Define all coordinator transaction types

coordinator/src/main.rs

@@ -1,2 +1,7 @@
+mod transaction;
+
+#[cfg(test)]
+mod tests;
+
 #[tokio::main]
 async fn main() {}

coordinator/src/tests/mod.rs

@@ -0,0 +1 @@
+mod transaction;

coordinator/src/tests/transaction.rs

@@ -0,0 +1,81 @@
+use core::fmt::Debug;
+use std::collections::HashMap;
+
+use rand_core::{RngCore, OsRng};
+
+use frost::Participant;
+
+use tributary::{ReadWrite, tests::random_signed};
+
+use crate::transaction::{SignData, Transaction};
+
+fn random_u32<R: RngCore>(rng: &mut R) -> u32 {
+  u32::try_from(rng.next_u64() >> 32).unwrap()
+}
+
+fn random_vec<R: RngCore>(rng: &mut R, limit: usize) -> Vec<u8> {
+  let len = usize::try_from(rng.next_u64() % u64::try_from(limit).unwrap()).unwrap();
+  let mut res = vec![0; len];
+  rng.fill_bytes(&mut res);
+  res
+}
+
+fn random_sign_data<R: RngCore>(rng: &mut R) -> SignData {
+  let mut plan = [0; 32];
+  rng.fill_bytes(&mut plan);
+
+  SignData {
+    plan,
+    attempt: random_u32(&mut OsRng),
+
+    data: random_vec(&mut OsRng, 512),
+
+    signed: random_signed(&mut OsRng),
+  }
+}
+
+fn test_read_write<RW: Eq + Debug + ReadWrite>(value: RW) {
+  assert_eq!(value, RW::read::<&[u8]>(&mut value.serialize().as_ref()).unwrap());
+}
+
+#[test]
+fn serialize_sign_data() {
+  test_read_write(random_sign_data(&mut OsRng));
+}
+
+#[test]
+fn serialize_transaction() {
+  test_read_write(Transaction::DkgCommitments(
+    random_u32(&mut OsRng),
+    random_vec(&mut OsRng, 512),
+    random_signed(&mut OsRng),
+  ));
+
+  {
+    // This supports a variable share length, yet share length is expected to be constant among
+    // shares
+    let share_len = usize::try_from(96 + (OsRng.next_u64() % 32)).unwrap();
+    // Create a valid map of shares
+    let mut shares = HashMap::new();
+    // Create up to 500 participants
+    for i in 0 .. (OsRng.next_u64() % 500) {
+      let mut share = vec![0; share_len];
+      OsRng.fill_bytes(&mut share);
+      shares.insert(Participant::new(u16::try_from(i + 1).unwrap()).unwrap(), share);
+    }
+
+    test_read_write(Transaction::DkgShares(
+      random_u32(&mut OsRng),
+      shares,
+      random_signed(&mut OsRng),
+    ));
+  }
+
+  test_read_write(Transaction::SignPreprocess(random_sign_data(&mut OsRng)));
+  test_read_write(Transaction::SignShare(random_sign_data(&mut OsRng)));
+
+  test_read_write(Transaction::FinalizedBlock(OsRng.next_u64()));
+
+  test_read_write(Transaction::BatchPreprocess(random_sign_data(&mut OsRng)));
+  test_read_write(Transaction::BatchShare(random_sign_data(&mut OsRng)));
+}

