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 <stdlib.h> 60#include <stdio.h> 61#include <string.h> 62#include <time.h> 63 64#if 0 65#include "cryptlib.h" 66#include <openssl/asn1.h> 67#include <openssl/bn.h> 68#else 69#include "cs-asn1.h" 70#include "cs-bn.h" 71#endif 72 73ASN1_INTEGER *ASN1_INTEGER_dup(ASN1_INTEGER *x) 74{ return M_ASN1_INTEGER_dup(x);} 75 76int ASN1_INTEGER_cmp(ASN1_INTEGER *x, ASN1_INTEGER *y) 77 { 78 int neg, ret; 79 /* Compare signs */ 80 neg = x->type & V_ASN1_NEG; 81 if (neg != (y->type & V_ASN1_NEG)) 82 { 83 if (neg) 84 return -1; 85 else 86 return 1; 87 } 88 89 ret = ASN1_STRING_cmp(x, y); 90 91 if (neg) 92 return -ret; 93 else 94 return ret; 95 } 96 97 98/* 99 * This converts an ASN1 INTEGER into its content encoding. 100 * The internal representation is an ASN1_STRING whose data is a big endian 101 * representation of the value, ignoring the sign. The sign is determined by 102 * the type: V_ASN1_INTEGER for positive and V_ASN1_NEG_INTEGER for negative. 103 * 104 * Positive integers are no problem: they are almost the same as the DER 105 * encoding, except if the first byte is >= 0x80 we need to add a zero pad. 106 * 107 * Negative integers are a bit trickier... 108 * The DER representation of negative integers is in 2s complement form. 109 * The internal form is converted by complementing each octet and finally 110 * adding one to the result. This can be done less messily with a little trick. 111 * If the internal form has trailing zeroes then they will become FF by the 112 * complement and 0 by the add one (due to carry) so just copy as many trailing 113 * zeros to the destination as there are in the source. The carry will add one 114 * to the last none zero octet: so complement this octet and add one and finally 115 * complement any left over until you get to the start of the string. 116 * 117 * Padding is a little trickier too. If the first bytes is > 0x80 then we pad 118 * with 0xff. However if the first byte is 0x80 and one of the following bytes 119 * is non-zero we pad with 0xff. The reason for this distinction is that 0x80 120 * followed by optional zeros isn't padded. 121 */ 122 123int i2c_ASN1_INTEGER(ASN1_INTEGER *a, unsigned char **pp) 124 { 125 int pad=0,ret,i,neg; 126 unsigned char *p,*n,pb=0; 127 128 if ((a == NULL) || (a->data == NULL)) return(0); 129 neg=a->type & V_ASN1_NEG; 130 if (a->length == 0) 131 ret=1; 132 else 133 { 134 ret=a->length; 135 i=a->data[0]; 136 if (!neg && (i > 127)) { 137 pad=1; 138 pb=0; 139 } else if(neg) { 140 if(i>128) { 141 pad=1; 142 pb=0xFF; 143 } else if(i == 128) { 144 /* 145 * Special case: if any other bytes non zero we pad: 146 * otherwise we don't. 147 */ 148 for(i = 1; i < a->length; i++) if(a->data[i]) { 149 pad=1; 150 pb=0xFF; 151 break; 152 } 153 } 154 } 155 ret+=pad; 156 } 157 if (pp == NULL) return(ret); 158 p= *pp; 159 160 if (pad) *(p++)=pb; 161 if (a->length == 0) *(p++)=0; 162 else if (!neg) memcpy(p,a->data,(unsigned int)a->length); 163 else { 164 /* Begin at the end of the encoding */ 165 n=a->data + a->length - 1; 166 p += a->length - 1; 167 i = a->length; 168 /* Copy zeros to destination as long as source is zero */ 169 while(!