release/src/router/openssl/crypto/asn1/a_int.c

   1 /* crypto/asn1/a_int.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 #include <openssl/bn.h>
  63
  64 ASN1_INTEGER *ASN1_INTEGER_dup(const ASN1_INTEGER *x)
  65 { return M_ASN1_INTEGER_dup(x);}
  66
  67 int ASN1_INTEGER_cmp(const ASN1_INTEGER *x, const ASN1_INTEGER *y)
  68         {
  69         int neg, ret;
  70         /* Compare signs */
  71         neg = x->type & V_ASN1_NEG;
  72         if (neg != (y->type & V_ASN1_NEG))
  73                 {
  74                 if (neg)
  75                         return -1;
  76                 else
  77                         return 1;
  78                 }
  79
  80         ret = ASN1_STRING_cmp(x, y);
  81
  82         if (neg)
  83                 return -ret;
  84         else
  85                 return ret;
  86         }
  87
  88
  89 /*
  90  * This converts an ASN1 INTEGER into its content encoding.
  91  * The internal representation is an ASN1_STRING whose data is a big endian
  92  * representation of the value, ignoring the sign. The sign is determined by
  93  * the type: V_ASN1_INTEGER for positive and V_ASN1_NEG_INTEGER for negative.
  94  *
  95  * Positive integers are no problem: they are almost the same as the DER
  96  * encoding, except if the first byte is >= 0x80 we need to add a zero pad.
  97  *
  98  * Negative integers are a bit trickier...
  99  * The DER representation of negative integers is in 2s complement form.
 100  * The internal form is converted by complementing each octet and finally
 101  * adding one to the result. This can be done less messily with a little trick.
 102  * If the internal form has trailing zeroes then they will become FF by the
 103  * complement and 0 by the add one (due to carry) so just copy as many trailing
 104  * zeros to the destination as there are in the source. The carry will add one
 105  * to the last none zero octet: so complement this octet and add one and finally
 106  * complement any left over until you get to the start of the string.
 107  *
 108  * Padding is a little trickier too. If the first bytes is > 0x80 then we pad
 109  * with 0xff. However if the first byte is 0x80 and one of the following bytes
 110  * is non-zero we pad with 0xff. The reason for this distinction is that 0x80
 111  * followed by optional zeros isn't padded.
 112  */
 113
 114 int i2c_ASN1_INTEGER(ASN1_INTEGER *a, unsigned char **pp)
 115         {
 116         int pad=0,ret,i,neg;
 117         unsigned char *p,*n,pb=0;
 118
 119         if ((a == NULL) || (a->data == NULL)) return(0);
 120         neg=a->type & V_ASN1_NEG;
 121         if (a->length == 0)
 122                 ret=1;
 123         else
 124                 {
 125                 ret=a->length;
 126                 i=a->data[0];
 127                 if (!neg && (i > 127)) {
 128                         pad=1;
 129                         pb=0;
 130                 } else if(neg) {
 131                         if(i>128) {
 132                                 pad=1;
 133                                 pb=0xFF;
 134                         } else if(i == 128) {
 135                         /*
 136                          * Special case: if any other bytes non zero we pad:
 137                          * otherwise we don't.
 138                          */
 139                                 for(i = 1; i < a->length; i++) if(a->data[i]) {
 140                                                 pad=1;
 141                                                 pb=0xFF;
 142                                                 break;
 143                                 }
 144                         }
 145                 }
 146                 ret+=pad;
 147                 }
 148         if (pp == NULL) return(ret);
 149         p= *pp;
 150
 151         if (pad) *(p++)=pb;
 152         if (a->length == 0) *(p++)=0;
 153         else if (!neg) memcpy(p,a->data,(unsigned int)a->length);
 154         else {
 155                 /* Begin at the end of the encoding */
 156                 n=a->data + a->length - 1;
 157                 p += a->length - 1;
 158                 i = a->length;
 159                 /* Copy zeros to destination as long as source is zero */
 160                 while(!*n) {
 161                         *(p--) = 0;
 162                         n--;
 163                         i--;
 164                 }
 165                 /* Complement and increment next octet */
 166                 *(p--) = ((*(n--)) ^ 0xff) + 1;
 167                 i--;
 168                 /* Complement any octets left */
 169                 for(;i > 0; i--) *(p--) = *(n--) ^ 0xff;
 170         }
 171
 172         *pp+=ret;
 173         return(ret);
 174         }
 175
 176 /* Convert just ASN1 INTEGER content octets to ASN1_INTEGER structure */
 177
 178 ASN1_INTEGER *c2i_ASN1_INTEGER(ASN1_INTEGER **a, const unsigned char **pp,
 179              long len)
 180         {
 181         ASN1_INTEGER *ret=NULL;
 182         const unsigned char *p, *pend;
 183         unsigned char *to,*s;
 184         int i;
 185
 186         if ((a == NULL) || ((*a) == NULL))
 187                 {
 188                 if ((ret=M_ASN1_INTEGER_new()) == NULL) return(NULL);
 189                 ret->type=V_ASN1_INTEGER;
 190                 }
 191         else
 192                 ret=(*a);
 193
 194         p= *pp;
 195         pend = p + len;
 196
 197         /* We must OPENSSL_malloc stuff, even for 0 bytes otherwise it
 198          * signifies a missing NULL parameter. */
 199         s=(unsigned char *)OPENSSL_malloc((int)len+1);
 200         if (s == NULL)
 201                 {
 202                 i=ERR_R_MALLOC_FAILURE;
 203                 goto err;
 204                 }
 205         to=s;
 206         if(!len) {
 207                 /* Strictly speaking this is an illegal INTEGER but we
 208                  * tolerate it.
