summaryrefslogtreecommitdiff
path: root/src/pluto/kernel_alg.c
blob: 571d9cc9bbd3b5b3d56c38e8de13329182d0a230 (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
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
/* Kernel runtime algorithm handling interface
 * Author: JuanJo Ciarlante <jjo-ipsec@mendoza.gov.ar>
 *
 * 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.
 *
 * RCSID $Id: kernel_alg.c 3252 2007-10-06 21:24:50Z andreas $
 */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <sys/queue.h>

#include <pfkeyv2.h>
#include <pfkey.h>

#include <freeswan.h>
#include <ipsec_policy.h>

#include "constants.h"
#include "defs.h"
#include "connections.h"
#include "state.h"
#include "packet.h"
#include "spdb.h"
#include "kernel.h"
#include "kernel_alg.h"
#include "alg_info.h"

#ifndef NO_PLUTO
#include "log.h"
#include "whack.h"
#include "db_ops.h"
#else
/*
 *	macros/functions for compilation without pluto (eg: spi for manual conns)
 */
extern int debug;
#include <assert.h>
#define passert(x) assert(x)
#define DBG(cond, action)   { if (debug) { action ; } }
#define DBG_log(x, args...) fprintf(stderr, x "\n" , ##args);
#define plog(x, args...) fprintf(stderr, x "\n" , ##args);
#endif /* NO_PLUTO */
/* ALG storage */
static struct sadb_alg esp_aalg[SADB_AALG_MAX+1];
static struct sadb_alg esp_ealg[SADB_EALG_MAX+1];
static int esp_ealg_num = 0;
static int esp_aalg_num = 0;

#define ESP_EALG_PRESENT(algo) (((algo)<=SADB_EALG_MAX)&&(esp_ealg[(algo)].sadb_alg_id==(algo)))
#define ESP_EALG_FOR_EACH_UPDOWN(algo) \
	for (algo=SADB_EALG_MAX; algo >0 ; algo--) \
		if (ESP_EALG_PRESENT(algo))
#define ESP_AALG_PRESENT(algo) ((algo<=SADB_AALG_MAX)&&(esp_aalg[(algo)].sadb_alg_id==(algo)))
#define ESP_AALG_FOR_EACH_UPDOWN(algo) \
	for (algo=SADB_AALG_MAX; algo >0 ; algo--) \
		if (ESP_AALG_PRESENT(algo))

static struct sadb_alg*
sadb_alg_ptr (int satype, int exttype, int alg_id, int rw)
{
    struct sadb_alg *alg_p = NULL;

    switch (exttype)
    {
    case SADB_EXT_SUPPORTED_AUTH:
	if (alg_id > SADB_AALG_MAX)
	    return NULL;
	break;
    case SADB_EXT_SUPPORTED_ENCRYPT:
	if (alg_id > SADB_EALG_MAX)
	    return NULL;
	break;
    default:
	return NULL;
    }

    switch (satype)
    {
    case SADB_SATYPE_ESP:
	alg_p = (exttype == SADB_EXT_SUPPORTED_ENCRYPT)?
		    &esp_ealg[alg_id] : &esp_aalg[alg_id];
	/* get for write: increment elem count */
	if (rw)
	{
	    (exttype == SADB_EXT_SUPPORTED_ENCRYPT)?
		esp_ealg_num++ : esp_aalg_num++;
	}
	break;
    case SADB_SATYPE_AH:
    default:
	return NULL;
    }
    
    return alg_p;
}

const struct sadb_alg *
kernel_alg_sadb_alg_get(int satype, int exttype, int alg_id)
{
    return sadb_alg_ptr(satype, exttype, alg_id, 0);
}

/*
 * 	Forget previous registration
 */
static void 
kernel_alg_init(void)
{
    DBG(DBG_KLIPS,
	DBG_log("alg_init(): memset(%p, 0, %d) memset(%p, 0, %d)",
		&esp_aalg,  (int)sizeof (esp_aalg),
		&esp_ealg,  (int)sizeof (esp_ealg))
    )
    memset (&esp_aalg, 0, sizeof (esp_aalg));
    memset (&esp_ealg, 0, sizeof (esp_ealg));
    esp_ealg_num=esp_aalg_num = 0;
}

static int
kernel_alg_add(int satype, int exttype, const struct sadb_alg *sadb_alg)
{
    struct sadb_alg *alg_p = NULL;
    int alg_id = sadb_alg->sadb_alg_id;

