feat: add validation for accept-withdrawal-request transactions

signer/src/bitcoin/utxo.rs

@@ -35,10 +35,9 @@ use crate::error::Error;
 use crate::keys::SignerScriptPubKey as _;
 use crate::storage::model;
 use crate::storage::model::ScriptPubKey;
-use crate::storage::model::SignerVote;
+use crate::storage::model::SignerVotes;
 use crate::storage::model::StacksBlockHash;
 use crate::storage::model::StacksTxId;
-use crate::MAX_KEYS;
 
 /// The minimum incremental fee rate in sats per virtual byte for RBF
 /// transactions.
@@ -348,32 +347,12 @@ impl DepositRequest {
     pub fn from_model(
         request: model::DepositRequest,
         signers_public_key: XOnlyPublicKey,
-        mut votes: Vec<SignerVote>,
+        votes: SignerVotes,
     ) -> Self {
-        let txid = request.txid.into();
-        let vout = request.output_index;
-
-        let mut signer_bitmap = BitArray::ZERO;
-        votes.sort_by_key(|vote| vote.signer_public_key);
-        votes
-            .into_iter()
-            .enumerate()
-            .take(signer_bitmap.len().min(MAX_KEYS as usize))
-            .for_each(|(index, vote)| {
-                // The BitArray::<[u8; 16]>::set function panics if the
-                // index is out of bounds but that cannot be the case here
-                // because we only take 128 values.
-                //
-                // Note that the signer bitmap here is true for votes
-                // *against*, and a missing vote is an implicit vote
-                // against.
-                signer_bitmap.set(index, !vote.is_accepted.unwrap_or(false));
-            });
-
         Self {
-            outpoint: OutPoint { txid, vout },
+            outpoint: request.outpoint(),
             max_fee: request.max_fee,
-            signer_bitmap,
+            signer_bitmap: votes.into(),
             amount: request.amount,
             deposit_script: ScriptBuf::from_bytes(request.spend_script),
             reclaim_script: ScriptBuf::from_bytes(request.reclaim_script),
@@ -448,29 +427,12 @@ impl WithdrawalRequest {
     }
 
     /// Try convert from a model::DepositRequest with some additional info.
-    pub fn from_model(request: model::WithdrawalRequest, mut votes: Vec<SignerVote>) -> Self {
-        let mut signer_bitmap = BitArray::ZERO;
-        votes.sort_by_key(|vote| vote.signer_public_key);
-        votes
-            .into_iter()
-            .enumerate()
-            .take(signer_bitmap.len().min(MAX_KEYS as usize))
-            .for_each(|(index, vote)| {
-                // The BitArray::<[u8; 16]>::set function panics if the
-                // index is out of bounds but that cannot be the case here
-                // because we only take 128 values.
-                //
-                // Note that the signer bitmap here is true for votes
-                // *against*, and a missing vote is an implicit vote
-                // against.
-                signer_bitmap.set(index, !vote.is_accepted.unwrap_or(false));
-            });
-
+    pub fn from_model(request: model::WithdrawalRequest, votes: SignerVotes) -> Self {
         Self {
             amount: request.amount,
             max_fee: request.max_fee,
             script_pubkey: request.recipient,
-            signer_bitmap,
+            signer_bitmap: votes.into(),
             request_id: request.request_id,
             txid: request.txid,
             block_hash: request.block_hash,
@@ -1012,6 +974,7 @@ mod tests {
     use bitcoin::CompressedPublicKey;
     use bitcoin::Txid;
     use fake::Fake as _;
+    use model::SignerVote;
     use rand::distributions::Distribution;
     use rand::distributions::Uniform;
     use rand::rngs::OsRng;
@@ -2071,7 +2034,7 @@ mod tests {
     /// the model type to the required type here.
     #[test]
     fn creating_deposit_request_from_model_bitmap_is_right() {
-        let mut votes = [
+        let signer_votes = [
             SignerVote {
                 signer_public_key: fake::Faker.fake_with_rng(&mut OsRng),
                 is_accepted: Some(true),
@@ -2093,15 +2056,15 @@ mod tests {
                 is_accepted: None,
             },
         ];
+        let votes = SignerVotes::from(signer_votes.to_vec());
         let request: model::DepositRequest = fake::Faker.fake_with_rng(&mut OsRng);
         let signers_public_key: PublicKey = fake::Faker.fake_with_rng(&mut OsRng);
         let deposit_request =
-            DepositRequest::from_model(request, signers_public_key.into(), votes.to_vec());
+            DepositRequest::from_model(request, signers_public_key.into(), votes.clone());
 
