Lev Walkin | 59b176e | 2005-11-26 11:25:14 +0000 | [diff] [blame] | 1 | /* |
Lev Walkin | 6c52784 | 2014-02-09 04:34:54 -0800 | [diff] [blame] | 2 | * Copyright (c) 2005-2014 Lev Walkin <vlm@lionet.info>. |
Lev Walkin | 9218bc1 | 2007-06-27 04:09:37 +0000 | [diff] [blame] | 3 | * All rights reserved. |
Lev Walkin | 59b176e | 2005-11-26 11:25:14 +0000 | [diff] [blame] | 4 | * Redistribution and modifications are permitted subject to BSD license. |
| 5 | */ |
| 6 | #include <asn_system.h> |
Lev Walkin | 9f5bb3a | 2006-08-18 01:46:46 +0000 | [diff] [blame] | 7 | #include <asn_internal.h> |
Lev Walkin | 59b176e | 2005-11-26 11:25:14 +0000 | [diff] [blame] | 8 | #include <per_support.h> |
| 9 | |
Lev Walkin | 59b176e | 2005-11-26 11:25:14 +0000 | [diff] [blame] | 10 | /* |
Lev Walkin | 5d20588 | 2017-08-06 00:03:46 -0700 | [diff] [blame] | 11 | * X.691-201508 #10.9 General rules for encoding a length determinant. |
| 12 | * Get the optionally constrained length "n" from the stream. |
Lev Walkin | 59b176e | 2005-11-26 11:25:14 +0000 | [diff] [blame] | 13 | */ |
| 14 | ssize_t |
Lev Walkin | 9d1b45f | 2017-10-01 17:04:48 -0700 | [diff] [blame] | 15 | uper_get_length(asn_per_data_t *pd, int ebits, size_t lower_bound, |
| 16 | int *repeat) { |
Lev Walkin | 5d20588 | 2017-08-06 00:03:46 -0700 | [diff] [blame] | 17 | ssize_t value; |
Lev Walkin | 59b176e | 2005-11-26 11:25:14 +0000 | [diff] [blame] | 18 | |
Lev Walkin | 5d20588 | 2017-08-06 00:03:46 -0700 | [diff] [blame] | 19 | *repeat = 0; |
Lev Walkin | 59b176e | 2005-11-26 11:25:14 +0000 | [diff] [blame] | 20 | |
Lev Walkin | 5d20588 | 2017-08-06 00:03:46 -0700 | [diff] [blame] | 21 | /* #11.9.4.1 Encoding if constrained (according to effective bits) */ |
| 22 | if(ebits >= 0 && ebits <= 16) { |
Lev Walkin | 9d1b45f | 2017-10-01 17:04:48 -0700 | [diff] [blame] | 23 | value = per_get_few_bits(pd, ebits); |
| 24 | if(value >= 0) value += lower_bound; |
| 25 | return value; |
Lev Walkin | 5d20588 | 2017-08-06 00:03:46 -0700 | [diff] [blame] | 26 | } |
Lev Walkin | 59b176e | 2005-11-26 11:25:14 +0000 | [diff] [blame] | 27 | |
| 28 | value = per_get_few_bits(pd, 8); |
Lev Walkin | 5d20588 | 2017-08-06 00:03:46 -0700 | [diff] [blame] | 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 | return -1; |
| 37 | } |
| 38 | value &= 0x3f; /* this is "m" from X.691, #11.9.3.8 */ |
| 39 | if(value < 1 || value > 4) { |
| 40 | return -1; /* Prohibited by #11.9.3.8 */ |
| 41 | } |
| 42 | *repeat = 1; |
| 43 | return (16384 * value); |
Lev Walkin | 59b176e | 2005-11-26 11:25:14 +0000 | [diff] [blame] | 44 | } |
| 45 | |
| 46 | /* |
Lev Walkin | 5b78e1c | 2007-06-24 06:26:47 +0000 | [diff] [blame] | 47 | * Get the normally small length "n". |
