Refactor QC traits

Cargo.toml

@@ -10,8 +10,8 @@ repository = "https://github.com/EspressoSystems/hotshot-primitives"
 
 [dependencies]
 anyhow = "1.0"
-ark-bls12-381 = "0.4.0"
 ark-bls12-377 = "0.4.0"
+ark-bls12-381 = "0.4.0"
 ark-bn254 = "0.4.0"
 ark-ec = "0.4.0"
 ark-ff = "0.4.0"
@@ -26,18 +26,18 @@ digest = { version = "0.10" }
 displaydoc = { version = "0.2.3", default-features = false }
 ethereum-types = { version = "0.14.1", features = ["impl-serde"] }
 generic-array = "0.14.7"
-jf-relation = { git = "https://github.com/espressosystems/jellyfish"}
-jf-primitives = { git = "https://github.com/espressosystems/jellyfish"}
-jf-utils = { git = "https://github.com/espressosystems/jellyfish"}
+jf-primitives = { git = "https://github.com/espressosystems/jellyfish" }
+jf-relation = { git = "https://github.com/espressosystems/jellyfish" }
+jf-utils = { git = "https://github.com/espressosystems/jellyfish" }
 serde = { version = "1.0", default-features = false, features = ["derive", "rc"] }
 sha3 = "0.10.7"
 tagged-base64 = { git = "https://github.com/espressosystems/tagged-base64", tag = "0.3.0" }
 thiserror = "1.0"
 typenum = { version = "1.16.0" }
 
 [dev-dependencies]
-jf-primitives = { git = "https://github.com/espressosystems/jellyfish", features = ["test-srs"]}
 criterion = { version = "0.5.1", features = ["html_reports"] }
+jf-primitives = { git = "https://github.com/espressosystems/jellyfish", features = ["test-srs"] }
 sha2 = { version = "0.10" }
 
 [[bench]]

flake.nix

@@ -19,19 +19,19 @@
   inputs.pre-commit-hooks.url = "github:cachix/pre-commit-hooks.nix";
   inputs.pre-commit-hooks.inputs.nixpkgs.follows = "nixpkgs";
 
-  outputs = { self, nixpkgs, flake-utils, flake-compat, rust-overlay, pre-commit-hooks, ... }:
+  outputs = { self, nixpkgs, flake-utils, flake-compat, rust-overlay
+    , pre-commit-hooks, ... }:
     flake-utils.lib.eachDefaultSystem (system:
       let
         overlays = [ (import rust-overlay) ];
         pkgs = import nixpkgs { inherit system overlays; };
-        nightlyToolchain = pkgs.rust-bin.selectLatestNightlyWith
-          (toolchain: toolchain.minimal.override { extensions = [ "rustfmt" ]; });
+        nightlyToolchain = pkgs.rust-bin.selectLatestNightlyWith (toolchain:
+          toolchain.minimal.override { extensions = [ "rustfmt" ]; });
 
         stableToolchain = pkgs.rust-bin.stable.latest.minimal.override {
           extensions = [ "clippy" "llvm-tools-preview" "rust-src" ];
         };
-      in with pkgs;
-      {
+      in with pkgs; {
         check = {
           pre-commit-check = pre-commit-hooks.lib.${system}.run {
             src = ./.;
@@ -74,18 +74,20 @@
             nightlyToolchain
             cargo-sort
 
-          ] ++ lib.optionals stdenv.isDarwin [ darwin.apple_sdk.frameworks.Security ];
+          ] ++ lib.optionals stdenv.isDarwin
+            [ darwin.apple_sdk.frameworks.Security ];
 
           shellHook = ''
             export RUST_BACKTRACE=full
             export PATH="$PATH:$(pwd)/target/debug:$(pwd)/target/release"
+            # Prevent cargo aliases from using programs in `~/.cargo` to avoid conflicts with local rustup installations.
+            export CARGO_HOME=$HOME/.cargo-nix
 