 209                  */
 210                 ret->type=V_ASN1_INTEGER;
 211         } else if (*p & 0x80) /* a negative number */
 212                 {
 213                 ret->type=V_ASN1_NEG_INTEGER;
 214                 if ((*p == 0xff) && (len != 1)) {
 215                         p++;
 216                         len--;
 217                 }
 218                 i = len;
 219                 p += i - 1;
 220                 to += i - 1;
 221                 while((!*p) && i) {
 222                         *(to--) = 0;
 223                         i--;
 224                         p--;
 225                 }
 226                 /* Special case: if all zeros then the number will be of
 227                  * the form FF followed by n zero bytes: this corresponds to
 228                  * 1 followed by n zero bytes. We've already written n zeros
 229                  * so we just append an extra one and set the first byte to
 230                  * a 1. This is treated separately because it is the only case
 231                  * where the number of bytes is larger than len.
 232                  */
 233                 if(!i) {
 234                         *s = 1;
 235                         s[len] = 0;
 236                         len++;
 237                 } else {
 238                         *(to--) = (*(p--) ^ 0xff) + 1;
 239                         i--;
 240                         for(;i > 0; i--) *(to--) = *(p--) ^ 0xff;
 241                 }
 242         } else {
 243                 ret->type=V_ASN1_INTEGER;
 244                 if ((*p == 0) && (len != 1))
 245                         {
 246                         p++;
 247                         len--;
 248                         }
 249                 memcpy(s,p,(int)len);
 250         }
 251
 252         if (ret->data != NULL) OPENSSL_free(ret->data);
 253         ret->data=s;
 254         ret->length=(int)len;
 255         if (a != NULL) (*a)=ret;
 256         *pp=pend;
 257         return(ret);
 258 err:
 259         ASN1err(ASN1_F_C2I_ASN1_INTEGER,i);
 260         if ((ret != NULL) && ((a == NULL) || (*a != ret)))
 261                 M_ASN1_INTEGER_free(ret);
 262         return(NULL);
 263         }
 264
 265
 266 /* This is a version of d2i_ASN1_INTEGER that ignores the sign bit of
 267  * ASN1 integers: some broken software can encode a positive INTEGER
 268  * with its MSB set as negative (it doesn't add a padding zero).
 269  */
 270
 271 ASN1_INTEGER *d2i_ASN1_UINTEGER(ASN1_INTEGER **a, const unsigned char **pp,
 272              long length)
 273         {
 274         ASN1_INTEGER *ret=NULL;
 275         const unsigned char *p;
 276         unsigned char *s;
 277         long len;
 278         int inf,tag,xclass;
 279         int i;
 280
 281         if ((a == NULL) || ((*a) == NULL))
 282                 {
 283                 if ((ret=M_ASN1_INTEGER_new()) == NULL) return(NULL);
 284                 ret->type=V_ASN1_INTEGER;
 285                 }
 286         else
 287                 ret=(*a);
 288
 289         p= *pp;
 290         inf=ASN1_get_object(&p,&len,&tag,&xclass,length);
 291         if (inf & 0x80)
 292                 {
 293                 i=ASN1_R_BAD_OBJECT_HEADER;
 294                 goto err;
 295                 }
 296
 297         if (tag != V_ASN1_INTEGER)
 298                 {
 299                 i=ASN1_R_EXPECTING_AN_INTEGER;
 300                 goto err;
 301                 }
 302
 303         /* We must OPENSSL_malloc stuff, even for 0 bytes otherwise it
 304          * signifies a missing NULL parameter. */
 305         s=(unsigned char *)OPENSSL_malloc((int)len+1);
 306         if (s == NULL)
 307                 {
 308                 i=ERR_R_MALLOC_FAILURE;
 309                 goto err;
 310                 }
 311         ret->type=V_ASN1_INTEGER;
 312         if(len) {
 313                 if ((*p == 0) && (len != 1))
 314                         {
 315                         p++;
 316                         len--;
 317                         }
 318                 memcpy(s,p,(int)len);
 319                 p+=len;
 320         }
 321
 322         if (ret->data != NULL) OPENSSL_free(ret->data);
 323         ret->data=s;
 324         ret->length=(int)len;
 325         if (a != NULL) (*a)=ret;
 326         *pp=p;