| 48 | * This procedure used to decode length of extensions bit-maps |
| 49 | * for SET and SEQUENCE types. |
| 50 | */ |
| 51 | ssize_t |
| 52 | uper_get_nslength(asn_per_data_t *pd) { |
| 53 | ssize_t length; |
| 54 | |
Lev Walkin | a2987ea | 2007-06-26 23:56:54 +0000 | [diff] [blame] | 55 | ASN_DEBUG("Getting normally small length"); |
| 56 | |
Lev Walkin | 5b78e1c | 2007-06-24 06:26:47 +0000 | [diff] [blame] | 57 | if(per_get_few_bits(pd, 1) == 0) { |
Lev Walkin | a2987ea | 2007-06-26 23:56:54 +0000 | [diff] [blame] | 58 | length = per_get_few_bits(pd, 6) + 1; |
| 59 | if(length <= 0) return -1; |
Lev Walkin | fe1ffaf | 2010-10-25 21:07:59 -0700 | [diff] [blame] | 60 | ASN_DEBUG("l=%d", (int)length); |
Lev Walkin | a2987ea | 2007-06-26 23:56:54 +0000 | [diff] [blame] | 61 | return length; |
Lev Walkin | 5b78e1c | 2007-06-24 06:26:47 +0000 | [diff] [blame] | 62 | } else { |
| 63 | int repeat; |
Lev Walkin | 9d1b45f | 2017-10-01 17:04:48 -0700 | [diff] [blame] | 64 | length = uper_get_length(pd, -1, 0, &repeat); |
Lev Walkin | 5b78e1c | 2007-06-24 06:26:47 +0000 | [diff] [blame] | 65 | if(length >= 0 && !repeat) return length; |
| 66 | return -1; /* Error, or do not support >16K extensions */ |
| 67 | } |
| 68 | } |
| 69 | |
| 70 | /* |
Lev Walkin | 59b176e | 2005-11-26 11:25:14 +0000 | [diff] [blame] | 71 | * Get the normally small non-negative whole number. |
| 72 | * X.691, #10.6 |
| 73 | */ |
| 74 | ssize_t |
| 75 | uper_get_nsnnwn(asn_per_data_t *pd) { |
| 76 | ssize_t value; |
| 77 | |
| 78 | value = per_get_few_bits(pd, 7); |
| 79 | if(value & 64) { /* implicit (value < 0) */ |
| 80 | value &= 63; |
| 81 | value <<= 2; |
| 82 | value |= per_get_few_bits(pd, 2); |
| 83 | if(value & 128) /* implicit (value < 0) */ |
| 84 | return -1; |
| 85 | if(value == 0) |
| 86 | return 0; |
| 87 | if(value >= 3) |
| 88 | return -1; |
| 89 | value = per_get_few_bits(pd, 8 * value); |
| 90 | return value; |
| 91 | } |
| 92 | |
| 93 | return value; |
| 94 | } |
Lev Walkin | 523de9e | 2006-08-18 01:34:18 +0000 | [diff] [blame] | 95 | |
| 96 | /* |
Lev Walkin | 6c52784 | 2014-02-09 04:34:54 -0800 | [diff] [blame] | 97 | * X.691-11/2008, #11.6 |
| 98 | * Encoding of a normally small non-negative whole number |
Lev Walkin | 523de9e | 2006-08-18 01:34:18 +0000 | [diff] [blame] | 99 | */ |
| 100 | int |
| 101 | uper_put_nsnnwn(asn_per_outp_t *po, int n) { |
| 102 | int bytes; |
| 103 | |
| 104 | if(n <= 63) { |
| 105 | if(n < 0) return -1; |
| 106 | return per_put_few_bits(po, n, 7); |
| 107 | } |
| 108 | if(n < 256) |
| 109 | bytes = 1; |
| 110 | else if(n < 65536) |
| 111 | bytes = 2; |
| 112 | else if(n < 256 * 65536) |
| 113 | bytes = 3; |
