Avoid overriding $RUSTFLAGS when needed for rustc 1.63
[dnssec-prover] / src / rr.rs
index d3a6dd466927f235fb11165e5012276637810871..0733dd2fa2897d79836a5632e4d5c9d33d7df93b 100644 (file)
--- a/src/rr.rs
+++ b/src/rr.rs
@@ -9,6 +9,7 @@ use alloc::borrow::ToOwned;
 use alloc::format;
 
 use core::cmp::{self, Ordering};
+use core::fmt;
 use core::fmt::Write;
 
 use crate::ser::*;
@@ -22,11 +23,37 @@ pub struct Name(String);
 impl Name {
        /// Gets the underlying human-readable domain name
        pub fn as_str(&self) -> &str { &self.0 }
+       /// Gets the number of labels in this name
+       pub fn labels(&self) -> u8 {
+               if self.as_str() == "." {
+                       0
+               } else {
+                       self.as_str().chars().filter(|c| *c == '.').count() as u8
+               }
+       }
+       /// Gets a string containing the last `n` labels in this [`Name`] (which is also a valid name).
+       pub fn trailing_n_labels(&self, n: u8) -> Option<&str> {
+               let labels = self.labels();
+               if n > labels {
+                       None
+               } else if n == labels {
+                       Some(self.as_str())
+               } else if n == 0 {
+                       Some(".")
+               } else {
+                       self.as_str().splitn(labels as usize - n as usize + 1, '.').last()
+               }
+       }
 }
 impl core::ops::Deref for Name {
        type Target = str;
        fn deref(&self) -> &str { &self.0 }
 }
+impl fmt::Display for Name {
+       fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+               self.0.fmt(f)
+       }
+}
 impl TryFrom<String> for Name {
        type Error = ();
        fn try_from(s: String) -> Result<Name, ()> {
@@ -34,11 +61,11 @@ impl TryFrom<String> for Name {
                if *s.as_bytes().last().unwrap_or(&0) != b"."[0] { return Err(()); }
                if s.len() > 255 { return Err(()); }
                if s.chars().any(|c| !c.is_ascii_graphic() || c == '"') { return Err(()); }
-               for label in s.split(".") {
+               for label in s.split('.') {
                        if label.len() > 63 { return Err(()); }
                }
 
-               Ok(Name(s))
+               Ok(Name(s.to_ascii_lowercase()))
        }
 }
 impl TryFrom<&str> for Name {
@@ -66,12 +93,18 @@ pub enum RR {
        TLSA(TLSA),
        /// A Canonical Name record
        CName(CName),
+       /// A Delegation Name record
+       DName(DName),
        /// A DNS (Public) Key resource record
        DnsKey(DnsKey),
        /// A Delegated Signer resource record
        DS(DS),
        /// A Resource Record Signature record
        RRSig(RRSig),
+       /// A Next Secure Record record
+       NSec(NSec),
+       /// A Next Secure Record version 3 record
+       NSec3(NSec3),
 }
 impl RR {
        /// Gets the name this record refers to.