*n) { 170 *(p--) = 0; 171 n--; 172 i--; 173 } 174 /* Complement and increment next octet */ 175 *(p--) = ((*(n--)) ^ 0xff) + 1; 176 i--; 177 /* Complement any octets left */ 178 for(;i > 0; i--) *(p--) = *(n--) ^ 0xff; 179 } 180 181 *pp+=ret; 182 return(ret); 183 } 184 185/* Convert just ASN1 INTEGER content octets to ASN1_INTEGER structure */ 186 187ASN1_INTEGER *c2i_ASN1_INTEGER(ASN1_INTEGER **a, const unsigned char **pp, 188 long len) 189 { 190 ASN1_INTEGER *ret=NULL; 191 const unsigned char *p, *pend; 192 unsigned char *to,*s; 193 int i; 194 195 if ((a == NULL) || ((*a) == NULL)) 196 { 197 if ((ret=M_ASN1_INTEGER_new()) == NULL) return(NULL); 198 ret->type=V_ASN1_INTEGER; 199 } 200 else 201 ret=(*a); 202 203 p= *pp; 204 pend = p + len; 205 206 /* We must OPENSSL_malloc stuff, even for 0 bytes otherwise it 207 * signifies a missing NULL parameter. */ 208 s=(unsigned char *)malloc((int)len+1); 209 if (s == NULL) 210 { 211 /* i=ERR_R_MALLOC_FAILURE; */ 212 i = -1; 213 goto err; 214 } 215 to=s; 216 if(!len) { 217 /* Strictly speaking this is an illegal INTEGER but we 218 * tolerate it. 219 */ 220 ret->type=V_ASN1_INTEGER; 221 } else if (*p & 0x80) /* a negative number */ 222 { 223 ret->type=V_ASN1_NEG_INTEGER; 224 if ((*p == 0xff) && (len != 1)) { 225 p++; 226 len--; 227 } 228 i = len; 229 p += i - 1; 230 to += i - 1; 231 while((!*p) && i) { 232 *(to--) = 0; 233 i--; 234 p--; 235 } 236 /* Special case: if all zeros then the number will be of 237 * the form FF followed by n zero bytes: this corresponds to 238 * 1 followed by n zero bytes. We've already written n zeros 239 * so we just append an extra one and set the first byte to 240 * a 1. This is treated separately because it is the only case 241 * where the number of bytes is larger than len. 242 */ 243 if(!i) { 244 *s = 1; 245 s[len] = 0; 246 len++; 247 } else { 248 *(to--) = (*(p--) ^ 0xff) + 1; 249 i--; 250 for(;i > 0; i--) *(to--) = *(p--) ^ 0xff; 251 } 252 } else { 253 ret->type=V_ASN1_INTEGER; 254 if ((*p == 0) && (len != 1)) 255 { 256 p++; 257 len--; 258 } 259 memcpy(s,p,(int)len); 260 } 261 262 if (ret->data != NULL) free(ret->data); 263 ret->data=s; 264 ret->length=(int)len; 265 if (a != NULL) (*a)=ret; 266 *pp=pend; 267 return(ret); 268err: 269 /* ASN1err(ASN1_F_C2I_ASN1_INTEGER,i); */ 270 if ((ret != NULL) && ((a == NULL) || (*a != ret))) 271 M_ASN1_INTEGER_free(ret); 272 return(NULL); 273 } 274 275 276/* This is a version of d2i_ASN1_INTEGER that ignores the sign bit of 277 * ASN1 integers: some broken software can encode a positive INTEGER 278 * with its MSB set as negative (it doesn't add a padding zero). 279 */ 280 281ASN1_INTEGER *d2i_ASN1_UINTEGER(ASN1_INTEGER **a, const unsigned char **pp, 282 long length) 283 { 284 ASN1_INTEGER *ret=NULL; 285 const unsigned char *p; 286 unsigned char *s; 287 long len; 288 int inf,tag,xclass; 289 int i; 290 291 if ((a == NULL) || ((*a) == NULL)) 292 { 293 if ((ret=M_ASN1_INTEGER_new()) == NULL) return(NULL); 294 ret->type=V_ASN1_INTEGER; 295 } 296 else 297 ret=(*a); 298 299 p= *pp; 300 inf=ASN1_get_object(&p,&len,&tag,&xclass,length); 301 if (inf & 0x80) 302 { 303 i=ASN1_R_BAD_OBJECT_HEADER; 304 goto err; 305 } 306 307 if (tag != V_ASN1_INTEGER) 308 { 309 i=ASN1_R_EXPECTING_AN_INTEGER; 310 goto err; 311 } 312 313 /* We must OPENSSL_malloc stuff, even for 0 bytes otherwise it 314 * signifies a missing NULL parameter. */ 315 s=(unsigned char *)malloc((int)len+1); 316 if (s == NULL) 317 { 318 /* i=ERR_R_MALLOC_FAILURE; */ 319 i = -1; 320 goto err; 321 } 322 ret->type=V_ASN1_INTEGER; 323 if(len) { 324 if ((*p == 0) && (len != 1)) 325 { 326 p++; 327 len--; 328 } 329 memcpy(s,p,(int)len); 330 p+=len; 331 } 332 333 if (ret->data != NULL) free(ret->data); 334 ret->data=s; 335 ret->length=(int)len; 336 if (a != NULL) (*a)=ret; 337 *pp=p; 338 return(ret); 339err: 340 /* ASN1err(ASN1_F_D2I_ASN1_UINTEGER,i); */ 341 if ((ret != NULL) && ((a == NULL) || (*a != ret))) 342 M_ASN1_INTEGER_free(ret); 343 return(NULL); 344 } 345 346int ASN1_INTEGER_set(ASN1_INTEGER *a, long v) 347 { 348 int j,k; 349 unsigned int i; 350 unsigned char buf[sizeof(long)+1]; 351 long d; 352 353 a->type=V_ASN1_INTEGER; 354 if (a->length < (int)(sizeof(long)+1)) 355 { 356 if (a->data != NULL) 357 free(a->data); 358 if ((a->data=(unsigned char *)malloc(sizeof(long)+1)) != NULL) 359 memset((char *)a->data,0,sizeof(long)+1); 360 } 361 if (a->data == NULL) 362 { 363 /* ASN1err(ASN1_F_ASN1_INTEGER_SET,ERR_R_MALLOC_FAILURE); */ 364 return(0); 365 } 366 d=v; 367 if (d < 0) 368 { 369 d= -d; 370 a->type=V_ASN1_NEG_INTEGER; 371 } 372 373 for (i=0; i<sizeof(long); i++) 374 { 375 if (d == 0) break; 376 buf[i]=(int)d&0xff; 377 d>>=8; 378 } 379 j=0; 380 for (k=i-1; k >=0; k--) 381 a->data[j++]=buf[k]; 382 a->length=j; 383 return(1); 384 } 385 386long ASN1_INTEGER_get(ASN1_INTEGER *a) 387 { 388 int neg=0,i; 389 long r=0; 390 391 if (a == NULL) return(0L); 392 i=a->type; 393 if (i == V_ASN1_NEG_INTEGER) 394 neg=1; 395 else if (i != V_ASN1_INTEGER) 396 return -1; 397 398 if (a->length > (int)sizeof(long)) 399 { 400 /* hmm... a bit ugly */ 401 return(0xffffffffL); 402 } 403 if (a->data == NULL) 404 return 0; 405 406 for (i=0; i<a->length; i++) 407 { 408 r<<=8; 409 r|=(unsigned char)a->data[i]; 410 } 411 if (neg) r= -r; 412 return(r); 413 } 414 415ASN1_INTEGER *BN_to_ASN1_INTEGER(BIGNUM *bn, ASN1_INTEGER *ai) 416 { 417 ASN1_INTEGER *ret; 418 int len,j; 419 420 if (ai == NULL) 421 ret=M_ASN1_INTEGER_new(); 422 else 423 ret=ai; 424 if (ret == NULL) 425 { 426 /* ASN1err(ASN1_F_BN_TO_ASN1_INTEGER,ERR_R_NESTED_ASN1_ERROR); */ 427 goto err; 428 } 429 if (BN_is_negative(bn)) 430 ret->type = V_ASN1_NEG_INTEGER; 431 else ret->type=V_ASN1_INTEGER; 432 j=BN_num_bits(bn); 433 len=((j == 0)?0:((j/8)+1)); 434 if (ret->length < len+4) 435 { 436 unsigned char *new_data=realloc(ret->data, len+4); 437 if (!new_data) 438 { 439 /* ASN1err(ASN1_F_BN_TO_ASN1_INTEGER,ERR_R_MALLOC_FAILURE); */ 440 goto err; 441 } 442 ret->data=new_data; 443 } 444 ret->length=BN_bn2bin(bn,ret->data); 445 /* Correct zero case */ 446 if(!ret->length) 447 { 448 ret->data[0] = 0; 449 ret->length = 1; 450 } 451 return(ret); 452err: 453 if (ret != ai) M_ASN1_INTEGER_free(ret); 454 return(NULL); 455 } 456 457BIGNUM *ASN1_INTEGER_to_BN(ASN1_INTEGER *ai, BIGNUM *bn) 458 { 459 BIGNUM *ret; 460 461 if ((ret=BN_bin2bn(ai->data,ai->length,bn)) == NULL) 462 /* ASN1err(ASN1_F_ASN1_INTEGER_TO_BN,ASN1_R_BN_LIB); */ 463 ; 464 else if(ai->type == V_ASN1_NEG_INTEGER) 465 BN_set_negative(ret, 1); 466 return(ret); 467 } 468 469IMPLEMENT_STACK_OF(ASN1_INTEGER) 470IMPLEMENT_ASN1_SET_OF(ASN1_INTEGER) 471