summaryrefslogtreecommitdiff
path: root/bsnmp/asn1.c
blob: 8a206eed3fdfb2ebadd9b0f4e592d2bc873fed77 (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
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
 * Copyright (c) 2001-2003
 *	Fraunhofer Institute for Open Communication Systems (FhG Fokus).
 *	All rights reserved.
 *
 * Author: Harti Brandt <harti@freebsd.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $Begemot: bsnmp/lib/asn1.c,v 1.28 2004/08/06 08:46:49 brandt Exp $
 *
 * ASN.1 for SNMP.
 */
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <stdint.h>
#include <assert.h>
#include "asn1.h"

static void asn_error_func(const struct asn_buf *, const char *, ...);

void (*asn_error)(const struct asn_buf *, const char *, ...) = asn_error_func;

/*
 * Read the next header. This reads the tag (note, that only single
 * byte tags are supported for now) and the length field. The length field
 * is restricted to a 32-bit value.
 * All errors of this function stop the decoding.
 */
enum asn_err
asn_get_header(struct asn_buf *b, u_char *type, asn_len_t *len)
{
	u_int length;

	if (b->asn_len == 0) {
		asn_error(b, "no identifier for header");
		return (ASN_ERR_EOBUF);
	}
	*type = *b->asn_cptr;
	if ((*type & ASN_TYPE_MASK) > 0x30) {
		asn_error(b, "types > 0x30 not supported (%u)",
		    *type & ASN_TYPE_MASK);
		return (ASN_ERR_FAILED);
	}
	b->asn_cptr++;
	b->asn_len--;
	if (b->asn_len == 0) {
		asn_error(b, "no length field");
		return (ASN_ERR_EOBUF);
	}
	if (*b->asn_cptr & 0x80) {
		length = *b->asn_cptr++ & 0x7f;
		b->asn_len--;
		if (length == 0) {
			asn_error(b, "indefinite length not supported");
			return (ASN_ERR_FAILED);
		}
		if (length > ASN_MAXLENLEN) {
			asn_error(b, "long length too long (%u)", length);
			return (ASN_ERR_FAILED);
		}
		if (length > b->asn_len) {
			asn_error(b, "long length truncated");
			return (ASN_ERR_EOBUF);
		}
		*len = 0;
		while (length--) {
			*len = (*len << 8) | *b->asn_cptr++;
			b->asn_len--;
		}
	} else {
		*len = *b->asn_cptr++;
		b->asn_len--;
	}
	return (ASN_ERR_OK);
}

/*
 * Write a length field (restricted to values < 2^32-1) and return the
 * number of bytes this field takes. If ptr is NULL, the length is computed
 * but nothing is written. If the length would be too large return 0.
 */
static u_int
asn_put_len(u_char *ptr, asn_len_t len)
{
	u_int lenlen, lenlen1;
	asn_len_t tmp;

	if (len > ASN_MAXLEN) {
		asn_error(NULL, "encoding length too long: (%u)", len);
		return (0);
	}

	if (len <= 127) {
		if (ptr)
			*ptr++ = (u_char)len;
		return (1);
	} else {
		lenlen = 0;
		/* compute number of bytes for value (is at least 1) */
		for (tmp = len; tmp != 0; tmp >>= 8)
			lenlen++;
		if (ptr != NULL) {
			*ptr++ = (u_char)lenlen | 0x80;
			lenlen1 = lenlen;
			while (lenlen1-- > 0) {
				ptr[lenlen1] = len & 0xff;
				len >>= 8;
			}
		}
		return (lenlen + 1);
	}
}

/*
 * Write a header (tag and length fields).
 * Tags are restricted to one byte tags (value <= 0x30) and the
 * lenght field to 16-bit. All errors stop the encoding.
 */
enum asn_err
asn_put_header(struct asn_buf *b, u_char type, asn_len_t len)
{
	u_int lenlen;

	/* tag field */
	if ((type & ASN_TYPE_MASK) > 0x30) {
		asn_error(NULL, "types > 0x30 not supported (%u)",
		    type & ASN_TYPE_MASK);
		return (ASN_ERR_FAILED);
	}
	if (b->asn_len == 0)
		return (ASN_ERR_EOBUF);

	*b->asn_ptr++ = type;
	b->asn_len--;

