der/asn1/
printable_string.rs

1//! ASN.1 `PrintableString` 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 `PrintableString` 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 following ASCII characters/ranges are supported:
22///
23/// - `A..Z`
24/// - `a..z`
25/// - `0..9`
26/// - "` `" (i.e. space)
27/// - `\`
28/// - `(`
29/// - `)`
30/// - `+`
31/// - `,`
32/// - `-`
33/// - `.`
34/// - `/`
35/// - `:`
36/// - `=`
37/// - `?`
38#[derive(Copy, Clone, Eq, PartialEq, PartialOrd, Ord)]
39pub struct PrintableStringRef<'a> {
40    /// Inner value
41    inner: StrSlice<'a>,
42}
43
44impl<'a> PrintableStringRef<'a> {
45    /// Create a new ASN.1 `PrintableString`.
46    pub fn new<T>(input: &'a T) -> Result<Self>
47    where
48        T: AsRef<[u8]> + ?Sized,
49    {
50        let input = input.as_ref();
51
52        // Validate all characters are within PrintableString's allowed set
53        for &c in input.iter() {
54            match c {
55                b'A'..=b'Z'
56                | b'a'..=b'z'
57                | b'0'..=b'9'
58                | b' '
59                | b'\''
60                | b'('
61                | b')'
62                | b'+'
63                | b','
64                | b'-'
65                | b'.'
66                | b'/'
67                | b':'
68                | b'='
69                | b'?' => (),
70                _ => return Err(Self::TAG.value_error()),
71            }
72        }
73
74        StrSlice::from_bytes(input)
75            .map(|inner| Self { inner })
76            .map_err(|_| Self::TAG.value_error())
77    }
78}
79
80impl<'a> Deref for PrintableStringRef<'a> {
81    type Target = StrSlice<'a>;
82
83    fn deref(&self) -> &Self::Target {
84        &self.inner
85    }
86}
87
88impl AsRef<str> for PrintableStringRef<'_> {
89    fn as_ref(&self) -> &str {
90        self.as_str()
91    }
92}
93
94impl AsRef<[u8]> for PrintableStringRef<'_> {
95    fn as_ref(&self) -> &[u8] {
96        self.as_bytes()
97    }
98}
99
100impl<'a> DecodeValue<'a> for PrintableStringRef<'a> {
101    fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> Result<Self> {
102        Self::new(ByteSlice::decode_value(reader, header)?.as_slice())
103    }
104}
105
106impl<'a> EncodeValue for PrintableStringRef<'a> {
107    fn value_len(&self) -> Result<Length> {
108        self.inner.value_len()
109    }
110
111    fn encode_value(&self, writer: &mut dyn Writer) -> Result<()> {
112        self.inner.encode_value(writer)
113    }
114}
115
116impl FixedTag for PrintableStringRef<'_> {
117    const TAG: Tag = Tag::PrintableString;
118}
119
120impl OrdIsValueOrd for PrintableStringRef<'_> {}
121
122impl<'a> From<&PrintableStringRef<'a>> for PrintableStringRef<'a> {
123    fn from(value: &PrintableStringRef<'a>) -> PrintableStringRef<'a> {
124        *value
125    }
126}
127
128impl<'a> TryFrom<AnyRef<'a>> for PrintableStringRef<'a> {
129    type Error = Error;
130
131    fn try_from(any: AnyRef<'a>) -> Result<PrintableStringRef<'a>> {
132        any.decode_into()
133    }
134}
135
136impl<'a> From<PrintableStringRef<'a>> for AnyRef<'a> {
137    fn from(printable_string: PrintableStringRef<'a>) -> AnyRef<'a> {
138        AnyRef::from_tag_and_value(Tag::PrintableString, printable_string.inner.into())
139    }
140}
141
142impl<'a> fmt::Display for PrintableStringRef<'a> {
143    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
144        f.write_str(self.as_str())
145    }
146}
147
148impl<'a> fmt::Debug for PrintableStringRef<'a> {
149    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
150        write!(f, "PrintableString({:?})", self.as_str())
151    }
152}
153
154#[cfg(test)]
155mod tests {
156    use super::PrintableStringRef;
157    use crate::Decode;
158
159    #[test]
160    fn parse_bytes() {
161        let example_bytes = &[
162            0x13, 0x0b, 0x54, 0x65, 0x73, 0x74, 0x20, 0x55, 0x73, 0x65, 0x72, 0x20, 0x31,
163        ];
164
165        let printable_string = PrintableStringRef::from_der(example_bytes).unwrap();
166        assert_eq!(printable_string.as_str(), "Test User 1");
167    }
168}
der/asn1/printable_string.rs

der/asn1/
printable_string.rs
