1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
|
/* $OpenBSD: a_time_posix.c,v 1.5 2024/02/18 16:28:38 tb Exp $ */
/*
* Copyright (c) 2022, Google Inc.
* Copyright (c) 2022, Bob Beck <beck@obtuse.com>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
* Time conversion to/from POSIX time_t and struct tm, with no support
* for time zones other than UTC
*/
#include <inttypes.h>
#include <limits.h>
#include <stdint.h>
#include <string.h>
#include <time.h>
#include <openssl/asn1.h>
#include <openssl/posix_time.h>
#include "crypto_internal.h"
#define SECS_PER_HOUR (int64_t)(60 * 60)
#define SECS_PER_DAY (int64_t)(24 * SECS_PER_HOUR)
/*
* Is a year/month/day combination valid, in the range from year 0000
* to 9999?
*/
static int
is_valid_date(int64_t year, int64_t month, int64_t day)
{
int days_in_month;
if (day < 1 || month < 1 || year < 0 || year > 9999)
return 0;
switch (month) {
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:
days_in_month = 31;
break;
case 4:
case 6:
case 9:
case 11:
days_in_month = 30;
break;
case 2:
if ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0)
days_in_month = 29;
else
days_in_month = 28;
break;
default:
return 0;
}
return day <= days_in_month;
}
/*
* Is a time valid? Leap seconds of 60 are not considered valid, as
* the POSIX time in seconds does not include them.
*/
static int
is_valid_time(int hours, int minutes, int seconds)
{
return hours >= 0 && minutes >= 0 && seconds >= 0 && hours <= 23 &&
minutes <= 59 && seconds <= 59;
}
/* 0000-01-01 00:00:00 UTC */
#define MIN_POSIX_TIME INT64_C(-62167219200)
/* 9999-12-31 23:59:59 UTC */
#define MAX_POSIX_TIME INT64_C(253402300799)
/* Is a int64 time representing a time within our expected range? */
static int
is_valid_posix_time(int64_t time)
{
return MIN_POSIX_TIME <= time && time <= MAX_POSIX_TIME;
}
/*
* Inspired by algorithms presented in
* https://howardhinnant.github.io/date_algorithms.html
* (Public Domain)
*/
static int
posix_time_from_utc(int64_t year, int64_t month, int64_t day, int64_t hours,
int64_t minutes, int64_t seconds, int64_t *out_time)
{
int64_t era, year_of_era, day_of_year, day_of_era, posix_days;
if (!is_valid_date(year, month, day) ||
!is_valid_time(hours, minutes, seconds))
return 0;
if (month <= 2)
year--; /* Start years on Mar 1, so leap days end a year. */
/* At this point year will be in the range -1 and 9999.*/
era = (year >= 0 ? year : year - 399) / 400;
year_of_era = year - era * 400;
day_of_year = (153 * (month > 2 ? month - 3 : month + 9) + 2) /
5 + day - 1;
day_of_era = year_of_era * 365 + year_of_era / 4 - year_of_era /
100 + day_of_year;
posix_days = era * 146097 + day_of_era - 719468;
*out_time = posix_days * SECS_PER_DAY + hours * SECS_PER_HOUR +
minutes * 60 + seconds;
return 1;
}
/*
* Inspired by algorithms presented in
* https://howardhinnant.github.io/date_algorithms.html
* (Public Domain)
*/
static int
utc_from_posix_time(int64_t time, int *out_year, int *out_month, int *out_day,
int *out_hours, int *out_minutes, int *out_seconds)
{
int64_t days, leftover_seconds, era, day_of_era, year_of_era,
day_of_year, month_of_year;
if (!is_valid_posix_time(time))
return 0;
days = time / SECS_PER_DAY;
leftover_seconds = time % SECS_PER_DAY;
if (leftover_seconds < 0) {
days--;
leftover_seconds += SECS_PER_DAY;
}
days += 719468; /* Shift to starting epoch of Mar 1 0000. */