| 114 | else |
| 115 | return -1; /* This is not a "normally small" value */ |
| 116 | if(per_put_few_bits(po, bytes, 8)) |
| 117 | return -1; |
| 118 | |
| 119 | return per_put_few_bits(po, n, 8 * bytes); |
| 120 | } |
| 121 | |
| 122 | |
Lev Walkin | 6c52784 | 2014-02-09 04:34:54 -0800 | [diff] [blame] | 123 | /* X.691-2008/11, #11.5.6 -> #11.3 */ |
| 124 | int uper_get_constrained_whole_number(asn_per_data_t *pd, unsigned long *out_value, int nbits) { |
| 125 | unsigned long lhalf; /* Lower half of the number*/ |
| 126 | long half; |
| 127 | |
| 128 | if(nbits <= 31) { |
| 129 | half = per_get_few_bits(pd, nbits); |
| 130 | if(half < 0) return -1; |
| 131 | *out_value = half; |
| 132 | return 0; |
| 133 | } |
| 134 | |
| 135 | if((size_t)nbits > 8 * sizeof(*out_value)) |
| 136 | return -1; /* RANGE */ |
| 137 | |
| 138 | half = per_get_few_bits(pd, 31); |
| 139 | if(half < 0) return -1; |
| 140 | |
| 141 | if(uper_get_constrained_whole_number(pd, &lhalf, nbits - 31)) |
| 142 | return -1; |
| 143 | |
| 144 | *out_value = ((unsigned long)half << (nbits - 31)) | lhalf; |
| 145 | return 0; |
| 146 | } |
| 147 | |
| 148 | |
| 149 | /* X.691-2008/11, #11.5.6 -> #11.3 */ |
| 150 | int uper_put_constrained_whole_number_s(asn_per_outp_t *po, long v, int nbits) { |
| 151 | /* |
| 152 | * Assume signed number can be safely coerced into |
| 153 | * unsigned of the same range. |
| 154 | * The following testing code will likely be optimized out |
| 155 | * by compiler if it is true. |
| 156 | */ |
| 157 | unsigned long uvalue1 = ULONG_MAX; |
| 158 | long svalue = uvalue1; |
| 159 | unsigned long uvalue2 = svalue; |
| 160 | assert(uvalue1 == uvalue2); |
| 161 | return uper_put_constrained_whole_number_u(po, v, nbits); |
| 162 | } |
| 163 | |
| 164 | int uper_put_constrained_whole_number_u(asn_per_outp_t *po, unsigned long v, int nbits) { |
| 165 | if(nbits <= 31) { |
| 166 | return per_put_few_bits(po, v, nbits); |
| 167 | } else { |
| 168 | /* Put higher portion first, followed by lower 31-bit */ |
| 169 | if(uper_put_constrained_whole_number_u(po, v >> 31, nbits - 31)) |
| 170 | return -1; |
| 171 | return per_put_few_bits(po, v, 31); |
| 172 | } |
| 173 | } |
| 174 | |
Lev Walkin | 523de9e | 2006-08-18 01:34:18 +0000 | [diff] [blame] | 175 | /* |
Lev Walkin | 9d1b45f | 2017-10-01 17:04:48 -0700 | [diff] [blame] | 176 | * X.691 (08/2015) #11.9 "General rules for encoding a length determinant" |
Lev Walkin | 523de9e | 2006-08-18 01:34:18 +0000 | [diff] [blame] | 177 | * Put the length "n" (or part of it) into the stream. |
| 178 | */ |
| 179 | ssize_t |
Lev Walkin | 5d947a8 | 2017-10-03 01:04:03 -0700 | [diff] [blame] | 180 | uper_put_length(asn_per_outp_t *po, size_t length, int *need_eom) { |
