1 /* 2 * Copyright 1999-2019 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 /*- 11 * This is an implementation of the ASN1 Time structure which is: 12 * Time ::= CHOICE { 13 * utcTime UTCTime, 14 * generalTime GeneralizedTime } 15 */ 16 17 #include <stdio.h> 18 #include <time.h> 19 #include "crypto/ctype.h" 20 #include "internal/cryptlib.h" 21 #include <openssl/asn1t.h> 22 #include "asn1_local.h" 23 24 IMPLEMENT_ASN1_MSTRING(ASN1_TIME, B_ASN1_TIME) 25 26 IMPLEMENT_ASN1_FUNCTIONS(ASN1_TIME) 27 28 static int is_utc(const int year) 29 { 30 if (50 <= year && year <= 149) 31 return 1; 32 return 0; 33 } 34 35 static int leap_year(const int year) 36 { 37 if (year % 400 == 0 || (year % 100 != 0 && year % 4 == 0)) 38 return 1; 39 return 0; 40 } 41 42 /* 43 * Compute the day of the week and the day of the year from the year, month 44 * and day. The day of the year is straightforward, the day of the week uses 45 * a form of Zeller's congruence. For this months start with March and are 46 * numbered 4 through 15. 47 */ 48 static void determine_days(struct tm *tm) 49 { 50 static const int ydays[12] = { 51 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 52 }; 53 int y = tm->tm_year + 1900; 54 int m = tm->tm_mon; 55 int d = tm->tm_mday; 56 int c; 57 58 tm->tm_yday = ydays[m] + d - 1; 59 if (m >= 2) { 60 /* March and onwards can be one day further into the year */ 61 tm->tm_yday += leap_year(y); 62 m += 2; 63 } else { 64 /* Treat January and February as part of the previous year */ 65 m += 14; 66 y--; 67 } 68 c = y / 100; 69 y %= 100; 70 /* Zeller's congruence */ 71 tm->tm_wday = (d + (13 * m) / 5 + y + y / 4 + c / 4 + 5 * c + 6) % 7; 72 } 73 74 int asn1_time_to_tm(struct tm *tm, const ASN1_TIME *d) 75 { 76 static const int min[9] = { 0, 0, 1, 1, 0, 0, 0, 0, 0 }; 77 static const int max[9] = { 99, 99, 12, 31, 23, 59, 59, 12, 59 }; 78 static const int mdays[12] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; 79 char *a; 80 int n, i, i2, l, o, min_l = 11, strict = 0, end = 6, btz = 5, md; 81 struct tm tmp; 82 #if defined(CHARSET_EBCDIC) 83 const char upper_z = 0x5A, num_zero = 0x30, period = 0x2E, minus = 0x2D, plus = 0x2B; 84 #else 85 const char upper_z = 'Z', num_zero = '0', period = '.', minus = '-', plus = '+'; 86 #endif 87 /* 88 * ASN1_STRING_FLAG_X509_TIME is used to enforce RFC 5280 89 * time string format, in which: 90 * 91 * 1. "seconds" is a 'MUST' 92 * 2. "Zulu" timezone is a 'MUST' 93 * 3. "+|-" is not allowed to indicate a time zone 94 */ 95 if (d->type == V_ASN1_UTCTIME) { 96 if (d->flags & ASN1_STRING_FLAG_X509_TIME) { 97 min_l = 13; 98 strict = 1; 99 } 100 } else if (d->type == V_ASN1_GENERALIZEDTIME) { 101 end = 7; 102 btz = 6; 103 if (d->flags & ASN1_STRING_FLAG_X509_TIME) { 