@@ -82,10 +115,13 @@ impl RR {
                        RR::NS(rr) => &rr.name,
                        RR::Txt(rr) => &rr.name,
                        RR::CName(rr) => &rr.name,
+                       RR::DName(rr) => &rr.name,
                        RR::TLSA(rr) => &rr.name,
                        RR::DnsKey(rr) => &rr.name,
                        RR::DS(rr) => &rr.name,
                        RR::RRSig(rr) => &rr.name,
+                       RR::NSec(rr) => &rr.name,
+                       RR::NSec3(rr) => &rr.name,
                }
        }
        /// Gets a JSON encoding of this record
@@ -96,10 +132,13 @@ impl RR {
                        RR::NS(rr) => StaticRecord::json(rr),
                        RR::Txt(rr) => StaticRecord::json(rr),
                        RR::CName(rr) => StaticRecord::json(rr),
+                       RR::DName(rr) => StaticRecord::json(rr),
                        RR::TLSA(rr) => StaticRecord::json(rr),
                        RR::DnsKey(rr) => StaticRecord::json(rr),
                        RR::DS(rr) => StaticRecord::json(rr),
                        RR::RRSig(rr) => StaticRecord::json(rr),
+                       RR::NSec(rr) => StaticRecord::json(rr),
+                       RR::NSec3(rr) => StaticRecord::json(rr),
                }
        }
        fn ty(&self) -> u16 {
@@ -109,23 +148,46 @@ impl RR {
                        RR::NS(_) => NS::TYPE,
                        RR::Txt(_) => Txt::TYPE,
                        RR::CName(_) => CName::TYPE,
+                       RR::DName(_) => DName::TYPE,
                        RR::TLSA(_) => TLSA::TYPE,
                        RR::DnsKey(_) => DnsKey::TYPE,
                        RR::DS(_) => DS::TYPE,
                        RR::RRSig(_) => RRSig::TYPE,
+                       RR::NSec(_) => NSec::TYPE,
+                       RR::NSec3(_) => NSec3::TYPE,
                }
        }
-       fn write_u16_len_prefixed_data(&self, out: &mut Vec<u8>) {
+       fn write_u16_len_prefixed_data<W: Writer>(&self, out: &mut W) {
                match self {
                        RR::A(rr) => StaticRecord::write_u16_len_prefixed_data(rr, out),
                        RR::AAAA(rr) => StaticRecord::write_u16_len_prefixed_data(rr, out),
                        RR::NS(rr) => StaticRecord::write_u16_len_prefixed_data(rr, out),
                        RR::Txt(rr) => StaticRecord::write_u16_len_prefixed_data(rr, out),
                        RR::CName(rr) => StaticRecord::write_u16_len_prefixed_data(rr, out),
+                       RR::DName(rr) => StaticRecord::write_u16_len_prefixed_data(rr, out),
                        RR::TLSA(rr) => StaticRecord::write_u16_len_prefixed_data(rr, out),
                        RR::DnsKey(rr) => StaticRecord::write_u16_len_prefixed_data(rr, out),
                        RR::DS(rr) => StaticRecord::write_u16_len_prefixed_data(rr, out),
                        RR::RRSig(rr) => StaticRecord::write_u16_len_prefixed_data(rr, out),
+                       RR::NSec(rr) => StaticRecord::write_u16_len_prefixed_data(rr, out),
+                       RR::NSec3(rr) => StaticRecord::write_u16_len_prefixed_data(rr, out),
+               }
+       }
+       fn ty_to_rr_name(ty: u16) -> Option<&'static str> {
+               match ty {
+                       A::TYPE => Some("A"),
+                       AAAA::TYPE => Some("AAAA"),
+                       NS::TYPE => Some("NS"),
+                       Txt::TYPE => Some("TXT"),
+                       CName::TYPE => Some("CNAME"),
+                       DName::TYPE => Some("DNAME"),
+                       TLSA::TYPE => Some("TLSA"),
+                       DnsKey::TYPE => Some("DNSKEY"),
+                       DS::TYPE => Some("DS"),
+                       RRSig::TYPE => Some("RRSIG"),
+                       NSec::TYPE => Some("NSEC"),
+                       NSec3::TYPE => Some("NSEC3"),
+                       _ => None,
                }
        }
 }