    DBG(DBG_KLIPS,
	DBG_log("kernel_alg_add(): satype=%d, exttype=%d, alg_id=%d",
		satype, exttype, sadb_alg->sadb_alg_id)
    )
    if (!(alg_p = sadb_alg_ptr(satype, exttype, alg_id, 1)))
	return -1;

    /* This logic "mimics" KLIPS: first algo implementation will be used */
    if (alg_p->sadb_alg_id)
    {
	DBG(DBG_KLIPS,
	    DBG_log("kernel_alg_add(): discarding already setup "
		    "satype=%d, exttype=%d, alg_id=%d",
		    satype, exttype, sadb_alg->sadb_alg_id)
	)
	return 0;
    }
    *alg_p = *sadb_alg;
    return 1;
}

bool
kernel_alg_esp_enc_ok(u_int alg_id, u_int key_len,
		struct alg_info_esp *alg_info __attribute__((unused)))
{
    struct sadb_alg *alg_p = NULL;

    /*
     * test #1: encrypt algo must be present
     */
    int ret = ESP_EALG_PRESENT(alg_id);
    if (!ret) goto out;

    alg_p = &esp_ealg[alg_id];
    
    /*
     * test #2: if key_len specified, it must be in range
     */
    if (key_len
    && (key_len < alg_p->sadb_alg_minbits || key_len > alg_p->sadb_alg_maxbits))
    {
	plog("kernel_alg_db_add() key_len not in range: alg_id=%d, "
	     "key_len=%d, alg_minbits=%d, alg_maxbits=%d"
	     , alg_id, key_len
	     , alg_p->sadb_alg_minbits
	     , alg_p->sadb_alg_maxbits);
	ret = FALSE;
    }

out:
    if (ret)
    {
	DBG(DBG_KLIPS,
	    DBG_log("kernel_alg_esp_enc_ok(%d,%d): "
		    "alg_id=%d, "
		    "alg_ivlen=%d, alg_minbits=%d, alg_maxbits=%d, "
		    "res=%d, ret=%d"
		    , alg_id, key_len
		    , alg_p->sadb_alg_id
		    , alg_p->sadb_alg_ivlen
		    , alg_p->sadb_alg_minbits
		    , alg_p->sadb_alg_maxbits
		    , alg_p->sadb_alg_reserved
		    , ret);
	)
    }
    else
    {
	DBG(DBG_KLIPS,
	    DBG_log("kernel_alg_esp_enc_ok(%d,%d): NO", alg_id, key_len);
	)
    }
    return ret;
}

/* 
 * ML: make F_STRICT logic consider enc,auth algorithms 
 */
#ifndef NO_PLUTO
bool
kernel_alg_esp_ok_final(u_int ealg, u_int key_len, u_int aalg, struct alg_info_esp *alg_info)
{
    int ealg_insecure;

    /*
     * key_len passed comes from esp_attrs read from peer
     * For many older algoritms (eg 3DES) this key_len is fixed
     * and get passed as 0.
     * ... then get default key_len
     */
    if (key_len == 0)
	key_len = kernel_alg_esp_enc_keylen(ealg) * BITS_PER_BYTE;

    /*
     * simple test to toss low key_len, will accept it only
     * if specified in "esp" string
     */
    ealg_insecure = (key_len < 128) ;

    if (ealg_insecure
    || (alg_info && alg_info->alg_info_flags & ALG_INFO_F_STRICT))
    {
	int i;
	struct esp_info *esp_info;

	if (alg_info)
	{
	    ALG_INFO_ESP_FOREACH(alg_info, esp_info, i)
	    {
		if (esp_info->esp_ealg_id == ealg
		&& (esp_info->esp_ealg_keylen == 0 || key_len == 0
		    || esp_info->esp_ealg_keylen == key_len)
		&&  esp_info->esp_aalg_id == aalg)
		{
		    if (ealg_insecure)
		    {
			loglog(RC_LOG_SERIOUS
			    , "You should NOT use insecure ESP algorithms [%s (%d)]!"
			    , enum_name(&esp_transformid_names, ealg), key_len);
		    }
		    return TRUE;
		}
	    }
	}
	plog("IPSec Transform [%s (%d), %s] refused due to %s",
		enum_name(&esp_transformid_names, ealg), key_len,
		enum_name(&auth_alg_names, aalg),
		ealg_insecure ? "insecure key_len and enc. alg. not listed in \"esp\" string" : "strict flag");
	return FALSE;
    }
    return TRUE;
}
#endif /* NO_PLUTO */

