/* $OpenBSD: o_time.c,v 1.16 2021/10/27 09:50:56 beck Exp $ */ /* Written by Richard Levitte (richard@levitte.org) for the OpenSSL * project 2001. */ /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL * project 2008. */ /* ==================================================================== * Copyright (c) 2001 The OpenSSL Project. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. All advertising materials mentioning features or use of this * software must display the following acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" * * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to * endorse or promote products derived from this software without * prior written permission. For written permission, please contact * licensing@OpenSSL.org. * * 5. Products derived from this software may not be called "OpenSSL" * nor may "OpenSSL" appear in their names without prior written * permission of the OpenSSL Project. * * 6. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" * * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED * OF THE POSSIBILITY OF SUCH DAMAGE. * ==================================================================== * * This product includes cryptographic software written by Eric Young * (eay@cryptsoft.com). This product includes software written by Tim * Hudson (tjh@cryptsoft.com). * */ #include <string.h> #include "o_time.h" /* 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 offset_hms, offset_day; long 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; /* 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 = offset_hms / 3600; tm->tm_min = (offset_hms / 60) % 60; tm->tm_sec = offset_hms % 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 time_year, time_month, time_day; long offset_day, time_jd; int offset_hms; /* 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; }
