set */
		result = out_msg->send(out_msg, TRUE);
	}
	out_msg->destroy(out_msg);

	return result;
}

METHOD(imv_agent_if_t, receive_message, TNC_Result,
	private_imv_swid_agent_t *this, TNC_ConnectionID id,
	TNC_MessageType msg_type, chunk_t msg)
{
	imv_state_t *state;
	imv_msg_t *in_msg;
	TNC_Result result;

	if (!this->agent->get_state(this->agent, id, &state))
	{
		return TNC_RESULT_FATAL;
	}
	in_msg = imv_msg_create_from_data(this->agent, state, id, msg_type, msg);
	result = receive_msg(this, state, in_msg);
	in_msg->destroy(in_msg);

	return result;
}

METHOD(imv_agent_if_t, receive_message_long, TNC_Result,
	private_imv_swid_agent_t *this, TNC_ConnectionID id,
	TNC_UInt32 src_imc_id, TNC_UInt32 dst_imv_id,
	TNC_VendorID msg_vid, TNC_MessageSubtype msg_subtype, chunk_t msg)
{
	imv_state_t *state;
	imv_msg_t *in_msg;
	TNC_Result result;

	if (!this->agent->get_state(this->agent, id, &state))
	{
		return TNC_RESULT_FATAL;
	}
	in_msg = imv_msg_create_from_long_data(this->agent, state, id,
					src_imc_id, dst_imv_id, msg_vid, msg_subtype, msg);
	result = receive_msg(this, state, in_msg);
	in_msg->destroy(in_msg);

	return result;

}

METHOD(imv_agent_if_t, batch_ending, TNC_Result,
	private_imv_swid_agent_t *this, TNC_ConnectionID id)
{
	imv_msg_t *out_msg;
	imv_state_t *state;
	imv_session_t *session;
	imv_workitem_t *workitem;
	imv_swid_state_t *swid_state;
	imv_swid_handshake_state_t handshake_state;
	pa_tnc_attr_t *attr;
	TNC_IMVID imv_id;
	TNC_Result result = TNC_RESULT_SUCCESS;
	bool no_workitems = TRUE;
	uint32_t request_id, received;
	uint8_t flags;
	enumerator_t *enumerator;

	if (!this->agent->get_state(this->agent, id, &state))
	{
		return TNC_RESULT_FATAL;
	}
	swid_state = (imv_swid_state_t*)state;
	handshake_state = swid_state->get_handshake_state(swid_state);
	session = state->get_session(state);
	imv_id = this->agent->get_id(this->agent);

	if (handshake_state == IMV_SWID_STATE_END)
	{
		return TNC_RESULT_SUCCESS;
	}

	/* Create an empty out message - we might need it */
	out_msg = imv_msg_create(this->agent, state, id, imv_id, TNC_IMCID_ANY,
							 msg_types[0]);

	if (!imcv_db)
	{
		DBG2(DBG_IMV, "no workitems available - no evaluation possible");
		state->set_recommendation(state,
							TNC_IMV_ACTION_RECOMMENDATION_ALLOW,
							TNC_IMV_EVALUATION_RESULT_DONT_KNOW);
		result = out_msg->send_assessment(out_msg);
		out_msg->destroy(out_msg);
		swid_state->set_handshake_state(swid_state, IMV_SWID_STATE_END);

		if (result != TNC_RESULT_SUCCESS)
		{
			return result;
		}
		return this->agent->provide_recommendation(this->agent, state);
	}

	/* Look for SWID tag workitem and create SWID tag request */
	if (handshake_state == IMV_SWID_STATE_INIT &&
		session->get_policy_started(session))
	{
		size_t max_attr_size = SWID_MAX_ATTR_SIZE;
		size_t max_seg_size;
		seg_contract_t *contract;
		seg_contract_manager_t *contracts;
		char buf[BUF_LEN];

		enumerator = session->create_workitem_enumerator(session);
		if (enumerator)
		{
			while (enumerator->enumerate(enumerator, &workitem))
			{
				if (workitem->get_imv_id(workitem) != TNC_IMVID_ANY ||
					workitem->get_type(workitem) != IMV_WORKITEM_SWID_TAGS)
				{
					continue;
				}
				
				flags = TCG_SWID_ATTR_REQ_FLAG_NONE;
				if (strchr(workitem->get_arg_str(workitem), 'R'))
				{
					flags |= TCG_SWID_ATTR_REQ_FLAG_R;
				}
				if (strchr(workitem->get_arg_str(workitem), 'S'))
				{
					flags |= TCG_SWID_ATTR_REQ_FLAG_S;
				}
				if (strchr(workitem->get_arg_str(workitem), 'C'))
				{
					flags |= TCG_SWID_ATTR_REQ_FLAG_C;
				}

				/* Determine maximum PA-TNC attribute segment size */
				max_seg_size = state->get_max_msg_len(state)
								- PA_TNC_HEADER_SIZE 
								- PA_TNC_ATTR_HEADER_SIZE
								- TCG_SEG_ATTR_SEG_ENV_HEADER;