         // One explicit vote against and one implicit vote against.
         assert_eq!(deposit_request.votes_against(), 2);
         // An appropriately named function ...
-        votes.sort_by_key(|x| x.signer_public_key);
         votes.iter().enumerate().for_each(|(index, vote)| {
             let vote_against = *deposit_request.signer_bitmap.get(index).unwrap();
             assert_eq!(vote_against, !vote.is_accepted.unwrap_or(false));
@@ -2112,7 +2075,7 @@ mod tests {
     /// the model type to the required type here.
     #[test]
     fn creating_withdrawal_request_from_model_bitmap_is_right() {
-        let mut votes = [
+        let signer_votes = [
             SignerVote {
                 signer_public_key: fake::Faker.fake_with_rng(&mut OsRng),
                 is_accepted: Some(true),
@@ -2138,13 +2101,13 @@ mod tests {
                 is_accepted: None,
             },
         ];
+        let votes = SignerVotes::from(signer_votes.to_vec());
         let request: model::WithdrawalRequest = fake::Faker.fake_with_rng(&mut OsRng);
-        let withdrawal_request = WithdrawalRequest::from_model(request, votes.to_vec());
+        let withdrawal_request = WithdrawalRequest::from_model(request, votes.clone());
 
         // One explicit vote against and one implicit vote against.
         assert_eq!(withdrawal_request.votes_against(), 3);
         // An appropriately named function ...
-        votes.sort_by_key(|x| x.signer_public_key);
         votes.iter().enumerate().for_each(|(index, vote)| {
             let vote_against = *withdrawal_request.signer_bitmap.get(index).unwrap();
             assert_eq!(vote_against, !vote.is_accepted.unwrap_or(false));

signer/src/bitcoin/zmq.rs

@@ -131,7 +131,8 @@ pub fn parse_bitcoin_core_message(message: ZmqMessage) -> Result<BitcoinCoreMess
         }
         // We do not implement parsing for any other message types but if
         // we're here, then we probably have a valid message from
-        // bitcoin-core. Let's try to note the topic for easier debugging.
+        // bitcoin-core (we know `data` has three parts). Let's try to note
+        // the topic for easier debugging.
         _ => {
             let topic = core::str::from_utf8(data[0]).map(ToString::to_string);
             Err(Error::BitcoinCoreZmqUnsupported(topic))

signer/src/error.rs

@@ -3,6 +3,8 @@ use std::borrow::Cow;
 
 use blockstack_lib::types::chainstate::StacksBlockId;
 
+use crate::stacks::contracts::DepositValidationError;
+use crate::stacks::contracts::WithdrawalAcceptValidationError;
 use crate::{codec, ecdsa, network};
 
 /// Top-level signer error
@@ -91,6 +93,10 @@ pub enum Error {
     #[error("could not decode Nakamoto block from tenure with block: {1}; {0}")]
     DecodeNakamotoTenure(#[source] blockstack_lib::codec::Error, StacksBlockId),
 
+    /// Failed to validate the complete-deposit contract call transaction.
+    #[error("{0}")]
+    DepositValidation(#[from] Box<DepositValidationError>),
+
     /// An error when serializing an object to JSON
     #[error("{0}")]
     JsonSerialize(#[source] serde_json::Error),
@@ -295,6 +301,11 @@ pub enum Error {
     #[error("unexpected public key from signature. key {0}; digest: {1}")]
     UnknownPublicKey(crate::keys::PublicKey, secp256k1::Message),
 
+    /// The error for when the request to sign a withdrawal-accept
+    /// transaction fails at the validation step.
+    #[error("{0}")]
+    WithdrawalAcceptValidation(#[source] Box<WithdrawalAcceptValidationError>),
+
     /// WSTS error.
     #[error("WSTS error: {0}")]
     Wsts(#[source] wsts::state_machine::signer::Error),

signer/src/keys.rs

@@ -41,6 +41,7 @@ use crate::error::Error;
 
 /// The public key type for the secp256k1 elliptic curve.
 #[derive(Copy, Clone, Debug, PartialOrd, Ord, PartialEq, Eq, Hash, Serialize, Deserialize)]
+#[serde(transparent)]
 pub struct PublicKey(secp256k1::PublicKey);
 
 impl From<&secp256k1::PublicKey> for PublicKey {
@@ -182,6 +183,12 @@ impl From<&PublicKey> for stacks_common::util::secp256k1::Secp256k1PublicKey {
     }
 }
 
+impl From<PublicKey> for stacks_common::util::secp256k1::Secp256k1PublicKey {
+    fn from(value: PublicKey) -> Self {
+        Self::from(&value)
+    }
+}
+
 impl From<&stacks_common::util::secp256k1::Secp256k1PublicKey> for PublicKey {
     fn from(value: &stacks_common::util::secp256k1::Secp256k1PublicKey) -> Self {
         let key = secp256k1::PublicKey::from_slice(&value.to_bytes_compressed())
@@ -231,6 +238,7 @@ impl std::fmt::Display for PublicKey {
 
 /// A private key type for the secp256k1 elliptic curve.
 #[derive(Copy, Clone, Debug, PartialEq, Eq, Deserialize)]
+#[serde(transparent)]
 pub struct PrivateKey(secp256k1::SecretKey);
 
 impl FromStr for PrivateKey {