1/* $OpenBSD: a_bitstr.c,v 1.42 2023/12/25 22:02:59 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 71const ASN1_ITEM ASN1_BIT_STRING_it = { 72 .itype = ASN1_ITYPE_PRIMITIVE, 73 .utype = V_ASN1_BIT_STRING, 74 .sname = "ASN1_BIT_STRING", 75}; 76 77ASN1_BIT_STRING * 78ASN1_BIT_STRING_new(void) 79{ 80 return (ASN1_BIT_STRING *)ASN1_item_new(&ASN1_BIT_STRING_it); 81} 82LCRYPTO_ALIAS(ASN1_BIT_STRING_new); 83 84void 85ASN1_BIT_STRING_free(ASN1_BIT_STRING *a) 86{ 87 ASN1_item_free((ASN1_VALUE *)a, &ASN1_BIT_STRING_it); 88} 89LCRYPTO_ALIAS(ASN1_BIT_STRING_free); 90 91static void 92asn1_abs_clear_unused_bits(ASN1_BIT_STRING *abs) 93{ 94 abs->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07); 95} 96 97int 98asn1_abs_set_unused_bits(ASN1_BIT_STRING *abs, uint8_t unused_bits) 99{ 100 if (unused_bits > 7) 101 return 0; 102 103 asn1_abs_clear_unused_bits(abs); 104 105 abs->flags |= ASN1_STRING_FLAG_BITS_LEFT | unused_bits; 106 107 return 1; 108} 109 110int 111ASN1_BIT_STRING_set(ASN1_BIT_STRING *x, unsigned char *d, int len) 112{ 113 return ASN1_STRING_set(x, d, len); 114} 115LCRYPTO_ALIAS(ASN1_BIT_STRING_set); 116 117int 118ASN1_BIT_STRING_set_bit(ASN1_BIT_STRING *a, int n, int value) 119{ 120 int w, v, iv; 121 unsigned char *c; 122 123 if (a == NULL) 124 return 0; 125 if (n < 0) 126 return 0; 127 128 w = n / 8; 129 v = 1 << (7 - (n & 0x07)); 130 iv = ~v; 131 132 if (value == 0) 133 v = 0; 134 135 asn1_abs_clear_unused_bits(a); 136 137 if (a->length < w + 1 || a->data == NULL) { 138 /* Don't expand if there's no bit to set. */ 139 if (value == 0) 140 return 1; 141 if ((c = recallocarray(a->data, a->length, w + 1, 1)) == NULL) { 142 ASN1error(ERR_R_MALLOC_FAILURE); 143 return 0; 144 } 145 a->data = c; 146 a->length = w + 1; 147 } 148 149 a->data[w] = ((a->data[w]) & iv) | v; 150 while (a->length > 0 && a->data[a->length - 1] == 0) 151 a->length--; 152 153 return 1; 154} 155LCRYPTO_ALIAS(ASN1_BIT_STRING_set_bit); 156 157int 158ASN1_BIT_STRING_get_bit(const ASN1_BIT_STRING *a, int n) 159{ 160 int w, v; 161 162 if (a == NULL) 163 return 0; 164 if (n < 0) 165 return 0; 166 167 w = n / 8; 168 v = 1 << (7 - (n & 0x07)); 169 170 if (a->length < w + 1 || a->data == NULL) 171 return 0; 172 173 return (a->data[w] & v) != 0; 174} 175LCRYPTO_ALIAS(ASN1_BIT_STRING_get_bit); 176 177int 178i2c_ASN1_BIT_STRING(ASN1_BIT_STRING *a, unsigned char **pp) 179{ 180 int ret, j, bits, len; 181 unsigned char *p, *d; 182 183 if (a == NULL) 184 return (0); 185 186 if (a->length == INT_MAX) 187 return (0); 188 189 ret = a->length + 1; 190 191 if (pp == NULL) 192 return (ret); 193 194 len = a->length; 195 196 if (len > 0) { 197 if (a->flags & ASN1_STRING_FLAG_BITS_LEFT) { 198 bits = (int)a->flags & 0x07; 199 } else { 200 j = 0; 201 for (; len > 0; len--) { 202 if (a->data[len - 1]) 203 break; 204 } 