3 * Copyright (c) 2005-2017 Lev Walkin <vlm@lionet.info>. All rights reserved.
4 * Redistribution and modifications are permitted subject to BSD license.
6 #include <asn_system.h>
7 #include <asn_internal.h>
8 #include <per_support.h>
11 * X.691-201508 #10.9 General rules for encoding a length determinant.
12 * Get the optionally constrained length "n" from the stream.
15 uper_get_length(asn_per_data_t *pd, int ebits, size_t lower_bound,
21 /* #11.9.4.1 Encoding if constrained (according to effective bits) */
22 if(ebits >= 0 && ebits <= 16) {
23 value = per_get_few_bits(pd, ebits);
24 if(value >= 0) value += lower_bound;
28 value = per_get_few_bits(pd, 8);
29 if((value & 0x80) == 0) { /* #11.9.3.6 */
30 return (value & 0x7F);
31 } else if((value & 0x40) == 0) { /* #11.9.3.7 */
32 /* bit 8 ... set to 1 and bit 7 ... set to zero */
33 value = ((value & 0x3f) << 8) | per_get_few_bits(pd, 8);
34 return value; /* potential -1 from per_get_few_bits passes through. */
35 } else if(value < 0) {
36 ASN_DEBUG("END of stream reached for PER");
39 value &= 0x3f; /* this is "m" from X.691, #11.9.3.8 */
40 if(value < 1 || value > 4) {
41 return -1; /* Prohibited by #11.9.3.8 */
44 return (16384 * value);
48 * Get the normally small length "n".
49 * This procedure used to decode length of extensions bit-maps
50 * for SET and SEQUENCE types.
53 uper_get_nslength(asn_per_data_t *pd) {
56 ASN_DEBUG("Getting normally small length");
58 if(per_get_few_bits(pd, 1) == 0) {
59 length = per_get_few_bits(pd, 6) + 1;
60 if(length <= 0) return -1;
61 ASN_DEBUG("l=%d", (int)length);
65 length = uper_get_length(pd, -1, 0, &repeat);
66 if(length >= 0 && !repeat) return length;
67 return -1; /* Error, or do not support >16K extensions */
72 * Get the normally small non-negative whole number.
76 uper_get_nsnnwn(asn_per_data_t *pd) {
79 value = per_get_few_bits(pd, 7);
80 if(value & 64) { /* implicit (value < 0) */
83 value |= per_get_few_bits(pd, 2);
84 if(value & 128) /* implicit (value < 0) */
90 value = per_get_few_bits(pd, 8 * value);
98 * X.691-11/2008, #11.6
99 * Encoding of a normally small non-negative whole number
102 uper_put_nsnnwn(asn_per_outp_t *po, int n) {
107 return per_put_few_bits(po, n, 7);
113 else if(n < 256 * 65536)
116 return -1; /* This is not a "normally small" value */
117 if(per_put_few_bits(po, bytes, 8))
120 return per_put_few_bits(po, n, 8 * bytes);
124 /* X.691-2008/11, #11.5.6 -> #11.3 */
125 int uper_get_constrained_whole_number(asn_per_data_t *pd, unsigned long *out_value, int nbits) {
126 unsigned long lhalf; /* Lower half of the number*/
130 half = per_get_few_bits(pd, nbits);
131 if(half < 0) return -1;
136 if((size_t)nbits > 8 * sizeof(*out_value))
137 return -1; /* RANGE */
139 half = per_get_few_bits(pd, 31);
140 if(half < 0) return -1;
142 if(uper_get_constrained_whole_number(pd, &lhalf, nbits - 31))
145 *out_value = ((unsigned long)half << (nbits - 31)) | lhalf;
150 /* X.691-2008/11, #11.5.6 -> #11.3 */
152 uper_put_constrained_whole_number_u(asn_per_outp_t *po, unsigned long v,
155 return per_put_few_bits(po, v, nbits);
157 /* Put higher portion first, followed by lower 31-bit */
158 if(uper_put_constrained_whole_number_u(po, v >> 31, nbits - 31))
160 return per_put_few_bits(po, v, 31);
165 * X.691 (08/2015) #11.9 "General rules for encoding a length determinant"
166 * Put the length "n" (or part of it) into the stream.
169 uper_put_length(asn_per_outp_t *po, size_t length, int *need_eom) {
171 if(!need_eom) need_eom = &dummy;
173 if(length <= 127) { /* #11.9.3.6 */
175 return per_put_few_bits(po, length, 8)
176 ? -1 : (ssize_t)length;
177 } else if(length < 16384) { /* #10.9.3.7 */
179 return per_put_few_bits(po, length|0x8000, 16)
180 ? -1 : (ssize_t)length;
183 *need_eom = 0 == (length & 16383);
190 return per_put_few_bits(po, 0xC0 | length, 8)
191 ? -1 : (ssize_t)(length << 14);
197 * Put the normally small length "n" into the stream.
198 * This procedure used to encode length of extensions bit-maps
199 * for SET and SEQUENCE types.
202 uper_put_nslength(asn_per_outp_t *po, size_t length) {
205 if(length == 0) return -1;
206 return per_put_few_bits(po, length - 1, 7) ? -1 : 0;
209 if(uper_put_length(po, length, &need_eom) != (ssize_t)length
211 /* This might happen in case of >16K extensions */
220 per__long_range(long lb, long ub, unsigned long *range_r) {
221 unsigned long bounds_range;
222 if((ub < 0) == (lb < 0)) {
223 bounds_range = ub - lb;
226 bounds_range = 1 + ((unsigned long)ub + (unsigned long)-(lb + 1));
228 assert(!"Unreachable");
231 *range_r = bounds_range;
236 per_long_range_rebase(long v, long lb, long ub, unsigned long *output) {
241 if(v < lb || v > ub || per__long_range(lb, ub, &range) < 0) {
247 * Fundamentally what we're doing is returning (v-lb).