/*	
 *	Load kernel_alg arrays from /proc
 * 	used in manual mode from klips/utils/spi.c
 */
int
kernel_alg_proc_read(void)
{
    int satype;
    int supp_exttype;
    int alg_id, ivlen, minbits, maxbits;
    struct sadb_alg sadb_alg;
    int ret;
    char buf[128];

    FILE *fp=fopen("/proc/net/pf_key_supported", "r");

    if (!fp)
	return -1;

    kernel_alg_init();

    while (fgets(buf, sizeof(buf), fp))
    {
	if (buf[0] != ' ') /* skip titles */
	    continue;

	sscanf(buf, "%d %d %d %d %d %d"
		,&satype, &supp_exttype
		, &alg_id, &ivlen
		, &minbits, &maxbits);

	switch (satype)
	{
	case SADB_SATYPE_ESP:
	    switch(supp_exttype)
	    {
	    case SADB_EXT_SUPPORTED_AUTH:
	    case SADB_EXT_SUPPORTED_ENCRYPT:
		sadb_alg.sadb_alg_id = alg_id;
		sadb_alg.sadb_alg_ivlen = ivlen;
		sadb_alg.sadb_alg_minbits = minbits;
		sadb_alg.sadb_alg_maxbits = maxbits;
		ret = kernel_alg_add(satype, supp_exttype, &sadb_alg);
		DBG(DBG_CRYPT,
		    DBG_log("kernel_alg_proc_read() alg_id=%d, "
			    "alg_ivlen=%d, alg_minbits=%d, alg_maxbits=%d, "
			    "ret=%d"
			    , sadb_alg.sadb_alg_id
			    , sadb_alg.sadb_alg_ivlen
			    , sadb_alg.sadb_alg_minbits
			    , sadb_alg.sadb_alg_maxbits
			    , ret)
		)
	    }
	default:
	    continue;
	}
    }
    fclose(fp);
    return 0;
}

/*	
 *	Load kernel_alg arrays pluto's SADB_REGISTER	
 * 	user by pluto/kernel.c
 */

void
kernel_alg_register_pfkey(const struct sadb_msg *msg_buf, int buflen)
{
    /* Trick: one 'type-mangle-able' pointer to ease offset/assign */
    union {
	const struct sadb_msg *msg;
	const struct sadb_supported *supported;
	const struct sadb_ext *ext;
	const struct sadb_alg *alg;
	const char *ch;
    } sadb;

    int satype;
    int msglen;
    int i = 0;

    /* Initialize alg arrays */
    kernel_alg_init();
    satype = msg_buf->sadb_msg_satype;
    sadb.msg = msg_buf;
    msglen = sadb.msg->sadb_msg_len*IPSEC_PFKEYv2_ALIGN;
    msglen -= sizeof(struct sadb_msg);
    buflen -= sizeof(struct sadb_msg);
    passert(buflen > 0);

    sadb.msg++;

    while(msglen)
    {
	int supp_exttype = sadb.supported->sadb_supported_exttype;
	int supp_len = sadb.supported->sadb_supported_len*IPSEC_PFKEYv2_ALIGN;

	DBG(DBG_KLIPS,
	    DBG_log("kernel_alg_register_pfkey(): SADB_SATYPE_%s: "
		    "sadb_msg_len=%d sadb_supported_len=%d"
		    , satype==SADB_SATYPE_ESP? "ESP" : "AH"
		    , msg_buf->sadb_msg_len, supp_len)
	)
	sadb.supported++;
	msglen -= supp_len;
	buflen -= supp_len;
	passert(buflen >= 0);

	for (supp_len -= sizeof(struct sadb_supported);
	     supp_len;
	     supp_len -= sizeof(struct sadb_alg), sadb.alg++,i++)
	{
	    int ret = kernel_alg_add(satype, supp_exttype, sadb.alg);