	/* length field */
	if ((lenlen = asn_put_len(NULL, len)) == 0)
		return (ASN_ERR_FAILED);
	if (b->asn_len < lenlen)
		return (ASN_ERR_EOBUF);

	(void)asn_put_len(b->asn_ptr, len);
	b->asn_ptr += lenlen;
	b->asn_len -= lenlen;
	return (ASN_ERR_OK);
}


/*
 * This constructs a temporary sequence header with space for the maximum
 * length field (three byte). Set the pointer that ptr points to to the
 * start of the encoded header. This is used for a later call to
 * asn_commit_header which will fix-up the length field and move the
 * value if needed. All errors should stop the encoding.
 */
#define	TEMP_LEN (1 + ASN_MAXLENLEN + 1)
enum asn_err
asn_put_temp_header(struct asn_buf *b, u_char type, u_char **ptr)
{
	int ret;

	if (b->asn_len < TEMP_LEN)
		return (ASN_ERR_EOBUF);
	*ptr = b->asn_ptr;
	if ((ret = asn_put_header(b, type, ASN_MAXLEN)) == ASN_ERR_OK)
		assert(b->asn_ptr == *ptr + TEMP_LEN);
	return (ret);
}
enum asn_err
asn_commit_header(struct asn_buf *b, u_char *ptr)
{
	asn_len_t len;
	u_int lenlen, shift;

	/* compute length of encoded value without header */
	len = b->asn_ptr - (ptr + TEMP_LEN);

	/* insert length. may not fail. */
	lenlen = asn_put_len(ptr + 1, len);
	if (lenlen > TEMP_LEN - 1)
		return (ASN_ERR_FAILED);

	if (lenlen < TEMP_LEN - 1) {
		/* shift value down */
		shift = (TEMP_LEN - 1) - lenlen;
		memmove(ptr + 1 + lenlen, ptr + TEMP_LEN, len);
		b->asn_ptr -= shift;
		b->asn_len += shift;
	}
	return (ASN_ERR_OK);
}
#undef TEMP_LEN

/*
 * BER integer. This may be used to get a signed 64 bit integer at maximum.
 * The maximum length should be checked by the caller. This cannot overflow
 * if the caller ensures that len is at maximum 8.
 *
 * <bytes>
 */
static enum asn_err
asn_get_real_integer(struct asn_buf *b, asn_len_t len, int64_t *vp)
{
	uint64_t val;
	int neg = 0;
	enum asn_err err;

	if (b->asn_len < len) {
		asn_error(b, "truncated integer");
		return (ASN_ERR_EOBUF);
	}
	if (len == 0) {
		asn_error(b, "zero-length integer");
		*vp = 0;
		return (ASN_ERR_BADLEN);
	}
	err = ASN_ERR_OK;
	if (len > 8)
		err = ASN_ERR_RANGE;
	else if (len > 1 &&
	    ((*b->asn_cptr == 0x00 && (b->asn_cptr[1] & 0x80) == 0) ||
	    (*b->asn_cptr == 0xff && (b->asn_cptr[1] & 0x80) == 0x80))) {
		asn_error(b, "non-minimal integer");
		err = ASN_ERR_BADLEN;
	}

	if (*b->asn_cptr & 0x80)
		neg = 1;
	val = 0;
	while (len--) {
		val <<= 8;
		val |= neg ? (u_char)~*b->asn_cptr : *b->asn_cptr;
		b->asn_len--;
		b->asn_cptr++;
	}
	if (neg) {
		*vp = -(int64_t)val - 1;
	} else
		*vp = (int64_t)val;
	return (err);
}

/*
 * Write a signed integer with the given type. The caller has to ensure
 * that the actual value is ok for this type.
 */
static enum asn_err
asn_put_real_integer(struct asn_buf *b, u_char type, int64_t ival)
{
	int i, neg = 0;
# define OCTETS 8
	u_char buf[OCTETS];
	uint64_t val;
	enum asn_err ret;

	if (ival < 0) {
		/* this may fail if |INT64_MIN| > |INT64_MAX| and
		 * the value is between * INT64_MIN <= ival < -(INT64_MAX+1) */
		val = (uint64_t)-(ival + 1);
		neg = 1;
	} else
		val = (uint64_t)ival;

