1 /* crypto/asn1/a_bitstr.c */
   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 "cryptlib.h"
  61 #include <openssl/asn1.h>
  62 
  63 int ASN1_BIT_STRING_set(ASN1_BIT_STRING *x, unsigned char *d, int len)
  64 { return M_ASN1_BIT_STRING_set(x, d, len); }
  65 
  66 int i2c_ASN1_BIT_STRING(ASN1_BIT_STRING *a, unsigned char **pp)
  67         {
  68         int ret,j,bits,len;
  69         unsigned char *p,*d;
  70 
  71         if (a == NULL) return(0);
  72 
  73         len=a->length;
  74 
  75         if (len > 0)
  76                 {
  77                 if (a->flags & ASN1_STRING_FLAG_BITS_LEFT)
  78                         {
  79                         bits=(int)a->flags&0x07;
  80                         }
  81                 else
  82                         {
  83                         for ( ; len > 0; len--)
  84                                 {
  85                                 if (a->data[len-1]) break;
  86                                 }
  87                         j=a->data[len-1];
  88                         if      (j & 0x01) bits=0;
  89                         else if (j & 0x02) bits=1;
  90                         else if (j & 0x04) bits=2;
  91                         else if (j & 0x08) bits=3;
  92                         else if (j & 0x10) bits=4;
  93                         else if (j & 0x20) bits=5;
  94                         else if (j & 0x40) bits=6;
  95                         else if (j & 0x80) bits=7;
  96                         else bits=0; /* should not happen */
  97                         }
  98                 }
  99         else
 100                 bits=0;
 101 
 102         ret=1+len;
 103         if (pp == NULL) return(ret);
 104 
 105         p= *pp;
 106 
 107         *(p++)=(unsigned char)bits;
 108         d=a->data;
 109         memcpy(p,d,len);
 110         p+=len;
 111         if (len > 0) p[-1]&=(0xff<<bits);
 112         *pp=p;
 113         return(ret);
 114         }
 115 
 116 ASN1_BIT_STRING *c2i_ASN1_BIT_STRING(ASN1_BIT_STRING **a,
 117         const unsigned char **pp, long len)
 118         {
 119         ASN1_BIT_STRING *ret=NULL;
 120         const unsigned char *p;
 121         unsigned char *s;
 122         int i;
 123 
 124         if (len < 1)
 125                 {
 126                 i=ASN1_R_STRING_TOO_SHORT;
 127                 goto err;
 128                 }
 129 
 130         if ((a == NULL) || ((*a) == NULL))
 131                 {
 132                 if ((ret=M_ASN1_BIT_STRING_new()) == NULL) return(NULL);
 133                 }
 134         else
 135                 ret=(*a);
 136 
 137         p= *pp;
 138         i= *(p++);
 139         /* We do this to preserve the settings.  If we modify
 140          * the settings, via the _set_bit function, we will recalculate
 141          * on output */
 142         ret->flags&= ~(ASN1_STRING_FLAG_BITS_LEFT|0x07); /* clear */
 143         ret->flags|=(ASN1_STRING_FLAG_BITS_LEFT|(i&0x07)); /* set */
 144 
 145         if (len-- > 1) /* using one because of the bits left byte */
 146                 {
 147                 s=(unsigned char *)OPENSSL_malloc((int)len);
 148                 if (s == NULL)
 149                         {
 150                         i=ERR_R_MALLOC_FAILURE;
 151                         goto err;
 152                         }
 153                 memcpy(s,p,(int)len);
 154                 s[len-1]&=(0xff<<i);
 155                 p+=len;
 156                 }
 157         else
 158                 s=NULL;
 159 
 160         ret->length=(int)len;
 161         if (ret->data != NULL) OPENSSL_free(ret->data);
 162         ret->data=s;
 163         ret->type=V_ASN1_BIT_STRING;
 164         if (a != NULL) (*a)=ret;
 165         *pp=p;
 166         return(ret);
 167 err:
 168         ASN1err(ASN1_F_C2I_ASN1_BIT_STRING,i);
 169         if ((ret != NULL) && ((a == NULL) || (*a != ret)))
 170                 M_ASN1_BIT_STRING_free(ret);
 171         return(NULL);
 172         }
 173 
 174 /* These next 2 functions from Goetz Babin-Ebell <babinebell@trustcenter.de>
 175  */
 176 int ASN1_BIT_STRING_set_bit(ASN1_BIT_STRING *a, int n, int value)
 177         {
 178         int w,v,iv;
 179         unsigned char *c;
 180 
 181         w=n/8;
 182         v=1<<(7-(n&0x07));
 183         iv= ~v;
 184         if (!value) v=0;
 185 
 186         if (a == NULL)
 187                 return 0;
 188 
 189         a->flags&= ~(ASN1_STRING_FLAG_BITS_LEFT|0x07); /* clear, set on write */
 190 
 191         if ((a->length < (w+1)) || (a->data == NULL))
 192                 {
 193                 if (!value) return(1); /* Don't need to set */
 194                 if (a->data == NULL)
 195                         c=(unsigned char *)OPENSSL_malloc(w+1);
 196                 else
 197                         c=(unsigned char *)OPENSSL_realloc_clean(a->data,
 198                                                                  a->length,
 199                                                                  w+1);
 200                 if (c == NULL)
 201                         {
 202                         ASN1err(ASN1_F_ASN1_BIT_STRING_SET_BIT,ERR_R_MALLOC_FAILURE);
 203                         return 0;
 204                         }
 205                 if (w+1-a->length > 0) memset(c+a->length, 0, w+1-a->length);
 206                 a->data=c;
 207                 a->length=w+1;
 208         }
 209         a->data[w]=((a->data[w])&iv)|v;
 210         while ((a->length > 0) && (a->data[a->length-1] == 0))
 211                 a->length--;
 212         return(1);
 213         }
 214 
 215 int ASN1_BIT_STRING_get_bit(ASN1_BIT_STRING *a, int n)
 216         {
 217         int w,v;
 218 
 219         w=n/8;
 220         v=1<<(7-(n&0x07));
 221         if ((a == NULL) || (a->length < (w+1)) || (a->data == NULL))
 222                 return(0);
 223         return((a->data[w]&v) != 0);
 224         }
 225 
 226 /*
 227  * Checks if the given bit string contains only bits specified by
 228  * the flags vector. Returns 0 if there is at least one bit set in 'a'
 229  * which is not specified in 'flags', 1 otherwise.
 230  * 'len' is the length of 'flags'.
 231  */
 232 int ASN1_BIT_STRING_check(ASN1_BIT_STRING *a,
 233                           unsigned char *flags, int flags_len)
 234         {
 235         int i, ok;
 236         /* Check if there is one bit set at all. */
 237         if (!a || !a->data) return 1;
 238 
 239         /* Check each byte of the internal representation of the bit string. */
 240         ok = 1;
 241         for (i = 0; i < a->length && ok; ++i)
 242                 {
 243                 unsigned char mask = i < flags_len ? ~flags[i] : 0xff;
 244                 /* We are done if there is an unneeded bit set. */
 245                 ok = (a->data[i] & mask) == 0;
 246                 }
 247         return ok;
 248         }