ethereum: implement schnorr verification contract deployment and related crypto (#36)

* basic schnorr verify working

* add schnorr-verify as submodule

* remove previous code

* Misc Ethereum work which will probably be disregarded

* add ecrecover hack test, worksgit add src/

* merge w develop

* starting w/ rust-web3

* trying to use ethers

* deploy_schnorr_verifier_contract finally working

* modify EthereumHram to use 27/28 for point parity

* updated address calc, solidity schnorr verify now working

* add verify failure to test

* update readme

* move ethereum/ to coins/

* un fmt coins/monero

* update .gitmodules

* fix cargo paths

* fix coins/monero

* add #[allow(non_snake_case)]

* un-fmt stuff

* move crypto to coins/ethereum

* move unit tests to ethereum/tests

* remove js, build w ethers

* update .gitignore

* address comments

* add q != 0 check

* update contract param order

* update contract license to AGPL

* update ethereum-serai license to GPL and fmt

* GPLv3 for ethereum-serai

* AGPLv3 for ethereum-serai

* actually fix license

Co-authored-by: Luke Parker <lukeparker5132@gmail.com>

coins/ethereum/tests/contract.rs

@@ -0,0 +1,60 @@
+use ethereum_serai::contract::{call_verify, deploy_schnorr_verifier_contract};
+use ethers::{prelude::*, utils::Anvil};
+use std::{convert::TryFrom, sync::Arc, time::Duration};
+
+#[tokio::test]
+async fn test_deploy_contract() {
+  let anvil = Anvil::new().spawn();
+  let wallet: LocalWallet = anvil.keys()[0].clone().into();
+  let provider =
+    Provider::<Http>::try_from(anvil.endpoint()).unwrap().interval(Duration::from_millis(10u64));
+  let client = Arc::new(SignerMiddleware::new(provider, wallet));
+
+  let _contract = deploy_schnorr_verifier_contract(client).await.unwrap();
+}
+
+#[tokio::test]
+async fn test_ecrecover_hack() {
+  use ethereum_serai::crypto;
+  use ethers::utils::keccak256;
+  use frost::{
+    algorithm::Schnorr,
+    curve::Secp256k1,
+    tests::{algorithm_machines, key_gen, sign},
+  };
+  use k256::elliptic_curve::bigint::ArrayEncoding;
+  use k256::{Scalar, U256};
+  use rand::rngs::OsRng;
+
+  let anvil = Anvil::new().spawn();
+  let wallet: LocalWallet = anvil.keys()[0].clone().into();
+  let provider =
+    Provider::<Http>::try_from(anvil.endpoint()).unwrap().interval(Duration::from_millis(10u64));
+  let chain_id = provider.get_chainid().await.unwrap();
+  let client = Arc::new(SignerMiddleware::new(provider, wallet));
+
+  let keys = key_gen::<_, Secp256k1>(&mut OsRng);
+  let group_key = keys[&1].group_key();
+
+  const MESSAGE: &'static [u8] = b"Hello, World!";
+  let hashed_message = keccak256(MESSAGE);
+  let chain_id = U256::from(Scalar::from(chain_id.as_u32()));
+
+  let full_message = &[chain_id.to_be_byte_array().as_slice(), &hashed_message].concat();
+
+  let sig = sign(
+    &mut OsRng,
+    algorithm_machines(&mut OsRng, Schnorr::<Secp256k1, crypto::EthereumHram>::new(), &keys),
+    full_message,
+  );
+  let mut processed_sig =
+    crypto::process_signature_for_contract(hashed_message, &sig.R, sig.s, &group_key, chain_id);
+
+  let contract = deploy_schnorr_verifier_contract(client).await.unwrap();
+  call_verify(&contract, &processed_sig).await.unwrap();
+
+  // test invalid signature fails
+  processed_sig.message[0] = 0;
+  let res = call_verify(&contract, &processed_sig).await;
+  assert!(res.is_err());
+}