104 min_l = 15; 105 strict = 1; 106 } else { 107 min_l = 13; 108 } 109 } else { 110 return 0; 111 } 112 113 l = d->length; 114 a = (char *)d->data; 115 o = 0; 116 memset(&tmp, 0, sizeof(tmp)); 117 118 /* 119 * GENERALIZEDTIME is similar to UTCTIME except the year is represented 120 * as YYYY. This stuff treats everything as a two digit field so make 121 * first two fields 00 to 99 122 */ 123 124 if (l < min_l) 125 goto err; 126 for (i = 0; i < end; i++) { 127 if (!strict && (i == btz) && ((a[o] == upper_z) || (a[o] == plus) || (a[o] == minus))) { 128 i++; 129 break; 130 } 131 if (!ascii_isdigit(a[o])) 132 goto err; 133 n = a[o] - num_zero; 134 /* incomplete 2-digital number */ 135 if (++o == l) 136 goto err; 137 138 if (!ascii_isdigit(a[o])) 139 goto err; 140 n = (n * 10) + a[o] - num_zero; 141 /* no more bytes to read, but we haven't seen time-zone yet */ 142 if (++o == l) 143 goto err; 144 145 i2 = (d->type == V_ASN1_UTCTIME) ? i + 1 : i; 146 147 if ((n < min[i2]) || (n > max[i2])) 148 goto err; 149 switch (i2) { 150 case 0: 151 /* UTC will never be here */ 152 tmp.tm_year = n * 100 - 1900; 153 break; 154 case 1: 155 if (d->type == V_ASN1_UTCTIME) 156 tmp.tm_year = n < 50 ? n + 100 : n; 157 else 158 tmp.tm_year += n; 159 break; 160 case 2: 161 tmp.tm_mon = n - 1; 162 break; 163 case 3: 164 /* check if tm_mday is valid in tm_mon */ 165 if (tmp.tm_mon == 1) { 166 /* it's February */ 167 md = mdays[1] + leap_year(tmp.tm_year + 1900); 168 } else { 169 md = mdays[tmp.tm_mon]; 170 } 171 if (n > md) 172 goto err; 173 tmp.tm_mday = n; 174 determine_days(&tmp); 175 break; 176 case 4: 177 tmp.tm_hour = n; 178 break; 179 case 5: 180 tmp.tm_min = n; 181 break; 182 case 6: 183 tmp.tm_sec = n; 184 break; 185 } 186 } 187 188 /* 189 * Optional fractional seconds: decimal point followed by one or more 190 * digits. 191 */ 192 if (d->type == V_ASN1_GENERALIZEDTIME && a[o] == period) { 193 if (strict) 194 /* RFC 5280 forbids fractional seconds */ 195 goto err; 196 if (++o == l) 197 goto err; 198 i = o; 199 while ((o < l) && ascii_isdigit(a[o])) 200 o++; 201 /* Must have at least one digit after decimal point */ 202 if (i == o) 203 goto err; 204 /* no more bytes to read, but we haven't seen time-zone yet */ 205 if (o == l) 206 goto err; 207 } 208 209 /* 210 * 'o' will never point to '\0' at this point, the only chance 211 * 'o' can point to '\0' is either the subsequent if or the first 212 * else if is true. 213 */ 214 if (a[o] == upper_z) { 215 o++; 216 } else if (!strict && ((a[o] == plus) || (a[o] == minus))) { 217 int offsign = a[o] == minus ? 1 : -1; 218 int offset = 0; 219 220 o++; 221 /* 222 * if not equal, no need to do subsequent checks 223 * since the following for-loop will add 'o' by 4 224 * and the final return statement will check if 'l' 225 * and 'o' are equal. 