248 * However, this triggers undefined behavior when the word width
249 * of signed (v) is the same as the size of unsigned (*output).
250 * In practice, it triggers the UndefinedSanitizer. Therefore we shall
251 * compute the ranges accurately to avoid C's undefined behavior.
253 if((v < 0) == (lb < 0)) {
257 unsigned long rebased = 1 + (unsigned long)-(v+1) + (unsigned long)lb;
258 assert(rebased <= range); /* By construction */
262 unsigned long rebased = 1 + (unsigned long)-(lb+1) + (unsigned long)v;
263 assert(rebased <= range); /* By construction */
267 assert(!"Unreachable");
273 per_long_range_unrebase(unsigned long inp, long lb, long ub, long *outp) {
276 if(per__long_range(lb, ub, &range) != 0) {
282 * We can encode something in the given number of bits that technically
283 * exceeds the range. This is an avenue for security errors,
284 * so we don't allow that.
289 if(inp <= LONG_MAX) {
290 *outp = (long)inp + lb;
292 *outp = (lb + LONG_MAX + 1) + (long)((inp - LONG_MAX) - 1);
299 aper_get_align(asn_per_data_t *pd) {
301 if(pd->nboff & 0x7) {
302 ASN_DEBUG("Aligning %ld bits", 8 - ((unsigned long)pd->nboff & 0x7));
303 return per_get_few_bits(pd, 8 - (pd->nboff & 0x7));
309 aper_get_length(asn_per_data_t *pd, int range, int ebits, int *repeat) {
314 if (range <= 65536 && range >= 0)
315 return aper_get_nsnnwn(pd, range);
317 if (aper_get_align(pd) < 0)
320 if(ebits >= 0) return per_get_few_bits(pd, ebits);
322 value = per_get_few_bits(pd, 8);
323 if(value < 0) return -1;
324 if((value & 128) == 0) /* #10.9.3.6 */
325 return (value & 0x7F);
326 if((value & 64) == 0) { /* #10.9.3.7 */
327 value = ((value & 63) << 8) | per_get_few_bits(pd, 8);
328 if(value < 0) return -1;
331 value &= 63; /* this is "m" from X.691, #10.9.3.8 */
332 if(value < 1 || value > 4)
335 return (16384 * value);
339 aper_get_nslength(asn_per_data_t *pd) {
342 ASN_DEBUG("Getting normally small length");
344 if(per_get_few_bits(pd, 1) == 0) {
345 length = per_get_few_bits(pd, 6) + 1;
346 if(length <= 0) return -1;
347 ASN_DEBUG("l=%ld", length);
351 length = aper_get_length(pd, -1, -1, &repeat);
352 if(length >= 0 && !repeat) return length;
353 return -1; /* Error, or do not support >16K extensions */
358 aper_get_nsnnwn(asn_per_data_t *pd, int range) {
362 ASN_DEBUG("getting nsnnwn with range %d", range);
367 if (range < 0) return -1;
369 for (i = 1; i <= 8; i++) {
374 value = per_get_few_bits(pd, i);
376 } else if (range == 256){
379 } else if (range <= 65536) {
385 if (aper_get_align(pd) < 0)
387 value = per_get_few_bits(pd, 8 * bytes);
391 int aper_put_align(asn_per_outp_t *po) {
393 if(po->nboff & 0x7) {
394 ASN_DEBUG("Aligning %ld bits", 8 - ((unsigned long)po->nboff & 0x7));
395 if(per_put_few_bits(po, 0x00, (8 - (po->nboff & 0x7))))
402 aper_put_length(asn_per_outp_t *po, int range, size_t length) {
404 ASN_DEBUG("APER put length %zu with range %d", length, range);
406 /* 10.9 X.691 Note 2 */
407 if (range <= 65536 && range >= 0)
408 return aper_put_nsnnwn(po, range, length);
410 if (aper_put_align(po) < 0)
413 if(length <= 127) /* #10.9.3.6 */{
414 return per_put_few_bits(po, length, 8)
415 ? -1 : (ssize_t)length;
417 else if(length < 16384) /* #10.9.3.7 */
418 return per_put_few_bits(po, length|0x8000, 16)
419 ? -1 : (ssize_t)length;
422 if(length > 4) length = 4;
424 return per_put_few_bits(po, 0xC0 | length, 8)
425 ? -1 : (ssize_t)(length << 14);
430 aper_put_nslength(asn_per_outp_t *po, size_t length) {
434 if(length == 0) return -1;
435 return per_put_few_bits(po, length-1, 7) ? -1 : 0;
437 if(aper_put_length(po, -1, length) != (ssize_t)length) {
438 /* This might happen in case of >16K extensions */
447 aper_put_nsnnwn(asn_per_outp_t *po, int range, int number) {
450 ASN_DEBUG("aper put nsnnwn %d with range %d", number, range);
455 int bits = 1 << (8 * i);
464 for (i = 1; i <= 8; i++) {
469 return per_put_few_bits(po, number, i);
470 } else if(range == 256) {
472 } else if(range <= 65536) {
474 } else { /* Ranges > 64K */
477 int bits = 1 << (8 * i);
484 if(aper_put_align(po) < 0) /* Aligning on octet */
486 /* if(per_put_few_bits(po, bytes, 8))
489 return per_put_few_bits(po, number, 8 * bytes);