crypto/asn1/a_time.c

   1 /*
   2  * Copyright 1999-2020 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (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 IMPLEMENT_ASN1_DUP_FUNCTION(ASN1_TIME)
  28
  29 static int is_utc(const int year)
  30 {
  31     if (50 <= year && year <= 149)
  32         return 1;
  33     return 0;
  34 }
  35
  36 static int leap_year(const int year)
  37 {
  38     if (year % 400 == 0 || (year % 100 != 0 && year % 4 == 0))
  39         return 1;
  40     return 0;
  41 }
  42
  43 /*
  44  * Compute the day of the week and the day of the year from the year, month
  45  * and day.  The day of the year is straightforward, the day of the week uses
  46  * a form of Zeller's congruence.  For this months start with March and are
  47  * numbered 4 through 15.
  48  */
  49 static void determine_days(struct tm *tm)
  50 {
  51     static const int ydays[12] = {
  52         0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
  53     };
  54     int y = tm->tm_year + 1900;
  55     int m = tm->tm_mon;
  56     int d = tm->tm_mday;
  57     int c;
  58
  59     tm->tm_yday = ydays[m] + d - 1;
  60     if (m >= 2) {
  61         /* March and onwards can be one day further into the year */
  62         tm->tm_yday += leap_year(y);
  63         m += 2;
  64     } else {
  65         /* Treat January and February as part of the previous year */
  66         m += 14;
  67         y--;
  68     }
  69     c = y / 100;
  70     y %= 100;
  71     /* Zeller's congruence */
  72     tm->tm_wday = (d + (13 * m) / 5 + y + y / 4 + c / 4 + 5 * c + 6) % 7;
  73 }
  74
  75 int asn1_time_to_tm(struct tm *tm, const ASN1_TIME *d)
  76 {
  77     static const int min[9] = { 0, 0, 1, 1, 0, 0, 0, 0, 0 };
  78     static const int max[9] = { 99, 99, 12, 31, 23, 59, 59, 12, 59 };
  79     static const int mdays[12] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
  80     char *a;
  81     int n, i, i2, l, o, min_l = 11, strict = 0, end = 6, btz = 5, md;
  82     struct tm tmp;
  83 #if defined(CHARSET_EBCDIC)
  84     const char upper_z = 0x5A, num_zero = 0x30, period = 0x2E, minus = 0x2D, plus = 0x2B;
  85 #else
  86     const char upper_z = 'Z', num_zero = '0', period = '.', minus = '-', plus = '+';
  87 #endif
  88     /*
  89      * ASN1_STRING_FLAG_X509_TIME is used to enforce RFC 5280
  90      * time string format, in which:
  91      *
  92      * 1. "seconds" is a 'MUST'
  93      * 2. "Zulu" timezone is a 'MUST'
  94      * 3. "+|-" is not allowed to indicate a time zone
  95      */
  96     if (d->type == V_ASN1_UTCTIME) {
  97         if (d->flags & ASN1_STRING_FLAG_X509_TIME) {
  98             min_l = 13;
  99             strict = 1;
 100         }
 101     } else if (d->type == V_ASN1_GENERALIZEDTIME) {
 102         end = 7;
 103         btz = 6;
 104         if (d->flags & ASN1_STRING_FLAG_X509_TIME) {
 105             min_l = 15;
 106             strict = 1;
 107         } else {
 108             min_l = 13;
 109         }
 110     } else {
 111         return 0;
 112     }
 113
 114     l = d->length;
 115     a = (char *)d->data;
 116     o = 0;
 117     memset(&tmp, 0, sizeof(tmp));
 118
 119     /*
 120      * GENERALIZEDTIME is similar to UTCTIME except the year is represented
 121      * as YYYY. This stuff treats everything as a two digit field so make
 122      * first two fields 00 to 99
 123      */
 124
