1 /* $OpenBSD: a_bitstr.c,v 1.28 2018/05/13 13:48:08 jsing 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 memcpy(p, d, len); 122 p += len; 123 if (len > 0) 124 p[-1]&=(0xff << bits); 125 *pp = p; 126 return (ret); 127 } 128 129 ASN1_BIT_STRING * 130 c2i_ASN1_BIT_STRING(ASN1_BIT_STRING **a, const unsigned char **pp, long len) 131 { 132 ASN1_BIT_STRING *ret = NULL; 133 const unsigned char *p; 134 unsigned char *s; 135 int i; 136 137 if (len < 1) { 138 ASN1error(ASN1_R_STRING_TOO_SHORT); 139 goto err; 140 } 141 142 if (a == NULL || *a == NULL) { 143 if ((ret = ASN1_BIT_STRING_new()) == NULL) 144 return (NULL); 145 } else 146 ret = *a; 147 148 p = *pp; 149 i = *(p++); 150 if (i > 7) { 151 ASN1error(ASN1_R_INVALID_BIT_STRING_BITS_LEFT); 152 goto err; 153 } 154 155 /* 156 * We do this to preserve the settings. If we modify the settings, 157 * via the _set_bit function, we will recalculate on output. 158 */ 159 ret->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07); /* clear */ 160 ret->flags |= (ASN1_STRING_FLAG_BITS_LEFT | i); /* set */ 161 162 /* using one because of the bits left byte */ 163 if (len-- > 1) { 164 if ((s = malloc(len)) == NULL) { 165 ASN1error(ERR_R_MALLOC_FAILURE); 166 goto err; 167 } 168 memcpy(s, p, len); 169 s[len - 1] &= (0xff << i); 170 p += len; 171 } else 172 s = NULL; 173 174 free(ret->data); 175 ret->data = s; 176 ret->length = (int)len; 177 ret->type = V_ASN1_BIT_STRING; 178 179 if (a != NULL) 180 *a = ret; 181 182 *pp = p; 183 184 return (ret); 185 186 err: 187 if (a == NULL || *a != ret) 188 ASN1_BIT_STRING_free(ret); 189 190 return (NULL); 191 } 192 193 int 194 ASN1_BIT_STRING_set_bit(ASN1_BIT_STRING *a, int n, int value) 195 { 196 int w, v, iv; 197 unsigned char *c; 198 199 w = n/8; 200 v = 1 << (7 - (n & 0x07)); 201 iv = ~v; 202 if (!value) 203 v = 0; 204 205 if (a == NULL) 206 return 0; 207 208 a->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07); /* clear, set on write */ 209 210 if ((a->length < (w + 1)) || (a->data == NULL)) { 211 if (!value) 212 return(1); /* Don't need to set */ 213 if ((c = recallocarray(a->data, a->length, w + 1, 1)) == NULL) { 214 ASN1error(ERR_R_MALLOC_FAILURE); 215 return 0; 216 } 217 if (w + 1 - a->length > 0) 218 memset(c + a->length, 0, w + 1 - a->length); 219 a->data = c; 220 a->length = w + 1; 221 } 222 a->data[w] = ((a->data[w]) & iv) | v; 223 while ((a->length > 0) && (a->data[a->length - 1] == 0)) 224 a->length--; 225 226 return (1); 227 } 228 229 int 230 ASN1_BIT_STRING_get_bit(const ASN1_BIT_STRING *a, int n) 231 { 232 int w, v; 233 234 w = n / 8; 235 v = 1 << (7 - (n & 0x07)); 236 if ((a == NULL) || (a->length < (w + 1)) || (a->data == NULL)) 237 return (0); 238 return ((a->data[w] & v) != 0); 239 } 240 241 /* 242 * Checks if the given bit string contains only bits specified by 243 * the flags vector. Returns 0 if there is at least one bit set in 'a' 244 * which is not specified in 'flags', 1 otherwise. 245 * 'len' is the length of 'flags'. 246 */ 247 int 248 ASN1_BIT_STRING_check(const ASN1_BIT_STRING *a, const unsigned char *flags, 249 int flags_len) 250 { 251 int i, ok; 252 253 /* Check if there is one bit set at all. */ 254 if (!a || !a->data) 255 return 1; 256 257 /* Check each byte of the internal representation of the bit string. */ 258 ok = 1; 259 for (i = 0; i < a->length && ok; ++i) { 260 unsigned char mask = i < flags_len ? ~flags[i] : 0xff; 261 /* We are done if there is an unneeded bit set. */ 262 ok = (a->data[i] & mask) == 0; 263 } 264 return ok; 265 } 266