205 if (len > 0) 206 j = a->data[len - 1]; 207 if (j & 0x01) 208 bits = 0; 209 else if (j & 0x02) 210 bits = 1; 211 else if (j & 0x04) 212 bits = 2; 213 else if (j & 0x08) 214 bits = 3; 215 else if (j & 0x10) 216 bits = 4; 217 else if (j & 0x20) 218 bits = 5; 219 else if (j & 0x40) 220 bits = 6; 221 else if (j & 0x80) 222 bits = 7; 223 else 224 bits = 0; /* should not happen */ 225 } 226 } else 227 bits = 0; 228 229 p= *pp; 230 231 *(p++) = (unsigned char)bits; 232 d = a->data; 233 if (len > 0) { 234 memcpy(p, d, len); 235 p += len; 236 p[-1] &= 0xff << bits; 237 } 238 *pp = p; 239 return (ret); 240} 241 242int 243c2i_ASN1_BIT_STRING_cbs(ASN1_BIT_STRING **out_abs, CBS *cbs) 244{ 245 ASN1_BIT_STRING *abs = NULL; 246 uint8_t *data = NULL; 247 size_t data_len = 0; 248 uint8_t unused_bits; 249 int ret = 0; 250 251 if (out_abs == NULL) 252 goto err; 253 254 if (*out_abs != NULL) { 255 ASN1_BIT_STRING_free(*out_abs); 256 *out_abs = NULL; 257 } 258 259 if (!CBS_get_u8(cbs, &unused_bits)) { 260 ASN1error(ASN1_R_STRING_TOO_SHORT); 261 goto err; 262 } 263 264 if (!CBS_stow(cbs, &data, &data_len)) 265 goto err; 266 if (data_len > INT_MAX) 267 goto err; 268 269 if ((abs = ASN1_BIT_STRING_new()) == NULL) 270 goto err; 271 272 abs->data = data; 273 abs->length = (int)data_len; 274 data = NULL; 275 276 /* 277 * We do this to preserve the settings. If we modify the settings, 278 * via the _set_bit function, we will recalculate on output. 279 */ 280 if (!asn1_abs_set_unused_bits(abs, unused_bits)) { 281 ASN1error(ASN1_R_INVALID_BIT_STRING_BITS_LEFT); 282 goto err; 283 } 284 if (abs->length > 0) 285 abs->data[abs->length - 1] &= 0xff << unused_bits; 286 287 *out_abs = abs; 288 abs = NULL; 289 290 ret = 1; 291 292 err: 293 ASN1_BIT_STRING_free(abs); 294 freezero(data, data_len); 295 296 return ret; 297} 298 299ASN1_BIT_STRING * 300c2i_ASN1_BIT_STRING(ASN1_BIT_STRING **out_abs, const unsigned char **pp, long len) 301{ 302 ASN1_BIT_STRING *abs = NULL; 303 CBS content; 304 305 if (out_abs != NULL) { 306 ASN1_BIT_STRING_free(*out_abs); 307 *out_abs = NULL; 308 } 309 310 if (len < 0) { 311 ASN1error(ASN1_R_LENGTH_ERROR); 312 return NULL; 313 } 314 315 CBS_init(&content, *pp, len); 316 317 if (!c2i_ASN1_BIT_STRING_cbs(&abs, &content)) 318 return NULL; 319 320 *pp = CBS_data(&content); 321 322 if (out_abs != NULL) 323 *out_abs = abs; 324 325 return abs; 326} 327 328int 329i2d_ASN1_BIT_STRING(ASN1_BIT_STRING *a, unsigned char **out) 330{ 331 return ASN1_item_i2d((ASN1_VALUE *)a, out, &ASN1_BIT_STRING_it); 332} 333LCRYPTO_ALIAS(i2d_ASN1_BIT_STRING); 334 335ASN1_BIT_STRING * 336d2i_ASN1_BIT_STRING(ASN1_BIT_STRING **a, const unsigned char **in, long len) 337{ 338 return (ASN1_BIT_STRING *)ASN1_item_d2i((ASN1_VALUE **)a, in, len, 339 &ASN1_BIT_STRING_it); 340} 341LCRYPTO_ALIAS(d2i_ASN1_BIT_STRING); 342