Ethx plugin (#1183)

Co-authored-by: Akshat Mittal <itsreallyakshat@gmail.com>
Co-authored-by: Dulguun <99845398+dulguun-staderlabs@users.noreply.github.com>
Co-authored-by: Taylor Brent <taylor.w.brent@gmail.com>

common/configuration.ts

@@ -66,6 +66,7 @@ export interface ITokens {
   stETH?: string
   wstETH?: string
   rETH?: string
+  ETHx?: string
   cUSDCv3?: string
   wcUSDCv3?: string
   cUSDbCv3?: string
@@ -221,6 +222,7 @@ export const networkConfig: { [key: string]: INetworkConfig } = {
       stETH: '0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84',
       wstETH: '0x7f39C581F595B53c5cb19bD0b3f8dA6c935E2Ca0',
       rETH: '0xae78736Cd615f374D3085123A210448E74Fc6393',
+      ETHx: '0xA35b1B31Ce002FBF2058D22F30f95D405200A15b',
       cUSDCv3: '0xc3d688B66703497DAA19211EEdff47f25384cdc3',
       wcUSDCv3: '0x27F2f159Fe990Ba83D57f39Fd69661764BEbf37a',
       ONDO: '0xfAbA6f8e4a5E8Ab82F62fe7C39859FA577269BE3',
@@ -268,6 +270,7 @@ export const networkConfig: { [key: string]: INetworkConfig } = {
       stETHETH: '0x86392dc19c0b719886221c78ab11eb8cf5c52812', // stETH/ETH
       stETHUSD: '0xCfE54B5cD566aB89272946F602D76Ea879CAb4a8', // stETH/USD
       rETH: '0x536218f9E9Eb48863970252233c8F271f554C2d0', // rETH/ETH
+      ETHx: '0xC5f8c4aB091Be1A899214c0C3636ca33DcA0C547', // ETHx/ETH
       cbETH: '0xf017fcb346a1885194689ba23eff2fe6fa5c483b', // cbETH/ETH
       frxETH: '0xc58f3385fbc1c8ad2c0c9a061d7c13b141d7a5df', // frxETH/ETH
       pyUSD: '0x8f1dF6D7F2db73eECE86a18b4381F4707b918FB1',