@@ -134,19 +196,38 @@ impl From<AAAA> for RR { fn from(aaaa: AAAA) -> RR { RR::AAAA(aaaa) } }
 impl From<NS> for RR { fn from(ns: NS) -> RR { RR::NS(ns) } }
 impl From<Txt> for RR { fn from(txt: Txt) -> RR { RR::Txt(txt) } }
 impl From<CName> for RR { fn from(cname: CName) -> RR { RR::CName(cname) } }
+impl From<DName> for RR { fn from(cname: DName) -> RR { RR::DName(cname) } }
 impl From<TLSA> for RR { fn from(tlsa: TLSA) -> RR { RR::TLSA(tlsa) } }
 impl From<DnsKey> for RR { fn from(dnskey: DnsKey) -> RR { RR::DnsKey(dnskey) } }
 impl From<DS> for RR { fn from(ds: DS) -> RR { RR::DS(ds) } }
 impl From<RRSig> for RR { fn from(rrsig: RRSig) -> RR { RR::RRSig(rrsig) } }
+impl From<NSec> for RR { fn from(nsec: NSec) -> RR { RR::NSec(nsec) } }
+impl From<NSec3> for RR { fn from(nsec3: NSec3) -> RR { RR::NSec3(nsec3) } }
 
 pub(crate) trait StaticRecord : Ord + Sized {
        // http://www.iana.org/assignments/dns-parameters/dns-parameters.xhtml#dns-parameters-4
        const TYPE: u16;
        fn name(&self) -> &Name;
        fn json(&self) -> String;
-       fn write_u16_len_prefixed_data(&self, out: &mut Vec<u8>);
+       fn write_u16_len_prefixed_data<W: Writer>(&self, out: &mut W);
        fn read_from_data(name: Name, data: &[u8], wire_packet: &[u8]) -> Result<Self, ()>;
 }
+
+/// A record that can be written to a generic [`Writer`]
+pub(crate) trait WriteableRecord : Record {
+       fn serialize_u16_len_prefixed<W: Writer>(&self, out: &mut W);
+}
+impl<RR: StaticRecord> WriteableRecord for RR {
+       fn serialize_u16_len_prefixed<W: Writer>(&self, out: &mut W) {
+               RR::write_u16_len_prefixed_data(self, out)
+       }
+}
+impl WriteableRecord for RR {
+       fn serialize_u16_len_prefixed<W: Writer>(&self, out: &mut W) {
+               RR::write_u16_len_prefixed_data(self, out)
+       }
+}
+
 /// A trait describing a resource record (including the [`RR`] enum).
 pub trait Record : Ord {
        /// The resource record type, as maintained by IANA.
@@ -178,7 +259,7 @@ impl Record for RR {
        }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Ord)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 /// A text resource record, containing arbitrary text data
 pub struct Txt {
        /// The name this record is at.
@@ -189,9 +270,11 @@ pub struct Txt {
        /// is an arbitrary series of bytes here.
        pub data: Vec<u8>,
 }
-impl PartialOrd for Txt {
-       fn partial_cmp(&self, o: &Txt) -> Option<Ordering> {
-               Some(self.name.cmp(&o.name)
+/// The wire type for TXT records
+pub const TXT_TYPE: u16 = 16;
+impl Ord for Txt {
+       fn cmp(&self, o: &Txt) -> Ordering {
+               self.name.cmp(&o.name)
                        .then_with(|| {
                                // Compare in wire encoding form, i.e. compare in 255-byte chunks
                                for i in 1..(self.data.len() / 255) + 2 {
@@ -203,42 +286,46 @@ impl PartialOrd for Txt {
                                        if !slice_cmp.is_eq() { return slice_cmp; }
                                }
                                Ordering::Equal
-                       }))
+                       })
        }
 }
+impl PartialOrd for Txt {
+       fn partial_cmp(&self, o: &Txt) -> Option<Ordering> { Some(self.cmp(o)) }
+}
 impl StaticRecord for Txt {
-       const TYPE: u16 = 16;
+       const TYPE: u16 = TXT_TYPE;
        fn name(&self) -> &Name { &self.name }
        fn json(&self) -> String {
                if let Ok(s) = core::str::from_utf8(&self.data) {
-                       if s.chars().all(|c| !c.is_control() && c != '"') {
+                       if s.chars().all(|c| !c.is_control() && c != '"' && c != '\\') {
                                return format!("{{\"type\":\"txt\",\"name\":\"{}\",\"contents\":\"{}\"}}", self.name.0, s);
                        }
                }
                format!("{{\"type\":\"txt\",\"name\":\"{}\",\"contents\":{:?}}}", self.name.0, &self.data[..])
