Lev Walkin | 59b176e | 2005-11-26 11:25:14 +0000 | [diff] [blame] | 1 | /* |
Lev Walkin | 523de9e | 2006-08-18 01:34:18 +0000 | [diff] [blame] | 2 | * Copyright (c) 2005, 2006 Lev Walkin <vlm@lionet.info>. All rights reserved. |
Lev Walkin | 59b176e | 2005-11-26 11:25:14 +0000 | [diff] [blame] | 3 | * Redistribution and modifications are permitted subject to BSD license. |
| 4 | */ |
| 5 | #include <asn_system.h> |
Lev Walkin | 9f5bb3a | 2006-08-18 01:46:46 +0000 | [diff] [blame] | 6 | #include <asn_internal.h> |
Lev Walkin | 59b176e | 2005-11-26 11:25:14 +0000 | [diff] [blame] | 7 | #include <per_support.h> |
| 8 | |
| 9 | /* |
Lev Walkin | 6036488 | 2005-11-28 06:58:11 +0000 | [diff] [blame] | 10 | * Extract a small number of bits (<= 31) from the specified PER data pointer. |
Lev Walkin | 59b176e | 2005-11-26 11:25:14 +0000 | [diff] [blame] | 11 | */ |
| 12 | int32_t |
| 13 | per_get_few_bits(asn_per_data_t *pd, int nbits) { |
| 14 | size_t off; /* Next after last bit offset */ |
| 15 | uint32_t accum; |
Lev Walkin | 1d9e8dd | 2005-12-07 05:46:03 +0000 | [diff] [blame] | 16 | const uint8_t *buf; |
Lev Walkin | 59b176e | 2005-11-26 11:25:14 +0000 | [diff] [blame] | 17 | |
| 18 | if(nbits < 0 || pd->nboff + nbits > pd->nbits) |
| 19 | return -1; |
Lev Walkin | 59b176e | 2005-11-26 11:25:14 +0000 | [diff] [blame] | 20 | |
| 21 | /* |
| 22 | * Normalize position indicator. |
| 23 | */ |
| 24 | if(pd->nboff >= 8) { |
| 25 | pd->buffer += (pd->nboff >> 3); |
| 26 | pd->nbits -= (pd->nboff & ~0x07); |
| 27 | pd->nboff &= 0x07; |
| 28 | } |
| 29 | off = (pd->nboff += nbits); |
| 30 | buf = pd->buffer; |
| 31 | |
| 32 | /* |
| 33 | * Extract specified number of bits. |
| 34 | */ |
| 35 | if(off <= 8) |
Lev Walkin | 6036488 | 2005-11-28 06:58:11 +0000 | [diff] [blame] | 36 | accum = nbits ? (buf[0]) >> (8 - off) : 0; |
Lev Walkin | 59b176e | 2005-11-26 11:25:14 +0000 | [diff] [blame] | 37 | else if(off <= 16) |
| 38 | accum = ((buf[0] << 8) + buf[1]) >> (16 - off); |
| 39 | else if(off <= 24) |
| 40 | accum = ((buf[0] << 16) + (buf[1] << 8) + buf[2]) >> (24 - off); |
| 41 | else if(off <= 31) |
| 42 | accum = ((buf[0] << 24) + (buf[1] << 16) |
| 43 | + (buf[2] << 8) + (buf[3])) >> (32 - off); |
Lev Walkin | 6036488 | 2005-11-28 06:58:11 +0000 | [diff] [blame] | 44 | else if(nbits <= 31) { |
| 45 | asn_per_data_t tpd = *pd; |
| 46 | /* Here are we with our 31-bits limit plus 1..7 bits offset. */ |
| 47 | tpd.nboff -= nbits; |
| 48 | accum = per_get_few_bits(&tpd, nbits - 24) << 24; |
| 49 | accum |= per_get_few_bits(&tpd, 24); |
| 50 | } else { |
Lev Walkin | 59b176e | 2005-11-26 11:25:14 +0000 | [diff] [blame] | 51 | pd->nboff -= nbits; /* Oops, revert back */ |
