simple_dns/dns/rdata/
ds.rs

1use crate::{bytes_buffer::BytesBuffer, dns::WireFormat};
2use std::borrow::Cow;
3
4use super::RR;
5
6/// A DS record see [rfc4034](https://www.rfc-editor.org/rfc/rfc4034#section-5)
7#[derive(Debug, PartialEq, Eq, Hash, Clone)]
8pub struct DS<'a> {
9    /// The key tag is a 16-bit value used to identify the DNSKEY record referenced by this DS record
10    pub key_tag: u16,
11    /// The algorithm number identifying the cryptographic algorithm used to create the signature
12    pub algorithm: u8,
13    /// The digest type number identifying the cryptographic hash algorithm used to create the digest
14    pub digest_type: u8,
15    /// The digest value calculated over the referenced DNSKEY record
16    pub digest: Cow<'a, [u8]>,
17}
18
19impl RR for DS<'_> {
20    const TYPE_CODE: u16 = 43;
21}
22
23impl<'a> WireFormat<'a> for DS<'a> {
24    const MINIMUM_LEN: usize = 4;
25
26    fn parse(data: &mut BytesBuffer<'a>) -> crate::Result<Self>
27    where
28        Self: Sized,
29    {
30        let key_tag = data.get_u16()?;
31        let algorithm = data.get_u8()?;
32        let digest_type = data.get_u8()?;
33        let digest = Cow::Borrowed(data.get_remaining());
34
35        Ok(Self {
36            key_tag,
37            algorithm,
38            digest_type,
39            digest,
40        })
41    }
42
43    fn write_to<T: std::io::Write>(&self, out: &mut T) -> crate::Result<()> {
44        out.write_all(&self.key_tag.to_be_bytes())?;
45        out.write_all(&[self.algorithm, self.digest_type])?;
46        out.write_all(&self.digest)?;
47
48        Ok(())
49    }
50
51    fn len(&self) -> usize {
52        self.digest.len() + Self::MINIMUM_LEN
53    }
54}
55
56impl DS<'_> {
57    /// Transforms the inner data into its owned type
58    pub fn into_owned<'b>(self) -> DS<'b> {
59        DS {
60            key_tag: self.key_tag,
61            algorithm: self.algorithm,
62            digest_type: self.digest_type,
63            digest: Cow::Owned(self.digest.into_owned()),
64        }
65    }
66}
67
68#[cfg(test)]
69mod tests {
70    use crate::{rdata::RData, ResourceRecord};
71
72    use super::*;
73
74    #[test]
75    fn parse_and_write_ds() {
76        let key_tag = 12345u16;
77        let algorithm = 8u8;
78        let digest_type = 2u8;
79        let digest = vec![1, 2, 3, 4, 5];
80        let rdata = DS {
81            key_tag,
82            algorithm,
83            digest_type,
84            digest: Cow::Owned(digest),
85        };
86        let mut writer = Vec::new();
87        rdata.write_to(&mut writer).unwrap();
88        let rdata = DS::parse(&mut (&writer[..]).into()).unwrap();
89        assert_eq!(rdata.key_tag, key_tag);
90        assert_eq!(rdata.algorithm, algorithm);
91        assert_eq!(rdata.digest_type, digest_type);
92        assert_eq!(&*rdata.digest, &[1, 2, 3, 4, 5]);
93    }
94
95    #[test]
96    fn parse_sample() -> Result<(), Box<dyn std::error::Error>> {
97        let sample_file = std::fs::read("samples/zonefile/DS.sample")?;
98
99        let sample_rdata = match ResourceRecord::parse(&mut (&sample_file[..]).into())?.rdata {
100            RData::DS(rdata) => rdata,
101            _ => unreachable!(),
102        };
103
104        assert_eq!(sample_rdata.algorithm, 5);
105        assert_eq!(sample_rdata.digest_type, 1);
106        assert_eq!(sample_rdata.key_tag, 60485);
107        assert_eq!(
108            *sample_rdata.digest,
109            *b"\x2B\xB1\x83\xAF\x5F\x22\x58\x81\x79\xA5\x3B\x0A\x98\x63\x1F\xAD\x1A\x29\x21\x18"
110        );
111
112        Ok(())
113    }
114}
simple_dns/dns/rdata/ds.rs

simple_dns/dns/rdata/
ds.rs
