1 /* $OpenBSD: a_bitstr.c,v 1.36 2022/05/17 09:17:20 tb Exp $ */ 2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 3 * All rights reserved. 4 * 5 * This package is an SSL implementation written 6 * by Eric Young (eay@cryptsoft.com). 7 * The implementation was written so as to conform with Netscapes SSL. 8 * 9 * This library is free for commercial and non-commercial use as long as 10 * the following conditions are aheared to. The following conditions 11 * apply to all code found in this distribution, be it the RC4, RSA, 12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 13 * included with this distribution is covered by the same copyright terms 14 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 15 * 16 * Copyright remains Eric Young's, and as such any Copyright notices in 17 * the code are not to be removed. 18 * If this package is used in a product, Eric Young should be given attribution 19 * as the author of the parts of the library used. 20 * This can be in the form of a textual message at program startup or 21 * in documentation (online or textual) provided with the package. 22 * 23 * Redistribution and use in source and binary forms, with or without 24 * modification, are permitted provided that the following conditions 25 * are met: 26 * 1. Redistributions of source code must retain the copyright 27 * notice, this list of conditions and the following disclaimer. 28 * 2. Redistributions in binary form must reproduce the above copyright 29 * notice, this list of conditions and the following disclaimer in the 30 * documentation and/or other materials provided with the distribution. 31 * 3. All advertising materials mentioning features or use of this software 32 * must display the following acknowledgement: 33 * "This product includes cryptographic software written by 34 * Eric Young (eay@cryptsoft.com)" 35 * The word 'cryptographic' can be left out if the rouines from the library 36 * being used are not cryptographic related :-). 37 * 4. If you include any Windows specific code (or a derivative thereof) from 38 * the apps directory (application code) you must include an acknowledgement: 39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 40 * 41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 51 * SUCH DAMAGE. 52 * 53 * The licence and distribution terms for any publically available version or 54 * derivative of this code cannot be changed. i.e. this code cannot simply be 55 * copied and put under another distribution licence 56 * [including the GNU Public Licence.] 57 */ 58 59 #include <limits.h> 60 #include <stdio.h> 61 #include <string.h> 62 63 #include <openssl/asn1.h> 64 #include <openssl/asn1t.h> 65 #include <openssl/conf.h> 66 #include <openssl/err.h> 67 #include <openssl/x509v3.h> 68 69 #include "bytestring.h" 70 71 const ASN1_ITEM ASN1_BIT_STRING_it = { 72 .itype = ASN1_ITYPE_PRIMITIVE, 73 .utype = V_ASN1_BIT_STRING, 74 .sname = "ASN1_BIT_STRING", 75 }; 76 77 ASN1_BIT_STRING * 78 ASN1_BIT_STRING_new(void) 79 { 80 return (ASN1_BIT_STRING *)ASN1_item_new(&ASN1_BIT_STRING_it); 81 } 82 83 void 84 ASN1_BIT_STRING_free(ASN1_BIT_STRING *a) 85 { 86 ASN1_item_free((ASN1_VALUE *)a, &ASN1_BIT_STRING_it); 87 } 88 89 static void 90 asn1_abs_clear_unused_bits(ASN1_BIT_STRING *abs) 91 { 92 abs->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07); 93 } 94 95 int 96 asn1_abs_set_unused_bits(ASN1_BIT_STRING *abs, uint8_t unused_bits) 97 { 98 if (unused_bits > 7) 99 return 0; 100 101 asn1_abs_clear_unused_bits(abs); 102 103 abs->flags |= ASN1_STRING_FLAG_BITS_LEFT | unused_bits; 104 105 return 1; 106 } 107 108 int 109 ASN1_BIT_STRING_set(ASN1_BIT_STRING *x, unsigned char *d, int len) 110 { 111 return ASN1_STRING_set(x, d, len); 112 } 113 114 int 115 ASN1_BIT_STRING_set_bit(ASN1_BIT_STRING *a, int n, int value) 116 { 117 int w, v, iv; 118 unsigned char *c; 119 120 w = n/8; 121 v = 1 << (7 - (n & 0x07)); 122 iv = ~v; 123 if (!value) 124 v = 0; 125 126 if (a == NULL) 127 return 0; 128 129 asn1_abs_clear_unused_bits(a); 130 131 if ((a->length < (w + 1)) || (a->data == NULL)) { 132 if (!value) 133 return(1); /* Don't need to set */ 134 if ((c = recallocarray(a->data, a->length, w + 1, 1)) == NULL) { 135 ASN1error(ERR_R_MALLOC_FAILURE); 136 return 0; 137 } 138 a->data = c; 139 a->length = w + 1; 140 } 141 a->data[w] = ((a->data[w]) & iv) | v; 142 while ((a->length > 0) && (a->data[a->length - 1] == 0)) 143 a->length--; 144 145 return (1); 146 } 147 148 int 149 ASN1_BIT_STRING_get_bit(const ASN1_BIT_STRING *a, int n) 150 { 151 int w, v; 152 153 w = n / 8; 154 v = 1 << (7 - (n & 0x07)); 155 if ((a == NULL) || (a->length < (w + 1)) || (a->data == NULL)) 156 return (0); 157 return ((a->data[w] & v) != 0); 158 } 159 160 /* 161 * Checks if the given bit string contains only bits specified by 162 * the flags vector. Returns 0 if there is at least one bit set in 'a' 163 * which is not specified in 'flags', 1 otherwise. 164 * 'len' is the length of 'flags'. 165 */ 166 int 167 ASN1_BIT_STRING_check(const ASN1_BIT_STRING *a, const unsigned char *flags, 168 int flags_len) 169 { 170 int i, ok; 171 172 /* Check if there is one bit set at all. */ 173 if (!a || !a->data) 174 return 1; 175 176 /* Check each byte of the internal representation of the bit string. */ 177 ok = 1; 178 for (i = 0; i < a->length && ok; ++i) { 179 unsigned char mask = i < flags_len ? ~flags[i] : 0xff; 180 /* We are done if there is an unneeded bit set. */ 181 ok = (a->data[i] & mask) == 0; 182 } 183 return ok; 184 } 185 186 int 187 ASN1_BIT_STRING_name_print(BIO *out, ASN1_BIT_STRING *bs, 188 BIT_STRING_BITNAME *tbl, int indent) 189 { 190 BIT_STRING_BITNAME *bnam; 191 char first = 1; 192 193 BIO_printf(out, "%*s", indent, ""); 194 for (bnam = tbl; bnam->lname; bnam++) { 195 if (ASN1_BIT_STRING_get_bit(bs, bnam->bitnum)) { 196 if (!first) 197 BIO_puts(out, ", "); 198 BIO_puts(out, bnam->lname); 199 first = 0; 200 } 201 } 202 BIO_puts(out, "\n"); 203 return 1; 204 } 205 206 int 207 ASN1_BIT_STRING_set_asc(ASN1_BIT_STRING *bs, const char *name, int value, 208 BIT_STRING_BITNAME *tbl) 209 { 210 int bitnum; 211 212 bitnum = ASN1_BIT_STRING_num_asc(name, tbl); 213 if (bitnum < 0) 214 return 0; 215 if (bs) { 216 if (!ASN1_BIT_STRING_set_bit(bs, bitnum, value)) 217 return 0; 218 } 219 return 1; 220 } 221 222 int 223 ASN1_BIT_STRING_num_asc(const char *name, BIT_STRING_BITNAME *tbl) 224 { 225 BIT_STRING_BITNAME *bnam; 226 227 for (bnam = tbl; bnam->lname; bnam++) { 228 if (!strcmp(bnam->sname, name) || 229 !strcmp(bnam->lname, name)) 