feat: add kzg_to_versioned_hash (#4085)

Co-authored-by: Dan Cline <6798349+Rjected@users.noreply.github.com>

crates/consensus/common/src/validation.rs

@@ -1,11 +1,11 @@
 //! Collection of methods for block validation.
 use reth_interfaces::{consensus::ConsensusError, Result as RethResult};
 use reth_primitives::{
-    blobfee::calculate_excess_blob_gas,
     constants::{
         self,
         eip4844::{DATA_GAS_PER_BLOB, MAX_DATA_GAS_PER_BLOCK},
     },
+    eip4844::calculate_excess_blob_gas,
     BlockNumber, ChainSpec, Hardfork, Header, InvalidTransactionError, SealedBlock, SealedHeader,
     Transaction, TransactionSignedEcRecovered, TxEip1559, TxEip2930, TxEip4844, TxLegacy,
 };

crates/primitives/Cargo.toml

@@ -61,6 +61,7 @@ once_cell = "1.17.0"
 zstd = { version = "0.12", features = ["experimental"] }
 paste = "1.0"
 tempfile = "3.3"
+sha2 = "0.10.7"
 
 # proof related
 triehash = "0.8"

crates/primitives/src/constants/eip4844.rs

@@ -37,3 +37,6 @@ pub static KZG_TRUSTED_SETUP: Lazy<Arc<KzgSettings>> = Lazy::new(|| {
     file.write_all(TRUSTED_SETUP_RAW.as_bytes()).unwrap();
     Arc::new(KzgSettings::load_trusted_setup_file(file.path().into()).unwrap())
 });
+
+/// Commitment version of a KZG commitment
+pub const VERSIONED_HASH_VERSION_KZG: u8 = 0x01;

crates/primitives/src/eip4844.rs

@@ -1,6 +1,19 @@
 //! Helpers for working with EIP-4844 blob fee
+use crate::{
+    constants::eip4844::{TARGET_DATA_GAS_PER_BLOCK, VERSIONED_HASH_VERSION_KZG},
+    kzg::KzgCommitment,
+    H256,
+};
+use sha2::{Digest, Sha256};
 
-use crate::constants::eip4844::TARGET_DATA_GAS_PER_BLOCK;
+/// Calculates the versioned hash for a KzgCommitment
+///
+/// Specified in [EIP-4844](https://eips.ethereum.org/EIPS/eip-4844#header-extension)
+pub fn kzg_to_versioned_hash(commitment: KzgCommitment) -> H256 {
+    let mut res = Sha256::digest(commitment.as_slice());
+    res[0] = VERSIONED_HASH_VERSION_KZG;
+    H256::from_slice(&res)
+}
 
 /// Calculates the excess data gas for the next block, after applying the current set of blobs on
 /// top of the excess data gas.

crates/primitives/src/header.rs

@@ -1,6 +1,6 @@
 use crate::{
     basefee::calculate_next_block_base_fee,
-    blobfee::calculate_excess_blob_gas,
+    eip4844::calculate_excess_blob_gas,
     keccak256,
     proofs::{EMPTY_LIST_HASH, EMPTY_ROOT},
     BaseFeeParams, BlockBodyRoots, BlockHash, BlockNumHash, BlockNumber, Bloom, Bytes, H160, H256,

crates/primitives/src/lib.rs

@@ -23,13 +23,13 @@ pub mod abi;
 mod account;
 pub mod basefee;
 mod bits;
-pub mod blobfee;
 mod block;
 pub mod bloom;
 mod chain;
 mod compression;
 pub mod constants;
 pub mod contract;
+pub mod eip4844;
 mod forkid;
 pub mod fs;
 mod genesis;