ethers-rs/ethers-providers/src/ens.rs

90 lines
2.9 KiB
Rust

//! [Ethereum Name Service](https://docs.ens.domains/) support
//! Adapted from https://github.com/hhatto/rust-ens/blob/master/src/lib.rs
use ethers_core::{
types::{Address, NameOrAddress, Selector, TransactionRequest, H160, H256},
utils::keccak256,
};
/// ENS registry address (`0x00000000000C2E074eC69A0dFb2997BA6C7d2e1e`)
pub const ENS_ADDRESS: Address = H160([
// cannot set type aliases as constructors
0, 0, 0, 0, 0, 12, 46, 7, 78, 198, 154, 13, 251, 41, 151, 186, 108, 125, 46, 30,
]);
// Selectors
const ENS_REVERSE_REGISTRAR_DOMAIN: &str = "addr.reverse";
/// resolver(bytes32)
const RESOLVER: Selector = [1, 120, 184, 191];
/// addr(bytes32)
pub const ADDR_SELECTOR: Selector = [59, 59, 87, 222];
/// name(bytes32)
pub const NAME_SELECTOR: Selector = [105, 31, 52, 49];
/// Returns a transaction request for calling the `resolver` method on the ENS server
pub fn get_resolver<T: Into<Address>>(ens_address: T, name: &str) -> TransactionRequest {
// keccak256('resolver(bytes32)')
let data = [&RESOLVER[..], &namehash(name).0].concat();
TransactionRequest {
data: Some(data.into()),
to: Some(NameOrAddress::Address(ens_address.into())),
..Default::default()
}
}
/// Returns a transaction request for calling
pub fn resolve<T: Into<Address>>(
resolver_address: T,
selector: Selector,
name: &str,
) -> TransactionRequest {
let data = [&selector[..], &namehash(name).0].concat();
TransactionRequest {
data: Some(data.into()),
to: Some(NameOrAddress::Address(resolver_address.into())),
..Default::default()
}
}
/// Returns the reverse-registrar name of an address.
pub fn reverse_address(addr: Address) -> String {
format!("{:?}.{}", addr, ENS_REVERSE_REGISTRAR_DOMAIN)[2..].to_string()
}
/// Returns the ENS namehash as specified in [EIP-137](https://eips.ethereum.org/EIPS/eip-137)
pub fn namehash(name: &str) -> H256 {
if name.is_empty() {
return H256::zero()
}
// iterate in reverse
name.rsplit('.')
.fold([0u8; 32], |node, label| keccak256(&[node, keccak256(label.as_bytes())].concat()))
.into()
}
#[cfg(test)]
mod tests {
use super::*;
fn assert_hex(hash: H256, val: &str) {
let v = if let Some(stripped) = val.strip_prefix("0x") { stripped } else { val };
assert_eq!(hash.0.to_vec(), hex::decode(v).unwrap());
}
#[test]
fn test_namehash() {
for (name, expected) in &[
("", "0000000000000000000000000000000000000000000000000000000000000000"),
("foo.eth", "de9b09fd7c5f901e23a3f19fecc54828e9c848539801e86591bd9801b019f84f"),
("eth", "0x93cdeb708b7545dc668eb9280176169d1c33cfd8ed6f04690a0bcc88a93fc4ae"),
("alice.eth", "0x787192fc5378cc32aa956ddfdedbf26b24e8d78e40109add0eea2c1a012c3dec"),
] {
assert_hex(namehash(name), expected);
}
}
}