				/* Announce support of PA-TNC segmentation to IMC */
				contract = seg_contract_create(msg_types[0], max_attr_size,
									max_seg_size, TRUE, imv_id, FALSE);
				contract->get_info_string(contract, buf, BUF_LEN, TRUE);
				DBG2(DBG_IMV, "%s", buf);
				contracts = state->get_contracts(state);
				contracts->add_contract(contracts, contract);
				attr = tcg_seg_attr_max_size_create(max_attr_size,
													max_seg_size, TRUE);
				out_msg->add_attribute(out_msg, attr);

				/* Issue a SWID request */
				request_id = workitem->get_id(workitem);
				swid_state->set_request_id(swid_state, request_id);
				attr = tcg_swid_attr_req_create(flags, request_id, 0);
				out_msg->add_attribute(out_msg, attr);
				workitem->set_imv_id(workitem, imv_id);
				no_workitems = FALSE;
				DBG2(DBG_IMV, "IMV %d issues SWID request %d",
							   imv_id, request_id);
				break;
			}
			enumerator->destroy(enumerator);

			if (no_workitems)
			{
				DBG2(DBG_IMV, "IMV %d has no workitems - "
							  "no evaluation requested", imv_id);
				state->set_recommendation(state,
								TNC_IMV_ACTION_RECOMMENDATION_ALLOW,
								TNC_IMV_EVALUATION_RESULT_DONT_KNOW);
			}
			handshake_state = IMV_SWID_STATE_WORKITEMS;
			swid_state->set_handshake_state(swid_state, handshake_state);
		}
	}

	received = state->get_action_flags(state);

	if (handshake_state == IMV_SWID_STATE_WORKITEMS &&
	   (received & (IMV_SWID_ATTR_TAG_INV|IMV_SWID_ATTR_TAG_ID_INV)) &&
		swid_state->get_angel_count(swid_state) <= 0)
	{
		TNC_IMV_Evaluation_Result eval;
		TNC_IMV_Action_Recommendation rec;
		char result_str[BUF_LEN], *error_str = "", *command;
		char *target, *separator;
		int tag_id_count, tag_count, i;
		size_t max_attr_size, attr_size, entry_size;
		chunk_t tag_creator, unique_sw_id;
		json_object *jrequest, *jresponse, *jvalue;
		tcg_swid_attr_req_t *cast_attr;
		swid_tag_id_t *tag_id;
		status_t status = SUCCESS;

		if (this->rest_api && (received & IMV_SWID_ATTR_TAG_ID_INV))
		{
			if (asprintf(&command, "sessions/%d/swid-measurement/",
						 session->get_session_id(session, NULL, NULL)) < 0)
			{
				error_str = "allocation of command string failed";
				status = FAILED;
			}
			else
			{
				jrequest = swid_state->get_swid_inventory(swid_state);
				status = this->rest_api->post(this->rest_api, command,
											  jrequest, &jresponse);
				if (status == FAILED)
				{
					error_str = "error in REST API swid-measurement request";
				}
				free(command);
			}
		}

		switch (status)
		{
			case SUCCESS:
				enumerator = session->create_workitem_enumerator(session);
				while (enumerator->enumerate(enumerator, &workitem))
				{
					if (workitem->get_type(workitem) == IMV_WORKITEM_SWID_TAGS)
					{
						swid_state->get_count(swid_state, &tag_id_count,
														  &tag_count);
						snprintf(result_str, BUF_LEN, "received inventory of "
								 "%d SWID tag ID%s and %d SWID tag%s",
								 tag_id_count, (tag_id_count == 1) ? "" : "s",
								 tag_count, (tag_count == 1) ? "" : "s");
						session->remove_workitem(session, enumerator);

						eval = TNC_IMV_EVALUATION_RESULT_COMPLIANT;
						rec = workitem->set_result(workitem, result_str, eval);
						state->update_recommendation(state, rec, eval);
						imcv_db->finalize_workitem(imcv_db, workitem);
						workitem->destroy(workitem);
						break;
					}
				}
				enumerator->destroy(enumerator);
				break;
			case NEED_MORE:
				if (received & IMV_SWID_ATTR_TAG_INV)
				{
					error_str = "not all requested SWID tags were received";
					status = FAILED;
					json_object_put(jresponse);
					break;
				}
				if (json_object_get_type(jresponse) != json_type_array)
				{
					error_str = "response was not a json_array";
					status = FAILED;
					json_object_put(jresponse);
					break;
				}

				/* Compute the maximum TCG SWID Request attribute size */
				max_attr_size = state->get_max_msg_len(state) -
								PA_TNC_HEADER_SIZE;

				/* Create the [first] TCG SWID Request attribute */
				attr_size = PA_TNC_ATTR_HEADER_SIZE + TCG_SWID_REQ_MIN_SIZE;			
				attr = tcg_swid_attr_req_create(TCG_SWID_ATTR_REQ_FLAG_NONE,
								swid_state->get_request_id(swid_state), 0);

				tag_id_count = json_object_array_length(jresponse);
				DBG1(DBG_IMV, "%d SWID tag target%s", tag_id_count,
							  (tag_id_count == 1) ? "" : "s");

				for (i = 0; i < tag_id_count; i++)
				{
					jvalue = json_object_array_get_idx(jresponse, i);
					if (json_object_get_type(jvalue) != json_type_string)
					{
						error_str = "json_string element expected in json_array";
						status = FAILED;
						json_object_put(jresponse);
						break;
					}
					target = (char*)json_object_get_string(jvalue);
					DBG1(DBG_IMV, "  %s", target);

