1/*
2 * Copyright 2001-2018 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#include <openssl/e_os2.h>
11#include <string.h>
12#include <openssl/crypto.h>
13
14struct tm *OPENSSL_gmtime(const time_t *timer, struct tm *result)
15{
16 struct tm *ts = NULL;
17
18#if defined(OPENSSL_THREADS) && defined(OPENSSL_SYS_VMS)
19 {
20 /*
21 * On VMS, gmtime_r() takes a 32-bit pointer as second argument.
22 * Since we can't know that |result| is in a space that can easily
23 * translate to a 32-bit pointer, we must store temporarily on stack
24 * and copy the result. The stack is always reachable with 32-bit
25 * pointers.
26 */
27#if defined(OPENSSL_SYS_VMS) && __INITIAL_POINTER_SIZE
28# pragma pointer_size save
29# pragma pointer_size 32
30#endif
31 struct tm data, *ts2 = &data;
32#if defined OPENSSL_SYS_VMS && __INITIAL_POINTER_SIZE
33# pragma pointer_size restore
34#endif
35 if (gmtime_r(timer, ts2) == NULL)
36 return NULL;
37 memcpy(result, ts2, sizeof(struct tm));
38 ts = result;
39 }
40#elif defined(OPENSSL_THREADS) && !defined(OPENSSL_SYS_WIN32) && !defined(OPENSSL_SYS_MACOSX)
41 if (gmtime_r(timer, result) == NULL)
42 return NULL;
43 ts = result;
44#elif defined (OPENSSL_SYS_WINDOWS) && defined(_MSC_VER) && _MSC_VER >= 1400
45 if (gmtime_s(result, timer))
46 return NULL;
47 ts = result;
48#else
49 ts = gmtime(timer);
50 if (ts == NULL)
51 return NULL;
52
53 memcpy(result, ts, sizeof(struct tm));
54 ts = result;
55#endif
56 return ts;
57}
58
59/*
60 * Take a tm structure and add an offset to it. This avoids any OS issues
61 * with restricted date types and overflows which cause the year 2038
62 * problem.
63 */
64
65#define SECS_PER_DAY (24 * 60 * 60)
66
67static long date_to_julian(int y, int m, int d);
68static void julian_to_date(long jd, int *y, int *m, int *d);
69static int julian_adj(const struct tm *tm, int off_day, long offset_sec,
70 long *pday, int *psec);
71
72int OPENSSL_gmtime_adj(struct tm *tm, int off_day, long offset_sec)
73{
74 int time_sec, time_year, time_month, time_day;
75 long time_jd;
76
77 /* Convert time and offset into Julian day and seconds */
78 if (!julian_adj(tm, off_day, offset_sec, &time_jd, &time_sec))
79 return 0;
80
81 /* Convert Julian day back to date */
82
83 julian_to_date(time_jd, &time_year, &time_month, &time_day);
84
85 if (time_year < 1900 || time_year > 9999)
86 return 0;
87
88 /* Update tm structure */
89
90 tm->tm_year = time_year - 1900;
91 tm->tm_mon = time_month - 1;
92 tm->tm_mday = time_day;
93
94 tm->tm_hour = time_sec / 3600;
95 tm->tm_min = (time_sec / 60) % 60;
96 tm->tm_sec = time_sec % 60;
97
98 return 1;
99
100}
101
102int OPENSSL_gmtime_diff(int *pday, int *psec,
103 const struct tm *from, const struct tm *to)
104{
105 int from_sec, to_sec, diff_sec;
106 long from_jd, to_jd, diff_day;
107 if (!julian_adj(from, 0, 0, &from_jd, &from_sec))
108 return 0;
109 if (!julian_adj(to, 0, 0, &to_jd, &to_sec))
110 return 0;
111 diff_day = to_jd - from_jd;
112 diff_sec = to_sec - from_sec;
113 /* Adjust differences so both positive or both negative */
114 if (diff_day > 0 && diff_sec < 0) {
115 diff_day--;
116 diff_sec += SECS_PER_DAY;
117 }
118 if (diff_day < 0 && diff_sec > 0) {
119 diff_day++;
120 diff_sec -= SECS_PER_DAY;
121 }
122
123 if (pday)
124 *pday = (int)diff_day;
125 if (psec)
126 *psec = diff_sec;
127
128 return 1;
129
130}
131
132/* Convert tm structure and offset into julian day and seconds */
133static int julian_adj(const struct tm *tm, int off_day, long offset_sec,
134 long *pday, int *psec)
135{
136 int offset_hms, offset_day;
137 long time_jd;
138 int time_year, time_month, time_day;
139 /* split offset into days and day seconds */
140 offset_day = offset_sec / SECS_PER_DAY;
141 /* Avoid sign issues with % operator */
142 offset_hms = offset_sec - (offset_day * SECS_PER_DAY);
143 offset_day += off_day;
144 /* Add current time seconds to offset */
145 offset_hms += tm->tm_hour * 3600 + tm->tm_min * 60 + tm->tm_sec;
146 /* Adjust day seconds if overflow */
147 if (offset_hms >= SECS_PER_DAY) {
148 offset_day++;
149 offset_hms -= SECS_PER_DAY;
150 } else if (offset_hms < 0) {
151 offset_day--;
152 offset_hms += SECS_PER_DAY;
153 }
154
155 /*
156 * Convert date of time structure into a Julian day number.
157 */
158
159 time_year = tm->tm_year + 1900;
160 time_month = tm->tm_mon + 1;
161 time_day = tm->tm_mday;
162
163 time_jd = date_to_julian(time_year, time_month, time_day);
164
165 /* Work out Julian day of new date */
166 time_jd += offset_day;
167
168 if (time_jd < 0)
169 return 0;
170
171 *pday = time_jd;
172 *psec = offset_hms;
173 return 1;
174}
175
176/*
177 * Convert date to and from julian day Uses Fliegel & Van Flandern algorithm
178 */
179static long date_to_julian(int y, int m, int d)
180{
181 return (1461 * (y + 4800 + (m - 14) / 12)) / 4 +
182 (367 * (m - 2 - 12 * ((m - 14) / 12))) / 12 -
183 (3 * ((y + 4900 + (m - 14) / 12) / 100)) / 4 + d - 32075;
184}
185
186static void julian_to_date(long jd, int *y, int *m, int *d)
187{
188 long L = jd + 68569;
189 long n = (4 * L) / 146097;
190 long i, j;
191
192 L = L - (146097 * n + 3) / 4;
193 i = (4000 * (L + 1)) / 1461001;
194 L = L - (1461 * i) / 4 + 31;
195 j = (80 * L) / 2447;
196 *d = L - (2447 * j) / 80;
197 L = j / 11;
198 *m = j + 2 - (12 * L);
199 *y = 100 * (n - 49) + i + L;
200}
201