der/asn1/
octet_string.rs

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1//! ASN.1 `OCTET STRING` support.
2
3use crate::{
4    asn1::AnyRef, ord::OrdIsValueOrd, BytesRef, Decode, DecodeValue, EncodeValue, ErrorKind,
5    FixedTag, Header, Length, Reader, Result, Tag, Writer,
6};
7
8/// ASN.1 `OCTET STRING` type: borrowed form.
9///
10/// Octet strings represent contiguous sequences of octets, a.k.a. bytes.
11///
12/// This is a zero-copy reference type which borrows from the input data.
13#[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
14pub struct OctetStringRef<'a> {
15    /// Inner value
16    inner: BytesRef<'a>,
17}
18
19impl<'a> OctetStringRef<'a> {
20    /// Create a new ASN.1 `OCTET STRING` from a byte slice.
21    pub fn new(slice: &'a [u8]) -> Result<Self> {
22        BytesRef::new(slice)
23            .map(|inner| Self { inner })
24            .map_err(|_| ErrorKind::Length { tag: Self::TAG }.into())
25    }
26
27    /// Borrow the inner byte slice.
28    pub fn as_bytes(&self) -> &'a [u8] {
29        self.inner.as_slice()
30    }
31
32    /// Get the length of the inner byte slice.
33    pub fn len(&self) -> Length {
34        self.inner.len()
35    }
36
37    /// Is the inner byte slice empty?
38    pub fn is_empty(&self) -> bool {
39        self.inner.is_empty()
40    }
41
42    /// Parse `T` from this `OCTET STRING`'s contents.
43    pub fn decode_into<T: Decode<'a>>(&self) -> Result<T> {
44        Decode::from_der(self.as_bytes())
45    }
46}
47
48impl_any_conversions!(OctetStringRef<'a>, 'a);
49
50impl AsRef<[u8]> for OctetStringRef<'_> {
51    fn as_ref(&self) -> &[u8] {
52        self.as_bytes()
53    }
54}
55
56impl<'a> DecodeValue<'a> for OctetStringRef<'a> {
57    fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> Result<Self> {
58        let inner = BytesRef::decode_value(reader, header)?;
59        Ok(Self { inner })
60    }
61}
62
63impl EncodeValue for OctetStringRef<'_> {
64    fn value_len(&self) -> Result<Length> {
65        self.inner.value_len()
66    }
67
68    fn encode_value(&self, writer: &mut impl Writer) -> Result<()> {
69        self.inner.encode_value(writer)
70    }
71}
72
73impl FixedTag for OctetStringRef<'_> {
74    const TAG: Tag = Tag::OctetString;
75}
76
77impl OrdIsValueOrd for OctetStringRef<'_> {}
78
79impl<'a> From<&OctetStringRef<'a>> for OctetStringRef<'a> {
80    fn from(value: &OctetStringRef<'a>) -> OctetStringRef<'a> {
81        *value
82    }
83}
84
85impl<'a> From<OctetStringRef<'a>> for AnyRef<'a> {
86    fn from(octet_string: OctetStringRef<'a>) -> AnyRef<'a> {
87        AnyRef::from_tag_and_value(Tag::OctetString, octet_string.inner)
88    }
89}
90
91impl<'a> From<OctetStringRef<'a>> for &'a [u8] {
92    fn from(octet_string: OctetStringRef<'a>) -> &'a [u8] {
93        octet_string.as_bytes()
94    }
95}
96
97#[cfg(feature = "alloc")]
98pub use self::allocating::OctetString;
99
100#[cfg(feature = "alloc")]
101mod allocating {
102    use super::*;
103    use crate::referenced::*;
104    use alloc::vec::Vec;
105
106    /// ASN.1 `OCTET STRING` type: owned form..
107    ///
108    /// Octet strings represent contiguous sequences of octets, a.k.a. bytes.
109    ///
110    /// This type provides the same functionality as [`OctetStringRef`] but owns
111    /// the backing data.
112    #[derive(Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
113    pub struct OctetString {
114        /// Bitstring represented as a slice of bytes.
115        pub(super) inner: Vec<u8>,
116    }
117
118    impl OctetString {
119        /// Create a new ASN.1 `OCTET STRING`.
120        pub fn new(bytes: impl Into<Vec<u8>>) -> Result<Self> {
121            let inner = bytes.into();
122
123            // Ensure the bytes parse successfully as an `OctetStringRef`
124            OctetStringRef::new(&inner)?;
125
126            Ok(Self { inner })
127        }
128
129        /// Borrow the inner byte slice.
