crypto/libressl/crypto/asn1/a_bitstr.c

   1 /* $OpenBSD: a_bitstr.c,v 1.22 2015/07/29 14:58:34 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                 i = 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         /* We do this to preserve the settings.  If we modify
 151          * the settings, via the _set_bit function, we will recalculate
 152          * on output */
 153         ret->flags&= ~(ASN1_STRING_FLAG_BITS_LEFT|0x07); /* clear */
 154         ret->flags|=(ASN1_STRING_FLAG_BITS_LEFT|(i&0x07)); /* set */
 155
 156         if (len-- > 1) /* using one because of the bits left byte */
 157         {
 158                 s = malloc(len);
 159                 if (s == NULL) {
 160                         i = ERR_R_MALLOC_FAILURE;
 161                         goto err;
 162                 }
 163                 memcpy(s, p, len);
 164                 s[len - 1] &= (0xff << i);
 165                 p += len;
 166         } else
 167                 s = NULL;
 168
 169         ret->length = (int)len;
 170         free(ret->data);
 171         ret->data = s;
 172         ret->type = V_ASN1_BIT_STRING;
 173         if (a != NULL)
 174                 (*a) = ret;
 175         *pp = p;
 176         return (ret);
 177
 178 err:
 179         ASN1err(ASN1_F_C2I_ASN1_BIT_STRING, i);
 180         if ((ret != NULL) && ((a == NULL) || (*a != ret)))
 181                 ASN1_BIT_STRING_free(ret);
 182         return (NULL);
 183 }
 184
 185 /* These next 2 functions from Goetz Babin-Ebell <babinebell@trustcenter.de>
 186  */
 187 int
 188 ASN1_BIT_STRING_set_bit(ASN1_BIT_STRING *a, int n, int value)
 189 {
 190         int w, v, iv;
 191         unsigned char *c;
 192
 193         w = n/8;
 194         v = 1 << (7 - (n & 0x07));
 195         iv = ~v;
 196         if (!value)
 197                 v = 0;
 198
 199         if (a == NULL)
 200                 return 0;
 201
 202         a->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07); /* clear, set on write */
 203
 204         if ((a->length < (w + 1)) || (a->data == NULL)) {
 205                 if (!value)
 206                         return(1); /* Don't need to set */
 207                 c = OPENSSL_realloc_clean(a->data, a->length, w + 1);
 208                 if (c == NULL) {
 209                         ASN1err(ASN1_F_ASN1_BIT_STRING_SET_BIT, ERR_R_MALLOC_FAILURE);
 210                         return 0;
 211                 }
 212                 if (w + 1 - a->length > 0)
 213                         memset(c + a->length, 0, w + 1 - a->length);
 214                 a->data = c;
 215                 a->length = w + 1;
 216         }
 217         a->data[w] = ((a->data[w]) & iv) | v;
 218         while ((a->length > 0) && (a->data[a->length - 1] == 0))
 219                 a->length--;
 220
 221         return (1);
 222 }
 223
 224 int
 225 ASN1_BIT_STRING_get_bit(ASN1_BIT_STRING *a, int n)
 226 {
 227         int w, v;
 228
 229         w = n / 8;
 230         v = 1 << (7 - (n & 0x07));
 231         if ((a == NULL) || (a->length < (w + 1)) || (a->data == NULL))
 232                 return (0);
 233         return ((a->data[w] & v) != 0);
 234 }
 235
 236 /*
 237  * Checks if the given bit string contains only bits specified by
 238  * the flags vector. Returns 0 if there is at least one bit set in 'a'
 239  * which is not specified in 'flags', 1 otherwise.
 240  * 'len' is the length of 'flags'.
 241  */
 242 int
 243 ASN1_BIT_STRING_check(ASN1_BIT_STRING *a, unsigned char *flags, int flags_len)
 244 {
 245         int i, ok;
 246
 247         /* Check if there is one bit set at all. */
 248         if (!a || !a->data)
 249                 return 1;
 250
 251         /* Check each byte of the internal representation of the bit string. */
 252         ok = 1;
 253         for (i = 0; i < a->length && ok; ++i) {
 254                 unsigned char mask = i < flags_len ? ~flags[i] : 0xff;
 255                 /* We are done if there is an unneeded bit set. */
 256                 ok = (a->data[i] & mask) == 0;
 257         }
 258         return ok;
 259 }