Introduce PartyId to shorten the list of bounds we need to repeat eve…

…ry time

CHANGELOG.md

@@ -30,6 +30,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `DirectMessage::assert_is_none()` and `verify_is_some()`, same for `EchoBroadcast`. Users can now check that a part of the round message (echo or direct) is `None` as expected, and make a verifiable evidence if it is not. ([#46])
 - Re-export `digest` from the `session` module. ([#56])
 - Added `Message::destination()`. ([#56])
+- `PartyId` trait alias for the combination of bounds needed for a party identifier. ([#59])
 
 
 [#32]: https://github.com/entropyxyz/manul/pull/32
@@ -43,6 +44,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 [#56]: https://github.com/entropyxyz/manul/pull/56
 [#57]: https://github.com/entropyxyz/manul/pull/57
 [#58]: https://github.com/entropyxyz/manul/pull/58
+[#59]: https://github.com/entropyxyz/manul/pull/59
 
 
 ## [0.0.1] - 2024-10-12

examples/src/simple.rs

@@ -149,7 +149,7 @@ struct Round1Payload {
     x: u8,
 }
 
-impl<Id: 'static + Debug + Clone + Ord + Send + Sync> FirstRound<Id> for Round1<Id> {
+impl<Id: PartyId> FirstRound<Id> for Round1<Id> {
     type Inputs = Inputs<Id>;
     fn new(
         _rng: &mut impl CryptoRngCore,
@@ -179,7 +179,7 @@ impl<Id: 'static + Debug + Clone + Ord + Send + Sync> FirstRound<Id> for Round1<
     }
 }
 
-impl<Id: 'static + Debug + Clone + Ord + Send + Sync> Round<Id> for Round1<Id> {
+impl<Id: PartyId> Round<Id> for Round1<Id> {
     type Protocol = SimpleProtocol;
 
     fn id(&self) -> RoundId {
@@ -305,7 +305,7 @@ pub(crate) struct Round2Message {
     pub(crate) your_position: u8,
 }
 
-impl<Id: 'static + Debug + Clone + Ord + Send + Sync> Round<Id> for Round2<Id> {
+impl<Id: PartyId> Round<Id> for Round2<Id> {
     type Protocol = SimpleProtocol;
 
     fn id(&self) -> RoundId {

examples/src/simple_malicious.rs

@@ -3,8 +3,8 @@ use core::fmt::Debug;
 
 use manul::{
     protocol::{
-        Artifact, DirectMessage, FinalizeError, FinalizeOutcome, FirstRound, LocalError, Payload, ProtocolMessagePart,
-        Round, Serializer,
+        Artifact, DirectMessage, FinalizeError, FinalizeOutcome, FirstRound, LocalError, PartyId, Payload,
+        ProtocolMessagePart, Round, Serializer,
     },
     session::signature::Keypair,
     testing::{
@@ -36,7 +36,7 @@ struct MaliciousRound1<Id> {
     behavior: Behavior,
 }
 
-impl<Id: 'static + Debug + Clone + Ord + Send + Sync> RoundWrapper<Id> for MaliciousRound1<Id> {
+impl<Id: PartyId> RoundWrapper<Id> for MaliciousRound1<Id> {
     type InnerRound = Round1<Id>;
     fn inner_round_ref(&self) -> &Self::InnerRound {
         &self.round
@@ -46,7 +46,7 @@ impl<Id: 'static + Debug + Clone + Ord + Send + Sync> RoundWrapper<Id> for Malic
     }
 }
 
-impl<Id: 'static + Debug + Clone + Ord + Send + Sync> FirstRound<Id> for MaliciousRound1<Id> {
+impl<Id: PartyId> FirstRound<Id> for MaliciousRound1<Id> {
     type Inputs = MaliciousInputs<Id>;
     fn new(
         rng: &mut impl CryptoRngCore,
@@ -62,7 +62,7 @@ impl<Id: 'static + Debug + Clone + Ord + Send + Sync> FirstRound<Id> for Malicio
     }
 }
 
-impl<Id: 'static + Debug + Clone + Ord + Send + Sync> RoundOverride<Id> for MaliciousRound1<Id> {
+impl<Id: PartyId> RoundOverride<Id> for MaliciousRound1<Id> {
     fn make_direct_message(
         &self,
         rng: &mut impl CryptoRngCore,
@@ -115,7 +115,7 @@ struct MaliciousRound2<Id> {
     behavior: Behavior,
 }
 
-impl<Id: 'static + Debug + Clone + Ord + Send + Sync> RoundWrapper<Id> for MaliciousRound2<Id> {
+impl<Id: PartyId> RoundWrapper<Id> for MaliciousRound2<Id> {
     type InnerRound = Round2<Id>;
     fn inner_round_ref(&self) -> &Self::InnerRound {
         &self.round
@@ -125,7 +125,7 @@ impl<Id: 'static + Debug + Clone + Ord + Send + Sync> RoundWrapper<Id> for Malic
     }
 }
 
