ethers-rs/ethers-middleware/src/signer.rs

347 lines
11 KiB
Rust

use ethers_core::types::{
transaction::eip2718::TypedTransaction, Address, BlockId, Bytes, Signature,
};
use ethers_providers::{maybe, FromErr, Middleware, PendingTransaction};
use ethers_signers::Signer;
use async_trait::async_trait;
use thiserror::Error;
#[derive(Clone, Debug)]
/// Middleware used for locally signing transactions, compatible with any implementer
/// of the [`Signer`] trait.
///
/// # Example
///
/// ```no_run
/// use ethers_providers::{Middleware, Provider, Http};
/// use ethers_signers::LocalWallet;
/// use ethers_middleware::SignerMiddleware;
/// use ethers_core::types::{Address, TransactionRequest};
/// use std::convert::TryFrom;
///
/// # async fn foo() -> Result<(), Box<dyn std::error::Error>> {
/// let provider = Provider::<Http>::try_from("http://localhost:8545")
/// .expect("could not instantiate HTTP Provider");
///
/// // Transactions will be signed with the private key below and will be broadcast
/// // via the eth_sendRawTransaction API)
/// let wallet: LocalWallet = "380eb0f3d505f087e438eca80bc4df9a7faa24f868e69fc0440261a0fc0567dc"
/// .parse()?;
///
/// let mut client = SignerMiddleware::new(provider, wallet);
///
/// // You can sign messages with the key
/// let signed_msg = client.sign(b"hello".to_vec(), &client.address()).await?;
///
/// // ...and sign transactions
/// let tx = TransactionRequest::pay("vitalik.eth", 100);
/// let pending_tx = client.send_transaction(tx, None).await?;
///
/// // You can `await` on the pending transaction to get the receipt with a pre-specified
/// // number of confirmations
/// let receipt = pending_tx.confirmations(6).await?;
///
/// // You can connect with other wallets at runtime via the `with_signer` function
/// let wallet2: LocalWallet = "cd8c407233c0560f6de24bb2dc60a8b02335c959a1a17f749ce6c1ccf63d74a7"
/// .parse()?;
///
/// let signed_msg2 = client.with_signer(wallet2).sign(b"hello".to_vec(), &client.address()).await?;
///
/// // This call will be made with `wallet2` since `with_signer` takes a mutable reference.
/// let tx2 = TransactionRequest::new()
/// .to("0xd8da6bf26964af9d7eed9e03e53415d37aa96045".parse::<Address>()?)
/// .value(200);
/// let tx_hash2 = client.send_transaction(tx2, None).await?;
///
/// # Ok(())
/// # }
///
/// ```
///
/// [`Provider`]: ethers_providers::Provider
pub struct SignerMiddleware<M, S> {
pub(crate) inner: M,
pub(crate) signer: S,
pub(crate) address: Address,
}
impl<M: Middleware, S: Signer> FromErr<M::Error> for SignerMiddlewareError<M, S> {
fn from(src: M::Error) -> SignerMiddlewareError<M, S> {
SignerMiddlewareError::MiddlewareError(src)
}
}
#[derive(Error, Debug)]
/// Error thrown when the client interacts with the blockchain
pub enum SignerMiddlewareError<M: Middleware, S: Signer> {
#[error("{0}")]
/// Thrown when the internal call to the signer fails
SignerError(S::Error),
#[error("{0}")]
/// Thrown when an internal middleware errors
MiddlewareError(M::Error),
/// Thrown if the `nonce` field is missing
#[error("no nonce was specified")]
NonceMissing,
/// Thrown if the `gas_price` field is missing
#[error("no gas price was specified")]
GasPriceMissing,
/// Thrown if the `gas` field is missing
#[error("no gas was specified")]
GasMissing,
/// Thrown if a signature is requested from a different address
#[error("specified from address is not signer")]
WrongSigner,
}
// Helper functions for locally signing transactions
impl<M, S> SignerMiddleware<M, S>
where
M: Middleware,
S: Signer,
{
/// Creates a new client from the provider and signer.
pub fn new(inner: M, signer: S) -> Self {
let address = signer.address();
SignerMiddleware {
inner,
signer,
address,
}
}
/// Signs and returns the RLP encoding of the signed transaction
async fn sign_transaction(
&self,
tx: TypedTransaction,
) -> Result<Bytes, SignerMiddlewareError<M, S>> {
let signature = self
.signer
.sign_transaction(&tx)
.await
.map_err(SignerMiddlewareError::SignerError)?;
// Return the raw rlp-encoded signed transaction
Ok(tx.rlp_signed(self.signer.chain_id(), &signature))
}
/// Returns the client's address
pub fn address(&self) -> Address {
self.address
}
/// Returns a reference to the client's signer
pub fn signer(&self) -> &S {
&self.signer
}
pub fn with_signer(&self, signer: S) -> Self
where
S: Clone,
M: Clone,
{
let mut this = self.clone();
this.address = signer.address();
this.signer = signer;
this
}
}
#[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
impl<M, S> Middleware for SignerMiddleware<M, S>
where
M: Middleware,
S: Signer,
{
type Error = SignerMiddlewareError<M, S>;
type Provider = M::Provider;
type Inner = M;
fn inner(&self) -> &M {
&self.inner
}
/// Returns the client's address
fn default_sender(&self) -> Option<Address> {
Some(self.address)
}
/// `SignerMiddleware` is instantiated with a signer.