 125     if (l < min_l)
 126         goto err;
 127     for (i = 0; i < end; i++) {
 128         if (!strict && (i == btz) && ((a[o] == upper_z) || (a[o] == plus) || (a[o] == minus))) {
 129             i++;
 130             break;
 131         }
 132         if (!ascii_isdigit(a[o]))
 133             goto err;
 134         n = a[o] - num_zero;
 135         /* incomplete 2-digital number */
 136         if (++o == l)
 137             goto err;
 138
 139         if (!ascii_isdigit(a[o]))
 140             goto err;
 141         n = (n * 10) + a[o] - num_zero;
 142         /* no more bytes to read, but we haven't seen time-zone yet */
 143         if (++o == l)
 144             goto err;
 145
 146         i2 = (d->type == V_ASN1_UTCTIME) ? i + 1 : i;
 147
 148         if ((n < min[i2]) || (n > max[i2]))
 149             goto err;
 150         switch (i2) {
 151         case 0:
 152             /* UTC will never be here */
 153             tmp.tm_year = n * 100 - 1900;
 154             break;
 155         case 1:
 156             if (d->type == V_ASN1_UTCTIME)
 157                 tmp.tm_year = n < 50 ? n + 100 : n;
 158             else
 159                 tmp.tm_year += n;
 160             break;
 161         case 2:
 162             tmp.tm_mon = n - 1;
 163             break;
 164         case 3:
 165             /* check if tm_mday is valid in tm_mon */
 166             if (tmp.tm_mon == 1) {
 167                 /* it's February */
 168                 md = mdays[1] + leap_year(tmp.tm_year + 1900);
 169             } else {
 170                 md = mdays[tmp.tm_mon];
 171             }
 172             if (n > md)
 173                 goto err;
 174             tmp.tm_mday = n;
 175             determine_days(&tmp);
 176             break;
 177         case 4:
 178             tmp.tm_hour = n;
 179             break;
 180         case 5:
 181             tmp.tm_min = n;
 182             break;
 183         case 6:
 184             tmp.tm_sec = n;
 185             break;
 186         }
 187     }
 188
 189     /*
 190      * Optional fractional seconds: decimal point followed by one or more
 191      * digits.
 192      */
 193     if (d->type == V_ASN1_GENERALIZEDTIME && a[o] == period) {
 194         if (strict)
 195             /* RFC 5280 forbids fractional seconds */
 196             goto err;
 197         if (++o == l)
 198             goto err;
 199         i = o;
 200         while ((o < l) && ascii_isdigit(a[o]))
 201             o++;
 202         /* Must have at least one digit after decimal point */
 203         if (i == o)
 204             goto err;
 205         /* no more bytes to read, but we haven't seen time-zone yet */
 206         if (o == l)
 207             goto err;
 208     }
 209
 210     /*
 211      * 'o' will never point to '\0' at this point, the only chance
 212      * 'o' can point to '\0' is either the subsequent if or the first
 213      * else if is true.
 214      */
 215     if (a[o] == upper_z) {
 216         o++;
 217     } else if (!strict && ((a[o] == plus) || (a[o] == minus))) {
 218         int offsign = a[o] == minus ? 1 : -1;
 219         int offset = 0;
 220
 221         o++;
 222         /*
 223          * if not equal, no need to do subsequent checks
 224          * since the following for-loop will add 'o' by 4
 225          * and the final return statement will check if 'l'
 226          * and 'o' are equal.
