Add ack signatures

Also modifies message signatures to be binding to from, not just from's key.
This commit is contained in:
Luke Parker
2023-07-17 17:40:34 -04:00
parent 6ccac2d0ab
commit 344ac9cbfc
4 changed files with 54 additions and 16 deletions

View File

@@ -42,7 +42,9 @@ lazy_static::lazy_static! {
fn queue_message(meta: Metadata, msg: Vec<u8>, sig: SchnorrSignature<Ristretto>) {
{
let from = (*KEYS).read().unwrap()[&meta.from];
assert!(sig.verify(from, message_challenge(from, meta.to, &meta.intent, &msg, sig.R)));
assert!(
sig.verify(from, message_challenge(meta.from, from, meta.to, &meta.intent, &msg, sig.R))
);
}
// Assert one, and only one of these, is the coordinator
@@ -85,8 +87,11 @@ fn get_next_message(service: Service, _expected: u64) -> Option<QueuedMessage> {
Acknowledges a message as received and handled, meaning it'll no longer be returned as the next
message.
*/
fn ack_message(service: Service, id: u64, _signature: SchnorrSignature<Ristretto>) {
// TODO: Verify the signature
fn ack_message(service: Service, id: u64, sig: SchnorrSignature<Ristretto>) {
{
let from = (*KEYS).read().unwrap()[&service];
assert!(sig.verify(from, ack_challenge(service, from, id, sig.R)));
}
// Is it:
// The acknowledged message should be > last acknowledged OR

View File

@@ -27,20 +27,39 @@ pub struct Metadata {
}
pub fn message_challenge(
from: <Ristretto as Ciphersuite>::G,
from: Service,
from_key: <Ristretto as Ciphersuite>::G,
to: Service,
intent: &[u8],
msg: &[u8],
nonce: <Ristretto as Ciphersuite>::G,
) -> <Ristretto as Ciphersuite>::F {
let mut transcript = RecommendedTranscript::new(b"Serai Message Queue v0.1");
let mut transcript = RecommendedTranscript::new(b"Serai Message Queue v0.1 Message");
transcript.domain_separate(b"metadata");
transcript.append_message(b"from", from.to_bytes());
transcript.append_message(b"from", bincode::serialize(&from).unwrap());
transcript.append_message(b"from_key", from_key.to_bytes());
transcript.append_message(b"to", bincode::serialize(&to).unwrap());
transcript.append_message(b"intent", intent);
transcript.domain_separate(b"message");
transcript.append_message(b"msg", msg);
transcript.domain_separate(b"signature");
transcript.append_message(b"nonce", nonce.to_bytes());
<Ristretto as Ciphersuite>::hash_to_F(b"challenge", &transcript.challenge(b"challenge"))
<Ristretto as Ciphersuite>::hash_to_F(b"message_challenge", &transcript.challenge(b"challenge"))
}
pub fn ack_challenge(
from: Service,
from_key: <Ristretto as Ciphersuite>::G,
id: u64,
nonce: <Ristretto as Ciphersuite>::G,
) -> <Ristretto as Ciphersuite>::F {
let mut transcript = RecommendedTranscript::new(b"Serai Message Queue v0.1 Ackowledgement");
transcript.domain_separate(b"metadata");
transcript.append_message(b"from", bincode::serialize(&from).unwrap());
transcript.append_message(b"from_key", from_key.to_bytes());
transcript.domain_separate(b"message");
transcript.append_message(b"id", id.to_le_bytes());
transcript.domain_separate(b"signature");
transcript.append_message(b"nonce", nonce.to_bytes());
<Ristretto as Ciphersuite>::hash_to_F(b"ack_challenge", &transcript.challenge(b"challenge"))
}

View File

@@ -46,7 +46,8 @@ impl<D: Db> Queue<D> {
}
pub(crate) fn get_message(&self, id: u64) -> Option<QueuedMessage> {
let msg = self.0.get(self.message_key(id)).map(|bytes| serde_json::from_slice(&bytes).unwrap());
let msg: Option<QueuedMessage> =
self.0.get(self.message_key(id)).map(|bytes| serde_json::from_slice(&bytes).unwrap());
if let Some(msg) = msg.as_ref() {
assert_eq!(msg.id, id, "message stored at {id} has ID {}", msg.id);
}