x509_parser/
time.rs

1use asn1_rs::nom::Err;
2use asn1_rs::{Error, FromDer, GeneralizedTime, Header, ParseResult, UtcTime};
3use der_parser::ber::{Tag, MAX_OBJECT_SIZE};
4use std::fmt;
5use std::ops::{Add, Sub};
6use time::macros::format_description;
7use time::{Duration, OffsetDateTime};
8
9use crate::error::{X509Error, X509Result};
10
11/// An ASN.1 timestamp.
12#[derive(Copy, Clone, Debug, Hash, Ord, PartialOrd, Eq, PartialEq)]
13pub struct ASN1Time(OffsetDateTime);
14
15impl ASN1Time {
16    pub(crate) fn from_der_opt(i: &[u8]) -> X509Result<Option<Self>> {
17        if i.is_empty() {
18            return Ok((i, None));
19        }
20        match parse_choice_of_time(i) {
21            Ok((rem, dt)) => Ok((rem, Some(ASN1Time(dt)))),
22            Err(Err::Error(Error::InvalidTag)) | Err(Err::Error(Error::UnexpectedTag { .. })) => {
23                Ok((i, None))
24            }
25            Err(_) => Err(Err::Error(X509Error::InvalidDate)),
26        }
27    }
28
29    #[inline]
30    pub const fn new(dt: OffsetDateTime) -> Self {
31        Self(dt)
32    }
33
34    #[inline]
35    pub const fn to_datetime(&self) -> OffsetDateTime {
36        self.0
37    }
38
39    /// Makes a new `ASN1Time` from the number of non-leap seconds since Epoch
40    pub fn from_timestamp(secs: i64) -> Result<Self, X509Error> {
41        let dt = OffsetDateTime::from_unix_timestamp(secs).map_err(|_| X509Error::InvalidDate)?;
42        Ok(ASN1Time(dt))
43    }
44
45    /// Returns the number of non-leap seconds since January 1, 1970 0:00:00 UTC (aka "UNIX timestamp").
46    #[inline]
47    pub fn timestamp(&self) -> i64 {
48        self.0.unix_timestamp()
49    }
50
51    /// Returns a `ASN1Time` which corresponds to the current date.
52    #[inline]
53    pub fn now() -> Self {
54        ASN1Time(OffsetDateTime::now_utc())
55    }
56
57    /// Returns an RFC 2822 date and time string such as `Tue, 1 Jul 2003 10:52:37 +0200`.
58    ///
59    /// Conversion to RFC2822 date can fail if date cannot be represented in this format,
60    /// for example if year < 1900.
61    ///
62    /// For an infallible conversion to string, use `.to_string()`.
63    #[inline]
64    pub fn to_rfc2822(self) -> Result<String, String> {
65        self.0
66            .format(&time::format_description::well_known::Rfc2822)
67            .map_err(|e| e.to_string())
68    }
69}
70
71impl<'a> FromDer<'a, X509Error> for ASN1Time {
72    fn from_der(i: &[u8]) -> X509Result<Self> {
73        let (rem, dt) = parse_choice_of_time(i).map_err(|_| X509Error::InvalidDate)?;
74        Ok((rem, ASN1Time(dt)))
75    }
76}
77
78pub(crate) fn parse_choice_of_time(i: &[u8]) -> ParseResult<OffsetDateTime> {
79    if let Ok((rem, t)) = UtcTime::from_der(i) {
80        let dt = t.utc_adjusted_datetime()?;
81        return Ok((rem, dt));
82    }
83    if let Ok((rem, t)) = GeneralizedTime::from_der(i) {
84        let dt = t.utc_datetime()?;
85        return Ok((rem, dt));
86    }
87    parse_malformed_date(i)
88}
89
90// allow relaxed parsing of UTCTime (ex: 370116130016+0000)
91fn parse_malformed_date(i: &[u8]) -> ParseResult<OffsetDateTime> {
92    #[allow(clippy::trivially_copy_pass_by_ref)]
93    // fn check_char(b: &u8) -> bool {
94    //     (0x20 <= *b && *b <= 0x7f) || (*b == b'+')
95    // }
96    let (_rem, hdr) = Header::from_der(i)?;
97    let len = hdr.length().definite()?;
98    if len > MAX_OBJECT_SIZE {
99        return Err(nom::Err::Error(Error::InvalidLength));
100    }
101    match hdr.tag() {
102        Tag::UtcTime => {
103            // // if we are in this function, the PrintableString could not be validated.
104            // // Accept it without validating charset, because some tools do not respect the charset
105            // // restrictions (for ex. they use '*' while explicingly disallowed)
106            // let (rem, data) = take(len as usize)(rem)?;
107            // if !data.iter().all(check_char) {
108            //     return Err(nom::Err::Error(BerError::BerValueError));
109            // }
110            // let s = std::str::from_utf8(data).map_err(|_| BerError::BerValueError)?;
111            // let content = BerObjectContent::UTCTime(s);
112            // let obj = DerObject::from_header_and_content(hdr, content);
113            // Ok((rem, obj))
114            Err(nom::Err::Error(Error::BerValueError))
115        }
116        _ => Err(nom::Err::Error(Error::unexpected_tag(None, hdr.tag()))),
117    }
118}
119
120impl fmt::Display for ASN1Time {
121    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
122        let format = format_description!("[month repr:short] [day padding:space] [hour]:[minute]:[second] [year padding:none] [offset_hour sign:mandatory]:[offset_minute]");
123        let s = self
124            .0
125            .format(format)
126            .unwrap_or_else(|e| format!("Invalid date: {}", e));
127        f.write_str(&s)
128    }
129}
130
131impl Add<Duration> for ASN1Time {
132    type Output = Option<ASN1Time>;
133
134    #[inline]
135    fn add(self, rhs: Duration) -> Option<ASN1Time> {
136        Some(ASN1Time(self.0 + rhs))
137    }
138}
139
140impl Sub<ASN1Time> for ASN1Time {
141    type Output = Option<Duration>;
142
143    #[inline]
144    fn sub(self, rhs: ASN1Time) -> Option<Duration> {
145        if self.0 > rhs.0 {
146            Some(self.0 - rhs.0)
147        } else {
148            None
149        }
150    }
151}
152
153impl From<OffsetDateTime> for ASN1Time {
154    fn from(dt: OffsetDateTime) -> Self {
155        ASN1Time(dt)
156    }
157}
158
159#[cfg(test)]
160mod tests {
161    use time::macros::datetime;
162
163    use super::ASN1Time;
164
165    #[test]
166    fn test_time_to_string() {
167        let d = datetime!(1 - 1 - 1 12:34:56 UTC);
168        let t = ASN1Time::from(d);
169        assert_eq!(t.to_string(), "Jan  1 12:34:56 1 +00:00".to_string());
170    }
171
172    #[test]
173    fn test_nonrfc2822_date() {
174        // test year < 1900
175        let d = datetime!(1 - 1 - 1 00:00:00 UTC);
176        let t = ASN1Time::from(d);
177        assert!(t.to_rfc2822().is_err());
178    }
179}
x509_parser/time.rs

x509_parser/
time.rs
