generalize-curve: move CurvePoint behind a trait

Cargo.toml

@@ -23,6 +23,7 @@ flamer = { version = "0.3", optional = true }
 generic-array = "0.14"
 hex = "0.4"
 k256 = { version = "0.13", features = ["arithmetic", "sha256", "ecdsa", "serde"] }
+p256 = { version = "0.13.2", features = ["arithmetic", "sha256", "ecdsa", "serde"] }
 lazy_static = "1"
 
 # libpaillier depends on `unknown_order` which in turn depends on `rug`.

benches/e2e_benchmark.rs

@@ -4,6 +4,7 @@ use rand::{prelude::IteratorRandom, rngs::OsRng, CryptoRng, Rng, RngCore};
 use std::collections::HashMap;
 use tss_ecdsa::{
     auxinfo::AuxInfoParticipant,
+    curve::TestCurve,
     errors::Result,
     keygen::KeygenParticipant,
     messages::Message,
@@ -106,25 +107,30 @@ fn run_benchmarks_for_given_size(c: &mut Criterion, num_players: usize) {
     let keygen_sid = Identifier::random(&mut rng);
     let keygen_inputs = std::iter::repeat(()).take(num_players).collect::<Vec<_>>();
     c.bench_function(&format!("Keygen with {num_players} nodes"), |b| {
-        b.iter(|| run_subprotocol::<KeygenParticipant>(keygen_sid, keygen_inputs.clone()))
+        b.iter(|| {
+            run_subprotocol::<KeygenParticipant<TestCurve>>(keygen_sid, keygen_inputs.clone())
+        })
     });
 
     // Benchmark auxinfo
     let auxinfo_sid = Identifier::random(&mut rng);
     let auxinfo_inputs = std::iter::repeat(()).take(num_players).collect::<Vec<_>>();
     c.bench_function(&format!("Auxinfo with {num_players} nodes"), |b| {
-        b.iter(|| run_subprotocol::<AuxInfoParticipant>(auxinfo_sid, auxinfo_inputs.clone()))
+        b.iter(|| {
+            run_subprotocol::<AuxInfoParticipant<TestCurve>>(auxinfo_sid, auxinfo_inputs.clone())
+        })
     });
 
     // Prepare to benchmark presign:
     // 1. Run keygen and get outputs
     let keygen_inputs = std::iter::repeat(()).take(num_players).collect();
-    let keygen_outputs = run_subprotocol::<KeygenParticipant>(keygen_sid, keygen_inputs).unwrap();
+    let keygen_outputs =
+        run_subprotocol::<KeygenParticipant<TestCurve>>(keygen_sid, keygen_inputs).unwrap();
 
     // 2. Run auxinfo and get outputs
     let auxinfo_inputs = std::iter::repeat(()).take(num_players).collect();
     let auxinfo_outputs =
-        run_subprotocol::<AuxInfoParticipant>(auxinfo_sid, auxinfo_inputs).unwrap();
+        run_subprotocol::<AuxInfoParticipant<TestCurve>>(auxinfo_sid, auxinfo_inputs).unwrap();
 
     // 3. Assemble presign input from keygen and auxinfo.
     let presign_inputs = auxinfo_outputs
@@ -138,7 +144,12 @@ fn run_benchmarks_for_given_size(c: &mut Criterion, num_players: usize) {
     // Benchmark presign
     let presign_identifier = Identifier::random(&mut rng);
     c.bench_function(&format!("Presign with {num_players} nodes"), |b| {
-        b.iter(|| run_subprotocol::<PresignParticipant>(presign_identifier, presign_inputs.clone()))
+        b.iter(|| {
+            run_subprotocol::<PresignParticipant<TestCurve>>(
+                presign_identifier,
+                presign_inputs.clone(),
+            )
+        })
     });
 }
 

