text: /* crypto/o_time.c -*- mode:C; c-file-style: "eay" -*- */
  /* 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 <openssl/e_os2.h>
  #include <string.h>
  #include "o_time.h"
  
  #ifdef OPENSSL_SYS_VMS
  # if __CRTL_VER >= 70000000 && \
       (defined _POSIX_C_SOURCE || !defined _ANSI_C_SOURCE)
  #  define VMS_GMTIME_OK
  # endif
  # ifndef VMS_GMTIME_OK
  #  include <libdtdef.h>
  #  include <lib$routines.h>
  #  include <lnmdef.h>
  #  include <starlet.h>
  #  include <descrip.h>
  #  include <stdlib.h>
  # endif /* ndef VMS_GMTIME_OK */
  #endif
  
  struct tm *OPENSSL_gmtime(const time_t *timer, struct tm *result)
  	{
  	struct tm *ts = NULL;
  
  #if defined(OPENSSL_THREADS) && !defined(OPENSSL_SYS_WIN32) && !defined(OPENSSL_SYS_OS2) && (!defined(OPENSSL_SYS_VMS) || defined(gmtime_r)) && !defined(OPENSSL_SYS_MACOSX) && !defined(OPENSSL_SYS_SUNOS)
  	/* should return &data, but doesn't on some systems,
  	   so we don't even look at the return value */
  	gmtime_r(timer,result);
  	ts = result;
  #elif !defined(OPENSSL_SYS_VMS) || defined(VMS_GMTIME_OK)
  	ts = gmtime(timer);
  	if (ts == NULL)
  		return NULL;
  
  	memcpy(result, ts, sizeof(struct tm));
  	ts = result;
  #endif
  #if defined( OPENSSL_SYS_VMS) && !defined( VMS_GMTIME_OK)
  	if (ts == NULL)
  		{
  		static $DESCRIPTOR(tabnam,"LNM$DCL_LOGICAL");
  		static $DESCRIPTOR(lognam,"SYS$TIMEZONE_DIFFERENTIAL");
  		char logvalue[256];
  		unsigned int reslen = 0;
  		struct {
  			short buflen;
  			short code;
  			void *bufaddr;
  			unsigned int *reslen;
  		} itemlist[] = {
  			{ 0, LNM$_STRING, 0, 0 },
  			{ 0, 0, 0, 0 },
  		};
  		int status;
  		time_t t;
  
  		/* Get the value for SYS$TIMEZONE_DIFFERENTIAL */
  		itemlist[0].buflen = sizeof(logvalue);
  		itemlist[0].bufaddr = logvalue;
  		itemlist[0].reslen = &reslen;
  		status = sys$trnlnm(0, &tabnam, &lognam, 0, itemlist);
  		if (!(status & 1))
  			return NULL;
  		logvalue[reslen] = '\0';
  
  		t = *timer;
  
  /* The following is extracted from the DEC C header time.h */
  /*
  **  Beginning in OpenVMS Version 7.0 mktime, time, ctime, strftime
  **  have two implementations.  One implementation is provided
  **  for compatibility and deals with time in terms of local time,
  **  the other __utc_* deals with time in terms of UTC.
  */
  /* We use the same conditions as in said time.h to check if we should
     assume that t contains local time (and should therefore be adjusted)
     or UTC (and should therefore be left untouched). */
  #if __CRTL_VER < 70000000 || defined _VMS_V6_SOURCE
  		/* Get the numerical value of the equivalence string */
  		status = atoi(logvalue);
  
  		/* and use it to move time to GMT */
  		t -= status;
  #endif
  
  		/* then convert the result to the time structure */
  
  		/* Since there was no gmtime_r() to do this stuff for us,
  		   we have to do it the hard way. */
  		{
  		/* The VMS epoch is the astronomical Smithsonian date,
  		   if I remember correctly, which is November 17, 1858.
  		   Furthermore, time is measure in thenths of microseconds
  		   and stored in quadwords (64 bit integers).  unix_epoch
  		   below is January 1st 1970 expressed as a VMS time.  The
  		   following code was used to get this number:
  
