Alexandre Savard | 1b09e31 | 2012-08-07 20:33:29 -0400 | [diff] [blame] | 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 | { |
Alexandre Savard | 7541067 | 2012-08-08 09:50:01 -0400 | [diff] [blame] | 389 | /* hmm... a bit ugly */ |
| 390 | return(0xffffffffL); |
Alexandre Savard | 1b09e31 | 2012-08-07 20:33:29 -0400 | [diff] [blame] | 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) |