226 */ 227 if (o + 4 != l) 228 goto err; 229 for (i = end; i < end + 2; i++) { 230 if (!ascii_isdigit(a[o])) 231 goto err; 232 n = a[o] - num_zero; 233 o++; 234 if (!ascii_isdigit(a[o])) 235 goto err; 236 n = (n * 10) + a[o] - num_zero; 237 i2 = (d->type == V_ASN1_UTCTIME) ? i + 1 : i; 238 if ((n < min[i2]) || (n > max[i2])) 239 goto err; 240 /* if tm is NULL, no need to adjust */ 241 if (tm != NULL) { 242 if (i == end) 243 offset = n * 3600; 244 else if (i == end + 1) 245 offset += n * 60; 246 } 247 o++; 248 } 249 if (offset && !OPENSSL_gmtime_adj(&tmp, 0, offset * offsign)) 250 goto err; 251 } else { 252 /* not Z, or not +/- in non-strict mode */ 253 goto err; 254 } 255 if (o == l) { 256 /* success, check if tm should be filled */ 257 if (tm != NULL) 258 *tm = tmp; 259 return 1; 260 } 261 err: 262 return 0; 263 } 264 265 ASN1_TIME *asn1_time_from_tm(ASN1_TIME *s, struct tm *ts, int type) 266 { 267 char* p; 268 ASN1_TIME *tmps = NULL; 269 const size_t len = 20; 270 271 if (type == V_ASN1_UNDEF) { 272 if (is_utc(ts->tm_year)) 273 type = V_ASN1_UTCTIME; 274 else 275 type = V_ASN1_GENERALIZEDTIME; 276 } else if (type == V_ASN1_UTCTIME) { 277 if (!is_utc(ts->tm_year)) 278 goto err; 279 } else if (type != V_ASN1_GENERALIZEDTIME) { 280 goto err; 281 } 282 283 if (s == NULL) 284 tmps = ASN1_STRING_new(); 285 else 286 tmps = s; 287 if (tmps == NULL) 288 return NULL; 289 290 if (!ASN1_STRING_set(tmps, NULL, len)) 291 goto err; 292 293 tmps->type = type; 294 p = (char*)tmps->data; 295 296 if (type == V_ASN1_GENERALIZEDTIME) 297 tmps->length = BIO_snprintf(p, len, "%04d%02d%02d%02d%02d%02dZ", 298 ts->tm_year + 1900, ts->tm_mon + 1, 299 ts->tm_mday, ts->tm_hour, ts->tm_min, 300 ts->tm_sec); 301 else 302 tmps->length = BIO_snprintf(p, len, "%02d%02d%02d%02d%02d%02dZ", 303 ts->tm_year % 100, ts->tm_mon + 1, 304 ts->tm_mday, ts->tm_hour, ts->tm_min, 305 ts->tm_sec); 306 307 #ifdef CHARSET_EBCDIC 308 ebcdic2ascii(tmps->data, tmps->data, tmps->length); 309 #endif 310 return tmps; 311 err: 312 if (tmps != s) 313 ASN1_STRING_free(tmps); 314 return NULL; 315 } 316 317 ASN1_TIME *ASN1_TIME_set(ASN1_TIME *s, time_t t) 318 { 319 return ASN1_TIME_adj(s, t, 0, 0); 320 } 321 322 ASN1_TIME *ASN1_TIME_adj(ASN1_TIME *s, time_t t, 323 int offset_day, long offset_sec) 324 { 325 struct tm *ts; 326 struct tm data; 327 328 ts = OPENSSL_gmtime(&t, &data); 329 if (ts == NULL) { 330 ASN1err(ASN1_F_ASN1_TIME_ADJ, ASN1_R_ERROR_GETTING_TIME); 331 return NULL; 332 } 333 if (offset_day || offset_sec) { 334 if (!OPENSSL_gmtime_adj(ts, offset_day, offset_sec)) 335 return NULL; 336 } 337 return asn1_time_from_tm(s, ts, V_ASN1_UNDEF); 338 } 339 340 int ASN1_TIME_check(const