	    DBG(DBG_KLIPS,
		DBG_log("kernel_alg_register_pfkey(): SADB_SATYPE_%s: "
			"alg[%d], exttype=%d, satype=%d, alg_id=%d, "
			"alg_ivlen=%d, alg_minbits=%d, alg_maxbits=%d, "
			"res=%d, ret=%d"
			, satype==SADB_SATYPE_ESP? "ESP" : "AH"
			, i
			, supp_exttype
			, satype
			, sadb.alg->sadb_alg_id
			, sadb.alg->sadb_alg_ivlen
			, sadb.alg->sadb_alg_minbits
			, sadb.alg->sadb_alg_maxbits
			, sadb.alg->sadb_alg_reserved
			, ret)
	    )
	}
    }
}

u_int
kernel_alg_esp_enc_keylen(u_int alg_id)
{
    u_int keylen = 0;

    if (!ESP_EALG_PRESENT(alg_id))
	goto none;

    keylen = esp_ealg[alg_id].sadb_alg_maxbits/BITS_PER_BYTE;

    switch (alg_id)
    {
	/*
	 * this is veryUgly[TM]
	 * Peer should have sent KEY_LENGTH attribute for ESP_AES
	 * but if not do force it to 128 instead of using sadb_alg_maxbits
	 * from kernel.
	 */
	case ESP_AES:
	    keylen = 128/BITS_PER_BYTE;
	    break;
    }

none:	
    DBG(DBG_KLIPS,
	DBG_log("kernel_alg_esp_enc_keylen():"
		"alg_id=%d, keylen=%d",
		alg_id, keylen)
    )
    return keylen;
}

struct sadb_alg *
kernel_alg_esp_sadb_alg(u_int alg_id)
{
    struct sadb_alg *sadb_alg = (ESP_EALG_PRESENT(alg_id))
		? &esp_ealg[alg_id] : NULL;

    DBG(DBG_KLIPS,
	DBG_log("kernel_alg_esp_sadb_alg(): alg_id=%d, sadb_alg=%p"
		, alg_id, sadb_alg)
    )
    return sadb_alg;
}

#ifndef NO_PLUTO
void kernel_alg_list(void)
{
    u_int sadb_id;

    whack_log(RC_COMMENT, " ");
    whack_log(RC_COMMENT, "List of registered ESP Encryption Algorithms:");
    whack_log(RC_COMMENT, " ");

    for (sadb_id = 1; sadb_id <= SADB_EALG_MAX; sadb_id++)
    {
	if (ESP_EALG_PRESENT(sadb_id))
	{
	    struct sadb_alg *alg_p = &esp_ealg[sadb_id];

	    whack_log(RC_COMMENT, "#%-5d %s, blocksize: %d, keylen: %d-%d"
		, sadb_id
		, enum_name(&esp_transformid_names, sadb_id)
		, alg_p->sadb_alg_ivlen
		, alg_p->sadb_alg_minbits
		, alg_p->sadb_alg_maxbits
	    );
	}
    }
    
    whack_log(RC_COMMENT, " ");
    whack_log(RC_COMMENT, "List of registered ESP Authentication Algorithms:");
    whack_log(RC_COMMENT, " ");

    for (sadb_id = 1; sadb_id <= SADB_AALG_MAX; sadb_id++)
    {
	if (ESP_AALG_PRESENT(sadb_id))
	{
	    u_int aaid = alg_info_esp_sadb2aa(sadb_id);
	    struct sadb_alg *alg_p = &esp_aalg[sadb_id];

	    whack_log(RC_COMMENT, "#%-5d %s, keylen: %d-%d"
		, aaid
		, enum_name(&auth_alg_names, aaid)
		, alg_p->sadb_alg_minbits
		, alg_p->sadb_alg_maxbits
	    );
	}
    }
}

void
kernel_alg_show_connection(struct connection *c, const char *instance)
{
    char buf[256];
    struct state *st;

    if (c->alg_info_esp)
    {
	alg_info_snprint(buf, sizeof(buf), (struct alg_info *)c->alg_info_esp);
	whack_log(RC_COMMENT
		, "\"%s\"%s:   ESP algorithms wanted: %s"
		, c->name
		, instance
		, buf);
    }
    if (c->alg_info_esp)
    {
	alg_info_snprint_esp(buf, sizeof(buf), c->alg_info_esp);
	whack_log(RC_COMMENT
		, "\"%s\"%s:   ESP algorithms loaded: %s"
		, c->name
		, instance
		, buf);
    }
    st = state_with_serialno(c->newest_ipsec_sa);
    if (st && st->st_esp.present)
	whack_log(RC_COMMENT
		, "\"%s\"%s:   ESP algorithm newest: %s_%d-%s; pfsgroup=%s"
		, c->name
		, instance
		, enum_show(&esp_transformid_names, st->st_esp.attrs.transid)
		+4 /* strlen("ESP_") */
		, st->st_esp.attrs.key_len
		, enum_show(&auth_alg_names, st->st_esp.attrs.auth)+
		+15 /* strlen("AUTH_ALGORITHM_") */
		, c->policy & POLICY_PFS ?
			c->alg_info_esp->esp_pfsgroup ?
					enum_show(&oakley_group_names, 
						c->alg_info_esp->esp_pfsgroup)
						+13 /*strlen("OAKLEY_GROUP_")*/
				: "<Phase1>"
			: "<N/A>"
	);
}
#endif /* NO_PLUTO */