/* At this point, days will be in the range -61 and 3652364. */
era = (days > 0 ? days : days - 146096) / 146097;
day_of_era = days - era * 146097;
year_of_era = (day_of_era - day_of_era / 1460 + day_of_era / 36524 -
day_of_era / 146096) /
365;
*out_year = year_of_era + era * 400; /* Year starts on Mar 1 */
day_of_year = day_of_era - (365 * year_of_era + year_of_era / 4 -
year_of_era / 100);
month_of_year = (5 * day_of_year + 2) / 153;
*out_month = (month_of_year < 10 ? month_of_year + 3 :
month_of_year - 9);
if (*out_month <= 2)
(*out_year)++; /* Adjust year back to Jan 1 start of year. */
*out_day = day_of_year - (153 * month_of_year + 2) / 5 + 1;
*out_hours = leftover_seconds / SECS_PER_HOUR;
leftover_seconds %= SECS_PER_HOUR;
*out_minutes = leftover_seconds / 60;
*out_seconds = leftover_seconds % 60;
return 1;
}
int
OPENSSL_tm_to_posix(const struct tm *tm, int64_t *out)
{
return posix_time_from_utc(tm->tm_year + (int64_t)1900,
tm->tm_mon + (int64_t)1, tm->tm_mday, tm->tm_hour, tm->tm_min,
tm->tm_sec, out);
}
LCRYPTO_ALIAS(OPENSSL_tm_to_posix);
int
OPENSSL_posix_to_tm(int64_t time, struct tm *out_tm)
{
struct tm tmp_tm = {0};
memset(out_tm, 0, sizeof(*out_tm));
if (!utc_from_posix_time(time, &tmp_tm.tm_year, &tmp_tm.tm_mon,
&tmp_tm.tm_mday, &tmp_tm.tm_hour, &tmp_tm.tm_min, &tmp_tm.tm_sec))
return 0;
tmp_tm.tm_year -= 1900;
tmp_tm.tm_mon -= 1;
*out_tm = tmp_tm;
return 1;
}
LCRYPTO_ALIAS(OPENSSL_posix_to_tm);
int
asn1_time_tm_to_time_t(const struct tm *tm, time_t *out)
{
int64_t posix_time;
if (!OPENSSL_tm_to_posix(tm, &posix_time))
return 0;
#ifdef SMALL_TIME_T
/* For portable. */
if (sizeof(time_t) == sizeof(int32_t) &&
(posix_time > INT32_MAX || posix_time < INT32_MIN))
return 0;
#endif
*out = posix_time;
return 1;
}
int
asn1_time_time_t_to_tm(const time_t *time, struct tm *out_tm)
{
int64_t posix_time = *time;
return OPENSSL_posix_to_tm(posix_time, out_tm);
}
int
OPENSSL_timegm(const struct tm *tm, time_t *out) {
return asn1_time_tm_to_time_t(tm, out);
}
LCRYPTO_ALIAS(OPENSSL_timegm);
struct tm *
OPENSSL_gmtime(const time_t *time, struct tm *out_tm) {
if (!asn1_time_time_t_to_tm(time, out_tm))
return NULL;
return out_tm;
}
LCRYPTO_ALIAS(OPENSSL_gmtime);
/* Public API in OpenSSL. BoringSSL uses int64_t instead of long. */
int
OPENSSL_gmtime_adj(struct tm *tm, int offset_day, int64_t offset_sec)
{
int64_t posix_time;
if (!OPENSSL_tm_to_posix(tm, &posix_time))
return 0;
CTASSERT(INT_MAX <= INT64_MAX / SECS_PER_DAY);
CTASSERT(MAX_POSIX_TIME <= INT64_MAX - INT_MAX * SECS_PER_DAY);
CTASSERT(MIN_POSIX_TIME >= INT64_MIN - INT_MIN * SECS_PER_DAY);
posix_time += offset_day * SECS_PER_DAY;
if (posix_time > 0 && offset_sec > INT64_MAX - posix_time)
return 0;
if (posix_time < 0 && offset_sec < INT64_MIN - posix_time)
return 0;
posix_time += offset_sec;
if (!OPENSSL_posix_to_tm(posix_time, tm))
return 0;
return 1;
}
int
OPENSSL_gmtime_diff(int *out_days, int *out_secs, const struct tm *from,
const struct tm *to)
{
int64_t time_to, time_from, timediff, daydiff;
if (!OPENSSL_tm_to_posix(to, &time_to) ||
!OPENSSL_tm_to_posix(from, &time_from))
return 0;
/* Times are in range, so these calculations cannot overflow. */
CTASSERT(SECS_PER_DAY <= INT_MAX);
CTASSERT((MAX_POSIX_TIME - MIN_POSIX_TIME) / SECS_PER_DAY <= INT_MAX);
timediff = time_to - time_from;
daydiff = timediff / SECS_PER_DAY;
timediff %= SECS_PER_DAY;
*out_secs = timediff;
*out_days = daydiff;
return 1;
}
|