	/* split the value into octets */
	for (i = OCTETS - 1; i >= 0; i--) {
		buf[i] = val & 0xff;
		if (neg)
			buf[i] = ~buf[i];
		val >>= 8;
	}
	/* no leading 9 zeroes or ones */
	for (i = 0; i < OCTETS - 1; i++)
		if (!((buf[i] == 0xff && (buf[i + 1] & 0x80) != 0) ||
		    (buf[i] == 0x00 && (buf[i + 1] & 0x80) == 0)))
			break;
	if ((ret = asn_put_header(b, type, OCTETS - i)))
		return (ret);
	if (OCTETS - (u_int)i > b->asn_len)
		return (ASN_ERR_EOBUF);

	while (i < OCTETS) {
		*b->asn_ptr++ = buf[i++];
		b->asn_len--;
	}
	return (ASN_ERR_OK);
# undef OCTETS
}


/*
 * The same for unsigned 64-bitters. Here we have the problem, that overflow
 * can happen, because the value maybe 9 bytes long. In this case the
 * first byte must be 0.
 */
static enum asn_err
asn_get_real_unsigned(struct asn_buf *b, asn_len_t len, uint64_t *vp)
{
	enum asn_err err;

	if (b->asn_len < len) {
		asn_error(b, "truncated integer");
		return (ASN_ERR_EOBUF);
	}
	if (len == 0) {
		asn_error(b, "zero-length integer");
		*vp = 0;
		return (ASN_ERR_BADLEN);
	}
	err = ASN_ERR_OK;
	*vp = 0;
	if ((*b->asn_cptr & 0x80) || (len == 9 && *b->asn_cptr != 0)) {
		/* negative integer or too larger */
		*vp = 0xffffffffffffffffULL;
		err = ASN_ERR_RANGE;
	} else if (len > 1 &&
	    *b->asn_cptr == 0x00 && (b->asn_cptr[1] & 0x80) == 0) {
		asn_error(b, "non-minimal unsigned");
		err = ASN_ERR_BADLEN;
	}

	while (len--) {
		*vp = (*vp << 8) | *b->asn_cptr++;
		b->asn_len--;
	}
	return (err);
}


/*
 * Values with the msb on need 9 octets.
 */
static int
asn_put_real_unsigned(struct asn_buf *b, u_char type, uint64_t val)
{
	int i;
# define OCTETS 9
	u_char buf[OCTETS];
	enum asn_err ret;

	/* split the value into octets */
	for (i = OCTETS - 1; i >= 0; i--) {
		buf[i] = val & 0xff;
		val >>= 8;
	}
	/* no leading 9 zeroes */
	for (i = 0; i < OCTETS - 1; i++)
		if (!(buf[i] == 0x00 && (buf[i + 1] & 0x80) == 0))
			break;
	if ((ret = asn_put_header(b, type, OCTETS - i)))
		return (ret);
	if (OCTETS - (u_int)i > b->asn_len)
		return (ASN_ERR_EOBUF);

	while (i < OCTETS) {
		*b->asn_ptr++ = buf[i++];
		b->asn_len--;
	}
#undef OCTETS
	return (ASN_ERR_OK);
}

/*
 * The ASN.1 INTEGER type is restricted to 32-bit signed by the SMI.
 */
enum asn_err
asn_get_integer_raw(struct asn_buf *b, asn_len_t len, int32_t *vp)
{
	int64_t val;
	enum asn_err ret;

	if ((ret = asn_get_real_integer(b, len, &val)) == ASN_ERR_OK) {
		if (len > 4)
			ret = ASN_ERR_BADLEN;
		else if (val > INT32_MAX || val < INT32_MIN)
			/* may not happen */
			ret = ASN_ERR_RANGE;
		*vp = (int32_t)val;
	}
	return (ret);
}

enum asn_err
asn_get_integer(struct asn_buf *b, int32_t *vp)
{
	asn_len_t len;
	u_char type;
	enum asn_err err;

	if ((err = asn_get_header(b, &type, &len)) != ASN_ERR_OK)
		return (err);
	if (type != ASN_TYPE_INTEGER) {
		asn_error(b, "bad type for integer (%u)", type);
		return (ASN_ERR_TAG);
	}

	return (asn_get_integer_raw(b, len, vp));
}

enum asn_err
asn_put_integer(struct asn_buf *b, int32_t val)
{
	return (asn_put_real_integer(b, ASN_TYPE_INTEGER, val));
}