 327         return(ret);
 328 err:
 329         ASN1err(ASN1_F_D2I_ASN1_UINTEGER,i);
 330         if ((ret != NULL) && ((a == NULL) || (*a != ret)))
 331                 M_ASN1_INTEGER_free(ret);
 332         return(NULL);
 333         }
 334
 335 int ASN1_INTEGER_set(ASN1_INTEGER *a, long v)
 336         {
 337         int j,k;
 338         unsigned int i;
 339         unsigned char buf[sizeof(long)+1];
 340         long d;
 341
 342         a->type=V_ASN1_INTEGER;
 343         if (a->length < (int)(sizeof(long)+1))
 344                 {
 345                 if (a->data != NULL)
 346                         OPENSSL_free(a->data);
 347                 if ((a->data=(unsigned char *)OPENSSL_malloc(sizeof(long)+1)) != NULL)
 348                         memset((char *)a->data,0,sizeof(long)+1);
 349                 }
 350         if (a->data == NULL)
 351                 {
 352                 ASN1err(ASN1_F_ASN1_INTEGER_SET,ERR_R_MALLOC_FAILURE);
 353                 return(0);
 354                 }
 355         d=v;
 356         if (d < 0)
 357                 {
 358                 d= -d;
 359                 a->type=V_ASN1_NEG_INTEGER;
 360                 }
 361
 362         for (i=0; i<sizeof(long); i++)
 363                 {
 364                 if (d == 0) break;
 365                 buf[i]=(int)d&0xff;
 366                 d>>=8;
 367                 }
 368         j=0;
 369         for (k=i-1; k >=0; k--)
 370                 a->data[j++]=buf[k];
 371         a->length=j;
 372         return(1);
 373         }
 374
 375 long ASN1_INTEGER_get(const ASN1_INTEGER *a)
 376         {
 377         int neg=0,i;
 378         long r=0;
 379
 380         if (a == NULL) return(0L);
 381         i=a->type;
 382         if (i == V_ASN1_NEG_INTEGER)
 383                 neg=1;
 384         else if (i != V_ASN1_INTEGER)
 385                 return -1;
 386
 387         if (a->length > (int)sizeof(long))
 388                 {
 389                 /* hmm... a bit ugly, return all ones */
 390                 return -1;
 391                 }
 392         if (a->data == NULL)
 393                 return 0;
 394
 395         for (i=0; i<a->length; i++)
 396                 {
 397                 r<<=8;
 398                 r|=(unsigned char)a->data[i];
 399                 }
 400         if (neg) r= -r;
 401         return(r);
 402         }
 403
 404 ASN1_INTEGER *BN_to_ASN1_INTEGER(const BIGNUM *bn, ASN1_INTEGER *ai)
 405         {
 406         ASN1_INTEGER *ret;
 407         int len,j;
 408
 409         if (ai == NULL)
 410                 ret=M_ASN1_INTEGER_new();
 411         else
 412                 ret=ai;
 413         if (ret == NULL)
 414                 {
 415                 ASN1err(ASN1_F_BN_TO_ASN1_INTEGER,ERR_R_NESTED_ASN1_ERROR);
 416                 goto err;
 417                 }
 418         if (BN_is_negative(bn))
 419                 ret->type = V_ASN1_NEG_INTEGER;
 420         else ret->type=V_ASN1_INTEGER;
 421         j=BN_num_bits(bn);
 422         len=((j == 0)?0:((j/8)+1));
 423         if (ret->length < len+4)
 424                 {
 425                 unsigned char *new_data=OPENSSL_realloc(ret->data, len+4);
 426                 if (!new_data)
 427                         {
 428                         ASN1err(ASN1_F_BN_TO_ASN1_INTEGER,ERR_R_MALLOC_FAILURE);
 429                         goto err;
 430                         }
 431                 ret->data=new_data;
 432                 }
 433         ret->length=BN_bn2bin(bn,ret->data);
 434         /* Correct zero case */
 435         if(!ret->length)
 436                 {
 437                 ret->data[0] = 0;
 438                 ret->length = 1;
 439                 }
 440         return(ret);
 441 err:
 442         if (ret != ai) M_ASN1_INTEGER_free(ret);
 443         return(NULL);
 444         }
 445
 446 BIGNUM *ASN1_INTEGER_to_BN(const ASN1_INTEGER *ai, BIGNUM *bn)
 447         {
 448         BIGNUM *ret;
 449
 450         if ((ret=BN_bin2bn(ai->data,ai->length,bn)) == NULL)
 451                 ASN1err(ASN1_F_ASN1_INTEGER_TO_BN,ASN1_R_BN_LIB);
 452         else if(ai->type == V_ASN1_NEG_INTEGER)
 453                 BN_set_negative(ret, 1);
 454         return(ret);
 455         }
 456
 457 IMPLEMENT_STACK_OF(ASN1_INTEGER)
 458 IMPLEMENT_ASN1_SET_OF(ASN1_INTEGER)