// In testing use a rather small buffer to ensure we hit the allocation paths sometimes. In
// production, we should generally never actually need to go to heap as DNS messages are rarely
// larger than a KiB or two.
-#[cfg(test)]
+#[cfg(any(test, fuzzing))]
const STACK_BUF_LIMIT: u16 = 32;
-#[cfg(not(test))]
+#[cfg(not(any(test, fuzzing)))]
const STACK_BUF_LIMIT: u16 = 2048;
/// A buffer for storing queries and responses.
len: u16,
}
impl QueryBuf {
- fn new_zeroed(len: u16) -> Self {
+ /// Generates a new buffer of the given length, consisting of all zeros.
+ pub fn new_zeroed(len: u16) -> Self {
let heap_buf = if len > STACK_BUF_LIMIT { vec![0; len as usize] } else { Vec::new() };
Self {
buf: [0; STACK_BUF_LIMIT as usize],
len
}
}
- pub(crate) fn extend_from_slice(&mut self, sl: &[u8]) {
+ /// Extends the size of this buffer by appending the given slice.
+ ///
+ /// If the total length of this buffer exceeds [`u16::MAX`] after appending, the buffer's state
+ /// is undefined, however pushing data beyond [`u16::MAX`] will not panic.
+ pub fn extend_from_slice(&mut self, sl: &[u8]) {
let new_len = self.len.saturating_add(sl.len() as u16);
let was_heap = self.len > STACK_BUF_LIMIT;
let is_heap = new_len > STACK_BUF_LIMIT;
target.copy_from_slice(sl);
self.len = new_len;
}
+ /// Converts this query into its bytes on the heap
+ pub fn into_vec(self) -> Vec<u8> {
+ if self.len > STACK_BUF_LIMIT {
+ self.heap_buf
+ } else {
+ self.buf[..self.len as usize].to_vec()
+ }
+ }
}
impl ops::Deref for QueryBuf {
type Target = [u8];
}
}
-// We don't care about transaction IDs as we're only going to accept signed data. Thus, we use
-// this constant instead of a random value.
-const TXID: u16 = 0x4242;
+// We don't care about transaction IDs as we're only going to accept signed data.
+// Further, if we're querying over DoH, the RFC says we SHOULD use a transaction ID of 0 here.
+const TXID: u16 = 0;
fn build_query(domain: &Name, ty: u16) -> QueryBuf {
let mut query = QueryBuf::new_zeroed(0);
- let query_msg_len: u16 = 2 + 2 + 8 + 2 + 2 + name_len(domain) + 11;
- query.extend_from_slice(&query_msg_len.to_be_bytes());
query.extend_from_slice(&TXID.to_be_bytes());
query.extend_from_slice(&[0x01, 0x20]); // Flags: Recursive, Authenticated Data
query.extend_from_slice(&[0, 1, 0, 0, 0, 0, 0, 1]); // One question, One additional
if questions != 1 { return Err(()); }
let answers = read_u16(&mut read)?;
if answers == 0 { return Err(()); }
- let _authorities = read_u16(&mut read)?;
+ let authorities = read_u16(&mut read)?;
let _additional = read_u16(&mut read)?;
for _ in 0..questions {
read_u16(&mut read)?; // class
}
- // Only read the answers (skip authorities and additional) as that's all we care about.
+ // Only read the answers and NSEC records in authorities, skipping additional entirely.
let mut min_ttl = u32::MAX;
for _ in 0..answers {
let (rr, ttl) = parse_wire_packet_rr(&mut read, &resp)?;
min_ttl = cmp::min(min_ttl, ttl);
if let RR::RRSig(rrsig) = rr { rrsig_key_names.push(rrsig.key_name); }
}
+
+ for _ in 0..authorities {
+ // Only include records from the authority section if they are NSEC/3 (or signatures
+ // thereover). We don't care about NS records here.
+ let (rr, ttl) = parse_wire_packet_rr(&mut read, &resp)?;
+ match &rr {
+ RR::RRSig(rrsig) => {
+ if rrsig.ty != NSec::TYPE && rrsig.ty != NSec3::TYPE {
+ continue;
+ }
+ },
+ RR::NSec(_)|RR::NSec3(_) => {},
+ _ => continue,
+ }
+ write_rr(&rr, ttl, proof);
+ min_ttl = cmp::min(min_ttl, ttl);
+ if let RR::RRSig(rrsig) = rr { rrsig_key_names.push(rrsig.key_name); }
+ }
+
Ok(min_ttl)
}
+#[cfg(fuzzing)]
+/// Read a stream of responses and handle them it as if they came from a server, for fuzzing.
