update ecrecover ref: polkadot-evm/frontier#964

modules/evm/src/precompiles/blake2/mod.rs

@@ -36,6 +36,7 @@ impl Precompile for Blake2F {
 		const BLAKE2_F_ARG_LEN: usize = 213;
 
 		let input = handle.input();
+
 		if input.len() != BLAKE2_F_ARG_LEN {
 			return Err(PrecompileFailure::Error {
 				exit_status: ExitError::Other(
@@ -50,6 +51,7 @@ impl Precompile for Blake2F {
 
 		let gas_cost: u64 = (rounds as u64) * Blake2F::GAS_COST_PER_ROUND;
 		handle.record_cost(gas_cost)?;
+
 		let input = handle.input();
 
 		// we use from_le_bytes below to effectively swap byte order to LE if architecture is BE

modules/evm/src/precompiles/ecrecover.rs

@@ -36,15 +36,15 @@ impl LinearCostPrecompile for ECRecover {
 		let mut sig = [0u8; 65];
 
 		msg[0..32].copy_from_slice(&input[0..32]);
-		sig[0..32].copy_from_slice(&input[64..96]);
-		sig[32..64].copy_from_slice(&input[96..128]);
-
-		sig[64] = match input[63] {
-			v if v > 26 && input[32..63] == [0; 31] => v - 27,
-			_ => {
-				return Ok((ExitSucceed::Returned, [0u8; 0].to_vec()));
-			}
-		};
+		sig[0..32].copy_from_slice(&input[64..96]); // r
+		sig[32..64].copy_from_slice(&input[96..128]); // s
+		sig[64] = input[63]; // v
+
+		// v can only be 27 or 28 on the full 32 bytes value.
+		// https://github.com/ethereum/go-ethereum/blob/a907d7e81aaeea15d80b2d3209ad8e08e3bf49e0/core/vm/contracts.go#L177
+		if input[32..63] != [0u8; 31] || ![27, 28].contains(&input[63]) {
+			return Ok((ExitSucceed::Returned, [0u8; 0].to_vec()));
+		}
 
 		let result = match sp_io::crypto::secp256k1_ecdsa_recover(&sig, &msg) {
 			Ok(pubkey) => {