| 181 | int dummy = 0; |
| 182 | if(!need_eom) need_eom = &dummy; |
Lev Walkin | 523de9e | 2006-08-18 01:34:18 +0000 | [diff] [blame] | 183 | |
Lev Walkin | 5d947a8 | 2017-10-03 01:04:03 -0700 | [diff] [blame] | 184 | if(length <= 127) { /* #11.9.3.6 */ |
| 185 | *need_eom = 0; |
Lev Walkin | 9d1b45f | 2017-10-01 17:04:48 -0700 | [diff] [blame] | 186 | return per_put_few_bits(po, length, 8) |
| 187 | ? -1 : (ssize_t)length; |
Lev Walkin | 5d947a8 | 2017-10-03 01:04:03 -0700 | [diff] [blame] | 188 | } else if(length < 16384) { /* #10.9.3.7 */ |
| 189 | *need_eom = 0; |
Lev Walkin | 9d1b45f | 2017-10-01 17:04:48 -0700 | [diff] [blame] | 190 | return per_put_few_bits(po, length|0x8000, 16) |
| 191 | ? -1 : (ssize_t)length; |
Lev Walkin | 5d947a8 | 2017-10-03 01:04:03 -0700 | [diff] [blame] | 192 | } |
Lev Walkin | 523de9e | 2006-08-18 01:34:18 +0000 | [diff] [blame] | 193 | |
Lev Walkin | 5d947a8 | 2017-10-03 01:04:03 -0700 | [diff] [blame] | 194 | *need_eom = 0 == (length & 16383); |
Lev Walkin | 9d1b45f | 2017-10-01 17:04:48 -0700 | [diff] [blame] | 195 | length >>= 14; |
Lev Walkin | 5d947a8 | 2017-10-03 01:04:03 -0700 | [diff] [blame] | 196 | if(length > 4) { |
| 197 | *need_eom = 0; |
| 198 | length = 4; |
| 199 | } |
Lev Walkin | 523de9e | 2006-08-18 01:34:18 +0000 | [diff] [blame] | 200 | |
Lev Walkin | 9d1b45f | 2017-10-01 17:04:48 -0700 | [diff] [blame] | 201 | return per_put_few_bits(po, 0xC0 | length, 8) |
| 202 | ? -1 : (ssize_t)(length << 14); |
| 203 | |
Lev Walkin | 523de9e | 2006-08-18 01:34:18 +0000 | [diff] [blame] | 204 | } |
| 205 | |
Lev Walkin | 62258e2 | 2007-06-23 23:50:25 +0000 | [diff] [blame] | 206 | |
| 207 | /* |
| 208 | * Put the normally small length "n" into the stream. |
| 209 | * This procedure used to encode length of extensions bit-maps |
| 210 | * for SET and SEQUENCE types. |
| 211 | */ |
| 212 | int |
| 213 | uper_put_nslength(asn_per_outp_t *po, size_t length) { |
Lev Walkin | 5d947a8 | 2017-10-03 01:04:03 -0700 | [diff] [blame] | 214 | if(length <= 64) { |
| 215 | /* #11.9.3.4 */ |
| 216 | if(length == 0) return -1; |
| 217 | return per_put_few_bits(po, length - 1, 7) ? -1 : 0; |
| 218 | } else { |
| 219 | int need_eom = 0; |
| 220 | if(uper_put_length(po, length, &need_eom) != (ssize_t)length |
| 221 | || need_eom) { |
| 222 | /* This might happen in case of >16K extensions */ |
| 223 | return -1; |
| 224 | } |
| 225 | } |
Lev Walkin | 62258e2 | 2007-06-23 23:50:25 +0000 | [diff] [blame] | 226 | |
Lev Walkin | 5d947a8 | 2017-10-03 01:04:03 -0700 | [diff] [blame] | 227 | return 0; |
Lev Walkin | 62258e2 | 2007-06-23 23:50:25 +0000 | [diff] [blame] | 228 | } |
| 229 | |