1 /* $OpenBSD: a_bitstr.c,v 1.43 2024/07/08 14:52:31 beck 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 LCRYPTO_ALIAS(ASN1_BIT_STRING_it); 77 78 ASN1_BIT_STRING * 79 ASN1_BIT_STRING_new(void) 80 { 81 return (ASN1_BIT_STRING *)ASN1_item_new(&ASN1_BIT_STRING_it); 82 } 83 LCRYPTO_ALIAS(ASN1_BIT_STRING_new); 84 85 void 86 ASN1_BIT_STRING_free(ASN1_BIT_STRING *a) 87 { 88 ASN1_item_free((ASN1_VALUE *)a, &ASN1_BIT_STRING_it); 89 } 90 LCRYPTO_ALIAS(ASN1_BIT_STRING_free); 91 92 static void 93 asn1_abs_clear_unused_bits(ASN1_BIT_STRING *abs) 94 { 95 abs->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07); 96 } 97 98 int 99 asn1_abs_set_unused_bits(ASN1_BIT_STRING *abs, uint8_t unused_bits) 100 { 101 if (unused_bits > 7) 102 return 0; 103 104 asn1_abs_clear_unused_bits(abs); 105 106 abs->flags |= ASN1_STRING_FLAG_BITS_LEFT | unused_bits; 107 108 return 1; 109 } 110 111 int 112 ASN1_BIT_STRING_set(ASN1_BIT_STRING *x, unsigned char *d, int len) 113 { 114 return ASN1_STRING_set(x, d, len); 115 } 116 LCRYPTO_ALIAS(ASN1_BIT_STRING_set); 117 118 int 119 ASN1_BIT_STRING_set_bit(ASN1_BIT_STRING *a, int n, int value) 120 { 121 int w, v, iv; 122 unsigned char *c; 123 124 if (a == NULL) 125 return 0; 126 if (n < 0) 127 return 0; 128 129 w = n / 8; 130 v = 1 << (7 - (n & 0x07)); 131 iv = ~v; 132 133 if (value == 0) 134 v = 0; 135 136 asn1_abs_clear_unused_bits(a); 137 138 if (a->length < w + 1 || a->data == NULL) { 139 /* Don't expand if there's no bit to set. */ 140 if (value == 0) 141 return 1; 142 if ((c = recallocarray(a->data, a->length, w + 1, 1)) == NULL) { 143 ASN1error(ERR_R_MALLOC_FAILURE); 144 return 0; 145 } 146 a->data = c; 147 a->length = w + 1; 148 } 149 150 a->data[w] = ((a->data[w]) & iv) | v; 151 while (a->length > 0 && a->data[a->length - 1] == 0) 152 a->length--; 153 154 return 1; 155 } 156 LCRYPTO_ALIAS(ASN1_BIT_STRING_set_bit); 157 158 int 159 ASN1_BIT_STRING_get_bit(const ASN1_BIT_STRING *a, int n) 160 { 161 int w, v; 162 163 if (a == NULL) 164 return 0; 165 if (n < 0) 166 return 0; 167 168 w = n / 8; 169 v = 1 << (7 - (n & 0x07)); 170 171 if (a->length < w + 1 || a->data == NULL) 172 return 0; 173 174 return (a->data[w] & v) != 0; 175 } 176 LCRYPTO_ALIAS(ASN1_BIT_STRING_get_bit); 177 178 int 179 i2c_ASN1_BIT_STRING(ASN1_BIT_STRING *a, unsigned char **pp) 180 { 181 int ret, j, bits, len; 182 unsigned char *p, *d; 183 184 if (a == NULL) 185 return (0); 186 187 if (a->length == INT_MAX) 188 return (0); 189 190 ret = a->length + 1; 191 192 if (pp == NULL) 193 return (ret); 194 195 len = a->length; 196 197 if (len > 0) { 198 if (a->flags & ASN1_STRING_FLAG_BITS_LEFT) { 199 bits = (int)a->flags & 0x07; 200 } else { 201 j = 0; 202 for (; len > 0; len--) { 203 if (a->data[len - 1]) 204 break; 205 } 206 if (len > 0) 207 j = a->data[len - 1]; 