1 /* $OpenBSD: a_bitstr.c,v 1.30 2020/09/03 17:19:27 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 <stdio.h> 60 #include <string.h> 61 62 #include <openssl/asn1.h> 63 #include <openssl/err.h> 64 65 int 66 ASN1_BIT_STRING_set(ASN1_BIT_STRING *x, unsigned char *d, int len) 67 { 68 return ASN1_STRING_set(x, d, len); 69 } 70 71 int 72 i2c_ASN1_BIT_STRING(ASN1_BIT_STRING *a, unsigned char **pp) 73 { 74 int ret, j, bits, len; 75 unsigned char *p, *d; 76 77 if (a == NULL) 78 return (0); 79 80 len = a->length; 81 82 if (len > 0) { 83 if (a->flags & ASN1_STRING_FLAG_BITS_LEFT) { 84 bits = (int)a->flags & 0x07; 85 } else { 86 for (; len > 0; len--) { 87 if (a->data[len - 1]) 88 break; 89 } 90 j = a->data[len - 1]; 91 if (j & 0x01) 92 bits = 0; 93 else if (j & 0x02) 94 bits = 1; 95 else if (j & 0x04) 96 bits = 2; 97 else if (j & 0x08) 98 bits = 3; 99 else if (j & 0x10) 100 bits = 4; 101 else if (j & 0x20) 102 bits = 5; 103 else if (j & 0x40) 104 bits = 6; 105 else if (j & 0x80) 106 bits = 7; 107 else 108 bits = 0; /* should not happen */ 109 } 110 } else 111 bits = 0; 112 113 ret = 1 + len; 114 if (pp == NULL) 115 return (ret); 116 117 p= *pp; 118 119 *(p++) = (unsigned char)bits; 120 d = a->data; 121 if (len > 0) { 122 memcpy(p, d, len); 123 p += len; 124 p[-1] &= 0xff << bits; 125 } 126 *pp = p; 127 return (ret); 128 } 129 130 ASN1_BIT_STRING * 131 c2i_ASN1_BIT_STRING(ASN1_BIT_STRING **a, const unsigned char **pp, long len) 132 { 133 ASN1_BIT_STRING *ret = NULL; 134 const unsigned char *p; 135 unsigned char *s; 136 int i; 137 138 if (len < 1) { 139 ASN1error(ASN1_R_STRING_TOO_SHORT); 140 goto err; 141 } 142 143 if (a == NULL || *a == NULL) { 144 if ((ret = ASN1_BIT_STRING_new()) == NULL) 145 return (NULL); 146 } else 147 ret = *a; 148 149 p = *pp; 150 i = *(p++); 151 if (i > 7) { 152 ASN1error(ASN1_R_INVALID_BIT_STRING_BITS_LEFT); 153 goto err; 154 } 155 156 /* 157 * We do this to preserve the settings. If we modify the settings, 158 * via the _set_bit function, we will recalculate on output. 159 */ 160 ret->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07); /* clear */ 161 ret->flags |= (ASN1_STRING_FLAG_BITS_LEFT | i); /* set */ 162 163 /* using one because of the bits left byte */ 164 if (len-- > 1) { 165 if ((s = malloc(len)) == NULL) { 166 ASN1error(ERR_R_MALLOC_FAILURE); 167 goto err; 168 } 169 memcpy(s, p, len); 170 s[len - 1] &= (0xff << i); 171 p += len; 172 } else 173 s = NULL; 174 175 free(ret->data); 176 ret->data = s; 177 ret->length = (int)len; 178 ret->type = V_ASN1_BIT_STRING; 179 180 if (a != NULL) 181 *a = ret; 182 183 *pp = p; 184 185 return (ret); 186 187 err: 188 if (a == NULL || *a != ret) 189 ASN1_BIT_STRING_free(ret); 190 191 return (NULL); 192 } 193 194 int 195 ASN1_BIT_STRING_set_bit(ASN1_BIT_STRING *a, int n, int value) 196 { 197 int w, v, iv; 198 unsigned char *c; 199 200 w = n/8; 201 v = 1 << (7 - (n & 0x07)); 202 iv = ~v; 203 if (!value) 204 v = 0; 205 206 if (a == NULL) 207 return 0; 208 209 a->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07); /* clear, set on write */ 210 211 if ((a->length < (w + 1)) || (a->data == NULL)) { 212 if (!value) 213 return(1); /* Don't need to set */ 214 if ((c = recallocarray(a->data, a->length, w + 1, 1)) == NULL) { 215 ASN1error(ERR_R_MALLOC_FAILURE); 216 return 0; 217 } 218 a->data = c; 219 a->length = w + 1; 220 } 221 a->data[w] = ((a->data[w]) & iv) | v; 222 while ((a->length > 0) && (a->data[a->length - 1] == 0)) 223 a->length--; 224 225 return (1); 226 } 227 228 int 229 ASN1_BIT_STRING_get_bit(const ASN1_BIT_STRING *a, int n) 230 { 231 int w, v; 232 233 w = n / 8; 234 v = 1 << (7 - (n & 0x07)); 235 if ((a == NULL) || (a->length < (w + 1)) || (a->data == NULL)) 236 return (0); 237 return ((a->data[w] & v) != 0); 238 } 239 240 /* 241 * Checks if the given bit string contains only bits specified by 242 * the flags vector. Returns 0 if there is at least one bit set in 'a' 243 * which is not specified in 'flags', 1 otherwise. 244 * 'len' is the length of 'flags'. 245 */ 246 int 247 ASN1_BIT_STRING_check(const ASN1_BIT_STRING *a, const unsigned char *flags, 248 int flags_len) 249 { 250 int i, ok; 251 252 /* Check if there is one bit set at all. */ 253 if (!a || !a->data) 254 return 1; 255 256 /* Check each byte of the internal representation of the bit string. */ 257 ok = 1; 258 for (i = 0; i < a->length && ok; ++i) { 259 unsigned char mask = i < flags_len ? ~flags[i] : 0xff; 260 /* We are done if there is an unneeded bit set. */ 261 ok = (a->data[i] & mask) == 0; 262 } 263 return ok; 264 } 265