        }
        fn read_from_data(name: Name, mut data: &[u8], _wire_packet: &[u8]) -> Result<Self, ()> {
-               let mut parsed_data = Vec::with_capacity(data.len() - 1);
+               let mut parsed_data = Vec::with_capacity(data.len().saturating_sub(1));
                while !data.is_empty() {
                        let len = read_u8(&mut data)? as usize;
                        if data.len() < len { return Err(()); }
                        parsed_data.extend_from_slice(&data[..len]);
                        data = &data[len..];
                }
+               debug_assert!(data.is_empty());
                Ok(Txt { name, data: parsed_data })
        }
-       fn write_u16_len_prefixed_data(&self, out: &mut Vec<u8>) {
+       fn write_u16_len_prefixed_data<W: Writer>(&self, out: &mut W) {
                let len = (self.data.len() + (self.data.len() + 254) / 255) as u16;
-               out.extend_from_slice(&len.to_be_bytes());
+               out.write(&len.to_be_bytes());
 
                let mut data_write = &self.data[..];
-               out.extend_from_slice(&[data_write.len().try_into().unwrap_or(255)]);
+               out.write(&[data_write.len().try_into().unwrap_or(255)]);
                while !data_write.is_empty() {
                        let split_pos = core::cmp::min(255, data_write.len());
-                       out.extend_from_slice(&data_write[..split_pos]);
+                       out.write(&data_write[..split_pos]);
                        data_write = &data_write[split_pos..];
                        if !data_write.is_empty() {
-                               out.extend_from_slice(&[data_write.len().try_into().unwrap_or(255)]);
+                               out.write(&[data_write.len().try_into().unwrap_or(255)]);
                        }
                }
        }
@@ -263,8 +350,10 @@ pub struct TLSA {
        /// The certificate data or hash of the certificate data itself.
        pub data: Vec<u8>,
 }
+/// The wire type for TLSA records
+pub const TLSA_TYPE: u16 = 52;
 impl StaticRecord for TLSA {
-       const TYPE: u16 = 52;
+       const TYPE: u16 = TLSA_TYPE;
        fn name(&self) -> &Name { &self.name }
        fn json(&self) -> String {
                let mut out = String::with_capacity(128+self.data.len()*2);
@@ -285,11 +374,11 @@ impl StaticRecord for TLSA {
                        data_ty: read_u8(&mut data)?, data: data.to_vec(),
                })
        }
-       fn write_u16_len_prefixed_data(&self, out: &mut Vec<u8>) {
+       fn write_u16_len_prefixed_data<W: Writer>(&self, out: &mut W) {
                let len = 3 + self.data.len();
-               out.extend_from_slice(&(len as u16).to_be_bytes());
-               out.extend_from_slice(&[self.cert_usage, self.selector, self.data_ty]);
-               out.extend_from_slice(&self.data);
+               out.write(&(len as u16).to_be_bytes());
+               out.write(&[self.cert_usage, self.selector, self.data_ty]);
+               out.write(&self.data);
        }
 }
 
@@ -300,7 +389,7 @@ pub struct CName {
        pub name: Name,
        /// The canonical name.
        ///
-       /// A resolver should use this name when looking up any further records for [`Self::name`].
+       /// A resolver should use this name when looking up any further records for [`self.name`].
        pub canonical_name: Name,
 }
 impl StaticRecord for CName {
@@ -311,15 +400,49 @@ impl StaticRecord for CName {
                        self.name.0, self.canonical_name.0)
        }
        fn read_from_data(name: Name, mut data: &[u8], wire_packet: &[u8]) -> Result<Self, ()> {
-               Ok(CName { name, canonical_name: read_wire_packet_name(&mut data, wire_packet)? })
+               let res = CName { name, canonical_name: read_wire_packet_name(&mut data, wire_packet)? };
+               debug_assert!(data.is_empty());
+               Ok(res)
        }
-       fn write_u16_len_prefixed_data(&self, out: &mut Vec<u8>) {
+       fn write_u16_len_prefixed_data<W: Writer>(&self, out: &mut W) {
                let len: u16 = name_len(&self.canonical_name);
-               out.extend_from_slice(&len.to_be_bytes());
+               out.write(&len.to_be_bytes());
                write_name(out, &self.canonical_name);
        }
 }
 
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
+/// A Delegation Name resource record, referring all queries for subdomains of this name to another
+/// subtree of the DNS.
+pub struct DName {
+       /// The name this record is at.
+       pub name: Name,
+       /// The delegation name.
+       ///
+       /// A resolver should use this domain name tree when looking up any further records for
+       /// subdomains of [`self.name`].
