feat: implement eth2util/hash

crates/eth2util/src/hash.rs

@@ -0,0 +1,38 @@
+use pluto_eth2api::spec::phase0::{Root, Slot};
+use pluto_ssz::{HashWalker, Hasher, HasherError};
+
+/// Hashing error.
+#[derive(Debug, thiserror::Error)]
+pub enum HashError {
+    /// Failed to hash the slot root.
+    #[error("hash epoch: {0}")]
+    HashEpoch(#[from] HasherError),
+}
+
+/// Result type for hash helpers.
+type Result<T> = std::result::Result<T, HashError>;
+
+/// Returns the SSZ hash root of the slot.
+pub fn slot_hash_root(slot: Slot) -> Result<Root> {
+    let mut hasher = Hasher::default();
+    let index = hasher.index();
+
+    hasher.put_uint64(slot)?;
+    hasher.merkleize(index)?;
+
+    Ok(hasher.hash_root()?)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_slot_hash_root() {
+        let resp = slot_hash_root(2).expect("hash slot");
+        assert_eq!(
+            hex::encode(resp),
+            "0200000000000000000000000000000000000000000000000000000000000000"
+        );
+    }
+}

crates/eth2util/src/lib.rs

@@ -13,6 +13,9 @@ pub mod rlp;
 /// EIP712 utilities.
 pub mod eip712;
 
+/// SSZ hash helpers.
+pub mod hash;
+
 /// Network utilities.
 pub mod network;