der/asn1/
utf8_string.rs

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1//! ASN.1 `UTF8String` support.
2
3use crate::{
4    asn1::AnyRef, ord::OrdIsValueOrd, EncodeValue, Error, FixedTag, Length, Result, StrRef, Tag,
5    Writer,
6};
7use core::{fmt, ops::Deref, str};
8
9#[cfg(feature = "alloc")]
10use {
11    crate::{DecodeValue, Header, Reader},
12    alloc::{borrow::ToOwned, string::String},
13};
14
15/// ASN.1 `UTF8String` type.
16///
17/// Supports the full UTF-8 encoding.
18///
19/// Note that the [`Decode`][`crate::Decode`] and [`Encode`][`crate::Encode`]
20/// traits are impl'd for Rust's [`str`][`prim@str`] primitive, which
21/// decodes/encodes as a [`Utf8StringRef`].
22///
23/// You are free to use [`str`][`prim@str`] instead of this type, however it's
24/// still provided for explicitness in cases where it might be ambiguous with
25/// other ASN.1 string encodings such as
26/// [`PrintableStringRef`][`crate::asn1::PrintableStringRef`].
27///
28/// This is a zero-copy reference type which borrows from the input data.
29#[derive(Copy, Clone, Eq, PartialEq, PartialOrd, Ord)]
30pub struct Utf8StringRef<'a> {
31    /// Inner value
32    inner: StrRef<'a>,
33}
34
35impl<'a> Utf8StringRef<'a> {
36    /// Create a new ASN.1 `UTF8String`.
37    pub fn new<T>(input: &'a T) -> Result<Self>
38    where
39        T: AsRef<[u8]> + ?Sized,
40    {
41        StrRef::from_bytes(input.as_ref()).map(|inner| Self { inner })
42    }
43}
44
45impl_string_type!(Utf8StringRef<'a>, 'a);
46
47impl<'a> Deref for Utf8StringRef<'a> {
48    type Target = StrRef<'a>;
49
50    fn deref(&self) -> &Self::Target {
51        &self.inner
52    }
53}
54
55impl FixedTag for Utf8StringRef<'_> {
56    const TAG: Tag = Tag::Utf8String;
57}
58
59impl<'a> From<&Utf8StringRef<'a>> for Utf8StringRef<'a> {
60    fn from(value: &Utf8StringRef<'a>) -> Utf8StringRef<'a> {
61        *value
62    }
63}
64
65impl<'a> From<Utf8StringRef<'a>> for AnyRef<'a> {
66    fn from(utf_string: Utf8StringRef<'a>) -> AnyRef<'a> {
67        AnyRef::from_tag_and_value(Tag::Utf8String, utf_string.inner.into())
68    }
69}
70
71impl<'a> fmt::Debug for Utf8StringRef<'a> {
72    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
73        write!(f, "Utf8String({:?})", self.as_str())
74    }
75}
76
77impl<'a> TryFrom<AnyRef<'a>> for &'a str {
78    type Error = Error;
79
80    fn try_from(any: AnyRef<'a>) -> Result<&'a str> {
81        Utf8StringRef::try_from(any).map(|s| s.as_str())
82    }
83}
84
85impl EncodeValue for str {
86    fn value_len(&self) -> Result<Length> {
87        Utf8StringRef::new(self)?.value_len()
88    }
89
90    fn encode_value(&self, writer: &mut impl Writer) -> Result<()> {
91        Utf8StringRef::new(self)?.encode_value(writer)
92    }
93}
94
95impl FixedTag for str {
96    const TAG: Tag = Tag::Utf8String;
97}
98
99impl OrdIsValueOrd for str {}
100
101#[cfg(feature = "alloc")]
102impl<'a> From<Utf8StringRef<'a>> for String {
103    fn from(s: Utf8StringRef<'a>) -> String {
104        s.as_str().to_owned()
105    }
106}
107
108#[cfg(feature = "alloc")]
109impl<'a> TryFrom<AnyRef<'a>> for String {
110    type Error = Error;
111
112    fn try_from(any: AnyRef<'a>) -> Result<String> {
113        Utf8StringRef::try_from(any).map(|s| s.as_str().to_owned())
114    }
115}
116
117#[cfg(feature = "alloc")]
118impl<'a> DecodeValue<'a> for String {
119    fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> Result<Self> {
120        Ok(String::from_utf8(reader.read_vec(header.length)?)?)
121    }
122}
123
124#[cfg(feature = "alloc")]
125impl EncodeValue for String {
126    fn value_len(&self) -> Result<Length> {
127        Utf8StringRef::new(self)?.value_len()
128    }
129
130    fn encode_value(&self, writer: &mut impl Writer) -> Result<()> {
131        Utf8StringRef::new(self)?.encode_value(writer)
132    }
133}
134
135#[cfg(feature = "alloc")]
136impl FixedTag for String {
137    const TAG: Tag = Tag::Utf8String;
138}
139
140#[cfg(feature = "alloc")]
141impl OrdIsValueOrd for String {}
142
143#[cfg(test)]
144mod tests {
145    use super::Utf8StringRef;
146    use crate::Decode;
147
148    #[test]
149    fn parse_ascii_bytes() {
150        let example_bytes = &[
151            0x0c, 0x0b, 0x54, 0x65, 0x73, 0x74, 0x20, 0x55, 0x73, 0x65, 0x72, 0x20, 0x31,
152        ];
153
154        let utf8_string = Utf8StringRef::from_der(example_bytes).unwrap();
155        assert_eq!(utf8_string.as_str(), "Test User 1");
156    }
157
158    #[test]
159    fn parse_utf8_bytes() {
160        let example_bytes = &[0x0c, 0x06, 0x48, 0x65, 0x6c, 0x6c, 0xc3, 0xb3];
161        let utf8_string = Utf8StringRef::from_der(example_bytes).unwrap();
162        assert_eq!(utf8_string.as_str(), "Helló");
163    }
164}
der/asn1/utf8_string.rs

der/asn1/
utf8_string.rs