/*
 * OCTETSTRING
 *
 * <0x04> <len> <data ...>
 *
 * Get an octetstring. noctets must point to the buffer size and on
 * return will contain the size of the octetstring, regardless of the
 * buffer size.
 */
enum asn_err
asn_get_octetstring_raw(struct asn_buf *b, asn_len_t len, u_char *octets,
    u_int *noctets)
{
	enum asn_err err = ASN_ERR_OK;

	if (*noctets < len) {
		asn_error(b, "octetstring truncated");
		err = ASN_ERR_RANGE;
	}
	if (b->asn_len < len) {
		asn_error(b, "truncatet octetstring");
		return (ASN_ERR_EOBUF);
	}
	if (*noctets < len)
		memcpy(octets, b->asn_cptr, *noctets);
	else
		memcpy(octets, b->asn_cptr, len);
	*noctets = len;
	b->asn_cptr += len;
	b->asn_len -= len;
	return (err);
}

enum asn_err
asn_get_octetstring(struct asn_buf *b, u_char *octets, u_int *noctets)
{
	enum asn_err err;
	u_char type;
	asn_len_t len;

	if ((err = asn_get_header(b, &type, &len)) != ASN_ERR_OK)
		return (err);
	if (type != ASN_TYPE_OCTETSTRING) {
		asn_error(b, "bad type for octetstring (%u)", type);
		return (ASN_ERR_TAG);
	}
	return (asn_get_octetstring_raw(b, len, octets, noctets));
}

enum asn_err
asn_put_octetstring(struct asn_buf *b, const u_char *octets, u_int noctets)
{
	enum asn_err ret;

	if ((ret = asn_put_header(b, ASN_TYPE_OCTETSTRING, noctets)) != ASN_ERR_OK)
		return (ret);
	if (b->asn_len < noctets)
		return (ASN_ERR_EOBUF);

	memcpy(b->asn_ptr, octets, noctets);
	b->asn_ptr += noctets;
	b->asn_len -= noctets;
	return (ASN_ERR_OK);
}

/*
 * NULL
 *
 * <0x05> <0x00>
 */
enum asn_err
asn_get_null_raw(struct asn_buf *b, asn_len_t len)
{
	if (len != 0) {
		if (b->asn_len < len) {
			asn_error(b, "truncated NULL");
			return (ASN_ERR_EOBUF);
		}
		asn_error(b, "bad length for NULL (%u)", len);
		b->asn_len -= len;
		b->asn_ptr += len;
		return (ASN_ERR_BADLEN);
	}
	return (ASN_ERR_OK);
}

enum asn_err
asn_get_null(struct asn_buf *b)
{
	u_char type;
	asn_len_t len;
	enum asn_err err;

	if ((err = asn_get_header(b, &type, &len)) != ASN_ERR_OK)
		return (err);
	if (type != ASN_TYPE_NULL) {
		asn_error(b, "bad type for NULL (%u)", type);
		return (ASN_ERR_TAG);
	}
	return (asn_get_null_raw(b, len));
}

enum asn_err
asn_put_null(struct asn_buf *b)
{
	return (asn_put_header(b, ASN_TYPE_NULL, 0));
}

enum asn_err
asn_put_exception(struct asn_buf *b, u_int except)
{
	return (asn_put_header(b, ASN_CLASS_CONTEXT | except, 0));
}

/*
 * OBJID
 *
 * <0x06> <len> <subid...>
 */
enum asn_err
asn_get_objid_raw(struct asn_buf *b, asn_len_t len, struct asn_oid *oid)
{
	asn_subid_t subid;
	enum asn_err err;

	if (b->asn_len < len) {
		asn_error(b, "truncated OBJID");
		return (ASN_ERR_EOBUF);
	}
	oid->len = 0;
	if (len == 0) {
		asn_error(b, "short OBJID");
		oid->subs[oid->len++] = 0;
		oid->subs[oid->len++] = 0;
		return (ASN_ERR_BADLEN);
	}
	err = ASN_ERR_OK;
	while (len != 0) {
		if (oid->len == ASN_MAXOIDLEN) {
			asn_error(b, "OID too long (%u)", oid->len);
			b->asn_cptr += len;
			b->asn_len -= len;
			return (ASN_ERR_BADLEN);
		}
		subid = 0;
		do {
			if (len == 0) {
				asn_error(b, "unterminated subid");
				return (ASN_ERR_EOBUF);
			}
			if (subid > (ASN_MAXID >> 7)) {
				asn_error(b, "OBID subid too larger");
				err = ASN_ERR_RANGE;
			}
			subid = (subid << 7) | (*b->asn_cptr & 0x7f);
			len--;
			b->asn_len--;
		} while (*b->asn_cptr++ & 0x80);
		if (oid->len == 0) {
			if (subid < 80) {
				oid->subs[oid->len++] = subid / 40;
				oid->subs[oid->len++] = subid % 40;
			} else {
				oid->subs[oid->len++] = 2;
				oid->subs[oid->len++] = subid - 80;
			}
		} else {
			oid->subs[oid->len++] = subid;
		}
	}
	return (err);