208 if (j & 0x01) 209 bits = 0; 210 else if (j & 0x02) 211 bits = 1; 212 else if (j & 0x04) 213 bits = 2; 214 else if (j & 0x08) 215 bits = 3; 216 else if (j & 0x10) 217 bits = 4; 218 else if (j & 0x20) 219 bits = 5; 220 else if (j & 0x40) 221 bits = 6; 222 else if (j & 0x80) 223 bits = 7; 224 else 225 bits = 0; /* should not happen */ 226 } 227 } else 228 bits = 0; 229 230 p= *pp; 231 232 *(p++) = (unsigned char)bits; 233 d = a->data; 234 if (len > 0) { 235 memcpy(p, d, len); 236 p += len; 237 p[-1] &= 0xff << bits; 238 } 239 *pp = p; 240 return (ret); 241 } 242 243 int 244 c2i_ASN1_BIT_STRING_cbs(ASN1_BIT_STRING **out_abs, CBS *cbs) 245 { 246 ASN1_BIT_STRING *abs = NULL; 247 uint8_t *data = NULL; 248 size_t data_len = 0; 249 uint8_t unused_bits; 250 int ret = 0; 251 252 if (out_abs == NULL) 253 goto err; 254 255 if (*out_abs != NULL) { 256 ASN1_BIT_STRING_free(*out_abs); 257 *out_abs = NULL; 258 } 259 260 if (!CBS_get_u8(cbs, &unused_bits)) { 261 ASN1error(ASN1_R_STRING_TOO_SHORT); 262 goto err; 263 } 264 265 if (!CBS_stow(cbs, &data, &data_len)) 266 goto err; 267 if (data_len > INT_MAX) 268 goto err; 269 270 if ((abs = ASN1_BIT_STRING_new()) == NULL) 271 goto err; 272 273 abs->data = data; 274 abs->length = (int)data_len; 275 data = NULL; 276 277 /* 278 * We do this to preserve the settings. If we modify the settings, 279 * via the _set_bit function, we will recalculate on output. 280 */ 281 if (!asn1_abs_set_unused_bits(abs, unused_bits)) { 282 ASN1error(ASN1_R_INVALID_BIT_STRING_BITS_LEFT); 283 goto err; 284 } 285 if (abs->length > 0) 286 abs->data[abs->length - 1] &= 0xff << unused_bits; 287 288 *out_abs = abs; 289 abs = NULL; 290 291 ret = 1; 292 293 err: 294 ASN1_BIT_STRING_free(abs); 295 freezero(data, data_len); 296 297 return ret; 298 } 299 300 ASN1_BIT_STRING * 301 c2i_ASN1_BIT_STRING(ASN1_BIT_STRING **out_abs, const unsigned char **pp, long len) 302 { 303 ASN1_BIT_STRING *abs = NULL; 304 CBS content; 305 306 if (out_abs != NULL) { 307 ASN1_BIT_STRING_free(*out_abs); 308 *out_abs = NULL; 309 } 310 311 if (len < 0) { 312 ASN1error(ASN1_R_LENGTH_ERROR); 313 return NULL; 314 } 315 316 CBS_init(&content, *pp, len); 317 318 if (!c2i_ASN1_BIT_STRING_cbs(&abs, &content)) 319 return NULL; 320 321 *pp = CBS_data(&content); 322 323 if (out_abs != NULL) 324 *out_abs = abs; 325 326 return abs; 327 } 328 329 int 330 i2d_ASN1_BIT_STRING(ASN1_BIT_STRING *a, unsigned char **out) 331 { 332 return ASN1_item_i2d((ASN1_VALUE *)a, out, &ASN1_BIT_STRING_it); 333 } 334 LCRYPTO_ALIAS(i2d_ASN1_BIT_STRING); 335 336 ASN1_BIT_STRING * 337 d2i_ASN1_BIT_STRING(ASN1_BIT_STRING **a, const unsigned char **in, long len) 338 { 339 return (ASN1_BIT_STRING *)ASN1_item_d2i((ASN1_VALUE **)a, in, len, 340 &ASN1_BIT_STRING_it); 341 } 342 LCRYPTO_ALIAS(d2i_ASN1_BIT_STRING); 343