examples/threaded_example/threaded.rs

@@ -38,6 +38,7 @@ use tracing::{debug, info, instrument, span, trace, Level};
 use tracing_subscriber::{self, EnvFilter};
 use tss_ecdsa::{
     auxinfo::{self, AuxInfoParticipant},
+    curve::{CurveTrait, TestCurve},
     keygen::{self, KeygenParticipant, Output},
     messages::Message,
     presign::{self, PresignParticipant},
@@ -183,7 +184,7 @@ fn main() -> anyhow::Result<()> {
         worker_messages.insert(config.id(), from_coordinator_tx);
 
         let outgoing = outgoing_tx.clone();
-        thread::spawn(|| participant_worker(config, from_coordinator_rx, outgoing));
+        thread::spawn(|| participant_worker::<TestCurve>(config, from_coordinator_rx, outgoing));
     }
 
     // Coordinator initiates entire protocol.
@@ -330,26 +331,26 @@ fn threshold_participants(mut pids: Vec<ParticipantIdentifier>) -> Vec<Participa
 }
 
 /// Worker participating in tss-ecdsa protocols.
-struct Worker {
+struct Worker<C: CurveTrait + 'static> {
     /// Configuration for this participant.
     config: ParticipantConfig,
     /// Stored participants executed by this worker.
     participants: ParticipantStorage,
     /// Outputs of successful key generation.
-    key_gen_material: StoredOutput<KeygenParticipant>,
+    key_gen_material: StoredOutput<KeygenParticipant<C>>,
     /// Outputs of successful aux info.
-    aux_info: StoredOutput<AuxInfoParticipant>,
+    aux_info: StoredOutput<AuxInfoParticipant<C>>,
     /// Outputs of successful tshare.
-    tshares: StoredOutput<TshareParticipant>,
+    tshares: StoredOutput<TshareParticipant<C>>,
     /// Outputs of successful presign.
-    presign_records: StoredOutput<PresignParticipant>,
+    presign_records: StoredOutput<PresignParticipant<C>>,
     /// Signatures generated from successful signing runs.
-    signatures: StoredOutput<SignParticipant>,
+    signatures: StoredOutput<SignParticipant<C>>,
     /// Channel for sending messages to the coordinator.
     outgoing: Sender<MessageFromWorker>,
 }
 
-impl Worker {
+impl<C: CurveTrait> Worker<C> {
     /// Create new worker.
     fn new(config: ParticipantConfig, outgoing: Sender<MessageFromWorker>) -> Self {
         Worker {
@@ -422,16 +423,16 @@ impl Worker {
 
 /// Sub-protocol wrappers around `new_sub_protocol`.
 /// These functions fetch the required inputs from storage.
-impl Worker {
+impl<C: CurveTrait> Worker<C> {
     fn new_keygen(&mut self, sid: SessionId, key_id: KeyId) -> anyhow::Result<()> {
-        self.new_sub_protocol::<KeygenParticipant>(self.config.clone(), sid, (), key_id)
+        self.new_sub_protocol::<KeygenParticipant<C>>(self.config.clone(), sid, (), key_id)
     }
 
     fn new_auxinfo(&mut self, sid: SessionId, key_id: KeyId) -> anyhow::Result<()> {
         // Note: Missing inputs to aux-info see issues
         // #242 and #243.
-        let _output: &Output = self.key_gen_material.retrieve(&key_id);
-        self.new_sub_protocol::<AuxInfoParticipant>(self.config.clone(), sid, (), key_id)
+        let _output: &Output<C> = self.key_gen_material.retrieve(&key_id);
+        self.new_sub_protocol::<AuxInfoParticipant<C>>(self.config.clone(), sid, (), key_id)
     }
 
     fn new_tshare(&mut self, sid: SessionId, key_id: KeyId) -> anyhow::Result<()> {
@@ -443,14 +444,14 @@ impl Worker {
         let auxinfo_output = self.aux_info.retrieve(&key_id);
 
         let inputs = tshare::Input::new(auxinfo_output.clone(), Some(private_share), THRESHOLD)?;
-        self.new_sub_protocol::<TshareParticipant>(self.config.clone(), sid, inputs, key_id)
+        self.new_sub_protocol::<TshareParticipant<C>>(self.config.clone(), sid, inputs, key_id)
     }
 