}

enum asn_err
asn_get_objid(struct asn_buf *b, struct asn_oid *oid)
{
	u_char type;
	asn_len_t len;
	enum asn_err err;

	if ((err = asn_get_header(b, &type, &len)) != ASN_ERR_OK)
		return (err);
	if (type != ASN_TYPE_OBJID) {
		asn_error(b, "bad type for OBJID (%u)", type);
		return (ASN_ERR_TAG);
	}
	return (asn_get_objid_raw(b, len, oid));
}

enum asn_err
asn_put_objid(struct asn_buf *b, const struct asn_oid *oid)
{
	asn_subid_t first, sub;
	enum asn_err err, err1;
	u_int i, oidlen;
	asn_len_t len;

	err = ASN_ERR_OK;
	if (oid->len == 0) {
		/* illegal */
		asn_error(NULL, "short oid");
		err = ASN_ERR_RANGE;
		first = 0;
		oidlen = 2;
	} else if (oid->len == 1) {
		/* illegal */
		asn_error(b, "short oid");
		if (oid->subs[0] > 2)
			asn_error(NULL, "oid[0] too large (%u)", oid->subs[0]);
		err = ASN_ERR_RANGE;
		first = oid->subs[0] * 40;
		oidlen = 2;
	} else {
		if (oid->len > ASN_MAXOIDLEN) {
			asn_error(NULL, "oid too long %u", oid->len);
			err = ASN_ERR_RANGE;
		}
		if (oid->subs[0] > 2 ||
		    (oid->subs[0] < 2 && oid->subs[0] >= 40)) {
			asn_error(NULL, "oid out of range (%u,%u)",
			    oid->subs[0], oid->subs[1]);
			err = ASN_ERR_RANGE;
		}
		first = 40 * oid->subs[0] + oid->subs[1];
		oidlen = oid->len;
	}
	len = 0;
	for (i = 1; i < oidlen; i++) {
		sub = (i == 1) ? first : oid->subs[i];
		if (sub > ASN_MAXID) {
			asn_error(NULL, "oid subid too large");
			err = ASN_ERR_RANGE;
		}
		len += (sub <= 0x7f) ? 1
		    : (sub <= 0x3fff) ? 2
		    : (sub <= 0x1fffff) ? 3
		    : (sub <= 0xfffffff) ? 4
		    : 5;
	}
	if ((err1 = asn_put_header(b, ASN_TYPE_OBJID, len)) != ASN_ERR_OK)
		return (err1);
	if (b->asn_len < len)
		return (ASN_ERR_EOBUF);

	for (i = 1; i < oidlen; i++) {
		sub = (i == 1) ? first : oid->subs[i];
		if (sub <= 0x7f) {
			*b->asn_ptr++ = sub;
			b->asn_len--;
		} else if (sub <= 0x3fff) {
			*b->asn_ptr++ = (sub >> 7) | 0x80;
			*b->asn_ptr++ = sub & 0x7f;
			b->asn_len -= 2;
		} else if (sub <= 0x1fffff) {
			*b->asn_ptr++ = (sub >> 14) | 0x80;
			*b->asn_ptr++ = ((sub >> 7) & 0x7f) | 0x80;
			*b->asn_ptr++ = sub & 0x7f;
			b->asn_len -= 3;
		} else if (sub <= 0xfffffff) {
			*b->asn_ptr++ = (sub >> 21) | 0x80;
			*b->asn_ptr++ = ((sub >> 14) & 0x7f) | 0x80;
			*b->asn_ptr++ = ((sub >> 7) & 0x7f) | 0x80;
			*b->asn_ptr++ = sub & 0x7f;
			b->asn_len -= 4;
		} else {
			*b->asn_ptr++ = (sub >> 28) | 0x80;
			*b->asn_ptr++ = ((sub >> 21) & 0x7f) | 0x80;
			*b->asn_ptr++ = ((sub >> 14) & 0x7f) | 0x80;
			*b->asn_ptr++ = ((sub >> 7) & 0x7f) | 0x80;
			*b->asn_ptr++ = sub & 0x7f;
			b->asn_len -= 5;
		}
	}
	return (err);
}
/*
 * SEQUENCE header
 *
 * <0x10|0x20> <len> <data...>
 */
enum asn_err
asn_get_sequence(struct asn_buf *b, asn_len_t *len)
{
	u_char type;
	enum asn_err err;

