From e1b511e78884255b7b64e816270f6fe44daa4fd0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bogdan-=C8=98tefan=20Neac=C5=9Fu?= <bogdan@nymtech.net>
Date: Thu, 8 Dec 2022 14:06:24 +0200
Subject: [PATCH] Feature/verify bte proof (#1866)

* Update lock file

* Include bte public key verification
---
 Cargo.lock                                  |  2 +-
 validator-api/src/coconut/dkg/complaints.rs |  1 +
 validator-api/src/coconut/dkg/dealing.rs    | 48 +++++++++++++++++++++
 validator-api/src/coconut/dkg/state.rs      |  4 ++
 4 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/Cargo.lock b/Cargo.lock
index f00cc44be4..9d687961cb 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -6537,7 +6537,7 @@ checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
 
 [[package]]
 name = "vesting-contract"
-version = "1.1.0"
+version = "1.1.2"
 dependencies = [
  "contracts-common",
  "cosmwasm-std",
diff --git a/validator-api/src/coconut/dkg/complaints.rs b/validator-api/src/coconut/dkg/complaints.rs
index e62d9feac3..0001e4f76d 100644
--- a/validator-api/src/coconut/dkg/complaints.rs
+++ b/validator-api/src/coconut/dkg/complaints.rs
@@ -4,6 +4,7 @@
 #[derive(Debug, Eq, PartialEq)]
 pub(crate) enum ComplaintReason {
     MalformedBTEPublicKey,
+    InvalidBTEPublicKey,
     MissingDealing,
     MalformedDealing,
     DealingVerificationError,
diff --git a/validator-api/src/coconut/dkg/dealing.rs b/validator-api/src/coconut/dkg/dealing.rs
index f3b1e97a42..b6ebed9853 100644
--- a/validator-api/src/coconut/dkg/dealing.rs
+++ b/validator-api/src/coconut/dkg/dealing.rs
@@ -54,6 +54,7 @@ pub(crate) async fn dealing_exchange(
 #[cfg(test)]
 pub(crate) mod tests {
     use super::*;
+    use crate::coconut::dkg::complaints::ComplaintReason;
     use crate::coconut::tests::DummyClient;
     use crate::coconut::KeyPair;
     use coconut_dkg_common::dealer::DealerDetails;
@@ -148,4 +149,51 @@ pub(crate) mod tests {
             .clone();
         assert_eq!(dealings, new_dealings);
     }
+
+    #[tokio::test]
+    #[ignore] // expensive test
+    async fn invalid_bte_proof_dealing_posted() {
+        let self_index = 2;
+        let dealer_details_db = Arc::new(RwLock::new(HashMap::new()));
+        let dealings_db = Arc::new(RwLock::new(HashMap::new()));
+        let dkg_client = DkgClient::new(
+            DummyClient::new(AccountId::from_str(TEST_VALIDATORS_ADDRESS[0]).unwrap())
+                .with_dealer_details(&dealer_details_db)
+                .with_dealings(&dealings_db),
+        );
+        let params = setup();
+        let mut state = State::new(
+            Url::parse("localhost:8000").unwrap(),
+            DkgKeyPair::new(&params, OsRng),
+            KeyPair::new(),
+        );
+        state.set_node_index(Some(self_index));
+        insert_dealers(&params, &dealer_details_db);
+
+        dealer_details_db
+            .write()
+            .unwrap()
+            .entry(TEST_VALIDATORS_ADDRESS[1].to_string())
+            .and_modify(|details| {
+                let mut bytes = bs58::decode(details.bte_public_key_with_proof.clone())
+                    .into_vec()
+                    .unwrap();
+                let last_byte = bytes.last_mut().unwrap();
+                *last_byte += 1;
+                details.bte_public_key_with_proof = bs58::encode(&bytes).into_string();
+            });
+
+        dealing_exchange(&dkg_client, &mut state, OsRng)
+            .await
+            .unwrap();
+        assert_eq!(
+            *state
+                .all_dealers()
+                .get(&Addr::unchecked(TEST_VALIDATORS_ADDRESS[1]))
+                .unwrap()
+                .as_ref()
+                .unwrap_err(),
+            ComplaintReason::InvalidBTEPublicKey
+        );
+    }
 }
diff --git a/validator-api/src/coconut/dkg/state.rs b/validator-api/src/coconut/dkg/state.rs
index b0b550304a..aebcdea495 100644
--- a/validator-api/src/coconut/dkg/state.rs
+++ b/validator-api/src/coconut/dkg/state.rs
@@ -30,6 +30,10 @@ impl TryFrom<DealerDetails> for DkgParticipant {
             .map_err(|_| ComplaintReason::MalformedBTEPublicKey)?
             .map_err(|_| ComplaintReason::MalformedBTEPublicKey)?;
 
+        if !bte_public_key_with_proof.verify() {
+            return Err(ComplaintReason::InvalidBTEPublicKey);
+        }
+
         Ok(DkgParticipant {
             _address: dealer.address,
             bte_public_key_with_proof,