async fn is_signer(&self) -> bool {
true
}
/// Helper for filling a transaction's nonce using the wallet
async fn fill_transaction(
&self,
tx: &mut TypedTransaction,
block: Option<BlockId>,
) -> Result<(), Self::Error> {
// get the `from` field's nonce if it's set, else get the signer's nonce
let from = if tx.from().is_some() && tx.from() != Some(&self.address()) {
*tx.from().unwrap()
} else {
self.address
};
tx.set_from(from);
let nonce = maybe(tx.nonce().cloned(), self.get_transaction_count(from, block)).await?;
tx.set_nonce(nonce);
self.inner()
.fill_transaction(tx, block)
.await
.map_err(SignerMiddlewareError::MiddlewareError)?;
Ok(())
}
/// Signs and broadcasts the transaction. The optional parameter `block` can be passed so that
/// gas cost and nonce calculations take it into account. For simple transactions this can be
/// left to `None`.
async fn send_transaction<T: Into<TypedTransaction> + Send + Sync>(
&self,
tx: T,
block: Option<BlockId>,
) -> Result<PendingTransaction<'_, Self::Provider>, Self::Error> {
let mut tx = tx.into();
// fill any missing fields
self.fill_transaction(&mut tx, block).await?;
// If the from address is set and is not our signer, delegate to inner
if tx.from().is_some() && tx.from() != Some(&self.address()) {
return self
.inner
.send_transaction(tx, block)
.await
.map_err(SignerMiddlewareError::MiddlewareError);
}
// if we have a nonce manager set, we should try handling the result in
// case there was a nonce mismatch
let signed_tx = self.sign_transaction(tx).await?;
// Submit the raw transaction
self.inner
.send_raw_transaction(signed_tx)
.await
.map_err(SignerMiddlewareError::MiddlewareError)
}
/// Signs a message with the internal signer, or if none is present it will make a call to
/// the connected node's `eth_call` API.
async fn sign<T: Into<Bytes> + Send + Sync>(
&self,
data: T,
_: &Address,
) -> Result<Signature, Self::Error> {
self.signer
.sign_message(data.into())
.await
.map_err(SignerMiddlewareError::SignerError)
}
}
#[cfg(all(test, not(feature = "celo"), not(target_arch = "wasm32")))]
mod tests {
use super::*;
use ethers_core::{
types::TransactionRequest,
utils::{self, keccak256, Ganache},
};
use ethers_providers::Provider;
use ethers_signers::LocalWallet;
use std::convert::TryFrom;
#[tokio::test]
async fn signs_tx() {
// retrieved test vector from:
// https://web3js.readthedocs.io/en/v1.2.0/web3-eth-accounts.html#eth-accounts-signtransaction
let tx = TransactionRequest {
from: None,
to: Some(
"F0109fC8DF283027b6285cc889F5aA624EaC1F55"
.parse::<Address>()
.unwrap()
.into(),
),
value: Some(1_000_000_000.into()),
gas: Some(2_000_000.into()),
nonce: Some(0.into()),
gas_price: Some(21_000_000_000u128.into()),
data: None,
}
.into();
let chain_id = 1u64;
let provider = Provider::try_from("http://localhost:8545").unwrap();
let key = "4c0883a69102937d6231471b5dbb6204fe5129617082792ae468d01a3f362318"
.parse::<LocalWallet>()
.unwrap()
.with_chain_id(chain_id);
let client = SignerMiddleware::new(provider, key);
let tx = client.sign_transaction(tx).await.unwrap();
assert_eq!(
keccak256(&tx)[..],
hex::decode("de8db924885b0803d2edc335f745b2b8750c8848744905684c20b987443a9593")
.unwrap()
);
let expected_rlp = Bytes::from(hex::decode("f869808504e3b29200831e848094f0109fc8df283027b6285cc889f5aa624eac1f55843b9aca008025a0c9cf86333bcb065d140032ecaab5d9281bde80f21b9687b3e94161de42d51895a0727a108a0b8d101465414033c3f705a9c7b826e596766046ee1183dbc8aeaa68").unwrap());
assert_eq!(tx, expected_rlp);
}
#[tokio::test]
async fn handles_tx_from_field() {
let ganache = Ganache::new().spawn();
let acc = ganache.addresses()[0];
let provider = Provider::try_from(ganache.endpoint()).unwrap();
let key = LocalWallet::new(&mut rand::thread_rng()).with_chain_id(1u32);
provider
.send_transaction(
TransactionRequest::pay(key.address(), utils::parse_ether(1u64).unwrap()).from(acc),
None,
)
.await
.unwrap();
let client = SignerMiddleware::new(provider, key);
let request = TransactionRequest::new();
// signing a TransactionRequest with a from field of None should yield
// a signed transaction from the signer address
let request_from_none = request.clone();
let hash = *client
.send_transaction(request_from_none, None)
.await
.unwrap();
let tx = client.get_transaction(hash).await.unwrap().unwrap();
assert_eq!(tx.from, client.address());
// signing a TransactionRequest with the signer as the from address
// should yield a signed transaction from the signer
let request_from_signer = request.clone().from(client.address());
let hash = *client
.send_transaction(request_from_signer, None)
.await
.unwrap();
let tx = client.get_transaction(hash).await.unwrap().unwrap();
assert_eq!(tx.from, client.address());
// signing a TransactionRequest with a from address that is not the
// signer should result in the default ganache account being used
let request_from_other = request.from(acc);
let hash = *client
.send_transaction(request_from_other, None)
.await
.unwrap();
let tx = client.get_transaction(hash).await.unwrap().unwrap();
assert_eq!(tx.from, acc);
}
}