     /// Pick a quorum of participants. Return the corresponding additive shares.
     fn make_quorum(
         &self,
         key_id: KeyId,
-    ) -> anyhow::Result<(ParticipantConfig, keygen::Output, auxinfo::Output)> {
+    ) -> anyhow::Result<(ParticipantConfig, keygen::Output<C>, auxinfo::Output)> {
         let participants = threshold_participants(self.config.all_participants());
 
         let keygen_output = self.key_gen_material.retrieve(&key_id);
@@ -477,7 +478,7 @@ impl Worker {
         let (config, keygen_quorum, auxinfo_quorum) = self.make_quorum(key_id)?;
 
         let inputs = presign::Input::new(auxinfo_quorum, keygen_quorum)?;
-        self.new_sub_protocol::<PresignParticipant>(config, sid, inputs, key_id)
+        self.new_sub_protocol::<PresignParticipant<C>>(config, sid, inputs, key_id)
     }
 
     fn new_sign(&mut self, sid: SessionId, key_id: KeyId) -> anyhow::Result<()> {
@@ -486,14 +487,14 @@ impl Worker {
         let record = self.presign_records.take(&key_id);
 
         let inputs = sign::Input::new(b"hello world", record, key_shares.to_vec(), THRESHOLD, None);
-        self.new_sub_protocol::<SignParticipant>(config, sid, inputs, key_id)
+        self.new_sub_protocol::<SignParticipant<C>>(config, sid, inputs, key_id)
     }
 }
 
 /// Sub-protocol wrappers around `process_message` method.
-impl Worker {
+impl<C: CurveTrait> Worker<C> {
     fn process_keygen(&mut self, sid: SessionId, incoming: Message) -> anyhow::Result<()> {
-        let (p, key_id) = self.participants.get_mut::<KeygenParticipant>(&sid);
+        let (p, key_id) = self.participants.get_mut::<KeygenParticipant<C>>(&sid);
         Self::process_message(
             p,
             key_id,
@@ -504,17 +505,17 @@ impl Worker {
     }
 
     fn process_auxinfo(&mut self, sid: SessionId, incoming: Message) -> anyhow::Result<()> {
-        let (p, key_id) = self.participants.get_mut::<AuxInfoParticipant>(&sid);
+        let (p, key_id) = self.participants.get_mut::<AuxInfoParticipant<C>>(&sid);
         Self::process_message(p, key_id, incoming, &mut self.aux_info, &self.outgoing)
     }
 
     fn process_tshare(&mut self, sid: SessionId, incoming: Message) -> anyhow::Result<()> {
-        let (p, key_id) = self.participants.get_mut::<TshareParticipant>(&sid);
+        let (p, key_id) = self.participants.get_mut::<TshareParticipant<C>>(&sid);
         Self::process_message(p, key_id, incoming, &mut self.tshares, &self.outgoing)
     }
 
     fn process_presign(&mut self, sid: SessionId, incoming: Message) -> anyhow::Result<()> {
-        let (p, key_id) = self.participants.get_mut::<PresignParticipant>(&sid);
+        let (p, key_id) = self.participants.get_mut::<PresignParticipant<C>>(&sid);
         Self::process_message(
             p,
             key_id,
@@ -525,21 +526,21 @@ impl Worker {
     }
 
     fn process_sign(&mut self, sid: SessionId, incoming: Message) -> anyhow::Result<()> {
-        let (p, key_id) = self.participants.get_mut::<SignParticipant>(&sid);
+        let (p, key_id) = self.participants.get_mut::<SignParticipant<C>>(&sid);
         Self::process_message(p, key_id, incoming, &mut self.signatures, &self.outgoing)
     }
 }
 