+       pub delegation_name: Name,
+}
+impl StaticRecord for DName {
+       const TYPE: u16 = 39;
+       fn name(&self) -> &Name { &self.name }
+       fn json(&self) -> String {
+               format!("{{\"type\":\"dname\",\"name\":\"{}\",\"delegation_name\":\"{}\"}}",
+                       self.name.0, self.delegation_name.0)
+       }
+       fn read_from_data(name: Name, mut data: &[u8], wire_packet: &[u8]) -> Result<Self, ()> {
+               let res = DName { name, delegation_name: read_wire_packet_name(&mut data, wire_packet)? };
+               debug_assert!(data.is_empty());
+               Ok(res)
+       }
+       fn write_u16_len_prefixed_data<W: Writer>(&self, out: &mut W) {
+               let len: u16 = name_len(&self.delegation_name);
+               out.write(&len.to_be_bytes());
+               write_name(out, &self.delegation_name);
+       }
+}
+
+
 #[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
 /// A public key resource record which can be used to validate [`RRSig`]s.
 pub struct DnsKey {
@@ -356,13 +479,13 @@ impl StaticRecord for DnsKey {
                        alg: read_u8(&mut data)?, pubkey: data.to_vec(),
                })
        }
-       fn write_u16_len_prefixed_data(&self, out: &mut Vec<u8>) {
+       fn write_u16_len_prefixed_data<W: Writer>(&self, out: &mut W) {
                let len = 2 + 1 + 1 + self.pubkey.len();
-               out.extend_from_slice(&(len as u16).to_be_bytes());
-               out.extend_from_slice(&self.flags.to_be_bytes());
-               out.extend_from_slice(&self.protocol.to_be_bytes());
-               out.extend_from_slice(&self.alg.to_be_bytes());
-               out.extend_from_slice(&self.pubkey);
+               out.write(&(len as u16).to_be_bytes());
+               out.write(&self.flags.to_be_bytes());
+               out.write(&self.protocol.to_be_bytes());
+               out.write(&self.alg.to_be_bytes());
+               out.write(&self.pubkey);
        }
 }
 impl DnsKey {
@@ -385,7 +508,7 @@ impl DnsKey {
 
 #[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
 /// A Delegation Signer resource record which indicates that some alternative [`DnsKey`] can sign
-/// for records in the zone which matches [`DS::name`].
+/// for records in the zone which matches [`self.name`].
 pub struct DS {
        /// The name this record is at.
        ///
@@ -427,13 +550,13 @@ impl StaticRecord for DS {
                        digest_type: read_u8(&mut data)?, digest: data.to_vec(),
                })
        }
-       fn write_u16_len_prefixed_data(&self, out: &mut Vec<u8>) {
+       fn write_u16_len_prefixed_data<W: Writer>(&self, out: &mut W) {
                let len = 2 + 1 + 1 + self.digest.len();
-               out.extend_from_slice(&(len as u16).to_be_bytes());
-               out.extend_from_slice(&self.key_tag.to_be_bytes());
-               out.extend_from_slice(&self.alg.to_be_bytes());
-               out.extend_from_slice(&self.digest_type.to_be_bytes());
-               out.extend_from_slice(&self.digest);
+               out.write(&(len as u16).to_be_bytes());
+               out.write(&self.key_tag.to_be_bytes());
+               out.write(&self.alg.to_be_bytes());
+               out.write(&self.digest_type.to_be_bytes());
+               out.write(&self.digest);
        }
 }
 
@@ -447,7 +570,7 @@ pub struct RRSig {
        pub name: Name,
        /// The resource record type which this [`RRSig`] is signing.
        ///
-       /// All resources records of this type at the same name as [`Self::name`] must be signed by
+       /// All resources records of this type at the same name as [`self.name`] must be signed by
        /// this [`RRSig`].
        pub ty: u16,
        /// The algorithm which is being used to sign.
@@ -456,7 +579,7 @@ pub struct RRSig {
        pub alg: u8,
        /// The number of labels in the name of the records that this signature is signing.
        ///
-       /// If this is less than the number of labels in [`Self::name`], this signature is covering a
+       /// If this is less than the number of labels in [`self.name`], this signature is covering a
        /// wildcard entry.
        pub labels: u8,
        /// The TTL of the records which this [`RRSig`] is signing.
@@ -471,7 +594,11 @@ pub struct RRSig {
        pub key_tag: u16,
        /// The [`DnsKey::name`] in the [`DnsKey`] which created this signature.
        ///
-       /// This must be a parent of the [`Self::name`].
+       /// This must be a parent of [`self.name`].
