1 /* $NetBSD: timegm.c,v 1.1.1.1 2011/04/13 18:14:41 elric Exp $ */ 2 3 /* 4 * Copyright (c) 1997 Kungliga Tekniska Högskolan 5 * (Royal Institute of Technology, Stockholm, Sweden). 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * 3. Neither the name of the Institute nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include "der_locl.h" 37 38 __RCSID("$NetBSD: timegm.c,v 1.1.1.1 2011/04/13 18:14:41 elric Exp $"); 39 40 static int 41 is_leap(unsigned y) 42 { 43 y += 1900; 44 return (y % 4) == 0 && ((y % 100) != 0 || (y % 400) == 0); 45 } 46 47 static const unsigned ndays[2][12] ={ 48 {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}, 49 {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}}; 50 51 /* 52 * This is a simplifed version of timegm(3) that doesn't accept out of 53 * bound values that timegm(3) normally accepts but those are not 54 * valid in asn1 encodings. 55 */ 56 57 time_t 58 _der_timegm (struct tm *tm) 59 { 60 time_t res = 0; 61 unsigned i; 62 63 if (tm->tm_year < 0) 64 return -1; 65 if (tm->tm_mon < 0 || tm->tm_mon > 11) 66 return -1; 67 if (tm->tm_mday < 1 || tm->tm_mday > ndays[is_leap(tm->tm_year)][tm->tm_mon]) 68 return -1; 69 if (tm->tm_hour < 0 || tm->tm_hour > 23) 70 return -1; 71 if (tm->tm_min < 0 || tm->tm_min > 59) 72 return -1; 73 if (tm->tm_sec < 0 || tm->tm_sec > 59) 74 return -1; 75 76 for (i = 70; i < tm->tm_year; ++i) 77 res += is_leap(i) ? 366 : 365; 78 79 for (i = 0; i < tm->tm_mon; ++i) 80 res += ndays[is_leap(tm->tm_year)][i]; 81 res += tm->tm_mday - 1; 82 res *= 24; 83 res += tm->tm_hour; 84 res *= 60; 85 res += tm->tm_min; 86 res *= 60; 87 res += tm->tm_sec; 88 return res; 89 } 90 91 struct tm * 92 _der_gmtime(time_t t, struct tm *tm) 93 { 94 time_t secday = t % (3600 * 24); 95 time_t days = t / (3600 * 24); 96 97 memset(tm, 0, sizeof(*tm)); 98 99 tm->tm_sec = secday % 60; 100 tm->tm_min = (secday % 3600) / 60; 101 tm->tm_hour = secday / 3600; 102 103 tm->tm_year = 70; 104 while(1) { 105 unsigned dayinyear = (is_leap(tm->tm_year) ? 366 : 365); 106 if (days < dayinyear) 107 break; 108 tm->tm_year += 1; 109 days -= dayinyear; 110 } 111 tm->tm_mon = 0; 112 113 while (1) { 114 unsigned daysinmonth = ndays[is_leap(tm->tm_year)][tm->tm_mon]; 115 if (days < daysinmonth) 116 break; 117 days -= daysinmonth; 118 tm->tm_mon++; 119 } 120 tm->tm_mday = days + 1; 121 122 return tm; 123 } 124