bool
kernel_alg_esp_auth_ok(u_int auth,
		struct alg_info_esp *alg_info __attribute__((unused)))
{
    return ESP_AALG_PRESENT(alg_info_esp_aa2sadb(auth));
}

u_int
kernel_alg_esp_auth_keylen(u_int auth)
{
    u_int sadb_aalg = alg_info_esp_aa2sadb(auth);

    u_int a_keylen = (sadb_aalg)
		   ? esp_aalg[sadb_aalg].sadb_alg_maxbits/BITS_PER_BYTE
		   : 0;

    DBG(DBG_CONTROL | DBG_CRYPT | DBG_PARSING,
	DBG_log("kernel_alg_esp_auth_keylen(auth=%d, sadb_aalg=%d): "
		"a_keylen=%d", auth, sadb_aalg, a_keylen)
    )
    return a_keylen;
}

struct esp_info *
kernel_alg_esp_info(int transid, int auth)
{
    int sadb_aalg, sadb_ealg;
    static struct esp_info ei_buf;

    sadb_ealg = transid;
    sadb_aalg = alg_info_esp_aa2sadb(auth);

    if (!ESP_EALG_PRESENT(sadb_ealg))
	goto none;
    if (!ESP_AALG_PRESENT(sadb_aalg))
	goto none;

    memset(&ei_buf, 0, sizeof (ei_buf));
    ei_buf.transid = transid;
    ei_buf.auth = auth;

    /* don't return "default" keylen because this value is used from
     * setup_half_ipsec_sa() to "validate" keylen
     * In effect,  enckeylen will be used as "max" value
     */
    ei_buf.enckeylen = esp_ealg[sadb_ealg].sadb_alg_maxbits/BITS_PER_BYTE;
    ei_buf.authkeylen = esp_aalg[sadb_aalg].sadb_alg_maxbits/BITS_PER_BYTE;
    ei_buf.encryptalg = sadb_ealg;
    ei_buf.authalg = sadb_aalg;

    DBG(DBG_PARSING,
	DBG_log("kernel_alg_esp_info():"
		"transid=%d, auth=%d, ei=%p, "
		"enckeylen=%d, authkeylen=%d, encryptalg=%d, authalg=%d",
		transid, auth, &ei_buf,
		(int)ei_buf.enckeylen, (int)ei_buf.authkeylen,
		ei_buf.encryptalg, ei_buf.authalg)
    )
    return &ei_buf;

none:
    DBG(DBG_PARSING,
	DBG_log("kernel_alg_esp_info():"
		"transid=%d, auth=%d, ei=NULL",
		transid, auth)
    )
    return NULL;
}

#ifndef NO_PLUTO
static void
kernel_alg_policy_algorithms(struct esp_info *esp_info)
{
    u_int ealg_id = esp_info->esp_ealg_id;

    switch(ealg_id)
    {
    case 0:
    case ESP_DES:
    case ESP_3DES:
    case ESP_NULL:
    case ESP_CAST:
            break;
    default:
	if (!esp_info->esp_ealg_keylen)
	{
	    /* algos that need  KEY_LENGTH
	     *
	     * Note: this is a very dirty hack ;-)
	     * Idea: Add a key_length_needed attribute to
	     * esp_ealg ??
	     */
	    esp_info->esp_ealg_keylen = esp_ealg[ealg_id].sadb_alg_maxbits;
	}
    }
}

static bool 
kernel_alg_db_add(struct db_context *db_ctx, struct esp_info *esp_info, lset_t policy)
{
    u_int ealg_id, aalg_id;

    ealg_id = esp_info->esp_ealg_id;

    if (!ESP_EALG_PRESENT(ealg_id))
    {
	DBG_log("kernel_alg_db_add() kernel enc ealg_id=%d not present", ealg_id);
	return FALSE;
    }
    
    if (!(policy & POLICY_AUTHENTICATE))    /* skip ESP auth attrs for AH */
    {
	aalg_id = alg_info_esp_aa2sadb(esp_info->esp_aalg_id);

	if (!ESP_AALG_PRESENT(aalg_id))
	{
	    DBG_log("kernel_alg_db_add() kernel auth "
		    "aalg_id=%d not present", aalg_id);
	    return FALSE;
	}
    }