+       ///
+       /// [`DnsKey::name`]: Record::name
+       // We'd like to just link to the `DnsKey` member variable called `name`, but there doesn't
+       // appear to be a way to actually do that, so instead we have to link to the trait method.
        pub key_name: Name,
        /// The signature itself.
        pub signature: Vec<u8>,
@@ -502,18 +629,174 @@ impl StaticRecord for RRSig {
                        signature: data.to_vec(),
                })
        }
-       fn write_u16_len_prefixed_data(&self, out: &mut Vec<u8>) {
+       fn write_u16_len_prefixed_data<W: Writer>(&self, out: &mut W) {
                let len = 2 + 1 + 1 + 4*3 + 2 + name_len(&self.key_name) + self.signature.len() as u16;
-               out.extend_from_slice(&len.to_be_bytes());
-               out.extend_from_slice(&self.ty.to_be_bytes());
-               out.extend_from_slice(&self.alg.to_be_bytes());
-               out.extend_from_slice(&self.labels.to_be_bytes());
-               out.extend_from_slice(&self.orig_ttl.to_be_bytes());
-               out.extend_from_slice(&self.expiration.to_be_bytes());
-               out.extend_from_slice(&self.inception.to_be_bytes());
-               out.extend_from_slice(&self.key_tag.to_be_bytes());
+               out.write(&len.to_be_bytes());
+               out.write(&self.ty.to_be_bytes());
+               out.write(&self.alg.to_be_bytes());
+               out.write(&self.labels.to_be_bytes());
+               out.write(&self.orig_ttl.to_be_bytes());
+               out.write(&self.expiration.to_be_bytes());
+               out.write(&self.inception.to_be_bytes());
+               out.write(&self.key_tag.to_be_bytes());
                write_name(out, &self.key_name);
-               out.extend_from_slice(&self.signature);
+               out.write(&self.signature);
+       }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
+/// A mask used in [`NSec`] and [`NSec3`] records which indicates the resource record types which
+/// exist at the (hash of the) name described in [`Record::name`].
+pub struct NSecTypeMask([u8; 8192]);
+impl NSecTypeMask {
+       /// Constructs a new, empty, type mask.
+       pub fn new() -> Self { Self([0; 8192]) }
+       /// Builds a new type mask with the given types set
+       pub fn from_types(types: &[u16]) -> Self {
+               let mut flags = [0; 8192];
+               for t in types {
+                       flags[*t as usize >> 3] |= 1 << (7 - (*t as usize % 8));
+               }
+               let res = Self(flags);
+               for t in types {
+                       debug_assert!(res.contains_type(*t));
+               }
+               res
+       }
+       /// Checks if the given type (from [`Record::ty`]) is set, indicating a record of this type
+       /// exists.
+       pub fn contains_type(&self, ty: u16) -> bool {
+               let f = self.0[(ty >> 3) as usize];
+               // DNSSEC's bit fields are in wire order, so the high bit is type 0, etc.
+               f & (1 << (7 - (ty % 8))) != 0
+       }
+       fn write_json(&self, s: &mut String) {
+               *s += "[";
+               let mut have_written = false;
+               for (idx, mask) in self.0.iter().enumerate() {
+                       if *mask == 0 { continue; }
+                       for b in 0..8 {
+                               if *mask & (1 << b) != 0 {
+                                       if have_written {
+                                               *s += ",";
+                                       }
+                                       have_written = true;
+                                       let ty = ((idx as u16) << 3) | (7 - b);
+                                       match RR::ty_to_rr_name(ty) {
+                                               Some(name) => write!(s, "\"{}\"", name).expect("Writes to a string shouldn't fail"),
+                                               _ => write!(s, "{}", ty).expect("Writes to a string shouldn't fail"),
+                                       }
+                               }
+                       }
+               }
+               *s += "]";
+       }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
+/// A Next Secure Record resource record. This indicates a range of possible names for which there
+/// is no such record.
+pub struct NSec {
+       /// The name this record is at.
+       pub name: Name,
+       /// The next name which contains a record. There are no names between `name` and
+       /// [`Self::next_name`].
+       pub next_name: Name,
+       /// The set of record types which exist at `name`. Any other record types do not exist at
+       /// `name`.
