der/asn1/
teletex_string.rs

1//! ASN.1 `TeletexString` support.
2
3use crate::{
4    asn1::AnyRef, ord::OrdIsValueOrd, ByteSlice, DecodeValue, EncodeValue, Error, FixedTag, Header,
5    Length, Reader, Result, StrSlice, Tag, Writer,
6};
7use core::{fmt, ops::Deref, str};
8
9/// ASN.1 `TeletexString` type.
10///
11/// Supports a subset the ASCII character set (described below).
12///
13/// For UTF-8, use [`Utf8StringRef`][`crate::asn1::Utf8StringRef`] instead.
14/// For the full ASCII character set, use
15/// [`Ia5StringRef`][`crate::asn1::Ia5StringRef`].
16///
17/// This is a zero-copy reference type which borrows from the input data.
18///
19/// # Supported characters
20///
21/// The standard defines a complex character set allowed in this type. However, quoting the ASN.1
22/// mailing list, "a sizable volume of software in the world treats TeletexString (T61String) as a
23/// simple 8-bit string with mostly Windows Latin 1 (superset of iso-8859-1) encoding".
24///
25#[derive(Copy, Clone, Eq, PartialEq, PartialOrd, Ord)]
26pub struct TeletexStringRef<'a> {
27    /// Inner value
28    inner: StrSlice<'a>,
29}
30
31impl<'a> TeletexStringRef<'a> {
32    /// Create a new ASN.1 `TeletexString`.
33    pub fn new<T>(input: &'a T) -> Result<Self>
34    where
35        T: AsRef<[u8]> + ?Sized,
36    {
37        let input = input.as_ref();
38
39        // FIXME: support higher part of the charset
40        if input.iter().any(|&c| c > 0x7F) {
41            return Err(Self::TAG.value_error());
42        }
43
44        StrSlice::from_bytes(input)
45            .map(|inner| Self { inner })
46            .map_err(|_| Self::TAG.value_error())
47    }
48}
49
50impl<'a> Deref for TeletexStringRef<'a> {
51    type Target = StrSlice<'a>;
52
53    fn deref(&self) -> &Self::Target {
54        &self.inner
55    }
56}
57
58impl AsRef<str> for TeletexStringRef<'_> {
59    fn as_ref(&self) -> &str {
60        self.as_str()
61    }
62}
63
64impl AsRef<[u8]> for TeletexStringRef<'_> {
65    fn as_ref(&self) -> &[u8] {
66        self.as_bytes()
67    }
68}
69
70impl<'a> DecodeValue<'a> for TeletexStringRef<'a> {
71    fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> Result<Self> {
72        Self::new(ByteSlice::decode_value(reader, header)?.as_slice())
73    }
74}
75
76impl<'a> EncodeValue for TeletexStringRef<'a> {
77    fn value_len(&self) -> Result<Length> {
78        self.inner.value_len()
79    }
80
81    fn encode_value(&self, writer: &mut dyn Writer) -> Result<()> {
82        self.inner.encode_value(writer)
83    }
84}
85
86impl FixedTag for TeletexStringRef<'_> {
87    const TAG: Tag = Tag::TeletexString;
88}
89
90impl OrdIsValueOrd for TeletexStringRef<'_> {}
91
92impl<'a> From<&TeletexStringRef<'a>> for TeletexStringRef<'a> {
93    fn from(value: &TeletexStringRef<'a>) -> TeletexStringRef<'a> {
94        *value
95    }
96}
97
98impl<'a> TryFrom<AnyRef<'a>> for TeletexStringRef<'a> {
99    type Error = Error;
100
101    fn try_from(any: AnyRef<'a>) -> Result<TeletexStringRef<'a>> {
102        any.decode_into()
103    }
104}
105
106impl<'a> From<TeletexStringRef<'a>> for AnyRef<'a> {
107    fn from(teletex_string: TeletexStringRef<'a>) -> AnyRef<'a> {
108        AnyRef::from_tag_and_value(Tag::TeletexString, teletex_string.inner.into())
109    }
110}
111
112impl<'a> fmt::Display for TeletexStringRef<'a> {
113    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
114        f.write_str(self.as_str())
115    }
116}
117
118impl<'a> fmt::Debug for TeletexStringRef<'a> {
119    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
120        write!(f, "TeletexString({:?})", self.as_str())
121    }
122}
123
124#[cfg(test)]
125mod tests {
126    use super::TeletexStringRef;
127    use crate::Decode;
128    use crate::SliceWriter;
129
130    #[test]
131    fn parse_bytes() {
132        let example_bytes = &[
133            0x14, 0x0b, 0x54, 0x65, 0x73, 0x74, 0x20, 0x55, 0x73, 0x65, 0x72, 0x20, 0x31,
134        ];
135
136        let teletex_string = TeletexStringRef::from_der(example_bytes).unwrap();
137        assert_eq!(teletex_string.as_str(), "Test User 1");
138        let mut out = [0_u8; 30];
139        let mut writer = SliceWriter::new(&mut out);
140        writer.encode(&teletex_string).unwrap();
141        let encoded = writer.finish().unwrap();
142        assert_eq!(encoded, example_bytes);
143    }
144}
der/asn1/teletex_string.rs

der/asn1/
teletex_string.rs
