fix: construct v properly relative to upstream api changes (#47)

* fix: construct v properly relative to upstream api changes

* fix: helper function, plus a test

* fix: doc comments

* chore: fmt

Author: rswanson

src/lib.rs

@@ -2,3 +2,4 @@ pub mod config;
 pub mod service;
 pub mod signer;
 pub mod tasks;
+pub mod utils;

src/tasks/submit.rs

@@ -2,12 +2,12 @@ use crate::{
     config::{Provider, ZenithInstance},
     signer::LocalOrAws,
     tasks::block::InProgressBlock,
+    utils::extract_signature_components,
 };
 use alloy::{
     consensus::{constants::GWEI_TO_WEI, SimpleCoder},
     eips::BlockNumberOrTag,
-    network::TransactionBuilder,
-    network::TransactionBuilder4844,
+    network::{TransactionBuilder, TransactionBuilder4844},
     primitives::{FixedBytes, U256},
     providers::{Provider as _, SendableTx, WalletProvider},
     rpc::types::eth::TransactionRequest,
@@ -134,9 +134,7 @@ impl SubmitTask {
         resp: &SignResponse,
         in_progress: &InProgressBlock,
     ) -> eyre::Result<ControlFlow> {
-        let v = resp.sig.v().into();
-        let r: FixedBytes<32> = resp.sig.r().into();
-        let s: FixedBytes<32> = resp.sig.s().into();
+        let (v, r, s) = extract_signature_components(&resp.sig);
 
         let header = Zenith::BlockHeader {
             hostBlockNumber: resp.req.host_block_number,

src/utils.rs

@@ -0,0 +1,32 @@
+use alloy::primitives::{PrimitiveSignature, B256};
+
+/// Extracts the components of a signature.
+/// Currently alloy has no function for extracting the components of a signature.
+/// Returns a tuple of (v, r, s) where:
+/// - `v` is the recovery id
+/// - `r` is the r component of the signature
+/// - `s` is the s component of the signature
+pub fn extract_signature_components(sig: &PrimitiveSignature) -> (u8, B256, B256) {
+    let v = sig.as_bytes()[64];
+    let r = sig.r().into();
+    let s = sig.s().into();
+    (v, r, s)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use alloy::primitives::U256;
+
+    #[test]
+    fn test_extract_signature_components() {
+        let r = U256::from(123456789);
+        let s = U256::from(987654321);
+        let y_parity = true;
+        let sig = PrimitiveSignature::new(r, s, y_parity);
+        let (v, r_bytes, s_bytes) = extract_signature_components(&sig);
+        assert_eq!(v, 28);
+        assert_eq!(U256::from_be_bytes(r_bytes.0), r);
+        assert_eq!(U256::from_be_bytes(s_bytes.0), s);
+    }
+}