Add eHMND ERC20 precompile

crates/humanode-runtime/Cargo.toml

@@ -32,6 +32,7 @@ pallet-vesting = { path = "../pallet-vesting", default-features = false }
 precompile-bioauth = { path = "../precompile-bioauth", default-features = false }
 precompile-currency-swap = { path = "../precompile-currency-swap", default-features = false }
 precompile-evm-accounts-mapping = { path = "../precompile-evm-accounts-mapping", default-features = false }
+precompile-evm-balances-erc20 = { path = "../precompile-evm-balances-erc20", default-features = false }
 precompile-utils = { path = "../precompile-utils", default-features = false }
 primitives-auth-ticket = { path = "../primitives-auth-ticket", default-features = false }
 primitives-currency-swap-proxy = { path = "../primitives-currency-swap-proxy", default-features = false }
@@ -190,6 +191,7 @@ std = [
   "precompile-bioauth/std",
   "precompile-currency-swap/std",
   "precompile-evm-accounts-mapping/std",
+  "precompile-evm-balances-erc20/std",
   "precompile-utils/std",
   "primitives-auth-ticket/std",
   "primitives-currency-swap-proxy/std",

crates/humanode-runtime/src/frontier_precompiles.rs

@@ -5,7 +5,8 @@ use pallet_evm_precompile_simple::{ECRecover, ECRecoverPublicKey, Identity, Ripe
 use precompile_bioauth::Bioauth;
 use precompile_currency_swap::CurrencySwap;
 use precompile_evm_accounts_mapping::EvmAccountsMapping;
-use sp_core::H160;
+use precompile_evm_balances_erc20::EvmBalancesErc20;
+use sp_core::{H160, U256};
 use sp_std::marker::PhantomData;
 
 use crate::{currency_swap, AccountId, ConstU64, EvmAccountId};
@@ -23,7 +24,7 @@ where
     R: pallet_evm::Config,
 {
     pub fn used_addresses() -> sp_std::vec::Vec<H160> {
-        sp_std::vec![1_u64, 2, 3, 4, 5, 1024, 1025, 2048, 2049, 2304]
+        sp_std::vec![1_u64, 2, 3, 4, 5, 1024, 1025, 2048, 2049, 2050, 2304]
             .into_iter()
             .map(hash)
             .collect()
@@ -35,6 +36,9 @@ where
     R: pallet_evm::Config,
     R: pallet_bioauth::Config,
     R: pallet_evm_accounts_mapping::Config,
+    R: pallet_evm_balances::Config,
+    <R as pallet_evm_balances::Config>::Balance: Into<U256> + TryFrom<U256>,
+    <R as pallet_evm_balances::Config>::AccountId: From<H160>,
     R::ValidatorPublicKey: for<'a> TryFrom<&'a [u8]> + Eq,
 {
     fn execute(&self, handle: &mut impl PrecompileHandle) -> Option<PrecompileResult> {
@@ -51,6 +55,11 @@ where
             // Humanode precompiles:
             a if a == hash(2048) => Some(Bioauth::<R>::execute(handle)),
             a if a == hash(2049) => Some(EvmAccountsMapping::<R>::execute(handle)),
+            a if a == hash(2050) => {
+                Some(
+                    EvmBalancesErc20::<R, EvmBalancesErc20Metadata, ConstU64<200>>::execute(handle),
+                )
+            }
             a if a == hash(2304) => Some(CurrencySwap::<
                 currency_swap::EvmToNativeOneToOne,
                 EvmAccountId,
@@ -71,3 +80,19 @@ where
 fn hash(a: u64) -> H160 {
     H160::from_low_u64_be(a)
 }
+
+pub struct EvmBalancesErc20Metadata;
+
+impl precompile_evm_balances_erc20::Erc20Metadata for EvmBalancesErc20Metadata {
+    fn name() -> &'static str {
+        "Ethereum humanode token"
+    }
+
+    fn symbol() -> &'static str {
+        "eHMND"
+    }
+
+    fn decimals() -> u8 {
+        18
+    }
+}