ASN1_TIME *t) 341 { 342 if (t->type == V_ASN1_GENERALIZEDTIME) 343 return ASN1_GENERALIZEDTIME_check(t); 344 else if (t->type == V_ASN1_UTCTIME) 345 return ASN1_UTCTIME_check(t); 346 return 0; 347 } 348 349 /* Convert an ASN1_TIME structure to GeneralizedTime */ 350 ASN1_GENERALIZEDTIME *ASN1_TIME_to_generalizedtime(const ASN1_TIME *t, 351 ASN1_GENERALIZEDTIME **out) 352 { 353 ASN1_GENERALIZEDTIME *ret = NULL; 354 struct tm tm; 355 356 if (!ASN1_TIME_to_tm(t, &tm)) 357 return NULL; 358 359 if (out != NULL) 360 ret = *out; 361 362 ret = asn1_time_from_tm(ret, &tm, V_ASN1_GENERALIZEDTIME); 363 364 if (out != NULL && ret != NULL) 365 *out = ret; 366 367 return ret; 368 } 369 370 int ASN1_TIME_set_string(ASN1_TIME *s, const char *str) 371 { 372 /* Try UTC, if that fails, try GENERALIZED */ 373 if (ASN1_UTCTIME_set_string(s, str)) 374 return 1; 375 return ASN1_GENERALIZEDTIME_set_string(s, str); 376 } 377 378 int ASN1_TIME_set_string_X509(ASN1_TIME *s, const char *str) 379 { 380 ASN1_TIME t; 381 struct tm tm; 382 int rv = 0; 383 384 t.length = strlen(str); 385 t.data = (unsigned char *)str; 386 t.flags = ASN1_STRING_FLAG_X509_TIME; 387 388 t.type = V_ASN1_UTCTIME; 389 390 if (!ASN1_TIME_check(&t)) { 391 t.type = V_ASN1_GENERALIZEDTIME; 392 if (!ASN1_TIME_check(&t)) 393 goto out; 394 } 395 396 /* 397 * Per RFC 5280 (section 4.1.2.5.), the valid input time 398 * strings should be encoded with the following rules: 399 * 400 * 1. UTC: YYMMDDHHMMSSZ, if YY < 50 (20YY) --> UTC: YYMMDDHHMMSSZ 401 * 2. UTC: YYMMDDHHMMSSZ, if YY >= 50 (19YY) --> UTC: YYMMDDHHMMSSZ 402 * 3. G'd: YYYYMMDDHHMMSSZ, if YYYY >= 2050 --> G'd: YYYYMMDDHHMMSSZ 403 * 4. G'd: YYYYMMDDHHMMSSZ, if YYYY < 2050 --> UTC: YYMMDDHHMMSSZ 404 * 405 * Only strings of the 4th rule should be reformatted, but since a 406 * UTC can only present [1950, 2050), so if the given time string 407 * is less than 1950 (e.g. 19230419000000Z), we do nothing... 408 */ 409 410 if (s != NULL && t.type == V_ASN1_GENERALIZEDTIME) { 411 if (!asn1_time_to_tm(&tm, &t)) 412 goto out; 413 if (is_utc(tm.tm_year)) { 414 t.length -= 2; 415 /* 416 * it's OK to let original t.data go since that's assigned 417 * to a piece of memory allocated outside of this function. 418 * new t.data would be freed after ASN1_STRING_copy is done. 419 */ 420 t.data = OPENSSL_zalloc(t.length + 1); 421 if (t.data == NULL) 422 goto out; 423 memcpy(t.data, str + 2, t.length); 424 t.type = V_ASN1_UTCTIME; 425 } 426 } 427 428 if (s == NULL || ASN1_STRING_copy((ASN1_STRING *)s, (ASN1_STRING *)&t)) 429 rv = 1; 430 431 if (t.data != (unsigned char *)str) 432 OPENSSL_free(t.data); 433 out: 434 return rv; 435 } 436 437 int ASN1_TIME_to_tm(const ASN1_TIME *s, struct tm *tm) 438 { 439 if (s == NULL) { 