| 52 | return -1; |
| 53 | } |
| 54 | |
Lev Walkin | 6036488 | 2005-11-28 06:58:11 +0000 | [diff] [blame] | 55 | return (accum & (((uint32_t)1 << nbits) - 1)); |
Lev Walkin | 59b176e | 2005-11-26 11:25:14 +0000 | [diff] [blame] | 56 | } |
| 57 | |
| 58 | /* |
| 59 | * Extract a large number of bits from the specified PER data pointer. |
| 60 | */ |
| 61 | int |
| 62 | per_get_many_bits(asn_per_data_t *pd, uint8_t *dst, int alright, int nbits) { |
| 63 | int32_t value; |
| 64 | |
| 65 | if(alright && (nbits & 7)) { |
| 66 | /* Perform right alignment of a first few bits */ |
| 67 | value = per_get_few_bits(pd, nbits & 0x07); |
| 68 | if(value < 0) return -1; |
| 69 | *dst++ = value; /* value is already right-aligned */ |
| 70 | nbits &= ~7; |
| 71 | } |
| 72 | |
| 73 | while(nbits) { |
| 74 | if(nbits >= 24) { |
| 75 | value = per_get_few_bits(pd, 24); |
| 76 | if(value < 0) return -1; |
| 77 | *(dst++) = value >> 16; |
| 78 | *(dst++) = value >> 8; |
| 79 | *(dst++) = value; |
| 80 | nbits -= 24; |
| 81 | } else { |
| 82 | value = per_get_few_bits(pd, nbits); |
| 83 | if(value < 0) return -1; |
Lev Walkin | 523de9e | 2006-08-18 01:34:18 +0000 | [diff] [blame] | 84 | if(nbits & 7) { /* implies left alignment */ |
Lev Walkin | 59b176e | 2005-11-26 11:25:14 +0000 | [diff] [blame] | 85 | value <<= 8 - (nbits & 7), |
| 86 | nbits += 8 - (nbits & 7); |
| 87 | if(nbits > 24) |
| 88 | *dst++ = value >> 24; |
| 89 | } |
| 90 | if(nbits > 16) |
| 91 | *dst++ = value >> 16; |
| 92 | if(nbits > 8) |
| 93 | *dst++ = value >> 8; |
| 94 | *dst++ = value; |
| 95 | break; |
| 96 | } |
| 97 | } |
| 98 | |
| 99 | return 0; |
| 100 | } |
| 101 | |
| 102 | /* |
| 103 | * Get the length "n" from the stream. |
| 104 | */ |
| 105 | ssize_t |
| 106 | uper_get_length(asn_per_data_t *pd, int ebits, int *repeat) { |
| 107 | ssize_t value; |
| 108 | |
| 109 | *repeat = 0; |
| 110 | |
| 111 | if(ebits >= 0) return per_get_few_bits(pd, ebits); |
| 112 | |
| 113 | value = per_get_few_bits(pd, 8); |
| 114 | if(value < 0) return -1; |
| 115 | if((value & 128) == 0) /* #10.9.3.6 */ |
| 116 | return (value & 0x7F); |
| 117 | if((value & 64) == 0) { /* #10.9.3.7 */ |
| 118 | value = ((value & 63) << 8) | per_get_few_bits(pd, 8); |
| 119 | if(value < 0) return -1; |
| 120 | return value; |
| 121 | } |
| 122 | value &= 63; /* this is "m" from X.691, #10.9.3.8 */ |
| 123 | if(value < 1 || value > 4) |
| 124 | return -1; |
| 125 | *repeat = 1; |
| 126 | return (16384 * value); |
| 127 | } |
| 128 | |
| 129 | /* |
| 130 | * Get the normally small non-negative whole number. |
| 131 | * X.691, #10.6 |
| 132 | */ |
| 133 | ssize_t |
| 134 | uper_get_nsnnwn(asn_per_data_t *pd) { |
| 135 | ssize_t value; |