crates/precompile-evm-balances-erc20/Cargo.toml

@@ -0,0 +1,47 @@
+[package]
+name = "precompile-evm-balances-erc20"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+[dependencies]
+precompile-utils = { path = "../precompile-utils", default-features = false }
+primitives-currency-swap = { path = "../primitives-currency-swap", default-features = false }
+
+codec = { workspace = true, package = "parity-scale-codec", features = ["derive"] }
+fp-evm = { workspace = true }
+frame-support = { workspace = true }
+num_enum = { workspace = true }
+pallet-evm = { workspace = true }
+pallet-evm-balances = { workspace = true }
+scale-info = { workspace = true, features = ["derive"] }
+sp-core = { workspace = true }
+
+[dev-dependencies]
+precompile-utils = { path = "../precompile-utils", features = ["testing"] }
+
+frame-system = { workspace = true }
+hex-literal = { workspace = true }
+pallet-balances = { workspace = true, features = ["default"] }
+pallet-evm = { workspace = true }
+pallet-evm-system = { workspace = true, features = ["default"] }
+pallet-timestamp = { workspace = true, features = ["default"] }
+
+[features]
+default = ["std"]
+std = [
+  "codec/std",
+  "fp-evm/std",
+  "frame-support/std",
+  "frame-system/std",
+  "num_enum/std",
+  "pallet-balances/std",
+  "pallet-evm-balances/std",
+  "pallet-evm-system/std",
+  "pallet-evm/std",
+  "pallet-timestamp/std",
+  "precompile-utils/std",
+  "primitives-currency-swap/std",
+  "scale-info/std",
+  "sp-core/std",
+]

crates/precompile-evm-balances-erc20/ERC20.sol

@@ -0,0 +1,117 @@
+// SPDX-License-Identifier: UNLICENSED
+
+pragma solidity >=0.7.0 <0.9.0;
+
+/**
+ * @title ERC20 Interface
+ *
+ * An interface exposing native eHMND tokens as ERC20 tokens.
+ *
+ * Address: 0x0000000000000000000000000000000000000802
+ */
+interface IERC20 {
+    /**
+     * Returns the name of the token.
+     * Selector: 06fdde03
+     */
+    function name() external view returns (string memory);
+
+    /**
+     * Returns the symbol of the token.
+     * Selector: 95d89b41
+     */
+    function symbol() external view returns (string memory);
+
+    /**
+     * Returns the decimals places of the token.
+     * Selector: 313ce567
+     */
+    function decimals() external view returns (uint8);
+
+    /**
+     * Total number of tokens in existence.
+     * Selector: 18160ddd
+     */
+    function totalSupply() external view returns (uint256);
+
+    /**
+     * Gets the balance of the specified address.
+     * Selector: 70a08231
+     *
+     * @param owner The address to query the balance of.
+     * @return uint256 The amount owned by the passed address.
+     */
+    function balanceOf(address owner) external view returns (uint256);
+
+    /**
+     * Function to check the amount of tokens that an owner allowed to a spender.
+     * Selector: dd62ed3e
+     *
+     * @param owner The address which owns the funds.
+     * @param spender The address which will spend the funds.
+     * @return uint256 The amount of tokens still available for the spender.
+     */
+    function allowance(
+        address owner,
+        address spender
+    ) external view returns (uint256);
+
+    /**
+     * Transfer token for a specified address.
+     * Selector: a9059cbb
+     *
+     * @param to The address to transfer tokens to.
+     * @param value The amount to be transferred.
+     * @return true if the transfer was succesful, revert otherwise.
+     */
+    function transfer(address to, uint256 value) external returns (bool);
+
+    /**
+     * Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
+     * Selector: 095ea7b3
+     *
+     * @param spender The address which will spend the funds.
+     * @param value The amount of tokens to be spent.
+     * @return true, this cannot fail.
+     */
+    function approve(address spender, uint256 value) external returns (bool);
+
+    /**
+     * Transfer tokens from one address to another.
+     * Selector: 23b872dd
+     *
+     * @param from The address which you want to send tokens from.
+     * @param to The address which you want to transfer to.
+     * @param value The amount of tokens to be transferred.
+     * @return true if the transfer was succesful, revert otherwise.
+     */
+    function transferFrom(
+        address from,
+        address to,
+        uint256 value
+    ) external returns (bool);
+
+    /**
+     * Event emited when a transfer has been performed.
+     * Selector: ddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef
+     *
+     * @param from The address sending the tokens
+     * @param to The address receiving the tokens.
+     * @param value The amount of tokens transfered.
+     */
+    event Transfer(address indexed from, address indexed to, uint256 value);
+
+    /**
+     * Event emited when an approval has been registered.
+     * Selector: 8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925
+     *
+     * @param owner The owner address of the tokens.
+     * @param spender The allowed spender address.
+     * @param value The amount of tokens approved.
+     */
+    event Approval(
+        address indexed owner,
+        address indexed spender,
+        uint256 value
+    );
+}