+       pub types: NSecTypeMask,
+}
+impl StaticRecord for NSec {
+       const TYPE: u16 = 47;
+       fn name(&self) -> &Name { &self.name }
+       fn json(&self) -> String {
+               let mut out = String::with_capacity(256 + self.next_name.len());
+               write!(&mut out,
+                       "{{\"type\":\"nsec\",\"name\":\"{}\",\"next_name\":\"{}\",\"types\":",
+                       self.name.0, self.next_name.0,
+               ).expect("Write to a String shouldn't fail");
+               self.types.write_json(&mut out);
+               out += "}";
+               out
+       }
+       fn read_from_data(name: Name, mut data: &[u8], wire_packet: &[u8]) -> Result<Self, ()> {
+               let res = NSec {
+                       name, next_name: read_wire_packet_name(&mut data, wire_packet)?,
+                       types: NSecTypeMask(read_nsec_types_bitmap(&mut data)?),
+               };
+               debug_assert!(data.is_empty());
+               Ok(res)
+       }
+       fn write_u16_len_prefixed_data<W: Writer>(&self, out: &mut W) {
+               let len = name_len(&self.next_name) + nsec_types_bitmap_len(&self.types.0);
+               out.write(&len.to_be_bytes());
+               write_name(out, &self.next_name);
+               write_nsec_types_bitmap(out, &self.types.0);
+       }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
+/// A Next Secure Record resource record. This indicates a range of possible names for which there
+/// is no such record.
+pub struct NSec3 {
+       /// The name this record is at.
+       pub name: Name,
+       /// The hash algorithm used to hash the `name` and [`Self::next_name_hash`]. Currently only 1
+       /// (SHA-1) is defined.
+       pub hash_algo: u8,
+       /// Flags for this record. Currently only bit 0 (the "opt-out" bit) is defined.
+       pub flags: u8,
+       /// The number of hash iterations required.
+       ///
+       /// As of RFC 9276 this MUST be set to 0, but sadly is often still set higher in the wild. A
+       /// hard cap is applied in validation.
+       pub hash_iterations: u16,
+       /// The salt included in the hash.
+       ///
+       /// As of RFC 9276 this SHOULD be empty, but often isn't in the wild.
+       pub salt: Vec<u8>,
+       /// The hash of the next name which contains a record. There are no records who's name's hash
+       /// lies between `name` and [`Self::next_name_hash`].
+       pub next_name_hash: Vec<u8>,
+       /// The set of record types which exist at `name`. Any other record types do not exist at
+       /// `name`.
+       pub types: NSecTypeMask,
+}
+impl StaticRecord for NSec3 {
+       const TYPE: u16 = 50;
+       fn name(&self) -> &Name { &self.name }
+       fn json(&self) -> String {
+               let mut out = String::with_capacity(256);
+               write!(&mut out,
+                       "{{\"type\":\"nsec3\",\"name\":\"{}\",\"hash_algo\":{},\"flags\":{},\"hash_iterations\":{},\"salt\":{:?},\"next_name_hash\":{:?},\"types\":",
+                       self.name.0, self.hash_algo, self.flags, self.hash_iterations, &self.salt[..], &self.next_name_hash[..]
+               ).expect("Write to a String shouldn't fail");
+               self.types.write_json(&mut out);
+               out += "}";
+               out
+       }
+       fn read_from_data(name: Name, mut data: &[u8], _wire_packet: &[u8]) -> Result<Self, ()> {
+               let res = NSec3 {
+                       name, hash_algo: read_u8(&mut data)?, flags: read_u8(&mut data)?,
+                       hash_iterations: read_u16(&mut data)?, salt: read_u8_len_prefixed_bytes(&mut data)?,
+                       next_name_hash: read_u8_len_prefixed_bytes(&mut data)?,
+                       types: NSecTypeMask(read_nsec_types_bitmap(&mut data)?),
+               };
+               debug_assert!(data.is_empty());
+               Ok(res)
+       }
+       fn write_u16_len_prefixed_data<W: Writer>(&self, out: &mut W) {
+               let len = 4 + 2 + self.salt.len() as u16 + self.next_name_hash.len() as u16 +
+                       nsec_types_bitmap_len(&self.types.0);
+               out.write(&len.to_be_bytes());
+               out.write(&self.hash_algo.to_be_bytes());
+               out.write(&self.flags.to_be_bytes());
+               out.write(&self.hash_iterations.to_be_bytes());
+               out.write(&(self.salt.len() as u8).to_be_bytes());
+               out.write(&self.salt);
+               out.write(&(self.next_name_hash.len() as u8).to_be_bytes());
+               out.write(&self.next_name_hash);
+               write_nsec_types_bitmap(out, &self.types.0);
        }
 }
 
@@ -525,8 +808,10 @@ pub struct A {
        /// The bytes of the IPv4 address.