	if ((err = asn_get_header(b, &type, len)) != ASN_ERR_OK)
		return (err);
	if (type != (ASN_TYPE_SEQUENCE|ASN_TYPE_CONSTRUCTED)) {
		asn_error(b, "bad sequence type %u", type);
		return (ASN_ERR_TAG);
	}
	if (*len > b->asn_len) {
		asn_error(b, "truncated sequence");
		return (ASN_ERR_EOBUF);
	}
	return (ASN_ERR_OK);
}

/*
 * Application types
 *
 * 0x40 4 MSB 2MSB 2LSB LSB
 */
enum asn_err
asn_get_ipaddress_raw(struct asn_buf *b, asn_len_t len, u_char *addr)
{
	u_int i;

	if (b->asn_len < len) {
		asn_error(b, "truncated ip-address");
		return (ASN_ERR_EOBUF);
	}
	if (len < 4) {
		asn_error(b, "short length for ip-Address %u", len);
		for (i = 0; i < len; i++)
			*addr++ = *b->asn_cptr++;
		while (i++ < len)
			*addr++ = 0;
		b->asn_len -= len;
		return (ASN_ERR_BADLEN);
	}
	for (i = 0; i < 4; i++)
		*addr++ = *b->asn_cptr++;
	b->asn_cptr += len - 4;
	b->asn_len -= len;
	return (ASN_ERR_OK);
}

enum asn_err
asn_get_ipaddress(struct asn_buf *b, u_char *addr)
{
	u_char type;
	asn_len_t len;
	enum asn_err err;

	if ((err = asn_get_header(b, &type, &len)) != ASN_ERR_OK)
		return (err);
	if (type != (ASN_CLASS_APPLICATION|ASN_APP_IPADDRESS)) {
		asn_error(b, "bad type for ip-address %u", type);
		return (ASN_ERR_TAG);
	}
	return (asn_get_ipaddress_raw(b, len, addr));
}

enum asn_err
asn_put_ipaddress(struct asn_buf *b, const u_char *addr)
{
	enum asn_err err;

	if ((err = asn_put_header(b, ASN_CLASS_APPLICATION|ASN_APP_IPADDRESS,
	    4)) != ASN_ERR_OK)
		return (err);
	if (b->asn_len < 4)
		return (ASN_ERR_EOBUF);

	memcpy(b->asn_ptr, addr, 4);
	b->asn_ptr += 4;
	b->asn_len -= 4;
	return (ASN_ERR_OK);
}


/*
 * UNSIGNED32
 *
 * 0x42|0x41 <len> ...
 */
enum asn_err
asn_get_uint32_raw(struct asn_buf *b, asn_len_t len, uint32_t *vp)
{
	uint64_t v;
	enum asn_err err;

	if ((err = asn_get_real_unsigned(b, len, &v)) == ASN_ERR_OK) {
		if (len > 5) {
			asn_error(b, "uint32 too long %u", len);
			err = ASN_ERR_BADLEN;
		} else if (v > UINT32_MAX) {
			asn_error(b, "uint32 too large %llu", v);
			err = ASN_ERR_RANGE;
		}
		*vp = (uint32_t)v;
	}
	return (err);
}

enum asn_err
asn_put_uint32(struct asn_buf *b, u_char type, uint32_t val)
{
	uint64_t v = val;

	return (asn_put_real_unsigned(b, ASN_CLASS_APPLICATION|type, v));
}

/*
 * COUNTER64
 * 0x46 <len> ...
 */
enum asn_err
asn_get_counter64_raw(struct asn_buf *b, asn_len_t len, uint64_t *vp)
{
	return (asn_get_real_unsigned(b, len, vp));
}

enum asn_err
asn_put_counter64(struct asn_buf *b, uint64_t val)
{
	return (asn_put_real_unsigned(b,
	    ASN_CLASS_APPLICATION | ASN_APP_COUNTER64, val));
}