  		   #include <stdio.h>
  		   #include <stdlib.h>
  		   #include <lib$routines.h>
  		   #include <starlet.h>
  
  		   main()
  		   {
  		     unsigned long systime[2];
  		     unsigned short epoch_values[7] =
  		       { 1970, 1, 1, 0, 0, 0, 0 };
  
  		     lib$cvt_vectim(epoch_values, systime);
  
  		     printf("%u %u", systime[0], systime[1]);
  		   }
  		*/
  		unsigned long unix_epoch[2] = { 1273708544, 8164711 };
  		unsigned long deltatime[2];
  		unsigned long systime[2];
  		struct vms_vectime
  			{
  			short year, month, day, hour, minute, second,
  				centi_second;
  			} time_values;
  		long operation;
  
  		/* Turn the number of seconds since January 1st 1970 to
  		   an internal delta time.
  		   Note that lib$cvt_to_internal_time() will assume
  		   that t is signed, and will therefore break on 32-bit
  		   systems some time in 2038.
  		*/
  		operation = LIB$K_DELTA_SECONDS;
  		status = lib$cvt_to_internal_time(&operation,
  			&t, deltatime);
  
  		/* Add the delta time with the Unix epoch and we have
  		   the current UTC time in internal format */
  		status = lib$add_times(unix_epoch, deltatime, systime);
  
  		/* Turn the internal time into a time vector */
  		status = sys$numtim(&time_values, systime);
  
  		/* Fill in the struct tm with the result */
  		result->tm_sec = time_values.second;
  		result->tm_min = time_values.minute;
  		result->tm_hour = time_values.hour;
  		result->tm_mday = time_values.day;
  		result->tm_mon = time_values.month - 1;
  		result->tm_year = time_values.year - 1900;
  
  		operation = LIB$K_DAY_OF_WEEK;
  		status = lib$cvt_from_internal_time(&operation,
  			&result->tm_wday, systime);
  		result->tm_wday %= 7;
  
  		operation = LIB$K_DAY_OF_YEAR;
  		status = lib$cvt_from_internal_time(&operation,
  			&result->tm_yday, systime);
  		result->tm_yday--;
  
  		result->tm_isdst = 0; /* There's no way to know... */
  
  		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, 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;
  
  	*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;
  	}
  
  #ifdef OPENSSL_TIME_TEST
  
  #include <stdio.h>
  
  /* Time checking test code. Check times are identical for a wide range of
   * offsets. This should be run on a machine with 64 bit time_t or it will
   * trigger the very errors the routines fix.
   */
  
  int main(int argc, char **argv)
  	{
  	long offset;
  	for (offset = 0; offset < 1000000; offset++)
  		{
  		check_time(offset);
  		check_time(-offset);
  		check_time(offset * 1000);
  		check_time(-offset * 1000);
  		}
  	}
  
  int check_time(long offset)
  	{
  	struct tm tm1, tm2, o1;
  	int off_day, off_sec;
  	long toffset;
  	time_t t1, t2;
  	time(&t1);
  	t2 = t1 + offset;
  	OPENSSL_gmtime(&t2, &tm2);
  	OPENSSL_gmtime(&t1, &tm1);
  	o1 = tm1;
  	OPENSSL_gmtime_adj(&tm1, 0, offset);
  	if ((tm1.tm_year != tm2.tm_year) ||
  	    (tm1.tm_mon != tm2.tm_mon) ||
  	    (tm1.tm_mday != tm2.tm_mday) ||
  	    (tm1.tm_hour != tm2.tm_hour) ||
  	    (tm1.tm_min != tm2.tm_min) ||
  	    (tm1.tm_sec != tm2.tm_sec))
  		{
  		fprintf(stderr, "TIME ERROR!!\n");
  		fprintf(stderr, "Time1: %d/%d/%d, %d:%02d:%02d\n",
  				tm2.tm_mday, tm2.tm_mon + 1, tm2.tm_year + 1900,
  				tm2.tm_hour, tm2.tm_min, tm2.tm_sec);
  		fprintf(stderr, "Time2: %d/%d/%d, %d:%02d:%02d\n",
  				tm1.tm_mday, tm1.tm_mon + 1, tm1.tm_year + 1900,
  				tm1.tm_hour, tm1.tm_min, tm1.tm_sec);
  		return 0;
  		}
  	OPENSSL_gmtime_diff(&o1, &tm1, &off_day, &off_sec);
  	toffset = (long)off_day * SECS_PER_DAY + off_sec;
  	if (offset != toffset)
  		{
  		fprintf(stderr, "TIME OFFSET ERROR!!\n");
  		fprintf(stderr, "Expected %ld, Got %ld (%d:%d)\n",
  					offset, toffset, off_day, off_sec);
  		return 0;
  		}
  	return 1;
  	}
  
  #endif
  