coordinator/src/transaction.rs

@@ -0,0 +1,223 @@
+use std::{io, collections::HashMap};
+
+use blake2::{Digest, Blake2s256};
+
+use frost::Participant;
+
+#[rustfmt::skip]
+use tributary::{
+  ReadWrite, Signed, TransactionError, TransactionKind, Transaction as TransactionTrait
+};
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct SignData {
+  pub plan: [u8; 32],
+  pub attempt: u32,
+
+  pub data: Vec<u8>,
+
+  pub signed: Signed,
+}
+
+impl ReadWrite for SignData {
+  fn read<R: io::Read>(reader: &mut R) -> io::Result<Self> {
+    let mut plan = [0; 32];
+    reader.read_exact(&mut plan)?;
+
+    let mut attempt = [0; 4];
+    reader.read_exact(&mut attempt)?;
+    let attempt = u32::from_le_bytes(attempt);
+
+    let data = {
+      let mut data_len = [0; 2];
+      reader.read_exact(&mut data_len)?;
+      let mut data = vec![0; usize::from(u16::from_le_bytes(data_len))];
+      reader.read_exact(&mut data)?;
+      data
+    };
+
+    let signed = Signed::read(reader)?;
+
+    Ok(SignData { plan, attempt, data, signed })
+  }
+
+  fn write<W: io::Write>(&self, writer: &mut W) -> io::Result<()> {
+    writer.write_all(&self.plan)?;
+    writer.write_all(&self.attempt.to_le_bytes())?;
+
+    writer.write_all(&u16::try_from(self.data.len()).unwrap().to_le_bytes())?;
+    writer.write_all(&self.data)?;
+
+    self.signed.write(writer)
+  }
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub enum Transaction {
+  // Once this completes successfully, no more instances should be created.
+  DkgCommitments(u32, Vec<u8>, Signed),
+  DkgShares(u32, HashMap<Participant, Vec<u8>>, Signed),
+
+  SignPreprocess(SignData),
+  SignShare(SignData),
+
+  FinalizedBlock(u64),
+
+  BatchPreprocess(SignData),
+  BatchShare(SignData),
+}
+
+impl ReadWrite for Transaction {
+  fn read<R: io::Read>(reader: &mut R) -> io::Result<Self> {
+    let mut kind = [0];
+    reader.read_exact(&mut kind)?;
+
+    match kind[0] {
+      0 => {
+        let mut attempt = [0; 4];
+        reader.read_exact(&mut attempt)?;
+        let attempt = u32::from_le_bytes(attempt);
+
+        let commitments = {
+          let mut commitments_len = [0; 2];
+          reader.read_exact(&mut commitments_len)?;
+          let mut commitments = vec![0; usize::from(u16::from_le_bytes(commitments_len))];
+          reader.read_exact(&mut commitments)?;
+          commitments
+        };
+
+        let signed = Signed::read(reader)?;
+
+        Ok(Transaction::DkgCommitments(attempt, commitments, signed))
+      }
+
+      1 => {
+        let mut attempt = [0; 4];
+        reader.read_exact(&mut attempt)?;
+        let attempt = u32::from_le_bytes(attempt);
+
+        let shares = {
+          let mut share_quantity = [0; 2];
+          reader.read_exact(&mut share_quantity)?;
+
+          let mut share_len = [0; 1];
+          reader.read_exact(&mut share_len)?;
+          let share_len = usize::from(share_len[0]);
+
+          let mut shares = HashMap::new();
+          for i in 0 .. u16::from_le_bytes(share_quantity) {
+            let participant = Participant::new(i + 1).unwrap();
+            let mut share = vec![0; share_len];
+            reader.read_exact(&mut share)?;
+            shares.insert(participant, share);
+          }
+          shares
+        };
+
+        let signed = Signed::read(reader)?;
+
+        Ok(Transaction::DkgShares(attempt, shares, signed))
+      }
+
+      2 => SignData::read(reader).map(Transaction::SignPreprocess),
+      3 => SignData::read(reader).map(Transaction::SignShare),
+
+      4 => {
+        let mut block = [0; 8];
+        reader.read_exact(&mut block)?;
+        Ok(Transaction::FinalizedBlock(u64::from_le_bytes(block)))
+      }
+
+      5 => SignData::read(reader).map(Transaction::BatchPreprocess),
+      6 => SignData::read(reader).map(Transaction::BatchShare),
+      _ => Err(io::Error::new(io::ErrorKind::Other, "invalid transaction type")),
+    }
+  }
+
+  fn write<W: io::Write>(&self, writer: &mut W) -> io::Result<()> {
+    match self {
+      Transaction::DkgCommitments(attempt, commitments, signed) => {
+        writer.write_all(&[0])?;
+        writer.write_all(&attempt.to_le_bytes())?;
+        writer.write_all(&u16::try_from(commitments.len()).unwrap().to_le_bytes())?;
+        writer.write_all(commitments)?;
+        signed.write(writer)
+      }
+
+      Transaction::DkgShares(attempt, shares, signed) => {
+        writer.write_all(&[1])?;
+        writer.write_all(&attempt.to_le_bytes())?;
+        writer.write_all(&u16::try_from(shares.len()).unwrap().to_le_bytes())?;
+        let mut share_len = None;
+        for participant in 0 .. shares.len() {
+          let share = &shares[&Participant::new(u16::try_from(participant + 1).unwrap()).unwrap()];
+          if let Some(share_len) = share_len {
+            if share.len() != share_len {
+              panic!("variable length shares");
+            }
+          } else {
+            writer.write_all(&[u8::try_from(share.len()).unwrap()])?;
+            share_len = Some(share.len());
+          }
+
+          writer.write_all(share)?;
+        }
+        signed.write(writer)
+      }
+
+      Transaction::SignPreprocess(data) => {
+        writer.write_all(&[2])?;
+        data.write(writer)
+      }
+      Transaction::SignShare(data) => {
+        writer.write_all(&[3])?;
+        data.write(writer)
+      }
+
+      Transaction::FinalizedBlock(block) => {
+        writer.write_all(&[4])?;
+        writer.write_all(&block.to_le_bytes())
+      }
+
+      Transaction::BatchPreprocess(data) => {
+        writer.write_all(&[5])?;
+        data.write(writer)
+      }
+      Transaction::BatchShare(data) => {
+        writer.write_all(&[6])?;
+        data.write(writer)
+      }
+    }
+  }
+}
+
+impl TransactionTrait for Transaction {
+  fn kind(&self) -> TransactionKind {
+    match self {
+      Transaction::DkgCommitments(_, _, signed) => TransactionKind::Signed(signed.clone()),
+      Transaction::DkgShares(_, _, signed) => TransactionKind::Signed(signed.clone()),
+
+      Transaction::SignPreprocess(data) => TransactionKind::Signed(data.signed.clone()),
+      Transaction::SignShare(data) => TransactionKind::Signed(data.signed.clone()),
+
+      Transaction::FinalizedBlock(_) => TransactionKind::Provided,
+
+      Transaction::BatchPreprocess(data) => TransactionKind::Signed(data.signed.clone()),
+      Transaction::BatchShare(data) => TransactionKind::Signed(data.signed.clone()),
+    }
+  }
+
+  fn hash(&self) -> [u8; 32] {
+    let mut tx = self.serialize();
+    if let TransactionKind::Signed(signed) = self.kind() {
+      assert_eq!(&tx[(tx.len() - 64) ..], &signed.signature.serialize());
+      tx.truncate(tx.len() - 64);
+    }
+    Blake2s256::digest(tx).into()
+  }
+
+  fn verify(&self) -> Result<(), TransactionError> {
+    // TODO: Augment with checks that the Vecs can be deser'd and are for recognized IDs
+    Ok(())
+  }
+}