        pub address: [u8; 4],
 }
+/// The wire type for A records
+pub const A_TYPE: u16 = 1;
 impl StaticRecord for A {
-       const TYPE: u16 = 1;
+       const TYPE: u16 = A_TYPE;
        fn name(&self) -> &Name { &self.name }
        fn json(&self) -> String {
                format!("{{\"type\":\"a\",\"name\":\"{}\",\"address\":{:?}}}", self.name.0, self.address)
@@ -534,12 +819,12 @@ impl StaticRecord for A {
        fn read_from_data(name: Name, data: &[u8], _wire_packet: &[u8]) -> Result<Self, ()> {
                if data.len() != 4 { return Err(()); }
                let mut address = [0; 4];
-               address.copy_from_slice(&data);
+               address.copy_from_slice(data);
                Ok(A { name, address })
        }
-       fn write_u16_len_prefixed_data(&self, out: &mut Vec<u8>) {
-               out.extend_from_slice(&4u16.to_be_bytes());
-               out.extend_from_slice(&self.address);
+       fn write_u16_len_prefixed_data<W: Writer>(&self, out: &mut W) {
+               out.write(&4u16.to_be_bytes());
+               out.write(&self.address);
        }
 }
 
@@ -551,8 +836,10 @@ pub struct AAAA {
        /// The bytes of the IPv6 address.
        pub address: [u8; 16],
 }
+/// The wire type for AAAA records
+pub const AAAA_TYPE: u16 = 28;
 impl StaticRecord for AAAA {
-       const TYPE: u16 = 28;
+       const TYPE: u16 = AAAA_TYPE;
        fn name(&self) -> &Name { &self.name }
        fn json(&self) -> String {
                format!("{{\"type\":\"aaaa\",\"name\":\"{}\",\"address\":{:?}}}", self.name.0, self.address)
@@ -560,12 +847,12 @@ impl StaticRecord for AAAA {
        fn read_from_data(name: Name, data: &[u8], _wire_packet: &[u8]) -> Result<Self, ()> {
                if data.len() != 16 { return Err(()); }
                let mut address = [0; 16];
-               address.copy_from_slice(&data);
+               address.copy_from_slice(data);
                Ok(AAAA { name, address })
        }
-       fn write_u16_len_prefixed_data(&self, out: &mut Vec<u8>) {
-               out.extend_from_slice(&16u16.to_be_bytes());
-               out.extend_from_slice(&self.address);
+       fn write_u16_len_prefixed_data<W: Writer>(&self, out: &mut W) {
+               out.write(&16u16.to_be_bytes());
+               out.write(&self.address);
        }
 }
 
@@ -578,7 +865,7 @@ pub struct NS {
        /// This is also the zone which the server at [`Self::name_server`] is responsible for handling
        /// queries for.
        pub name: Name,
-       /// The name of the server which is responsible for handling queries for the [`Self::name`]
+       /// The name of the server which is responsible for handling queries for the [`self.name`]
        /// zone.
        pub name_server: Name,
 }
@@ -589,10 +876,12 @@ impl StaticRecord for NS {
                format!("{{\"type\":\"ns\",\"name\":\"{}\",\"ns\":\"{}\"}}", self.name.0, self.name_server.0)
        }
        fn read_from_data(name: Name, mut data: &[u8], wire_packet: &[u8]) -> Result<Self, ()> {
-               Ok(NS { name, name_server: read_wire_packet_name(&mut data, wire_packet)? })
+               let res = NS { name, name_server: read_wire_packet_name(&mut data, wire_packet)? };
+               debug_assert!(data.is_empty());
+               Ok(res)
        }
-       fn write_u16_len_prefixed_data(&self, out: &mut Vec<u8>) {
-               out.extend_from_slice(&name_len(&self.name_server).to_be_bytes());
+       fn write_u16_len_prefixed_data<W: Writer>(&self, out: &mut W) {
+               out.write(&name_len(&self.name_server).to_be_bytes());
                write_name(out, &self.name_server);
        }
 }