 /// Function to drive work for the workers. These workers execute in their
 /// own thread.
 #[instrument(skip_all)]
-fn participant_worker(
+fn participant_worker<C: CurveTrait + 'static>(
     config: ParticipantConfig,
     from_coordinator: Receiver<MessageFromCoordinator>,
     outgoing: Sender<MessageFromWorker>,
 ) -> anyhow::Result<()> {
     info!("Worker thread started.");
-    let mut worker = Worker::new(config, outgoing);
+    let mut worker: Worker<C> = Worker::new(config, outgoing);
     let mut current_subprotocol: HashMap<SessionId, SubProtocol> = Default::default();
 
     for incoming in from_coordinator {

src/auxinfo/auxinfo_commit.rs

@@ -8,6 +8,7 @@
 
 use crate::{
     auxinfo::{info::AuxInfoPublic, participant::AuxInfoParticipant},
+    curve::CurveTrait,
     errors::{InternalError, Result},
     messages::{AuxinfoMessageType, Message, MessageType},
     parameters::PRIME_BITS,
@@ -18,7 +19,7 @@ use libpaillier::unknown_order::BigNumber;
 use merlin::Transcript;
 use rand::{CryptoRng, RngCore};
 use serde::{Deserialize, Serialize};
-use std::fmt::Debug;
+use std::{fmt::Debug, marker::PhantomData};
 use tracing::{error, instrument};
 
 /// The commitment produced by [`CommitmentScheme`].
@@ -42,7 +43,7 @@ impl Commitment {
 /// to send decommit to a validly produced [`Commitment`] one needs to send
 /// [`CommitmentScheme`] itself.
 #[derive(Serialize, Deserialize, Clone)]
-pub(crate) struct CommitmentScheme {
+pub(crate) struct CommitmentScheme<C: CurveTrait> {
     /// A unique session identifier (`ssid` in the paper).
     sid: Identifier,
     /// This participant's [`ParticipantIdentifier`] (`i` in the paper).
@@ -60,9 +61,11 @@ pub(crate) struct CommitmentScheme {
     /// This randomness is to ensure that the hash-based commitment is properly
     /// randomized.
     commit_randomness: [u8; 32],
+    /// Phantom data to ensure that the commitment scheme is curve-agnostic.
+    _phantom: PhantomData<C>,
 }
 
-impl Debug for CommitmentScheme {
+impl<C: CurveTrait> Debug for CommitmentScheme<C> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         // Redacting randomness and commit_randomness because I'm not sure how
         // sensitive they are. If later analysis suggests they're fine to print,
@@ -77,7 +80,7 @@ impl Debug for CommitmentScheme {
     }
 }
 
-impl CommitmentScheme {
+impl<C: CurveTrait> CommitmentScheme<C> {
     /// Construct a new [`CommitmentScheme`] using the provided unique session
     /// [`Identifier`], [`AuxInfoParticipant`], and [`AuxInfoPublic`].
     ///
@@ -86,7 +89,7 @@ impl CommitmentScheme {
     /// [`AuxInfoParticipant`].
     pub(crate) fn new<R: RngCore + CryptoRng>(
         sid: Identifier,
-        auxinfo_participant: &AuxInfoParticipant,
+        auxinfo_participant: &AuxInfoParticipant<C>,
         public_key: AuxInfoPublic,
         rng: &mut R,
     ) -> Result<Self> {
@@ -109,6 +112,7 @@ impl CommitmentScheme {
             randomness: rid,
             commit_randomness: u_i,
             public_key,
+            _phantom: PhantomData,
         })
     }
 
@@ -117,10 +121,10 @@ impl CommitmentScheme {
     /// This method verifies all the internal [`CommitmentScheme`] values.
     pub(crate) fn from_message(
         message: &Message,
-        context: &<AuxInfoParticipant as InnerProtocolParticipant>::Context,
+        context: &<AuxInfoParticipant<C> as InnerProtocolParticipant>::Context,
     ) -> Result<Self> {
         message.check_type(MessageType::Auxinfo(AuxinfoMessageType::R2Decommit))?;
-        let scheme: CommitmentScheme = deserialize!(&message.unverified_bytes)?;
+        let scheme: CommitmentScheme<C> = deserialize!(&message.unverified_bytes)?;
 
         // Public parameters in this decommit must be consistent with each other...
         scheme.clone().public_key.verify(context)?;