openssl/crypto/o_time.c

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C
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2023-05-09 22:08:48 +00:00
/*
* Copyright 2001-2021 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <openssl/e_os2.h>
#include <string.h>
#include <openssl/crypto.h>
struct tm *OPENSSL_gmtime(const time_t *timer, struct tm *result)
{
struct tm *ts = NULL;
#if defined(OPENSSL_THREADS) && defined(OPENSSL_SYS_VMS)
{
/*
* On VMS, gmtime_r() takes a 32-bit pointer as second argument.
* Since we can't know that |result| is in a space that can easily
* translate to a 32-bit pointer, we must store temporarily on stack
* and copy the result. The stack is always reachable with 32-bit
* pointers.
*/
#if defined(OPENSSL_SYS_VMS) && __INITIAL_POINTER_SIZE
# pragma pointer_size save
# pragma pointer_size 32
#endif
struct tm data, *ts2 = &data;
#if defined OPENSSL_SYS_VMS && __INITIAL_POINTER_SIZE
# pragma pointer_size restore
#endif
if (gmtime_r(timer, ts2) == NULL)
return NULL;
memcpy(result, ts2, sizeof(struct tm));
ts = result;
}
#elif defined(OPENSSL_THREADS) && !defined(OPENSSL_SYS_WIN32) && !defined(OPENSSL_SYS_MACOSX)
if (gmtime_r(timer, result) == NULL)
return NULL;
ts = result;
#elif defined (OPENSSL_SYS_WINDOWS) && defined(_MSC_VER) && _MSC_VER >= 1400 && !defined(_WIN32_WCE)
if (gmtime_s(result, timer))
return NULL;
ts = result;
#else
ts = gmtime(timer);
if (ts == NULL)
return NULL;
memcpy(result, ts, sizeof(struct tm));
ts = result;
#endif
return ts;
}
/*
* Take a tm structure and add an offset to it. This avoids any OS issues
* with restricted date types and overflows which cause the year 2038
* problem.
*/
#define SECS_PER_DAY (24 * 60 * 60)
static long date_to_julian(int y, int m, int d);
static void julian_to_date(long jd, int *y, int *m, int *d);
static int julian_adj(const struct tm *tm, int off_day, long offset_sec,
long *pday, int *psec);
int OPENSSL_gmtime_adj(struct tm *tm, int off_day, long offset_sec)
{
int time_sec, time_year, time_month, time_day;
long time_jd;
/* Convert time and offset into Julian day and seconds */
if (!julian_adj(tm, off_day, offset_sec, &time_jd, &time_sec))
return 0;
/* Convert Julian day back to date */
julian_to_date(time_jd, &time_year, &time_month, &time_day);
if (time_year < 1900 || time_year > 9999)
return 0;
/* Update tm structure */
tm->tm_year = time_year - 1900;
tm->tm_mon = time_month - 1;
tm->tm_mday = time_day;
tm->tm_hour = time_sec / 3600;
tm->tm_min = (time_sec / 60) % 60;
tm->tm_sec = time_sec % 60;
return 1;
}
int OPENSSL_gmtime_diff(int *pday, int *psec,
const struct tm *from, const struct tm *to)
{
int from_sec, to_sec, diff_sec;
long from_jd, to_jd, diff_day;
if (!julian_adj(from, 0, 0, &from_jd, &from_sec))
return 0;
if (!julian_adj(to, 0, 0, &to_jd, &to_sec))
return 0;
diff_day = to_jd - from_jd;
diff_sec = to_sec - from_sec;
/* Adjust differences so both positive or both negative */
if (diff_day > 0 && diff_sec < 0) {
diff_day--;
diff_sec += SECS_PER_DAY;
}
if (diff_day < 0 && diff_sec > 0) {
diff_day++;
diff_sec -= SECS_PER_DAY;
}
if (pday)
*pday = (int)diff_day;
if (psec)
*psec = diff_sec;
return 1;
}
/* Convert tm structure and offset into julian day and seconds */
static int julian_adj(const struct tm *tm, int off_day, long offset_sec,
long *pday, int *psec)
{
int offset_hms;
long offset_day, time_jd;
int time_year, time_month, time_day;
/* split offset into days and day seconds */
offset_day = offset_sec / SECS_PER_DAY;
/* Avoid sign issues with % operator */
offset_hms = offset_sec - (offset_day * SECS_PER_DAY);
offset_day += off_day;
/* Add current time seconds to offset */
offset_hms += tm->tm_hour * 3600 + tm->tm_min * 60 + tm->tm_sec;
/* Adjust day seconds if overflow */
if (offset_hms >= SECS_PER_DAY) {
offset_day++;
offset_hms -= SECS_PER_DAY;
} else if (offset_hms < 0) {
offset_day--;
offset_hms += SECS_PER_DAY;
}
/*
* Convert date of time structure into a Julian day number.
*/
time_year = tm->tm_year + 1900;
time_month = tm->tm_mon + 1;
time_day = tm->tm_mday;
time_jd = date_to_julian(time_year, time_month, time_day);
/* Work out Julian day of new date */
time_jd += offset_day;
if (time_jd < 0)
return 0;
*pday = time_jd;
*psec = offset_hms;
return 1;
}
/*
* Convert date to and from julian day Uses Fliegel & Van Flandern algorithm
*/
static long date_to_julian(int y, int m, int d)
{
return (1461 * (y + 4800 + (m - 14) / 12)) / 4 +
(367 * (m - 2 - 12 * ((m - 14) / 12))) / 12 -
(3 * ((y + 4900 + (m - 14) / 12) / 100)) / 4 + d - 32075;
}
static void julian_to_date(long jd, int *y, int *m, int *d)
{
long L = jd + 68569;
long n = (4 * L) / 146097;
long i, j;
L = L - (146097 * n + 3) / 4;
i = (4000 * (L + 1)) / 1461001;
L = L - (1461 * i) / 4 + 31;
j = (80 * L) / 2447;
*d = L - (2447 * j) / 80;
L = j / 11;
*m = j + 2 - (12 * L);
*y = 100 * (n - 49) + i + L;
}