1/* $OpenBSD: a_time_tm.c,v 1.16 2020/12/16 18:35:59 tb Exp $ */ 2/* 3 * Copyright (c) 2015 Bob Beck <beck@openbsd.org> 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18#include "includes.h" 19 20#include <ctype.h> 21#include <limits.h> 22#include <stdio.h> 23#include <string.h> 24#include <time.h> 25 26#define GENTIME_LENGTH 15 27#define UTCTIME_LENGTH 13 28 29#define V_ASN1_UTCTIME 23 30#define V_ASN1_GENERALIZEDTIME 24 31 32int 33ASN1_time_tm_cmp(struct tm *tm1, struct tm *tm2) 34{ 35 if (tm1->tm_year < tm2->tm_year) 36 return (-1); 37 if (tm1->tm_year > tm2->tm_year) 38 return (1); 39 if (tm1->tm_mon < tm2->tm_mon) 40 return (-1); 41 if (tm1->tm_mon > tm2->tm_mon) 42 return (1); 43 if (tm1->tm_mday < tm2->tm_mday) 44 return (-1); 45 if (tm1->tm_mday > tm2->tm_mday) 46 return (1); 47 if (tm1->tm_hour < tm2->tm_hour) 48 return (-1); 49 if (tm1->tm_hour > tm2->tm_hour) 50 return (1); 51 if (tm1->tm_min < tm2->tm_min) 52 return (-1); 53 if (tm1->tm_min > tm2->tm_min) 54 return (1); 55 if (tm1->tm_sec < tm2->tm_sec) 56 return (-1); 57 if (tm1->tm_sec > tm2->tm_sec) 58 return (1); 59 return 0; 60} 61 62int 63ASN1_time_tm_clamp_notafter(struct tm *tm) 64{ 65#ifdef SMALL_TIME_T 66 struct tm broken_os_epoch_tm; 67 time_t broken_os_epoch_time = INT_MAX; 68 69 if (gmtime_r(&broken_os_epoch_time, &broken_os_epoch_tm) == NULL) 70 return 0; 71 72 if (ASN1_time_tm_cmp(tm, &broken_os_epoch_tm) == 1) 73 memcpy(tm, &broken_os_epoch_tm, sizeof(*tm)); 74#endif 75 return 1; 76} 77 78/* 79 * Parse an RFC 5280 format ASN.1 time string. 80 * 81 * mode must be: 82 * 0 if we expect to parse a time as specified in RFC 5280 for an X509 object. 83 * V_ASN1_UTCTIME if we wish to parse an RFC5280 format UTC time. 84 * V_ASN1_GENERALIZEDTIME if we wish to parse an RFC5280 format Generalized time. 85 * 86 * Returns: 87 * -1 if the string was invalid. 88 * V_ASN1_UTCTIME if the string validated as a UTC time string. 89 * V_ASN1_GENERALIZEDTIME if the string validated as a Generalized time string. 90 * 91 * Fills in *tm with the corresponding time if tm is non NULL. 92 */ 93#define ATOI2(ar) ((ar) += 2, ((ar)[-2] - '0') * 10 + ((ar)[-1] - '0')) 94int 95ASN1_time_parse(const char *bytes, size_t len, struct tm *tm, int mode) 96{ 97 size_t i; 98 int type = 0; 99 struct tm ltm; 100 struct tm *lt; 101 const char *p; 102 103 if (bytes == NULL) 104 return (-1); 105 106 /* Constrain to valid lengths. */ 107 if (len != UTCTIME_LENGTH && len != GENTIME_LENGTH) 108 return (-1); 109 110 lt = tm; 111 if (lt == NULL) 112 lt = <m; 113 memset(lt, 0, sizeof(*lt)); 114 115 /* Timezone is required and must be GMT (Zulu). */ 116 if (bytes[len - 1] != 'Z') 117 return (-1); 118 119 /* Make sure everything else is digits. */ 120 for (i = 0; i < len - 1; i++) { 121 if (isdigit((unsigned char)bytes[i])) 122 continue; 123 return (-1); 124 } 125 126 /* 127 * Validate and convert the time 128 */ 129 p = bytes; 130 switch (len) { 131 case GENTIME_LENGTH: 132 if (mode == V_ASN1_UTCTIME) 133 return (-1); 134 lt->tm_year = (ATOI2(p) * 100) - 1900; /* cc */ 135 type = V_ASN1_GENERALIZEDTIME; 136 /* FALLTHROUGH */ 137 case UTCTIME_LENGTH: 138 if (type == 0) { 139 if (mode == V_ASN1_GENERALIZEDTIME) 140 return (-1); 141 type = V_ASN1_UTCTIME; 142 } 143 lt->tm_year += ATOI2(p); /* yy */ 144 if (type == V_ASN1_UTCTIME) { 145 if (lt->tm_year < 50) 146 lt->tm_year += 100; 147 } 148 lt->tm_mon = ATOI2(p) - 1; /* mm */ 149 if (lt->tm_mon < 0 || lt->tm_mon > 11) 150 return (-1); 151 lt->tm_mday = ATOI2(p); /* dd */ 152 if (lt->tm_mday < 1 || lt->tm_mday > 31) 153 return (-1); 154 lt->tm_hour = ATOI2(p); /* HH */ 155 if (lt->tm_hour < 0 || lt->tm_hour > 23) 156 return (-1); 157 lt->tm_min = ATOI2(p); /* MM */ 158 if (lt->tm_min < 0 || lt->tm_min > 59) 159 return (-1); 160 lt->tm_sec = ATOI2(p); /* SS */ 161 /* Leap second 60 is not accepted. Reconsider later? */ 162 if (lt->tm_sec < 0 || lt->tm_sec > 59) 163 return (-1); 164 break; 165 default: 166 return (-1); 167 } 168 169 return (type); 170}