| 136 | |
| 137 | value = per_get_few_bits(pd, 7); |
| 138 | if(value & 64) { /* implicit (value < 0) */ |
| 139 | value &= 63; |
| 140 | value <<= 2; |
| 141 | value |= per_get_few_bits(pd, 2); |
| 142 | if(value & 128) /* implicit (value < 0) */ |
| 143 | return -1; |
| 144 | if(value == 0) |
| 145 | return 0; |
| 146 | if(value >= 3) |
| 147 | return -1; |
| 148 | value = per_get_few_bits(pd, 8 * value); |
| 149 | return value; |
| 150 | } |
| 151 | |
| 152 | return value; |
| 153 | } |
Lev Walkin | 523de9e | 2006-08-18 01:34:18 +0000 | [diff] [blame] | 154 | |
| 155 | /* |
| 156 | * Put the normally small non-negative whole number. |
| 157 | * X.691, #10.6 |
| 158 | */ |
| 159 | int |
| 160 | uper_put_nsnnwn(asn_per_outp_t *po, int n) { |
| 161 | int bytes; |
| 162 | |
| 163 | if(n <= 63) { |
| 164 | if(n < 0) return -1; |
| 165 | return per_put_few_bits(po, n, 7); |
| 166 | } |
| 167 | if(n < 256) |
| 168 | bytes = 1; |
| 169 | else if(n < 65536) |
| 170 | bytes = 2; |
| 171 | else if(n < 256 * 65536) |
| 172 | bytes = 3; |
| 173 | else |
| 174 | return -1; /* This is not a "normally small" value */ |
| 175 | if(per_put_few_bits(po, bytes, 8)) |
| 176 | return -1; |
| 177 | |
| 178 | return per_put_few_bits(po, n, 8 * bytes); |
| 179 | } |
| 180 | |
| 181 | |
| 182 | /* |
| 183 | * Put a small number of bits (<= 31). |
| 184 | */ |
| 185 | int |
| 186 | per_put_few_bits(asn_per_outp_t *po, uint32_t bits, int obits) { |
| 187 | size_t off; /* Next after last bit offset */ |
| 188 | size_t omsk; /* Existing last byte meaningful bits mask */ |
| 189 | uint8_t *buf; |
| 190 | |
| 191 | if(obits <= 0 || obits >= 32) return obits ? -1 : 0; |
| 192 | |
| 193 | /* |
| 194 | * Normalize position indicator. |
| 195 | */ |
| 196 | if(po->nboff >= 8) { |
| 197 | po->buffer += (po->nboff >> 3); |
| 198 | po->nbits -= (po->nboff & ~0x07); |
| 199 | po->nboff &= 0x07; |
| 200 | } |
| 201 | |
| 202 | /* |
| 203 | * Flush whole-bytes output, if necessary. |
| 204 | */ |
| 205 | if(po->nboff + obits > po->nbits) { |
| 206 | int complete_bytes = (po->buffer - po->tmpspace); |
| 207 | if(po->outper(po->buffer, complete_bytes, po->op_key) < 0) |
| 208 | return -1; |
| 209 | if(po->nboff) |
| 210 | po->tmpspace[0] = po->buffer[0]; |
| 211 | po->buffer = po->tmpspace; |
| 212 | po->nbits = 8 * sizeof(po->tmpspace); |
| 213 | } |
| 214 | |
| 215 | /* |
| 216 | * Now, due to sizeof(tmpspace), we are guaranteed large enough space. |
| 217 | */ |
| 218 | buf = po->buffer; |
| 219 | omsk = ~((1 << (8 - po->nboff)) - 1); |
| 220 | off = (po->nboff += obits); |
| 221 | |
| 222 | /* Clear data of debris before meaningful bits */ |
| 223 | bits &= (((uint32_t)1 << obits) - 1); |
