1 /* 2 * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the OpenSSL license (the "License"). You may not use 5 * this file except in compliance with the License. You can obtain a copy 6 * in the file LICENSE in the source distribution or at 7 * https://www.openssl.org/source/license.html 8 */ 9 10 #include <stdio.h> 11 #include <limits.h> 12 #include "internal/cryptlib.h" 13 #include <openssl/asn1.h> 14 #include "asn1_locl.h" 15 16 static int asn1_get_length(const unsigned char **pp, int *inf, long *rl, 17 long max); 18 static void asn1_put_length(unsigned char **pp, int length); 19 20 static int _asn1_check_infinite_end(const unsigned char **p, long len) 21 { 22 /* 23 * If there is 0 or 1 byte left, the length check should pick things up 24 */ 25 if (len <= 0) 26 return 1; 27 else if ((len >= 2) && ((*p)[0] == 0) && ((*p)[1] == 0)) { 28 (*p) += 2; 29 return 1; 30 } 31 return 0; 32 } 33 34 int ASN1_check_infinite_end(unsigned char **p, long len) 35 { 36 return _asn1_check_infinite_end((const unsigned char **)p, len); 37 } 38 39 int ASN1_const_check_infinite_end(const unsigned char **p, long len) 40 { 41 return _asn1_check_infinite_end(p, len); 42 } 43 44 int ASN1_get_object(const unsigned char **pp, long *plength, int *ptag, 45 int *pclass, long omax) 46 { 47 int i, ret; 48 long l; 49 const unsigned char *p = *pp; 50 int tag, xclass, inf; 51 long max = omax; 52 53 if (!max) 54 goto err; 55 ret = (*p & V_ASN1_CONSTRUCTED); 56 xclass = (*p & V_ASN1_PRIVATE); 57 i = *p & V_ASN1_PRIMITIVE_TAG; 58 if (i == V_ASN1_PRIMITIVE_TAG) { /* high-tag */ 59 p++; 60 if (--max == 0) 61 goto err; 62 l = 0; 63 while (*p & 0x80) { 64 l <<= 7L; 65 l |= *(p++) & 0x7f; 66 if (--max == 0) 67 goto err; 68 if (l > (INT_MAX >> 7L)) 69 goto err; 70 } 71 l <<= 7L; 72 l |= *(p++) & 0x7f; 73 tag = (int)l; 74 if (--max == 0) 75 goto err; 76 } else { 77 tag = i; 78 p++; 79 if (--max == 0) 80 goto err; 81 } 82 *ptag = tag; 83 *pclass = xclass; 84 if (!asn1_get_length(&p, &inf, plength, max)) 85 goto err; 86 87 if (inf && !(ret & V_ASN1_CONSTRUCTED)) 88 goto err; 89 90 if (*plength > (omax - (p - *pp))) { 91 ASN1err(ASN1_F_ASN1_GET_OBJECT, ASN1_R_TOO_LONG); 92 /* 93 * Set this so that even if things are not long enough the values are 94 * set correctly 95 */ 96 ret |= 0x80; 97 } 98 *pp = p; 99 return ret | inf; 100 err: 101 ASN1err(ASN1_F_ASN1_GET_OBJECT, ASN1_R_HEADER_TOO_LONG); 102 return 0x80; 103 } 104 105 /* 106 * Decode a length field. 107 * The short form is a single byte defining a length 0 - 127. 108 * The long form is a byte 0 - 127 with the top bit set and this indicates 109 * the number of following octets that contain the length. These octets 110 * are stored most significant digit first. 