             # Ensure `cargo fmt` uses `rustfmt` from nightly.
             export RUSTFMT="${nightlyToolchain}/bin/rustfmt"
           ''
-          # install pre-commit hooks
-          + self.check.${system}.pre-commit-check.shellHook;
+            # install pre-commit hooks
+            + self.check.${system}.pre-commit-check.shellHook;
         };
-      }
-    );
+      });
 }

src/lib.rs

@@ -2,7 +2,7 @@
 // #![warn(missing_docs)] // TODO need rustdoc for stake_table
 
 pub mod circuit;
-pub mod quorum_certificate;
+pub mod qc;
 pub mod stake_table;
 pub mod vdf;
 pub mod vid;

src/qc.rs

@@ -0,0 +1,75 @@
+//! Quorum Certificate traits and implementations.
+
+use ark_std::{
+    rand::{CryptoRng, RngCore},
+    vec::Vec,
+};
+use bitvec::prelude::*;
+use generic_array::{ArrayLength, GenericArray};
+use jf_primitives::errors::PrimitivesError;
+use jf_primitives::signatures::AggregateableSignatureSchemes;
+use serde::{Deserialize, Serialize};
+
+pub mod bit_vector;
+
+/// Trait for validating a QC built from different signatures on the same message
+pub trait QuorumCertificate<A: AggregateableSignatureSchemes + Serialize + for<'a> Deserialize<'a>>
+{
+    /// Public parameters for generating the QC
+    /// E.g: snark proving/verifying keys, list of (or pointer to) public keys stored in the smart contract.
+    type QCProverParams: Serialize + for<'a> Deserialize<'a>;
+
+    /// Public parameters for validating the QC
+    /// E.g: verifying keys, stake table commitment
+    type QCVerifierParams: Serialize + for<'a> Deserialize<'a>;
+
+    /// Allows to fix the size of the message at compilation time.
+    type MessageLength: ArrayLength<A::MessageUnit>;
+
+    /// Type of the actual quorum certificate object
+    type QC;
+
+    /// Produces a partial signature on a message with a single user signing key
+    /// NOTE: the original message (vote) should be prefixed with the hash of the stake table.
+    /// * `agg_sig_pp` - public parameters for aggregate signature
+    /// * `message` - message to be signed
+    /// * `sk` - user signing key
+    /// * `returns` - a "simple" signature
+    fn sign<R: CryptoRng + RngCore>(
+        agg_sig_pp: &A::PublicParameter,
+        message: &GenericArray<A::MessageUnit, Self::MessageLength>,
+        sk: &A::SigningKey,
+        prng: &mut R,
+    ) -> Result<A::Signature, PrimitivesError>;
+
+    /// Computes an aggregated signature from a set of partial signatures and the verification keys involved
+    /// * `qc_pp` - public parameters for generating the QC
+    /// * `signers` - a bool vector indicating the list of verification keys corresponding to the set of partial signatures
+    /// * `sigs` - partial signatures on the same message
+    /// * `returns` - an error if some of the partial signatures provided are invalid
+    ///     or the number of partial signatures / verifications keys are different.
+    ///     Otherwise return an obtained quorum certificate.
+    fn assemble(
+        qc_pp: &Self::QCProverParams,
+        signers: &BitSlice,
+        sigs: &[A::Signature],
+    ) -> Result<Self::QC, PrimitivesError>;
+
+    /// Checks an aggregated signature over some message provided as input
+    /// * `qc_vp` - public parameters for validating the QC
+    /// * `message` - message to check the aggregated signature against
+    /// * `qc` - quroum certificate
+    /// * `returns` - nothing if the signature is valid, an error otherwise.
+    fn check(
+        qc_vp: &Self::QCVerifierParams,
+        message: &GenericArray<A::MessageUnit, Self::MessageLength>,
+        qc: &Self::QC,
+    ) -> Result<(), PrimitivesError>;
+
+    /// Trace the list of signers given a qc.
+    fn trace(
+        qc_vp: &Self::QCVerifierParams,
+        message: &GenericArray<A::MessageUnit, Self::MessageLength>,
+        qc: &Self::QC,
+    ) -> Result<Vec<A::VerificationKey>, PrimitivesError>;
+}