130        pub fn as_bytes(&self) -> &[u8] {
131            self.inner.as_slice()
132        }
133
134        /// Take ownership of the octet string.
135        pub fn into_bytes(self) -> Vec<u8> {
136            self.inner
137        }
138
139        /// Get the length of the inner byte slice.
140        pub fn len(&self) -> Length {
141            self.value_len().expect("invalid OCTET STRING length")
142        }
143
144        /// Is the inner byte slice empty?
145        pub fn is_empty(&self) -> bool {
146            self.inner.is_empty()
147        }
148    }
149
150    impl_any_conversions!(OctetString);
151
152    impl AsRef<[u8]> for OctetString {
153        fn as_ref(&self) -> &[u8] {
154            self.as_bytes()
155        }
156    }
157
158    impl<'a> DecodeValue<'a> for OctetString {
159        fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> Result<Self> {
160            Self::new(reader.read_vec(header.length)?)
161        }
162    }
163
164    impl EncodeValue for OctetString {
165        fn value_len(&self) -> Result<Length> {
166            self.inner.len().try_into()
167        }
168
169        fn encode_value(&self, writer: &mut impl Writer) -> Result<()> {
170            writer.write(&self.inner)
171        }
172    }
173
174    impl FixedTag for OctetString {
175        const TAG: Tag = Tag::OctetString;
176    }
177
178    impl<'a> From<&'a OctetString> for OctetStringRef<'a> {
179        fn from(octet_string: &'a OctetString) -> OctetStringRef<'a> {
180            // Ensured to parse successfully in constructor
181            OctetStringRef::new(&octet_string.inner).expect("invalid OCTET STRING")
182        }
183    }
184
185    impl OrdIsValueOrd for OctetString {}
186
187    impl<'a> RefToOwned<'a> for OctetStringRef<'a> {
188        type Owned = OctetString;
189        fn ref_to_owned(&self) -> Self::Owned {
190            OctetString {
191                inner: Vec::from(self.inner.as_slice()),
192            }
193        }
194    }
195
196    impl OwnedToRef for OctetString {
197        type Borrowed<'a> = OctetStringRef<'a>;
198        fn owned_to_ref(&self) -> Self::Borrowed<'_> {
199            self.into()
200        }
201    }
202
203    // Implement by hand because the derive would create invalid values.
204    // Use the constructor to create a valid value.
205    #[cfg(feature = "arbitrary")]
206    impl<'a> arbitrary::Arbitrary<'a> for OctetString {
207        fn arbitrary(u: &mut arbitrary::Unstructured<'a>) -> arbitrary::Result<Self> {
208            Self::new(Vec::arbitrary(u)?).map_err(|_| arbitrary::Error::IncorrectFormat)
209        }
210
211        fn size_hint(depth: usize) -> (usize, Option<usize>) {
212            arbitrary::size_hint::and(u8::size_hint(depth), Vec::<u8>::size_hint(depth))
213        }
214    }
215}
216
217#[cfg(feature = "bytes")]
218mod bytes {
219    use super::OctetString;
220    use crate::{DecodeValue, EncodeValue, FixedTag, Header, Length, Reader, Result, Tag, Writer};
221    use bytes::Bytes;
222
223    impl<'a> DecodeValue<'a> for Bytes {
224        fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> Result<Self> {
225            OctetString::decode_value(reader, header).map(|octet_string| octet_string.inner.into())
226        }
227    }
228
229    impl EncodeValue for Bytes {
230        fn value_len(&self) -> Result<Length> {
231            self.len().try_into()
232        }
233
234        fn encode_value(&self, writer: &mut impl Writer) -> Result<()> {
235            writer.write(self.as_ref())
236        }
237    }
238
239    impl FixedTag for Bytes {
240        const TAG: Tag = Tag::OctetString;
241    }
242}
243
244#[cfg(test)]
245mod tests {
246    use crate::asn1::{OctetStringRef, PrintableStringRef};
247
248    #[test]
249    fn octet_string_decode_into() {
250        // PrintableString "hi"
251        let der = b"\x13\x02\x68\x69";
252        let oct = OctetStringRef::new(der).unwrap();
253
254        let res = oct.decode_into::<PrintableStringRef<'_>>().unwrap();
255        assert_eq!(AsRef::<str>::as_ref(&res), "hi");
256    }
257}
der/asn1/octet_string.rs

der/asn1/
octet_string.rs