 227          */
 228         if (o + 4 != l)
 229             goto err;
 230         for (i = end; i < end + 2; i++) {
 231             if (!ascii_isdigit(a[o]))
 232                 goto err;
 233             n = a[o] - num_zero;
 234             o++;
 235             if (!ascii_isdigit(a[o]))
 236                 goto err;
 237             n = (n * 10) + a[o] - num_zero;
 238             i2 = (d->type == V_ASN1_UTCTIME) ? i + 1 : i;
 239             if ((n < min[i2]) || (n > max[i2]))
 240                 goto err;
 241             /* if tm is NULL, no need to adjust */
 242             if (tm != NULL) {
 243                 if (i == end)
 244                     offset = n * 3600;
 245                 else if (i == end + 1)
 246                     offset += n * 60;
 247             }
 248             o++;
 249         }
 250         if (offset && !OPENSSL_gmtime_adj(&tmp, 0, offset * offsign))
 251             goto err;
 252     } else {
 253         /* not Z, or not +/- in non-strict mode */
 254         goto err;
 255     }
 256     if (o == l) {
 257         /* success, check if tm should be filled */
 258         if (tm != NULL)
 259             *tm = tmp;
 260         return 1;
 261     }
 262  err:
 263     return 0;
 264 }
 265
 266 ASN1_TIME *asn1_time_from_tm(ASN1_TIME *s, struct tm *ts, int type)
 267 {
 268     char* p;
 269     ASN1_TIME *tmps = NULL;
 270     const size_t len = 20;
 271
 272     if (type == V_ASN1_UNDEF) {
 273         if (is_utc(ts->tm_year))
 274             type = V_ASN1_UTCTIME;
 275         else
 276             type = V_ASN1_GENERALIZEDTIME;
 277     } else if (type == V_ASN1_UTCTIME) {
 278         if (!is_utc(ts->tm_year))
 279             goto err;
 280     } else if (type != V_ASN1_GENERALIZEDTIME) {
 281         goto err;
 282     }
 283
 284     if (s == NULL)
 285         tmps = ASN1_STRING_new();
 286     else
 287         tmps = s;
 288     if (tmps == NULL)
 289         return NULL;
 290
 291     if (!ASN1_STRING_set(tmps, NULL, len))
 292         goto err;
 293
 294     tmps->type = type;
 295     p = (char*)tmps->data;
 296
 297     if (type == V_ASN1_GENERALIZEDTIME)
 298         tmps->length = BIO_snprintf(p, len, "%04d%02d%02d%02d%02d%02dZ",
 299                                     ts->tm_year + 1900, ts->tm_mon + 1,
 300                                     ts->tm_mday, ts->tm_hour, ts->tm_min,
 301                                     ts->tm_sec);
 302     else
 303         tmps->length = BIO_snprintf(p, len, "%02d%02d%02d%02d%02d%02dZ",
 304                                     ts->tm_year % 100, ts->tm_mon + 1,
 305                                     ts->tm_mday, ts->tm_hour, ts->tm_min,
 306                                     ts->tm_sec);
 307
 308 #ifdef CHARSET_EBCDIC
 309     ebcdic2ascii(tmps->data, tmps->data, tmps->length);
 310 #endif
 311     return tmps;
 312  err:
 313     if (tmps != s)
 314         ASN1_STRING_free(tmps);
 315     return NULL;
 316 }
 317
 318 ASN1_TIME *ASN1_TIME_set(ASN1_TIME *s, time_t t)
 319 {
 320     return ASN1_TIME_adj(s, t, 0, 0);
 321 }
 322
 323 ASN1_TIME *ASN1_TIME_adj(ASN1_TIME *s, time_t t,
 324                          int offset_day, long offset_sec)
 325 {