-impl<Id: 'static + Debug + Clone + Ord + Send + Sync> RoundOverride<Id> for MaliciousRound2<Id> {
+impl<Id: PartyId> RoundOverride<Id> for MaliciousRound2<Id> {
     fn make_direct_message(
         &self,
         rng: &mut impl CryptoRngCore,

manul/src/protocol.rs

@@ -23,7 +23,7 @@ pub use errors::{
 };
 pub use message::{DirectMessage, EchoBroadcast, NormalBroadcast, ProtocolMessagePart};
 pub use round::{
-    AnotherRound, Artifact, FinalizeOutcome, FirstRound, Payload, Protocol, ProtocolError, Round, RoundId,
+    AnotherRound, Artifact, FinalizeOutcome, FirstRound, PartyId, Payload, Protocol, ProtocolError, Round, RoundId,
 };
 pub use serialization::{Deserializer, Serializer};
 

manul/src/protocol/object_safe.rs

@@ -10,7 +10,7 @@ use rand_core::{CryptoRng, CryptoRngCore, RngCore};
 use super::{
     errors::{FinalizeError, LocalError, ReceiveError},
     message::{DirectMessage, EchoBroadcast, NormalBroadcast},
-    round::{Artifact, FinalizeOutcome, Payload, Protocol, Round, RoundId},
+    round::{Artifact, FinalizeOutcome, PartyId, Payload, Protocol, Round, RoundId},
     serialization::{Deserializer, Serializer},
 };
 
@@ -39,7 +39,7 @@ impl RngCore for BoxedRng<'_> {
 // Since we want `Round` methods to take `&mut impl CryptoRngCore` arguments
 // (which is what all cryptographic libraries generally take), it cannot be object-safe.
 // Thus we have to add this crate-private object-safe layer on top of `Round`.
-pub(crate) trait ObjectSafeRound<Id>: 'static + Debug + Send + Sync {
+pub(crate) trait ObjectSafeRound<Id: PartyId>: 'static + Debug + Send + Sync {
     type Protocol: Protocol;
 
     fn id(&self) -> RoundId;
@@ -98,7 +98,11 @@ pub(crate) struct ObjectSafeRoundWrapper<Id, R> {
     phantom: PhantomData<fn(Id) -> Id>,
 }
 
-impl<Id: 'static, R: Round<Id>> ObjectSafeRoundWrapper<Id, R> {
+impl<Id, R> ObjectSafeRoundWrapper<Id, R>
+where
+    Id: PartyId,
+    R: Round<Id>,
+{
     pub fn new(round: R) -> Self {
         Self {
             round,
@@ -109,7 +113,7 @@ impl<Id: 'static, R: Round<Id>> ObjectSafeRoundWrapper<Id, R> {
 
 impl<Id, R> ObjectSafeRound<Id> for ObjectSafeRoundWrapper<Id, R>
 where
-    Id: 'static + Debug,
+    Id: PartyId,
     R: Round<Id>,
 {
     type Protocol = <R as Round<Id>>::Protocol;
@@ -203,7 +207,7 @@ where
 // so we have to provide this workaround.
 impl<Id, P> dyn ObjectSafeRound<Id, Protocol = P>
 where
-    Id: 'static,
+    Id: PartyId,
     P: Protocol,
 {
     pub fn try_downcast<T: Round<Id>>(self: Box<Self>) -> Result<T, Box<Self>> {

manul/src/protocol/round.rs

@@ -28,7 +28,7 @@ pub enum FinalizeOutcome<Id, P: Protocol> {
 
 impl<Id, P> FinalizeOutcome<Id, P>
 where
-    Id: 'static + Debug,
+    Id: PartyId,
     P: Protocol,
 {
     /// A helper method to create an [`AnotherRound`](`Self::AnotherRound`) variant.
@@ -44,7 +44,7 @@ pub struct AnotherRound<Id, P: Protocol>(Box<dyn ObjectSafeRound<Id, Protocol =
 
 impl<Id, P> AnotherRound<Id, P>
 where
-    Id: 'static + Debug,
+    Id: PartyId,
     P: Protocol,
 {
     /// Wraps an object implementing [`Round`].
@@ -301,7 +301,7 @@ impl Artifact {
 ///
 /// This is a round that can be created directly;
 /// all the others are only reachable throud [`Round::finalize`] by the execution layer.
-pub trait FirstRound<Id>: Round<Id> + Sized {
+pub trait FirstRound<Id: PartyId>: Round<Id> + Sized {
     /// Additional inputs for the protocol (besides the mandatory ones in [`new`](`Self::new`)).
     type Inputs;
 
@@ -317,6 +317,11 @@ pub trait FirstRound<Id>: Round<Id> + Sized {
     ) -> Result<Self, LocalError>;
 }
 
+/// A trait alias for the combination of traits needed for a party identifier.
+pub trait PartyId: 'static + Debug + Clone + Ord + Send + Sync {}
+
+impl<T> PartyId for T where T: 'static + Debug + Clone + Ord + Send + Sync {}
+
 /**
 A type representing a single round of a protocol.
 
