pallet-revive 0.7.2

// This file is part of Substrate.

// Copyright (C) Parity Technologies (UK) Ltd.
// SPDX-License-Identifier: Apache-2.0

// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use crate::{
	precompiles::{BuiltinAddressMatcher, Error, Ext, PrimitivePrecompile},
	wasm::RuntimeCosts,
	Config,
};
use alloc::vec::Vec;
use core::{marker::PhantomData, num::NonZero};

pub struct EcRecover<T>(PhantomData<T>);

impl<T: Config> PrimitivePrecompile for EcRecover<T> {
	type T = T;
	const MATCHER: BuiltinAddressMatcher = BuiltinAddressMatcher::Fixed(NonZero::new(1).unwrap());
	const HAS_CONTRACT_INFO: bool = false;

	fn call(
		_address: &[u8; 20],
		i: Vec<u8>,
		env: &mut impl Ext<T = Self::T>,
	) -> Result<Vec<u8>, Error> {
		env.gas_meter_mut().charge(RuntimeCosts::EcdsaRecovery)?;
		let mut input = [0u8; 128];
		let len = i.len().min(128);
		input[..len].copy_from_slice(&i[..len]);

		let mut msg = [0u8; 32];
		let mut sig = [0u8; 65];

		msg[0..32].copy_from_slice(&input[0..32]);
		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(Vec::new());
		}

		let data = match sp_io::crypto::secp256k1_ecdsa_recover(&sig, &msg) {
			Ok(pubkey) => {
				let mut address = sp_io::hashing::keccak_256(&pubkey);
				address[0..12].copy_from_slice(&[0u8; 12]);
				address.to_vec()
			},
			Err(_) => Vec::new(),
		};

		Ok(data)
	}
}

#[cfg(test)]
mod tests {
	use super::*;
	use crate::{precompiles::tests::run_test_vectors, tests::Test};

	#[test]
	fn test_ecrecover() {
		run_test_vectors::<EcRecover<Test>>(include_str!("./testdata/1-ecRecover.json"));
	}
}