 326     struct tm *ts;
 327     struct tm data;
 328
 329     ts = OPENSSL_gmtime(&t, &data);
 330     if (ts == NULL) {
 331         ASN1err(ASN1_F_ASN1_TIME_ADJ, ASN1_R_ERROR_GETTING_TIME);
 332         return NULL;
 333     }
 334     if (offset_day || offset_sec) {
 335         if (!OPENSSL_gmtime_adj(ts, offset_day, offset_sec))
 336             return NULL;
 337     }
 338     return asn1_time_from_tm(s, ts, V_ASN1_UNDEF);
 339 }
 340
 341 int ASN1_TIME_check(const ASN1_TIME *t)
 342 {
 343     if (t->type == V_ASN1_GENERALIZEDTIME)
 344         return ASN1_GENERALIZEDTIME_check(t);
 345     else if (t->type == V_ASN1_UTCTIME)
 346         return ASN1_UTCTIME_check(t);
 347     return 0;
 348 }
 349
 350 /* Convert an ASN1_TIME structure to GeneralizedTime */
 351 ASN1_GENERALIZEDTIME *ASN1_TIME_to_generalizedtime(const ASN1_TIME *t,
 352                                                    ASN1_GENERALIZEDTIME **out)
 353 {
 354     ASN1_GENERALIZEDTIME *ret = NULL;
 355     struct tm tm;
 356
 357     if (!ASN1_TIME_to_tm(t, &tm))
 358         return NULL;
 359
 360     if (out != NULL)
 361         ret = *out;
 362
 363     ret = asn1_time_from_tm(ret, &tm, V_ASN1_GENERALIZEDTIME);
 364
 365     if (out != NULL && ret != NULL)
 366         *out = ret;
 367
 368     return ret;
 369 }
 370
 371 int ASN1_TIME_set_string(ASN1_TIME *s, const char *str)
 372 {
 373     /* Try UTC, if that fails, try GENERALIZED */
 374     if (ASN1_UTCTIME_set_string(s, str))
 375         return 1;
 376     return ASN1_GENERALIZEDTIME_set_string(s, str);
 377 }
 378
 379 int ASN1_TIME_set_string_X509(ASN1_TIME *s, const char *str)
 380 {
 381     ASN1_TIME t;
 382     struct tm tm;
 383     int rv = 0;
 384
 385     t.length = strlen(str);
 386     t.data = (unsigned char *)str;
 387     t.flags = ASN1_STRING_FLAG_X509_TIME;
 388
 389     t.type = V_ASN1_UTCTIME;
 390
 391     if (!ASN1_TIME_check(&t)) {
 392         t.type = V_ASN1_GENERALIZEDTIME;
 393         if (!ASN1_TIME_check(&t))
 394             goto out;
 395     }
 396
 397     /*
 398      * Per RFC 5280 (section 4.1.2.5.), the valid input time
 399      * strings should be encoded with the following rules:
 400      *
 401      * 1. UTC: YYMMDDHHMMSSZ, if YY < 50 (20YY) --> UTC: YYMMDDHHMMSSZ
 402      * 2. UTC: YYMMDDHHMMSSZ, if YY >= 50 (19YY) --> UTC: YYMMDDHHMMSSZ
 403      * 3. G'd: YYYYMMDDHHMMSSZ, if YYYY >= 2050 --> G'd: YYYYMMDDHHMMSSZ
 404      * 4. G'd: YYYYMMDDHHMMSSZ, if YYYY < 2050 --> UTC: YYMMDDHHMMSSZ
 405      *
 406      * Only strings of the 4th rule should be reformatted, but since a
 407      * UTC can only present [1950, 2050), so if the given time string
 408      * is less than 1950 (e.g. 19230419000000Z), we do nothing...
 409      */
 410
 411     if (s != NULL && t.type == V_ASN1_GENERALIZEDTIME) {
 412         if (!asn1_time_to_tm(&tm, &t))
 413             goto out;
 414         if (is_utc(tm.tm_year)) {
 415             t.length -= 2;
 416             /*
 417              * it's OK to let original t.data go since that's assigned
 418              * to a piece of memory allocated outside of this function.
 419              * new t.data would be freed after ASN1_STRING_copy is done.