contracts/plugins/assets/ethx/ETHxCollateral.sol

@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: BlueOak-1.0.0
+pragma solidity 0.8.19;
+
+import { Math } from "@openzeppelin/contracts/utils/math/Math.sol";
+import { CEIL, FixLib, _safeWrap } from "../../../libraries/Fixed.sol";
+import { AggregatorV3Interface, OracleLib } from "../OracleLib.sol";
+import { CollateralConfig, AppreciatingFiatCollateral } from "../AppreciatingFiatCollateral.sol";
+import { IStaderStakePoolManager } from "./vendor/IStaderStakePoolManager.sol";
+import { IETHx } from "./vendor/IETHx.sol";
+
+/**
+ * @title Stader ETHx collateral
+ * @notice Collateral plugin for Stader ETHx
+ * tok = ETHx
+ * ref = ETH2
+ * tar = ETH
+ * UoA = USD
+ */
+contract ETHxCollateral is AppreciatingFiatCollateral {
+    using OracleLib for AggregatorV3Interface;
+    using FixLib for uint192;
+
+    AggregatorV3Interface public immutable targetPerTokChainlinkFeed;
+    uint48 public immutable targetPerTokChainlinkTimeout;
+
+    /// @param config.chainlinkFeed {UoA/target} price of ETH in USD terms
+    /// @param _targetPerTokChainlinkFeed {target/tok} price of ETHx in ETH terms
+    constructor(
+        CollateralConfig memory config,
+        uint192 revenueHiding,
+        AggregatorV3Interface _targetPerTokChainlinkFeed,
+        uint48 _targetPerTokChainlinkTimeout
+    ) AppreciatingFiatCollateral(config, revenueHiding) {
+        require(address(_targetPerTokChainlinkFeed) != address(0), "missing targetPerTok feed");
+        require(_targetPerTokChainlinkTimeout != 0, "targetPerTokChainlinkTimeout zero");
+        require(config.defaultThreshold != 0, "defaultThreshold zero");
+
+        targetPerTokChainlinkFeed = _targetPerTokChainlinkFeed;
+        targetPerTokChainlinkTimeout = _targetPerTokChainlinkTimeout;
+        maxOracleTimeout = uint48(Math.max(maxOracleTimeout, _targetPerTokChainlinkTimeout));
+    }
+
+    /// Can revert, used by other contract functions in order to catch errors
+    /// @return low {UoA/tok} The low price estimate
+    /// @return high {UoA/tok} The high price estimate
+    /// @return pegPrice {target/ref} The actual price observed in the peg
+    function tryPrice()
+        external
+        view
+        override
+        returns (
+            uint192 low,
+            uint192 high,
+            uint192 pegPrice
+        )
+    {
+        uint192 targetPerTok = targetPerTokChainlinkFeed.price(targetPerTokChainlinkTimeout);
+
+        // {UoA/tok} = {UoA/target} * {target/tok}
+        uint192 p = chainlinkFeed.price(oracleTimeout).mul(targetPerTok);
+        uint192 err = p.mul(oracleError, CEIL);
+
+        high = p + err;
+        low = p - err;
+        // assert(low <= high); obviously true just by inspection
+
+        // {target/ref} = {target/tok} / {ref/tok}
+        pegPrice = targetPerTok.div(underlyingRefPerTok());
+    }
+
+    /// @return {ref/tok} Quantity of whole reference units per whole collateral tokens
+    function underlyingRefPerTok() public view override returns (uint192) {
+        IStaderStakePoolManager staderStakePoolManager = IStaderStakePoolManager(
+            IETHx(address(erc20)).staderConfig().getStakePoolManager()
+        );
+        return _safeWrap(staderStakePoolManager.getExchangeRate());
+    }
+}

contracts/plugins/assets/ethx/README.md

@@ -0,0 +1,26 @@
+# Collateral Plugin - Stader - ETHx
+
+## Summary
+
+This plugin allows `ETHx` holders use their tokens as collateral in the Reserve Protocol.
+
+## Implementation
+
+### Units
+
+| tok  | ref  | target | UoA |
+| ---- | ---- | ------ | --- |
+| ETHx | ETH2 | ETH    | USD |
+
+### refPerTok()
+
+Gets the exchange rate for `ETHx` to `ETH2` from the ETHx token contract using the [getExchangeRate()]()
+function. This is the rate used by stader labs when converting between ethx and eth2 and is closely followed by secondary markets.
+While the value of ETH2/ETHx **should** be only-increasing, it is possible that slashing or inactivity events could occur for the ETHx
+validators. As such, `ETHx` inherits `AppreciatingFiatCollateral` to allow for some amount of revenue-hiding. The amount of
+revenue-hiding should be determined by the deployer, but can likely be quite high, as it is more likely that any dips, however large,
+would be temporary, and, in particularly bad instances, be covered by the Stader protocol.
+
+### claimRewards()
+
+There are no rewards to claim from ETHx.

contracts/plugins/assets/ethx/vendor/IETHx.sol

@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: BlueOak-1.0.0
+pragma solidity 0.8.19;
+
+import "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
+import { IStaderConfig } from "./IStaderConfig.sol";
+
+interface IETHx is IERC20Metadata {
+    function staderConfig() external view returns (IStaderConfig);
+}

contracts/plugins/assets/ethx/vendor/IStaderConfig.sol

@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: BlueOak-1.0.0
+pragma solidity 0.8.19;
+
+interface IStaderConfig {
+    function getStakePoolManager() external view returns (address);
+}