440 time_t now_t; 441 442 time(&now_t); 443 memset(tm, 0, sizeof(*tm)); 444 if (OPENSSL_gmtime(&now_t, tm) != NULL) 445 return 1; 446 return 0; 447 } 448 449 return asn1_time_to_tm(tm, s); 450 } 451 452 int ASN1_TIME_diff(int *pday, int *psec, 453 const ASN1_TIME *from, const ASN1_TIME *to) 454 { 455 struct tm tm_from, tm_to; 456 457 if (!ASN1_TIME_to_tm(from, &tm_from)) 458 return 0; 459 if (!ASN1_TIME_to_tm(to, &tm_to)) 460 return 0; 461 return OPENSSL_gmtime_diff(pday, psec, &tm_from, &tm_to); 462 } 463 464 static const char _asn1_mon[12][4] = { 465 "Jan", "Feb", "Mar", "Apr", "May", "Jun", 466 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" 467 }; 468 469 int ASN1_TIME_print(BIO *bp, const ASN1_TIME *tm) 470 { 471 char *v; 472 int gmt = 0, l; 473 struct tm stm; 474 const char upper_z = 0x5A, period = 0x2E; 475 476 if (!asn1_time_to_tm(&stm, tm)) { 477 /* asn1_time_to_tm will check the time type */ 478 goto err; 479 } 480 481 l = tm->length; 482 v = (char *)tm->data; 483 if (v[l - 1] == upper_z) 484 gmt = 1; 485 486 if (tm->type == V_ASN1_GENERALIZEDTIME) { 487 char *f = NULL; 488 int f_len = 0; 489 490 /* 491 * Try to parse fractional seconds. '14' is the place of 492 * 'fraction point' in a GeneralizedTime string. 493 */ 494 if (tm->length > 15 && v[14] == period) { 495 f = &v[14]; 496 f_len = 1; 497 while (14 + f_len < l && ascii_isdigit(f[f_len])) 498 ++f_len; 499 } 500 501 return BIO_printf(bp, "%s %2d %02d:%02d:%02d%.*s %d%s", 502 _asn1_mon[stm.tm_mon], stm.tm_mday, stm.tm_hour, 503 stm.tm_min, stm.tm_sec, f_len, f, stm.tm_year + 1900, 504 (gmt ? " GMT" : "")) > 0; 505 } else { 506 return BIO_printf(bp, "%s %2d %02d:%02d:%02d %d%s", 507 _asn1_mon[stm.tm_mon], stm.tm_mday, stm.tm_hour, 508 stm.tm_min, stm.tm_sec, stm.tm_year + 1900, 509 (gmt ? " GMT" : "")) > 0; 510 } 511 err: 512 BIO_write(bp, "Bad time value", 14); 513 return 0; 514 } 515 516 int ASN1_TIME_cmp_time_t(const ASN1_TIME *s, time_t t) 517 { 518 struct tm stm, ttm; 519 int day, sec; 520 521 if (!ASN1_TIME_to_tm(s, &stm)) 522 return -2; 523 524 if (!OPENSSL_gmtime(&t, &ttm)) 525 return -2; 526 527 if (!OPENSSL_gmtime_diff(&day, &sec, &ttm, &stm)) 528 return -2; 529 530 if (day > 0 || sec > 0) 531 return 1; 532 if (day < 0 || sec < 0) 533 return -1; 534 return 0; 535 } 536 537 int ASN1_TIME_normalize(ASN1_TIME *t) 538 { 539 struct tm tm; 540 541 if (!ASN1_TIME_to_tm(t, &tm)) 542 return 0; 543 544 return asn1_time_from_tm(t, &tm, V_ASN1_UNDEF) != NULL; 545 } 546 547 int ASN1_TIME_compare(const ASN1_TIME *a, const ASN1_TIME *b) 548 { 549 int day, sec; 550 551 if (!ASN1_TIME_diff(&day, &sec, b, a)) 552 return -2; 553 if (day > 0 || sec > 0) 554 return 1; 555 if (day < 0 || sec < 0) 556 return -1; 557 return 0; 558 } 559