230 return bnam->bitnum; 231 } 232 return -1; 233 } 234 235 int 236 i2c_ASN1_BIT_STRING(ASN1_BIT_STRING *a, unsigned char **pp) 237 { 238 int ret, j, bits, len; 239 unsigned char *p, *d; 240 241 if (a == NULL) 242 return (0); 243 244 len = a->length; 245 246 if (len > 0) { 247 if (a->flags & ASN1_STRING_FLAG_BITS_LEFT) { 248 bits = (int)a->flags & 0x07; 249 } else { 250 for (; len > 0; len--) { 251 if (a->data[len - 1]) 252 break; 253 } 254 j = a->data[len - 1]; 255 if (j & 0x01) 256 bits = 0; 257 else if (j & 0x02) 258 bits = 1; 259 else if (j & 0x04) 260 bits = 2; 261 else if (j & 0x08) 262 bits = 3; 263 else if (j & 0x10) 264 bits = 4; 265 else if (j & 0x20) 266 bits = 5; 267 else if (j & 0x40) 268 bits = 6; 269 else if (j & 0x80) 270 bits = 7; 271 else 272 bits = 0; /* should not happen */ 273 } 274 } else 275 bits = 0; 276 277 ret = 1 + len; 278 if (pp == NULL) 279 return (ret); 280 281 p= *pp; 282 283 *(p++) = (unsigned char)bits; 284 d = a->data; 285 if (len > 0) { 286 memcpy(p, d, len); 287 p += len; 288 p[-1] &= 0xff << bits; 289 } 290 *pp = p; 291 return (ret); 292 } 293 294 int 295 c2i_ASN1_BIT_STRING_cbs(ASN1_BIT_STRING **out_abs, CBS *cbs) 296 { 297 ASN1_BIT_STRING *abs = NULL; 298 uint8_t *data = NULL; 299 size_t data_len = 0; 300 uint8_t unused_bits; 301 int ret = 0; 302 303 if (out_abs == NULL) 304 goto err; 305 306 if (*out_abs != NULL) { 307 ASN1_BIT_STRING_free(*out_abs); 308 *out_abs = NULL; 309 } 310 311 if (!CBS_get_u8(cbs, &unused_bits)) { 312 ASN1error(ASN1_R_STRING_TOO_SHORT); 313 goto err; 314 } 315 316 if (!CBS_stow(cbs, &data, &data_len)) 317 goto err; 318 if (data_len > INT_MAX) 319 goto err; 320 321 if ((abs = ASN1_BIT_STRING_new()) == NULL) 322 goto err; 323 324 abs->data = data; 325 abs->length = (int)data_len; 326 data = NULL; 327 328 /* 329 * We do this to preserve the settings. If we modify the settings, 330 * via the _set_bit function, we will recalculate on output. 331 */ 332 if (!asn1_abs_set_unused_bits(abs, unused_bits)) { 333 ASN1error(ASN1_R_INVALID_BIT_STRING_BITS_LEFT); 334 goto err; 335 } 336 if (abs->length > 0) 337 abs->data[abs->length - 1] &= 0xff << unused_bits; 338 339 *out_abs = abs; 340 abs = NULL; 341 342 ret = 1; 343 344 err: 345 ASN1_BIT_STRING_free(abs); 346 freezero(data, data_len); 347 348 return ret; 349 } 350 351 ASN1_BIT_STRING * 352 c2i_ASN1_BIT_STRING(ASN1_BIT_STRING **out_abs, const unsigned char **pp, long len) 353 { 354 ASN1_BIT_STRING *abs = NULL; 355 CBS content; 356 357 if (out_abs != NULL) { 358 ASN1_BIT_STRING_free(*out_abs); 359 *out_abs = NULL; 360 } 361 362 if (len < 0) { 363 ASN1error(ASN1_R_LENGTH_ERROR); 364 return NULL; 365 } 366 367 CBS_init(&content, *pp, len); 368 369 if (!c2i_ASN1_BIT_STRING_cbs(&abs, &content)) 370 return NULL; 371 372 *pp = CBS_data(&content); 373 374 if (out_abs != NULL) 375 *out_abs = abs; 376 377 return abs; 378 } 379 380 int 381 i2d_ASN1_BIT_STRING(ASN1_BIT_STRING *a, unsigned char **out) 382 { 383 return ASN1_item_i2d((ASN1_VALUE *)a, out, &ASN1_BIT_STRING_it); 384 } 385 386 ASN1_BIT_STRING * 387 d2i_ASN1_BIT_STRING(ASN1_BIT_STRING **a, const unsigned char **in, long len) 388 { 389 return (ASN1_BIT_STRING *)ASN1_item_d2i((ASN1_VALUE **)a, in, len, 390 &ASN1_BIT_STRING_it); 391 } 392