111 */ 112 static int asn1_get_length(const unsigned char **pp, int *inf, long *rl, 113 long max) 114 { 115 const unsigned char *p = *pp; 116 unsigned long ret = 0; 117 int i; 118 119 if (max-- < 1) 120 return 0; 121 if (*p == 0x80) { 122 *inf = 1; 123 p++; 124 } else { 125 *inf = 0; 126 i = *p & 0x7f; 127 if (*p++ & 0x80) { 128 if (max < i + 1) 129 return 0; 130 /* Skip leading zeroes */ 131 while (i > 0 && *p == 0) { 132 p++; 133 i--; 134 } 135 if (i > (int)sizeof(long)) 136 return 0; 137 while (i > 0) { 138 ret <<= 8; 139 ret |= *p++; 140 i--; 141 } 142 if (ret > LONG_MAX) 143 return 0; 144 } else 145 ret = i; 146 } 147 *pp = p; 148 *rl = (long)ret; 149 return 1; 150 } 151 152 /* 153 * class 0 is constructed constructed == 2 for indefinite length constructed 154 */ 155 void ASN1_put_object(unsigned char **pp, int constructed, int length, int tag, 156 int xclass) 157 { 158 unsigned char *p = *pp; 159 int i, ttag; 160 161 i = (constructed) ? V_ASN1_CONSTRUCTED : 0; 162 i |= (xclass & V_ASN1_PRIVATE); 163 if (tag < 31) 164 *(p++) = i | (tag & V_ASN1_PRIMITIVE_TAG); 165 else { 166 *(p++) = i | V_ASN1_PRIMITIVE_TAG; 167 for (i = 0, ttag = tag; ttag > 0; i++) 168 ttag >>= 7; 169 ttag = i; 170 while (i-- > 0) { 171 p[i] = tag & 0x7f; 172 if (i != (ttag - 1)) 173 p[i] |= 0x80; 174 tag >>= 7; 175 } 176 p += ttag; 177 } 178 if (constructed == 2) 179 *(p++) = 0x80; 180 else 181 asn1_put_length(&p, length); 182 *pp = p; 183 } 184 185 int ASN1_put_eoc(unsigned char **pp) 186 { 187 unsigned char *p = *pp; 188 *p++ = 0; 189 *p++ = 0; 190 *pp = p; 191 return 2; 192 } 193 194 static void asn1_put_length(unsigned char **pp, int length) 195 { 196 unsigned char *p = *pp; 197 int i, l; 198 if (length <= 127) 199 *(p++) = (unsigned char)length; 200 else { 201 l = length; 202 for (i = 0; l > 0; i++) 203 l >>= 8; 204 *(p++) = i | 0x80; 205 l = i; 206 while (i-- > 0) { 207 p[i] = length & 0xff; 208 length >>= 8; 209 } 210 p += l; 211 } 212 *pp = p; 213 } 214 215 int ASN1_object_size(int constructed, int length, int tag) 216 { 217 int ret = 1; 218 if (length < 0) 219 return -1; 220 if (tag >= 31) { 221 while (tag > 0) { 222 tag >>= 7; 223 ret++; 224 } 225 } 226 if (constructed == 2) { 227 ret += 3; 228 } else { 229 ret++; 230 if (length > 127) { 231 int tmplen = length; 232 while (tmplen > 0) { 233 tmplen >>= 8; 234 ret++; 235 } 236 } 237 } 238 if (ret >= INT_MAX - length) 239 return -1; 240 return ret + length; 241 } 242 243 int ASN1_STRING_copy(ASN1_STRING *dst, const ASN1_STRING *str) 244 { 245 if (str == NULL) 246 return 0; 247 dst->type = str->type; 248 if (!ASN1_STRING_set(dst, str->data, str->length)) 249 return 0; 250 /* Copy flags but preserve embed value */ 251 dst->flags &= ASN1_STRING_FLAG_EMBED; 252 dst->flags |= str->flags & ~ASN1_STRING_FLAG_EMBED; 253 return 1; 254 } 255 256 ASN1_STRING *ASN1_STRING_dup(const ASN1_STRING *str) 257 { 258 ASN1_STRING *ret; 259 if (!str) 260 return NULL; 261 ret = ASN1_STRING_new(); 262 if (ret == NULL) 263 return NULL; 264 if (!ASN1_STRING_copy(ret, str)) { 265 ASN1_STRING_free(ret); 266 return NULL; 267 } 268 return ret; 269 } 270 271 int ASN1_STRING_set(ASN1_STRING *str, const void *_data, int len) 272 { 273 unsigned char *c; 274 const char *data = _data; 275 276 if (len < 0) { 277 if (data == NULL) 278 return 0; 279 else 280 len = strlen(data); 281 } 282 if ((str->length <= len) || (str->data == NULL)) { 283 c = str->data; 284 str->data = OPENSSL_realloc(c, len + 1); 285 if (str->data == NULL) { 286 ASN1err(ASN1_F_ASN1_STRING_SET, ERR_R_MALLOC_FAILURE); 287 str->data = c; 288 return 0; 289 } 290 } 291 str->length = len; 292 if (data != NULL) { 293 memcpy(str->data, data, len); 294 /* an allowance for strings :-) */ 295 str->data[len] = '\0'; 296 } 297 return 1; 298 } 299 300 void ASN1_STRING_set0(ASN1_STRING *str, void *data, int len) 301 { 302 OPENSSL_free(str->data); 303 str->data = data; 304 str->length = len; 305 } 306 307 ASN1_STRING *ASN1_STRING_new(void) 308 { 309 return ASN1_STRING_type_new(V_ASN1_OCTET_STRING); 310 } 311 312 ASN1_STRING *ASN1_STRING_type_new(int type) 313 { 314 ASN1_STRING *ret; 315 316 ret = OPENSSL_zalloc(sizeof(*ret)); 317 if (ret == NULL) { 318 ASN1err(ASN1_F_ASN1_STRING_TYPE_NEW, ERR_R_MALLOC_FAILURE); 319 return NULL; 320 } 321 ret->type = type; 322 return ret; 323 } 324 325 void asn1_string_embed_free(ASN1_STRING *a, int embed) 326 { 327 if (a == NULL) 328 return; 329 if (!(a->flags & ASN1_STRING_FLAG_NDEF)) 330 OPENSSL_free(a->data); 331 if (embed == 0) 332 OPENSSL_free(a); 333 } 334 335 void ASN1_STRING_free(ASN1_STRING *a) 336 { 337 if (a == NULL) 338 return; 339 asn1_string_embed_free(a, a->flags & ASN1_STRING_FLAG_EMBED); 340 } 341 342 void ASN1_STRING_clear_free(ASN1_STRING *a) 343 { 344 if (a == NULL) 345 return; 346 if (a->data && !(a->flags & ASN1_STRING_FLAG_NDEF)) 347 OPENSSL_cleanse(a->data, a->length); 348 ASN1_STRING_free(a); 349 } 350 351 int ASN1_STRING_cmp(const ASN1_STRING *a, const ASN1_STRING *b) 352 { 353 int i; 354 355 i = (a->length - b->length); 356 if (i == 0) { 357 i = memcmp(a->data, b->data, a->length); 358 if (i == 0) 359 return a->type - b->type; 360 else 361 return i; 362 } else 363 return i; 364 } 365 366 int ASN1_STRING_length(const ASN1_STRING *x) 367 { 368 return x->length; 369 } 370 371 void ASN1_STRING_length_set(ASN1_STRING *x, int len) 372 { 373 x->length = len; 374 } 375 376 int ASN1_STRING_type(const ASN1_STRING *x) 377 { 378 return x->type; 379 } 380 381 const unsigned char *ASN1_STRING_get0_data(const ASN1_STRING *x) 382 { 383 return x->data; 384 } 385 386 # if OPENSSL_API_COMPAT < 0x10100000L 387 unsigned char *ASN1_STRING_data(ASN1_STRING *x) 388 { 389 return x->data; 390 } 391 #endif 392