@@ -326,7 +331,7 @@ The way a round will be used by an external caller:
 - process received messages from other nodes (by calling [`receive_message`](`Self::receive_message`));
 - attempt to finalize (by calling [`finalize`](`Self::finalize`)) to produce the next round, or return a result.
 */
-pub trait Round<Id>: 'static + Debug + Send + Sync {
+pub trait Round<Id: PartyId>: 'static + Debug + Send + Sync {
     /// The protocol this round is a part of.
     type Protocol: Protocol;
 

manul/src/session/session.rs

@@ -24,8 +24,8 @@ use super::{
 };
 use crate::protocol::{
     Artifact, Deserializer, DirectMessage, EchoBroadcast, FinalizeError, FinalizeOutcome, FirstRound, NormalBroadcast,
-    ObjectSafeRound, ObjectSafeRoundWrapper, Payload, Protocol, ProtocolMessagePart, ReceiveError, ReceiveErrorType,
-    Round, RoundId, Serializer,
+    ObjectSafeRound, ObjectSafeRoundWrapper, PartyId, Payload, Protocol, ProtocolMessagePart, ReceiveError,
+    ReceiveErrorType, Round, RoundId, Serializer,
 };
 
 /// A set of types needed to execute a session.
@@ -40,14 +40,7 @@ pub trait SessionParameters: 'static {
     type Digest: Digest;
 
     /// The verifier type, which will also serve as a node identifier.
-    type Verifier: Debug
-        + Clone
-        + Ord
-        + DigestVerifier<Self::Digest, Self::Signature>
-        + Serialize
-        + for<'de> Deserialize<'de>
-        + Send
-        + Sync;
+    type Verifier: PartyId + DigestVerifier<Self::Digest, Self::Signature> + Serialize + for<'de> Deserialize<'de>;
 
     /// The signature type corresponding to [`Signer`](`Self::Signer`) and [`Verifier`](`Self::Verifier`).
     type Signature: Serialize + for<'de> Deserialize<'de>;

manul/src/testing/macros.rs

@@ -3,12 +3,12 @@ use alloc::collections::BTreeMap;
 use rand_core::CryptoRngCore;
 
 use crate::protocol::{
-    Artifact, DirectMessage, EchoBroadcast, FinalizeError, FinalizeOutcome, LocalError, NormalBroadcast, Payload,
-    Round, Serializer,
+    Artifact, DirectMessage, EchoBroadcast, FinalizeError, FinalizeOutcome, LocalError, NormalBroadcast, PartyId,
+    Payload, Round, Serializer,
 };
 
 /// A trait defining a wrapper around an existing type implementing [`Round`].
-pub trait RoundWrapper<Id>: 'static + Sized + Send + Sync {
+pub trait RoundWrapper<Id: PartyId>: 'static + Sized + Send + Sync {
     /// The inner round type.
     type InnerRound: Round<Id>;
 
@@ -24,7 +24,7 @@ pub trait RoundWrapper<Id>: 'static + Sized + Send + Sync {
 /// Intended to be used with the [`round_override`] macro to generate the [`Round`] implementation.
 ///
 /// The blanket implementations delegate to the methods of the wrapped round.
-pub trait RoundOverride<Id>: RoundWrapper<Id> {
+pub trait RoundOverride<Id: PartyId>: RoundWrapper<Id> {
     /// An override for [`Round::make_direct_message_with_artifact`].
     fn make_direct_message_with_artifact(
         &self,
@@ -90,8 +90,8 @@ macro_rules! round_override {
     ($round: ident) => {
         impl<Id> Round<Id> for $round<Id>
         where
-            Id: Debug,
-            $round<Id>: RoundOverride<Id>,
+            Id: $crate::protocol::PartyId,
+            $round<Id>: $crate::testing::RoundOverride<Id>,
         {
             type Protocol =
                 <<$round<Id> as $crate::testing::RoundWrapper<Id>>::InnerRound as $crate::protocol::Round<Id>>::Protocol;

manul/src/testing/run_sync.rs

@@ -34,8 +34,8 @@ fn propagate<P, SP>(
     accum: RoundAccumulator<P, SP>,
 ) -> Result<(State<P, SP>, Vec<RoundMessage<SP>>), LocalError>
 where
-    P: 'static + Protocol,
-    SP: 'static + SessionParameters,
+    P: Protocol,
+    SP: SessionParameters,
 {
     let mut messages = Vec::new();
 
@@ -94,8 +94,8 @@ pub fn run_sync<R, SP>(
     inputs: Vec<(SP::Signer, R::Inputs)>,
 ) -> Result<BTreeMap<SP::Verifier, SessionReport<R::Protocol, SP>>, LocalError>
 where
-    R: 'static + FirstRound<SP::Verifier>,
-    SP: 'static + SessionParameters,
+    R: FirstRound<SP::Verifier>,
+    SP: SessionParameters,
 {
     let session_id = SessionId::random::<SP>(rng);