 420              */
 421             t.data = OPENSSL_zalloc(t.length + 1);
 422             if (t.data == NULL)
 423                 goto out;
 424             memcpy(t.data, str + 2, t.length);
 425             t.type = V_ASN1_UTCTIME;
 426         }
 427     }
 428
 429     if (s == NULL || ASN1_STRING_copy((ASN1_STRING *)s, (ASN1_STRING *)&t))
 430         rv = 1;
 431
 432     if (t.data != (unsigned char *)str)
 433         OPENSSL_free(t.data);
 434 out:
 435     return rv;
 436 }
 437
 438 int ASN1_TIME_to_tm(const ASN1_TIME *s, struct tm *tm)
 439 {
 440     if (s == NULL) {
 441         time_t now_t;
 442
 443         time(&now_t);
 444         memset(tm, 0, sizeof(*tm));
 445         if (OPENSSL_gmtime(&now_t, tm) != NULL)
 446             return 1;
 447         return 0;
 448     }
 449
 450     return asn1_time_to_tm(tm, s);
 451 }
 452
 453 int ASN1_TIME_diff(int *pday, int *psec,
 454                    const ASN1_TIME *from, const ASN1_TIME *to)
 455 {
 456     struct tm tm_from, tm_to;
 457
 458     if (!ASN1_TIME_to_tm(from, &tm_from))
 459         return 0;
 460     if (!ASN1_TIME_to_tm(to, &tm_to))
 461         return 0;
 462     return OPENSSL_gmtime_diff(pday, psec, &tm_from, &tm_to);
 463 }
 464
 465 static const char _asn1_mon[12][4] = {
 466     "Jan", "Feb", "Mar", "Apr", "May", "Jun",
 467     "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
 468 };
 469
 470 int ASN1_TIME_print(BIO *bp, const ASN1_TIME *tm)
 471 {
 472     char *v;
 473     int gmt = 0, l;
 474     struct tm stm;
 475     const char upper_z = 0x5A, period = 0x2E;
 476
 477     if (!asn1_time_to_tm(&stm, tm)) {
 478         /* asn1_time_to_tm will check the time type */
 479         goto err;
 480     }
 481
 482     l = tm->length;
 483     v = (char *)tm->data;
 484     if (v[l - 1] == upper_z)
 485         gmt = 1;
 486
 487     if (tm->type == V_ASN1_GENERALIZEDTIME) {
 488         char *f = NULL;
 489         int f_len = 0;
 490
 491         /*
 492          * Try to parse fractional seconds. '14' is the place of
 493          * 'fraction point' in a GeneralizedTime string.
 494          */
 495         if (tm->length > 15 && v[14] == period) {
 496             f = &v[14];
 497             f_len = 1;
 498             while (14 + f_len < l && ascii_isdigit(f[f_len]))
 499                 ++f_len;
 500         }
 501
 502         return BIO_printf(bp, "%s %2d %02d:%02d:%02d%.*s %d%s",
 503                           _asn1_mon[stm.tm_mon], stm.tm_mday, stm.tm_hour,
 504                           stm.tm_min, stm.tm_sec, f_len, f, stm.tm_year + 1900,
 505                           (gmt ? " GMT" : "")) > 0;
 506     } else {
 507         return BIO_printf(bp, "%s %2d %02d:%02d:%02d %d%s",
 508                           _asn1_mon[stm.tm_mon], stm.tm_mday, stm.tm_hour,
 509                           stm.tm_min, stm.tm_sec, stm.tm_year + 1900,
 510                           (gmt ? " GMT" : "")) > 0;
 511     }
 512  err:
 513     BIO_write(bp, "Bad time value", 14);
 514     return 0;
 515 }
 516
 517 int ASN1_TIME_cmp_time_t(const ASN1_TIME *s, time_t t)
 518 {
 519     struct tm stm, ttm;
 520     int day, sec;
 521
 522     if (!ASN1_TIME_to_tm(s, &stm))
 523         return -2;
 524
 525     if (!OPENSSL_gmtime(&t, &ttm))
 526         return -2;
 527
 528     if (!OPENSSL_gmtime_diff(&day, &sec, &ttm, &stm))
 529         return -2;
 530
 531     if (day > 0 || sec > 0)
 532         return 1;
 533     if (day < 0 || sec < 0)
 534         return -1;
 535     return 0;
 536 }
 537
 538 int ASN1_TIME_normalize(ASN1_TIME *t)
 539 {
 540     struct tm tm;
 541
 542     if (!ASN1_TIME_to_tm(t, &tm))
 543         return 0;
 544
 545     return asn1_time_from_tm(t, &tm, V_ASN1_UNDEF) != NULL;
 546 }
 547
 548 int ASN1_TIME_compare(const ASN1_TIME *a, const ASN1_TIME *b)
 549 {
 550     int day, sec;
 551
 552     if (!ASN1_TIME_diff(&day, &sec, b, a))
 553         return -2;
 554     if (day > 0 || sec > 0)
 555         return 1;
 556     if (day < 0 || sec < 0)
 557         return -1;
 558     return 0;
 559 }