+pub fn fuzz_proof_builder(mut response_stream: &[u8]) {
+ let (mut builder, _) = ProofBuilder::new(&"example.com.".try_into().unwrap(), Txt::TYPE);
+ while builder.awaiting_responses() {
+ let len = if let Ok(len) = read_u16(&mut response_stream) { len } else { return };
+ let mut buf = QueryBuf::new_zeroed(len);
+ if response_stream.len() < len as usize { return; }
+ buf.copy_from_slice(&response_stream[..len as usize]);
+ response_stream = &response_stream[len as usize..];
+ let _ = builder.process_response(&buf);
+ }
+ let _ = builder.finish_proof();
+}
+
const MAX_REQUESTS: usize = 10;
/// A simple state machine which will generate a series of queries and process the responses until
/// it has built a DNSSEC proof.
/// [`ProofBuilder::process_response`] should be called, and each fresh query returned should be
/// sent to the resolver. Once [`ProofBuilder::awaiting_responses`] returns false,
/// [`ProofBuilder::finish_proof`] should be called to fetch the resulting proof.
+///
+/// To build a DNSSEC proof using a DoH server, take each [`QueryBuf`], encode it as base64url, and
+/// make a query to `https://doh-server/endpoint?dns=base64url_encoded_query` with an `Accept`
+/// header of `application/dns-message`. Each response, in raw binary, can be fed directly into
+/// [`ProofBuilder::process_response`].
+#[derive(Clone)]
pub struct ProofBuilder {
proof: Vec<u8>,
min_ttl: u32,
#[cfg(feature = "std")]
fn send_query(stream: &mut TcpStream, query: &[u8]) -> Result<(), Error> {
+ stream.write_all(&(query.len() as u16).to_be_bytes())?;
stream.write_all(&query)?;
Ok(())
}
#[cfg(feature = "tokio")]
async fn send_query_async(stream: &mut TokioTcpStream, query: &[u8]) -> Result<(), Error> {
+ stream.write_all(&(query.len() as u16).to_be_bytes()).await?;
stream.write_all(&query).await?;
Ok(())
}
fn test_cname_query() {
for resolver in ["1.1.1.1:53", "8.8.8.8:53", "9.9.9.9:53"] {
let sockaddr = resolver.to_socket_addrs().unwrap().next().unwrap();
- let query_name = "cname_test.matcorallo.com.".try_into().unwrap();
+ let query_name = "cname_test.dnssec_proof_tests.bitcoin.ninja.".try_into().unwrap();
let (proof, _) = build_txt_proof(sockaddr, &query_name).unwrap();
let mut rrs = parse_rr_stream(&proof).unwrap();
let resolved_rrs = verified_rrs.resolve_name(&query_name);
assert_eq!(resolved_rrs.len(), 1);
if let RR::Txt(txt) = &resolved_rrs[0] {
- assert_eq!(txt.name.as_str(), "txt_test.matcorallo.com.");
+ assert_eq!(txt.name.as_str(), "txt_test.dnssec_proof_tests.bitcoin.ninja.");
assert_eq!(txt.data, b"dnssec_prover_test");
} else { panic!(); }
}
async fn test_cross_domain_cname_query_async() {
for resolver in ["1.1.1.1:53", "8.8.8.8:53", "9.9.9.9:53"] {
let sockaddr = resolver.to_socket_addrs().unwrap().next().unwrap();
- let query_name = "wildcard.x_domain_cname_wild.matcorallo.com.".try_into().unwrap();
+ let query_name = "wildcard.x_domain_cname_wild.dnssec_proof_tests.bitcoin.ninja.".try_into().unwrap();
let (proof, _) = build_txt_proof_async(sockaddr, &query_name).await.unwrap();
let mut rrs = parse_rr_stream(&proof).unwrap();
} else { panic!(); }
}
}
+
+ #[cfg(feature = "tokio")]
+ #[tokio::test]
+ async fn test_dname_wildcard_query_async() {
+ for resolver in ["1.1.1.1:53", "8.8.8.8:53", "9.9.9.9:53"] {
+ let sockaddr = resolver.to_socket_addrs().unwrap().next().unwrap();
+ let query_name = "wildcard_a.wildcard_b.dname_test.dnssec_proof_tests.bitcoin.ninja.".try_into().unwrap();
+ let (proof, _) = build_txt_proof_async(sockaddr, &query_name).await.unwrap();
+
+ let mut rrs = parse_rr_stream(&proof).unwrap();
+ rrs.shuffle(&mut rand::rngs::OsRng);
+ let verified_rrs = verify_rr_stream(&rrs).unwrap();
+ assert_eq!(verified_rrs.verified_rrs.len(), 3);
+
+ let now = SystemTime::now().duration_since(SystemTime::UNIX_EPOCH).unwrap().as_secs();
+ assert!(verified_rrs.valid_from < now);
+ assert!(verified_rrs.expires > now);
+
+ let resolved_rrs = verified_rrs.resolve_name(&query_name);
+ assert_eq!(resolved_rrs.len(), 1);
+ if let RR::Txt(txt) = &resolved_rrs[0] {
+ assert_eq!(txt.name.as_str(), "cname.wildcard_test.dnssec_proof_tests.bitcoin.ninja.");
+ assert_eq!(txt.data, b"wildcard_test");
+ } else { panic!(); }
+ }
+ }
+
}
projects / dnssec-prover / blobdiff