1/* Written by Richard Levitte (richard@levitte.org) for the OpenSSL
2 * project 2001.
3 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
4 * project 2008.
5 */
6/* ====================================================================
7 * Copyright (c) 2001 The OpenSSL Project.  All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in
18 *    the documentation and/or other materials provided with the
19 *    distribution.
20 *
21 * 3. All advertising materials mentioning features or use of this
22 *    software must display the following acknowledgment:
23 *    "This product includes software developed by the OpenSSL Project
24 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25 *
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 *    endorse or promote products derived from this software without
28 *    prior written permission. For written permission, please contact
29 *    licensing@OpenSSL.org.
30 *
31 * 5. Products derived from this software may not be called "OpenSSL"
32 *    nor may "OpenSSL" appear in their names without prior written
33 *    permission of the OpenSSL Project.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 *    acknowledgment:
37 *    "This product includes software developed by the OpenSSL Project
38 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
53 *
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com).  This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com). */
57
58#if !defined(_BSD_SOURCE)
59#define _BSD_SOURCE /* for gmtime_r */
60#endif
61
62#include <openssl/time_support.h>
63
64#define SECS_PER_DAY (24 * 60 * 60)
65
66struct tm *OPENSSL_gmtime(const time_t *time, struct tm *result) {
67#if defined(OPENSSL_WINDOWS)
68  if (gmtime_s(result, time)) {
69    return NULL;
70  }
71  return result;
72#else
73  return gmtime_r(time, result);
74#endif
75}
76
77/* Convert date to and from julian day Uses Fliegel & Van Flandern algorithm */
78static long date_to_julian(int y, int m, int d) {
79  return (1461 * (y + 4800 + (m - 14) / 12)) / 4 +
80         (367 * (m - 2 - 12 * ((m - 14) / 12))) / 12 -
81         (3 * ((y + 4900 + (m - 14) / 12) / 100)) / 4 + d - 32075;
82}
83
84static void julian_to_date(long jd, int *y, int *m, int *d) {
85  long L = jd + 68569;
86  long n = (4 * L) / 146097;
87  long i, j;
88
89  L = L - (146097 * n + 3) / 4;
90  i = (4000 * (L + 1)) / 1461001;
91  L = L - (1461 * i) / 4 + 31;
92  j = (80 * L) / 2447;
93  *d = L - (2447 * j) / 80;
94  L = j / 11;
95  *m = j + 2 - (12 * L);
96  *y = 100 * (n - 49) + i + L;
97}
98
99/* Convert tm structure and offset into julian day and seconds */
100static int julian_adj(const struct tm *tm, int off_day, long offset_sec,
101                      long *pday, int *psec) {
102  int offset_hms, offset_day;
103  long time_jd;
104  int time_year, time_month, time_day;
105  /* split offset into days and day seconds */
106  offset_day = offset_sec / SECS_PER_DAY;
107  /* Avoid sign issues with % operator */
108  offset_hms = offset_sec - (offset_day * SECS_PER_DAY);
109  offset_day += off_day;
110  /* Add current time seconds to offset */
111  offset_hms += tm->tm_hour * 3600 + tm->tm_min * 60 + tm->tm_sec;
112  /* Adjust day seconds if overflow */
113  if (offset_hms >= SECS_PER_DAY) {
114    offset_day++;
115    offset_hms -= SECS_PER_DAY;
116  } else if (offset_hms < 0) {
117    offset_day--;
118    offset_hms += SECS_PER_DAY;
119  }
120
121  /* Convert date of time structure into a Julian day number. */
122
123  time_year = tm->tm_year + 1900;
124  time_month = tm->tm_mon + 1;
125  time_day = tm->tm_mday;
126
127  time_jd = date_to_julian(time_year, time_month, time_day);
128
129  /* Work out Julian day of new date */
130  time_jd += offset_day;
131
132  if (time_jd < 0)
133    return 0;
134
135  *pday = time_jd;
136  *psec = offset_hms;
137  return 1;
138}
139
140int OPENSSL_gmtime_adj(struct tm *tm, int off_day, long offset_sec) {
141  int time_sec, time_year, time_month, time_day;
142  long time_jd;
143
144  /* Convert time and offset into julian day and seconds */
145  if (!julian_adj(tm, off_day, offset_sec, &time_jd, &time_sec))
146    return 0;
147
148  /* Convert Julian day back to date */
149
150  julian_to_date(time_jd, &time_year, &time_month, &time_day);
151
152  if (time_year < 1900 || time_year > 9999)
153    return 0;
154
155  /* Update tm structure */
156
157  tm->tm_year = time_year - 1900;
158  tm->tm_mon = time_month - 1;
159  tm->tm_mday = time_day;
160
161  tm->tm_hour = time_sec / 3600;
162  tm->tm_min = (time_sec / 60) % 60;
163  tm->tm_sec = time_sec % 60;
164
165  return 1;
166}
167
168int OPENSSL_gmtime_diff(int *pday, int *psec, const struct tm *from,
169                        const struct tm *to) {
170  int from_sec, to_sec, diff_sec;
171  long from_jd, to_jd, diff_day;
172
173  if (!julian_adj(from, 0, 0, &from_jd, &from_sec)) {
174    return 0;
175  }
176  if (!julian_adj(to, 0, 0, &to_jd, &to_sec)) {
177    return 0;
178  }
179
180  diff_day = to_jd - from_jd;
181  diff_sec = to_sec - from_sec;
182  /* Adjust differences so both positive or both negative */
183  if (diff_day > 0 && diff_sec < 0) {
184    diff_day--;
185    diff_sec += SECS_PER_DAY;
186  }
187  if (diff_day < 0 && diff_sec > 0) {
188    diff_day++;
189    diff_sec -= SECS_PER_DAY;
190  }
191
192  if (pday) {
193    *pday = (int)diff_day;
194  }
195  if (psec) {
196    *psec = diff_sec;
197  }
198
199  return 1;
200}
201