contracts/plugins/assets/ethx/vendor/IStaderOracle.sol

@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: BlueOak-1.0.0
+pragma solidity 0.8.19;
+
+/// @title ExchangeRate
+/// @notice This struct holds data related to the exchange rate between ETH and ETHX.
+struct ExchangeRate {
+    /// @notice The block number when the exchange rate was last updated.
+    uint256 reportingBlockNumber;
+    /// @notice The total balance of Ether (ETH) in the system.
+    uint256 totalETHBalance;
+    /// @notice The total supply of the liquid staking token (ETHX) in the system.
+    uint256 totalETHXSupply;
+}
+
+struct SDPriceData {
+    uint256 reportingBlockNumber;
+    uint256 sdPriceInETH;
+}
+
+/// @title ValidatorStats
+/// @notice This struct holds statistics related to validators in the beaconchain.
+struct ValidatorStats {
+    /// @notice The block number when the validator stats was last updated.
+    uint256 reportingBlockNumber;
+    /// @notice The total balance of all exiting validators.
+    uint128 exitingValidatorsBalance;
+    /// @notice The total balance of all exited validators.
+    uint128 exitedValidatorsBalance;
+    /// @notice The total balance of all slashed validators.
+    uint128 slashedValidatorsBalance;
+    /// @notice The number of currently exiting validators.
+    uint32 exitingValidatorsCount;
+    /// @notice The number of validators that have exited.
+    uint32 exitedValidatorsCount;
+    /// @notice The number of validators that have been slashed.
+    uint32 slashedValidatorsCount;
+}
+
+interface IStaderOracle {
+    function getExchangeRate() external view returns (ExchangeRate memory);
+}

contracts/plugins/assets/ethx/vendor/IStaderStakePoolManager.sol

@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: BlueOak-1.0.0
+pragma solidity 0.8.19;
+
+interface IStaderStakePoolManager {
+    /**
+     * @notice returns the amount of ETH equivalent 1 ETHX (with 18 decimals)
+     */
+    function getExchangeRate() external view returns (uint256);
+}

contracts/plugins/assets/ethx/vendor/StaderOracleMock.sol

@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: BlueOak-1.0.0
+pragma solidity 0.8.19;
+
+import "./IStaderConfig.sol";
+import "./IStaderOracle.sol";
+import "./IStaderStakePoolManager.sol";
+
+import "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";
+import "@openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol";
+import "@openzeppelin/contracts-upgradeable/access/AccessControlUpgradeable.sol";
+import "@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol";
+
+contract StaderOracleMock is
+    IStaderOracle,
+    AccessControlUpgradeable,
+    PausableUpgradeable,
+    ReentrancyGuardUpgradeable
+{
+    bool public erInspectionMode;
+    bool public isPORFeedBasedERData;
+    SDPriceData public lastReportedSDPriceData;
+    IStaderConfig public staderConfig;
+    ExchangeRate public inspectionModeExchangeRate;
+    ExchangeRate public exchangeRate;
+    ValidatorStats public validatorStats;
+
+    uint256 public constant MAX_ER_UPDATE_FREQUENCY = 7200 * 7; // 7 days
+    uint256 public constant ER_CHANGE_MAX_BPS = 10000;
+    uint256 public erChangeLimit;
+    uint256 public constant MIN_TRUSTED_NODES = 5;
+    uint256 public trustedNodeChangeCoolingPeriod;
+
+    uint256 public trustedNodesCount;
+    uint256 public lastReportedMAPDIndex;
+    uint256 public erInspectionModeStartBlock;
+    uint256 public lastTrustedNodeCountChangeBlock;
+
+    // indicate the health of protocol on beacon chain
+    // enabled by `MANAGER` if heavy slashing on protocol on beacon chain
+    bool public safeMode;
+
+    mapping(address => bool) public isTrustedNode;
+    mapping(bytes32 => bool) private nodeSubmissionKeys;
+    mapping(bytes32 => uint8) private submissionCountKeys;
+    mapping(bytes32 => uint16) public missedAttestationPenalty;
+    mapping(uint8 => uint256) public lastReportingBlockNumberForWithdrawnValidatorsByPoolId;
+    mapping(uint8 => uint256) public lastReportingBlockNumberForValidatorVerificationDetailByPoolId;
+
+    uint256[] private sdPrices;
+
+    bytes32 public constant ETHX_ER_UF = keccak256("ETHX_ER_UF");
+    bytes32 public constant SD_PRICE_UF = keccak256("SD_PRICE_UF");
+    bytes32 public constant VALIDATOR_STATS_UF = keccak256("VALIDATOR_STATS_UF");
+    bytes32 public constant WITHDRAWN_VALIDATORS_UF = keccak256("WITHDRAWN_VALIDATORS_UF");
+    bytes32 public constant MISSED_ATTESTATION_PENALTY_UF =
+        keccak256("MISSED_ATTESTATION_PENALTY_UF");
+    // Ready to Deposit Validators Update Frequency Key
+    bytes32 public constant VALIDATOR_VERIFICATION_DETAIL_UF =
+        keccak256("VALIDATOR_VERIFICATION_DETAIL_UF");
+    mapping(bytes32 => uint256) public updateFrequencyMap;
+
+    function getExchangeRate() external view override returns (ExchangeRate memory) {
+        return (exchangeRate);
+    }
+
+    // Mock function to be able to override rate in tests
+    function setExchangeRate(ExchangeRate memory newExchangeRate) external {
+        exchangeRate = newExchangeRate;
+    }
+}