/*
 * TimeTicks
 * 0x43 <len> ...
 */
enum asn_err
asn_get_timeticks(struct asn_buf *b, uint32_t *vp)
{
	asn_len_t len;
	u_char type;
	enum asn_err err;

	if ((err = asn_get_header(b, &type, &len)) != ASN_ERR_OK)
		return (err);
	if (type != (ASN_CLASS_APPLICATION|ASN_APP_TIMETICKS)) {
		asn_error(b, "bad type for timeticks %u", type);
		return (ASN_ERR_TAG);
	}
	return (asn_get_uint32_raw(b, len, vp));
}

enum asn_err
asn_put_timeticks(struct asn_buf *b, uint32_t val)
{
	uint64_t v = val;

	return (asn_put_real_unsigned(b,
	    ASN_CLASS_APPLICATION | ASN_APP_TIMETICKS, v));
}

/*
 * Construct a new OID by taking a range of sub ids of the original oid.
 */
void
asn_slice_oid(struct asn_oid *dest, const struct asn_oid *src,
    u_int from, u_int to)
{
	if (from >= to) {
		dest->len = 0;
		return;
	}
	dest->len = to - from;
	memcpy(dest->subs, &src->subs[from], dest->len * sizeof(dest->subs[0]));
}

/*
 * Append from to to
 */
void
asn_append_oid(struct asn_oid *to, const struct asn_oid *from)
{
	memcpy(&to->subs[to->len], &from->subs[0],
	    from->len * sizeof(from->subs[0]));
	to->len += from->len;
}

/*
 * Skip a value
 */
enum asn_err
asn_skip(struct asn_buf *b, asn_len_t len)
{
	if (b->asn_len < len)
		return (ASN_ERR_EOBUF);
	b->asn_cptr += len;
	b->asn_len -= len;
	return (ASN_ERR_OK);
}

/*
 * Compare two OIDs.
 *
 * o1 < o2 : -1
 * o1 > o2 : +1
 * o1 = o2 :  0
 */
int
asn_compare_oid(const struct asn_oid *o1, const struct asn_oid *o2)
{
	u_long i;

	for (i = 0; i < o1->len && i < o2->len; i++) {
		if (o1->subs[i] < o2->subs[i])
			return (-1);
		if (o1->subs[i] > o2->subs[i])
			return (+1);
	}
	if (o1->len < o2->len)
		return (-1);
	if (o1->len > o2->len)
		return (+1);
	return (0);
}

/*
 * Check whether an OID is a sub-string of another OID.
 */
int
asn_is_suboid(const struct asn_oid *o1, const struct asn_oid *o2)
{
	u_long i;

	for (i = 0; i < o1->len; i++)
		if (i >= o2->len || o1->subs[i] != o2->subs[i])
			return (0);
	return (1);
}

/*
 * Put a string representation of an oid into a user buffer. This buffer
 * is assumed to be at least ASN_OIDSTRLEN characters long.
 *
 * sprintf is assumed not to fail here.
 */
char *
asn_oid2str_r(const struct asn_oid *oid, char *buf)
{
	u_int len, i;
	char *ptr;

	if ((len = oid->len) > ASN_MAXOIDLEN)
		len = ASN_MAXOIDLEN;
	buf[0] = '\0';
	for (i = 0, ptr = buf; i < len; i++) {
		if (i > 0)
			*ptr++ = '.';
		ptr += sprintf(ptr, "%u", oid->subs[i]);
	}
	return (buf);
}

/*
 * Make a string from an OID in a private buffer.
 */
char *
asn_oid2str(const struct asn_oid *oid)
{
	static char str[ASN_OIDSTRLEN];

	return (asn_oid2str_r(oid, str));
}


static void
asn_error_func(const struct asn_buf *b, const char *err, ...)
{
	va_list ap;
	u_long i;

	fprintf(stderr, "ASN.1: ");
	va_start(ap, err);
	vfprintf(stderr, err, ap);
	va_end(ap);

	if (b != NULL) {
		fprintf(stderr, " at");
		for (i = 0; b->asn_len > i; i++)
			fprintf(stderr, " %02x", b->asn_cptr[i]);
	}
	fprintf(stderr, "\n");
}