| 224 | |
| 225 | ASN_DEBUG("[PER out %d %u/%x (t=%d,o=%d) %x&%x=%x]", obits, bits, bits, |
| 226 | po->nboff - obits, off, buf[0], omsk&0xff, buf[0] & omsk); |
| 227 | |
| 228 | if(off <= 8) /* Completely within 1 byte */ |
| 229 | bits <<= (8 - off), |
| 230 | buf[0] = (buf[0] & omsk) | bits; |
| 231 | else if(off <= 16) |
| 232 | bits <<= (16 - off), |
| 233 | buf[0] = (buf[0] & omsk) | (bits >> 8), |
| 234 | buf[1] = bits; |
| 235 | else if(off <= 24) |
| 236 | bits <<= (24 - off), |
| 237 | buf[0] = (buf[0] & omsk) | (bits >> 16), |
| 238 | buf[1] = bits >> 8, |
| 239 | buf[2] = bits; |
| 240 | else if(off <= 31) |
| 241 | bits <<= (32 - off), |
| 242 | buf[0] = (buf[0] & omsk) | (bits >> 24), |
| 243 | buf[1] = bits >> 16, |
| 244 | buf[2] = bits >> 8, |
| 245 | buf[3] = bits; |
| 246 | else { |
| 247 | ASN_DEBUG("->[PER out split %d]", obits); |
| 248 | per_put_few_bits(po, bits >> 8, 24); |
| 249 | per_put_few_bits(po, bits, obits - 24); |
| 250 | ASN_DEBUG("<-[PER out split %d]", obits); |
| 251 | } |
| 252 | |
| 253 | ASN_DEBUG("[PER out %u/%x => %02x buf+%d]", |
| 254 | bits, bits, buf[0], po->buffer - po->tmpspace); |
| 255 | |
| 256 | return 0; |
| 257 | } |
| 258 | |
| 259 | |
| 260 | /* |
| 261 | * Output a large number of bits. |
| 262 | */ |
| 263 | int |
| 264 | per_put_many_bits(asn_per_outp_t *po, const uint8_t *src, int nbits) { |
| 265 | |
| 266 | while(nbits) { |
| 267 | uint32_t value; |
| 268 | |
| 269 | if(nbits >= 24) { |
| 270 | value = (src[0] << 16) | (src[1] << 8) | src[2]; |
| 271 | src += 3; |
| 272 | nbits -= 24; |
| 273 | if(per_put_few_bits(po, value, 24)) |
| 274 | return -1; |
| 275 | } else { |
| 276 | value = src[0]; |
| 277 | if(nbits > 8) |
| 278 | value = (value << 8) | src[1]; |
| 279 | if(nbits > 16) |
| 280 | value = (value << 8) | src[2]; |
| 281 | if(nbits & 0x07) |
| 282 | value >>= (8 - (nbits & 0x07)); |
| 283 | if(per_put_few_bits(po, value, nbits)) |
| 284 | return -1; |
| 285 | break; |
| 286 | } |
| 287 | } |
| 288 | |
| 289 | return 0; |
| 290 | } |
| 291 | |
| 292 | /* |
| 293 | * Put the length "n" (or part of it) into the stream. |
| 294 | */ |
| 295 | ssize_t |
| 296 | uper_put_length(asn_per_outp_t *po, size_t length) { |
| 297 | |
| 298 | if(length <= 127) /* #10.9.3.6 */ |
| 299 | return per_put_few_bits(po, length, 8) |
| 300 | ? -1 : (ssize_t)length; |
| 301 | else if(length < 16384) /* #10.9.3.7 */ |
| 302 | return per_put_few_bits(po, length|0x8000, 16) |
| 303 | ? -1 : (ssize_t)length; |
| 304 | |
| 305 | length >>= 14; |
| 306 | if(length > 4) length = 4; |
| 307 | |
| 308 | return per_put_few_bits(po, 0xC0 | length, 8) |
| 309 | ? -1 : (ssize_t)(length << 14); |
| 310 | } |
| 311 | |