1 /* $OpenBSD: a_bitstr.c,v 1.41 2023/07/28 10:33:13 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 LCRYPTO_ALIAS(ASN1_BIT_STRING_new); 83 84 void 85 ASN1_BIT_STRING_free(ASN1_BIT_STRING *a) 86 { 87 ASN1_item_free((ASN1_VALUE *)a, &ASN1_BIT_STRING_it); 88 } 89 LCRYPTO_ALIAS(ASN1_BIT_STRING_free); 90 91 static void 92 asn1_abs_clear_unused_bits(ASN1_BIT_STRING *abs) 93 { 94 abs->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07); 95 } 96 97 int 98 asn1_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 } 109 110 int 111 ASN1_BIT_STRING_set(ASN1_BIT_STRING *x, unsigned char *d, int len) 112 { 113 return ASN1_STRING_set(x, d, len); 114 } 115 LCRYPTO_ALIAS(ASN1_BIT_STRING_set); 116 117 int 118 ASN1_BIT_STRING_set_bit(ASN1_BIT_STRING *a, int n, int value) 119 { 120 int w, v, iv; 121 unsigned char *c; 122 123 w = n/8; 124 v = 1 << (7 - (n & 0x07)); 125 iv = ~v; 126 if (!value) 127 v = 0; 128 129 if (a == NULL) 130 return 0; 131 132 asn1_abs_clear_unused_bits(a); 133 134 if ((a->length < (w + 1)) || (a->data == NULL)) { 135 if (!value) 136 return(1); /* Don't need to set */ 137 if ((c = recallocarray(a->data, a->length, w + 1, 1)) == NULL) { 138 ASN1error(ERR_R_MALLOC_FAILURE); 139 return 0; 140 } 141 a->data = c; 142 a->length = w + 1; 143 } 144 a->data[w] = ((a->data[w]) & iv) | v; 145 while ((a->length > 0) && (a->data[a->length - 1] == 0)) 146 a->length--; 147 148 return (1); 149 } 150 LCRYPTO_ALIAS(ASN1_BIT_STRING_set_bit); 151 152 int 153 ASN1_BIT_STRING_get_bit(const ASN1_BIT_STRING *a, int n) 154 { 155 int w, v; 156 157 w = n / 8; 158 v = 1 << (7 - (n & 0x07)); 159 if ((a == NULL) || (a->length < (w + 1)) || (a->data == NULL)) 160 return (0); 161 return ((a->data[w] & v) != 0); 162 } 163 LCRYPTO_ALIAS(ASN1_BIT_STRING_get_bit); 164 165 int 166 i2c_ASN1_BIT_STRING(ASN1_BIT_STRING *a, unsigned char **pp) 167 { 168 int ret, j, bits, len; 169 unsigned char *p, *d; 170 171 if (a == NULL) 172 return (0); 173 174 if (a->length == INT_MAX) 175 return (0); 176 177 ret = a->length + 1; 178 179 if (pp == NULL) 180 return (ret); 181 182 len = a->length; 183 184 if (len > 0) { 185 if (a->flags & ASN1_STRING_FLAG_BITS_LEFT) { 186 bits = (int)a->flags & 0x07; 187 } else { 188 j = 0; 189 for (; len > 0; len--) { 190 if (a->data[len - 1]) 191 break; 192 } 193 if (len > 0) 194 j = a->data[len - 1]; 195 if (j & 0x01) 196 bits = 0; 197 else if (j & 0x02) 198 bits = 1; 199 else if (j & 0x04) 200 bits = 2; 201 else if (j & 0x08) 202 bits = 3; 203 else if (j & 0x10) 204 bits = 4; 205 else if (j & 0x20) 206 bits = 5; 207 else if (j & 0x40) 208 bits = 6; 209 else if (j & 0x80) 210 bits = 7; 211 else 212 bits = 0; /* should not happen */ 213 } 214 } else 215 bits = 0; 216 217 p= *pp; 218 219 *(p++) = (unsigned char)bits; 220 d = a->data; 221 if (len > 0) { 222 memcpy(p, d, len); 223 p += len; 224 p[-1] &= 0xff << bits; 225 } 226 *pp = p; 227 return (ret); 228 } 229 230 int 231 c2i_ASN1_BIT_STRING_cbs(ASN1_BIT_STRING **out_abs, CBS *cbs) 232 { 233 ASN1_BIT_STRING *abs = NULL; 234 uint8_t *data = NULL; 235 size_t data_len = 0; 236 uint8_t unused_bits; 237 int ret = 0; 238 239 if (out_abs == NULL) 240 goto err; 241 242 if (*out_abs != NULL) { 243 ASN1_BIT_STRING_free(*out_abs); 244 *out_abs = NULL; 245 } 246 247 if (!CBS_get_u8(cbs, &unused_bits)) { 248 ASN1error(ASN1_R_STRING_TOO_SHORT); 249 goto err; 250 } 251 252 if (!CBS_stow(cbs, &data, &data_len)) 253 goto err; 254 if (data_len > INT_MAX) 255 goto err; 256 257 if ((abs = ASN1_BIT_STRING_new()) == NULL) 258 goto err; 259 260 abs->data = data; 261 abs->length = (int)data_len; 262 data = NULL; 263 264 /* 265 * We do this to preserve the settings. If we modify the settings, 266 * via the _set_bit function, we will recalculate on output. 267 */ 268 if (!asn1_abs_set_unused_bits(abs, unused_bits)) { 269 ASN1error(ASN1_R_INVALID_BIT_STRING_BITS_LEFT); 270 goto err; 271 } 272 if (abs->length > 0) 273 abs->data[abs->length - 1] &= 0xff << unused_bits; 274 275 *out_abs = abs; 276 abs = NULL; 277 278 ret = 1; 279 280 err: 281 ASN1_BIT_STRING_free(abs); 282 freezero(data, data_len); 283 284 return ret; 285 } 286 287 ASN1_BIT_STRING * 288 c2i_ASN1_BIT_STRING(ASN1_BIT_STRING **out_abs, const unsigned char **pp, long len) 289 { 290 ASN1_BIT_STRING *abs = NULL; 291 CBS content; 292 293 if (out_abs != NULL) { 294 ASN1_BIT_STRING_free(*out_abs); 295 *out_abs = NULL; 296 } 297 298 if (len < 0) { 299 ASN1error(ASN1_R_LENGTH_ERROR); 300 return NULL; 301 } 302 303 CBS_init(&content, *pp, len); 304 305 if (!c2i_ASN1_BIT_STRING_cbs(&abs, &content)) 306 return NULL; 307 308 *pp = CBS_data(&content); 309 310 if (out_abs != NULL) 311 *out_abs = abs; 312 313 return abs; 314 } 315 316 int 317 i2d_ASN1_BIT_STRING(ASN1_BIT_STRING *a, unsigned char **out) 318 { 319 return ASN1_item_i2d((ASN1_VALUE *)a, out, &ASN1_BIT_STRING_it); 320 } 321 LCRYPTO_ALIAS(i2d_ASN1_BIT_STRING); 322 323 ASN1_BIT_STRING * 324 d2i_ASN1_BIT_STRING(ASN1_BIT_STRING **a, const unsigned char **in, long len) 325 { 326 return (ASN1_BIT_STRING *)ASN1_item_d2i((ASN1_VALUE **)a, in, len, 327 &ASN1_BIT_STRING_it); 328 } 329 LCRYPTO_ALIAS(d2i_ASN1_BIT_STRING); 330