scripts/addresses/1-tmp-assets-collateral.json

@@ -58,7 +58,8 @@
     "Re7WETH": "0xa0a6C06e45437d4Ae1D778AaeB4605AC2B62A870",
     "cvxCrvUSDUSDC": "0x9Fc0F31e2D26C437461a9eEBfe858d17e2611Ea5",
     "cvxCrvUSDUSDT": "0x69c6597690B8Df61D15F201519C03725bdec40c1",
-    "sfrxETH": "0x4c891fCa6319d492866672E3D2AfdAAA5bDcfF67"
+    "sfrxETH": "0x4c891fCa6319d492866672E3D2AfdAAA5bDcfF67",
+    "ETHx": "0x73a36258E6A48D0095D1997Fec7F51e191B4Ec81"
   },
   "erc20s": {
     "stkAAVE": "0x4da27a545c0c5B758a6BA100e3a049001de870f5",
@@ -117,6 +118,7 @@
     "cvxCrvUSDUSDT": "0x5d1B749bA7f689ef9f260EDC54326C48919cA88b",
     "sfrxETH": "0xac3E018457B222d93114458476f3E3416Abbe38F",
     "CRV": "0xD533a949740bb3306d119CC777fa900bA034cd52",
-    "CVX": "0x4e3FBD56CD56c3e72c1403e103b45Db9da5B9D2B"
+    "CVX": "0x4e3FBD56CD56c3e72c1403e103b45Db9da5B9D2B",
+    "ETHx": "0xA35b1B31Ce002FBF2058D22F30f95D405200A15b"
   }
 }

scripts/addresses/mainnet-4.0.0/1-tmp-assets-collateral.json

@@ -0,0 +1,9 @@
+{
+  "assets": {},
+  "collateral": {
+    "ETHx": "0x73a36258E6A48D0095D1997Fec7F51e191B4Ec81"
+  },
+  "erc20s": {
+    "ETHx": "0xA35b1B31Ce002FBF2058D22F30f95D405200A15b"
+  }
+}

scripts/deploy.ts

@@ -83,6 +83,7 @@ async function main() {
       'phase2-assets/collaterals/deploy_steakpyusd.ts',
       'phase2-assets/collaterals/deploy_bbusdt.ts',
       'phase2-assets/collaterals/deploy_re7weth.ts',
+      'phase2-assets/collaterals/deploy_ethx_collateral.ts',
       'phase2-assets/assets/deploy_crv.ts',
       'phase2-assets/assets/deploy_cvx.ts'
     )