1/*
2 * Copyright 1999-2017 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
24IMPLEMENT_ASN1_MSTRING(ASN1_TIME, B_ASN1_TIME)
25
26IMPLEMENT_ASN1_FUNCTIONS(ASN1_TIME)
27
28static int is_utc(const int year)
29{
30 if (50 <= year && year <= 149)
31 return 1;
32 return 0;
33}
34
35static 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 */
48static 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
74int 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
265ASN1_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
317ASN1_TIME *ASN1_TIME_set(ASN1_TIME *s, time_t t)
318{
319 return ASN1_TIME_adj(s, t, 0, 0);
320}
321
322ASN1_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
340int 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 */
350ASN1_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
370int 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
378int 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);
433out:
434 return rv;
435}
436
437int 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
452int 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
464static const char _asn1_mon[12][4] = {
465 "Jan", "Feb", "Mar", "Apr", "May", "Jun",
466 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
467};
468
469int 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
516int 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
537int 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
547int 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