    /* do algo policy */
    kernel_alg_policy_algorithms(esp_info);

    /*	open new transformation */
    db_trans_add(db_ctx, ealg_id);

    /* add ESP auth attr */
    if (!(policy & POLICY_AUTHENTICATE))
	db_attr_add_values(db_ctx, AUTH_ALGORITHM, esp_info->esp_aalg_id);

    /* add keylegth if specified in esp= string */
    if (esp_info->esp_ealg_keylen)
	db_attr_add_values(db_ctx, KEY_LENGTH, esp_info->esp_ealg_keylen);
	
    return TRUE;
}

/*	
 *	Create proposal with runtime kernel algos, merging
 *	with passed proposal if not NULL
 *
 *	for now this function does free() previous returned
 *	malloced pointer (this quirk allows easier spdb.c change)
 */
struct db_context * 
kernel_alg_db_new(struct alg_info_esp *alg_info, lset_t policy )
{
    const struct esp_info *esp_info;
    struct esp_info tmp_esp_info;
    struct db_context *ctx_new=NULL;
    struct db_trans *t;
    struct db_prop  *prop;
    u_int trans_cnt;
    int tn = 0;

    if (!(policy & POLICY_ENCRYPT))	/* not possible, I think  */
	return NULL;

    trans_cnt = esp_ealg_num * esp_aalg_num;
    DBG(DBG_EMITTING,
	DBG_log("kernel_alg_db_prop_new() initial trans_cnt=%d"
		, trans_cnt)
    )

    /* pass aprox. number of transforms and attributes */
    ctx_new = db_prop_new(PROTO_IPSEC_ESP, trans_cnt, trans_cnt * 2);

    /*
     * Loop: for each element (struct esp_info) of alg_info,
     *       if kernel support is present then build the transform (and attrs)
     *       if NULL alg_info, propose everything ...
     */

    if (alg_info)
    {
	int i;

	ALG_INFO_ESP_FOREACH(alg_info, esp_info, i)
	{
	    tmp_esp_info = *esp_info;
	    kernel_alg_db_add(ctx_new, &tmp_esp_info, policy);
	}
    }
    else
    {
	u_int ealg_id;
	
	ESP_EALG_FOR_EACH_UPDOWN(ealg_id)
	{
	    u_int aalg_id;

	    tmp_esp_info.esp_ealg_id = ealg_id;
	    tmp_esp_info.esp_ealg_keylen = 0;

	    for (aalg_id = 1; aalg_id <= SADB_AALG_MAX; aalg_id++)
	    {
		if (ESP_AALG_PRESENT(aalg_id))
		{
		    tmp_esp_info.esp_aalg_id = alg_info_esp_sadb2aa(aalg_id);
		    tmp_esp_info.esp_aalg_keylen = 0;
		    kernel_alg_db_add(ctx_new, &tmp_esp_info, policy);
		}
	    }
	}
    }

    prop = db_prop_get(ctx_new);

    DBG(DBG_CONTROL|DBG_EMITTING,
	DBG_log("kernel_alg_db_prop_new() "
		"will return p_new->protoid=%d, p_new->trans_cnt=%d"
		, prop->protoid, prop->trans_cnt)
    )

    for (t = prop->trans, tn = 0; tn < prop->trans_cnt; tn++)
    {
	DBG(DBG_CONTROL|DBG_EMITTING,
	    DBG_log("kernel_alg_db_prop_new() "
		    "    trans[%d]: transid=%d, attr_cnt=%d, "
		    "attrs[0].type=%d, attrs[0].val=%d"
		    , tn
		    , t[tn].transid, t[tn].attr_cnt
		    , t[tn].attrs[0].type, t[tn].attrs[0].val)
	)
    }
    return ctx_new;
}
#endif /* NO_PLUTO */