1 // Copyright 2015-2016 Brian Smith.
2 //
3 // Permission to use, copy, modify, and/or distribute this software for any
4 // purpose with or without fee is hereby granted, provided that the above
5 // copyright notice and this permission notice appear in all copies.
6 //
7 // THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
8 // WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9 // MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
10 // ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11 // WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
12 // ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
13 // OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
14 
15 use super::{time::Time, Error};
16 
time_from_ymdhms_utc( year: u64, month: u64, day_of_month: u64, hours: u64, minutes: u64, seconds: u64, ) -> Result<Time, Error>17 pub fn time_from_ymdhms_utc(
18     year: u64, month: u64, day_of_month: u64, hours: u64, minutes: u64, seconds: u64,
19 ) -> Result<Time, Error> {
20     let days_before_year_since_unix_epoch = days_before_year_since_unix_epoch(year)?;
21 
22     const JAN: u64 = 31;
23     let feb = days_in_feb(year);
24     const MAR: u64 = 31;
25     const APR: u64 = 30;
26     const MAY: u64 = 31;
27     const JUN: u64 = 30;
28     const JUL: u64 = 31;
29     const AUG: u64 = 31;
30     const SEP: u64 = 30;
31     const OCT: u64 = 31;
32     const NOV: u64 = 30;
33     let days_before_month_in_year = match month {
34         1 => 0,
35         2 => JAN,
36         3 => JAN + feb,
37         4 => JAN + feb + MAR,
38         5 => JAN + feb + MAR + APR,
39         6 => JAN + feb + MAR + APR + MAY,
40         7 => JAN + feb + MAR + APR + MAY + JUN,
41         8 => JAN + feb + MAR + APR + MAY + JUN + JUL,
42         9 => JAN + feb + MAR + APR + MAY + JUN + JUL + AUG,
43         10 => JAN + feb + MAR + APR + MAY + JUN + JUL + AUG + SEP,
44         11 => JAN + feb + MAR + APR + MAY + JUN + JUL + AUG + SEP + OCT,
45         12 => JAN + feb + MAR + APR + MAY + JUN + JUL + AUG + SEP + OCT + NOV,
46         _ => unreachable!(), // `read_two_digits` already bounds-checked it.
47     };
48 
49     let days_before =
50         days_before_year_since_unix_epoch + days_before_month_in_year + day_of_month - 1;
51 
52     let seconds_since_unix_epoch =
53         (days_before * 24 * 60 * 60) + (hours * 60 * 60) + (minutes * 60) + seconds;
54 
55     Ok(Time::from_seconds_since_unix_epoch(
56         seconds_since_unix_epoch,
57     ))
58 }
59 
days_before_year_since_unix_epoch(year: u64) -> Result<u64, Error>60 fn days_before_year_since_unix_epoch(year: u64) -> Result<u64, Error> {
61     // We don't support dates before January 1, 1970 because that is the
62     // Unix epoch. It is likely that other software won't deal well with
63     // certificates that have dates before the epoch.
64     if year < 1970 {
65         return Err(Error::BadDERTime);
66     }
67     let days_before_year_ad = days_before_year_ad(year);
68     debug_assert!(days_before_year_ad >= DAYS_BEFORE_UNIX_EPOCH_AD);
69     Ok(days_before_year_ad - DAYS_BEFORE_UNIX_EPOCH_AD)
70 }
71 
days_before_year_ad(year: u64) -> u6472 fn days_before_year_ad(year: u64) -> u64 {
73     ((year - 1) * 365)
74         + ((year - 1) / 4)    // leap years are every 4 years,
75         - ((year - 1) / 100)  // except years divisible by 100,
76         + ((year - 1) / 400) // except years divisible by 400.
77 }
78 
days_in_month(year: u64, month: u64) -> u6479 pub fn days_in_month(year: u64, month: u64) -> u64 {
80     match month {
81         1 | 3 | 5 | 7 | 8 | 10 | 12 => 31,
82         4 | 6 | 9 | 11 => 30,
83         2 => days_in_feb(year),
84         _ => unreachable!(), // `read_two_digits` already bounds-checked it.
85     }
86 }
87 
days_in_feb(year: u64) -> u6488 fn days_in_feb(year: u64) -> u64 {
89     if (year % 4 == 0) && ((year % 100 != 0) || (year % 400 == 0)) {
90         29
91     } else {
92         28
93     }
94 }
95 
96 const DAYS_BEFORE_UNIX_EPOCH_AD: u64 = 719162;
97 
98 #[cfg(test)]
99 mod tests {
100     #[test]
test_days_before_unix_epoch()101     fn test_days_before_unix_epoch() {
102         use super::{days_before_year_ad, DAYS_BEFORE_UNIX_EPOCH_AD};
103         assert_eq!(DAYS_BEFORE_UNIX_EPOCH_AD, days_before_year_ad(1970));
104     }
105 
106     #[test]
test_days_in_month()107     fn test_days_in_month() {
108         use super::days_in_month;
109         assert_eq!(days_in_month(2017, 1), 31);
110         assert_eq!(days_in_month(2017, 2), 28);
111         assert_eq!(days_in_month(2017, 3), 31);
112         assert_eq!(days_in_month(2017, 4), 30);
113         assert_eq!(days_in_month(2017, 5), 31);
114         assert_eq!(days_in_month(2017, 6), 30);
115         assert_eq!(days_in_month(2017, 7), 31);
116         assert_eq!(days_in_month(2017, 8), 31);
117         assert_eq!(days_in_month(2017, 9), 30);
118         assert_eq!(days_in_month(2017, 10), 31);
119         assert_eq!(days_in_month(2017, 11), 30);
120         assert_eq!(days_in_month(2017, 12), 31);
121 
122         // leap cases
123         assert_eq!(days_in_month(2000, 2), 29);
124         assert_eq!(days_in_month(2004, 2), 29);
125         assert_eq!(days_in_month(2016, 2), 29);
126         assert_eq!(days_in_month(2100, 2), 28);
127     }
128 
129     #[test]
test_time_from_ymdhms_utc()130     fn test_time_from_ymdhms_utc() {
131         use super::{time_from_ymdhms_utc, Time};
132 
133         // year boundary
134         assert_eq!(
135             Time::from_seconds_since_unix_epoch(1483228799),
136             time_from_ymdhms_utc(2016, 12, 31, 23, 59, 59).unwrap()
137         );
138         assert_eq!(
139             Time::from_seconds_since_unix_epoch(1483228800),
140             time_from_ymdhms_utc(2017, 1, 1, 0, 0, 0).unwrap()
141         );
142 
143         // not a leap year
144         assert_eq!(
145             Time::from_seconds_since_unix_epoch(1492449162),
146             time_from_ymdhms_utc(2017, 4, 17, 17, 12, 42).unwrap()
147         );
148 
149         // leap year, post-feb
150         assert_eq!(
151             Time::from_seconds_since_unix_epoch(1460913162),
152             time_from_ymdhms_utc(2016, 4, 17, 17, 12, 42).unwrap()
153         );
154     }
155 }
156