					/* Separate target into tag_creator and unique_sw_id */
					separator = strchr(target, '_');
					if (!separator)
					{
						error_str = "separation of regid from "
									"unique software ID failed";
						break;
					}
					tag_creator = chunk_create(target, separator - target);
					separator++;
					unique_sw_id = chunk_create(separator, strlen(target) -
												tag_creator.len - 1);
					tag_id = swid_tag_id_create(tag_creator, unique_sw_id,
												chunk_empty);
					entry_size = 2 + tag_creator.len + 2 + unique_sw_id.len;

					/* Have we reached the maximum attribute size? */
					if (attr_size + entry_size > max_attr_size)
					{
						out_msg->add_attribute(out_msg, attr);
						attr_size = PA_TNC_ATTR_HEADER_SIZE + 
									TCG_SWID_REQ_MIN_SIZE;			
						attr = tcg_swid_attr_req_create(
									TCG_SWID_ATTR_REQ_FLAG_NONE,
									swid_state->get_request_id(swid_state), 0);
					}
					cast_attr = (tcg_swid_attr_req_t*)attr;
					cast_attr->add_target(cast_attr, tag_id);
				}
				json_object_put(jresponse);

				out_msg->add_attribute(out_msg, attr);
				break;
			case FAILED:
			default:
				break;
		}

		if (status == FAILED)
		{
			enumerator = session->create_workitem_enumerator(session);
			while (enumerator->enumerate(enumerator, &workitem))
			{
				if (workitem->get_type(workitem) == IMV_WORKITEM_SWID_TAGS)
				{
					session->remove_workitem(session, enumerator);
					eval = TNC_IMV_EVALUATION_RESULT_ERROR;
					rec = workitem->set_result(workitem, error_str, eval);
					state->update_recommendation(state, rec, eval);
					imcv_db->finalize_workitem(imcv_db, workitem);
					workitem->destroy(workitem);
					break;
				}
			}
			enumerator->destroy(enumerator);
		}
	}

	/* finalized all workitems ? */
	if (handshake_state == IMV_SWID_STATE_WORKITEMS &&
		session->get_workitem_count(session, imv_id) == 0)
	{
		result = out_msg->send_assessment(out_msg);
		out_msg->destroy(out_msg);
		swid_state->set_handshake_state(swid_state, IMV_SWID_STATE_END);

		if (result != TNC_RESULT_SUCCESS)
		{
			return result;
		}
		return this->agent->provide_recommendation(this->agent, state);
	}

	/* send non-empty PA-TNC message with excl flag not set */
	if (out_msg->get_attribute_count(out_msg))
	{
		result = out_msg->send(out_msg, FALSE);
	}
	out_msg->destroy(out_msg);

	return result;
}

METHOD(imv_agent_if_t, solicit_recommendation, TNC_Result,
	private_imv_swid_agent_t *this, TNC_ConnectionID id)
{
	imv_state_t *state;

	if (!this->agent->get_state(this->agent, id, &state))
	{
		return TNC_RESULT_FATAL;
	}
	return this->agent->provide_recommendation(this->agent, state);
}

METHOD(imv_agent_if_t, destroy, void,
	private_imv_swid_agent_t *this)
{
	DESTROY_IF(this->rest_api);
	this->agent->destroy(this->agent);
	free(this);
}

/**
 * Described in header.
 */
imv_agent_if_t *imv_swid_agent_create(const char *name, TNC_IMVID id,
										 TNC_Version *actual_version)
{
	private_imv_swid_agent_t *this;
	imv_agent_t *agent;
	char *rest_api_uri;
	u_int rest_api_timeout;

	agent = imv_agent_create(name, msg_types, countof(msg_types), id,
							 actual_version);
	if (!agent)
	{
		return NULL;
	}
	agent->add_non_fatal_attr_type(agent,
				pen_type_create(PEN_TCG, TCG_SEG_MAX_ATTR_SIZE_REQ));

	INIT(this,
		.public = {
			.bind_functions = _bind_functions,
			.notify_connection_change = _notify_connection_change,
			.receive_message = _receive_message,
			.receive_message_long = _receive_message_long,
			.batch_ending = _batch_ending,
			.solicit_recommendation = _solicit_recommendation,
			.destroy = _destroy,
		},
		.agent = agent,
	);

	rest_api_uri = lib->settings->get_str(lib->settings,
						"%s.plugins.imv-swid.rest_api_uri", NULL, lib->ns);
	rest_api_timeout = lib->settings->get_int(lib->settings,
						"%s.plugins.imv-swid.rest_api_timeout", 120, lib->ns);
	if (rest_api_uri)
	{
		this->rest_api = imv_swid_rest_create(rest_api_uri, rest_api_timeout);
	}

	return &this->public;
}