DRAFT: metaDeposit and metaRedeem

src/contracts/StakeToken.sol

@@ -18,7 +18,7 @@ import {IAccessControl} from 'aave-v3-origin/core/contracts/dependencies/openzep
 
 import {PercentageMath} from './lib/PercentageMath.sol';
 
-import {ERC20PermitUpgradeable} from './ERC20PermitUpgradeable.sol';
+import {ERC20PermitUpgradeable, ECDSA} from './ERC20PermitUpgradeable.sol';
 import {ERC20Upgradeable} from './ERC20Upgradeable.sol';
 import {IStakeToken} from './interfaces/IStakeToken.sol';
 import {IRewardsController} from './interfaces/IRewardsController.sol';
@@ -28,7 +28,20 @@ contract StakeToken is ERC20PermitUpgradeable, IStakeToken, Rescuable {
   using SafeERC20 for IERC20;
   using PercentageMath for uint256;
   using SafeCast for uint256;
-  using SafeCast for uint104;
+
+  /// @dev type-hashes for meta transactions
+
+  /// @inheritdoc IStakeToken
+  bytes32 public constant METADEPOSIT_TYPEHASH =
+    keccak256(
+      'Deposit(address owner,address receiver,uint256 assets,uint256 nonce,uint256 deadline)'
+    );
+
+  /// @inheritdoc IStakeToken
+  bytes32 public constant METAREDEEM_TYPEHASH =
+    keccak256(
+      'Redeem(address owner,address receiver,uint256 shares,uint256 nonce,uint256 deadline)'
+    );
 
   /// @dev the exchange rate on stake-token "up only" and reflects hom many stk token you receive for the underlying
   uint216 public constant INITIAL_EXCHANGE_RATE = 1e18;
@@ -235,6 +248,75 @@ contract StakeToken is ERC20PermitUpgradeable, IStakeToken, Rescuable {
     return _stake(msg.sender, receiver, assets, true);
   }
 
+  /// @inheritdoc IStakeToken
+  function metaRedeem(
+    address owner,
+    address receiver,
+    uint256 shares,
+    uint256 deadline,
+    SignatureParams calldata sigParams
+  ) external returns (uint256) {
+    if (block.timestamp > deadline) {
+      revert ERC2612ExpiredSignature(deadline);
+    }
+
+    bytes32 structHash = keccak256(
+      abi.encode(METAREDEEM_TYPEHASH, owner, receiver, shares, _useNonce(owner), deadline)
+    );
+
+    bytes32 hash = _hashTypedDataV4(structHash);
+
+    address signer = ECDSA.recover(hash, sigParams.v, sigParams.r, sigParams.s);
+    if (signer != owner) {
+      revert ERC2612InvalidSigner(signer, owner);
+    }
+
+    return _redeem(owner, receiver, shares.toUint104());
+  }
+
+  /// @inheritdoc IStakeToken
+  function metaDeposit(
+    address owner,
+    address receiver,
+    uint256 assets,
+    uint256 deadline,
+    PermitParams calldata permit,
+    SignatureParams calldata sigParams
+  ) external returns (uint256) {
+    if (block.timestamp > deadline) {
+      revert ERC2612ExpiredSignature(deadline);
+    }
+
+    bytes32 structHash = keccak256(
+      abi.encode(METADEPOSIT_TYPEHASH, owner, receiver, assets, _useNonce(owner), deadline)
+    );
+
+    bytes32 hash = _hashTypedDataV4(structHash);
+
+    address signer = ECDSA.recover(hash, sigParams.v, sigParams.r, sigParams.s);
+    if (signer != owner) {
+      revert ERC2612InvalidSigner(signer, owner);
+    }
+
+    StakeTokenStorage storage $ = _getStakeTokenStorage();
+    // assume if deadline 0 no permit was supplied
+    if (permit.deadline != 0) {
+      try
+        IERC20Permit($._smConfig.stakedToken).permit(
+          owner,
+          address(this),
+          permit.value,
+          permit.deadline,
+          permit.v,
+          permit.r,
+          permit.s
+        )
+      {} catch {}
+    }
+
+    return _stake(owner, receiver, assets, true);
+  }
+
   ///@inheritdoc IERC4626
   function mint(
     uint256 shares,
@@ -245,33 +327,6 @@ contract StakeToken is ERC20PermitUpgradeable, IStakeToken, Rescuable {
     return assets;
   }
 
-  /// @inheritdoc IStakeToken
-  function stakeWithPermit(
-    uint256 amount,
-    uint256 deadline,
-    uint8 v,
-    bytes32 r,
-    bytes32 s
-  ) external whenNotPaused {
-    StakeTokenStorage storage $ = _getStakeTokenStorage();
-    try
-      IERC20Permit($._smConfig.stakedToken).permit(
-        msg.sender,
-        address(this),
-        amount,
-        deadline,
-        v,
-        r,
-        s
-      )
-    {
-      // do nothing
-    } catch (bytes memory) {
-      // do nothing
-    }
-    _stake(msg.sender, msg.sender, amount, true);
-  }
-
   /// @inheritdoc IStakeToken
   function cooldown() external whenNotPaused {
     _cooldown(msg.sender);

src/contracts/interfaces/IStakeToken.sol

@@ -21,6 +21,24 @@ interface IStakeToken is IERC4626 {
     // reserved for future use
   }
 
+  /// @notice v,r,s components of a signature
+  struct SignatureParams {
+    uint8 v;
+    bytes32 r;
+    bytes32 s;
+  }
+
+  struct PermitParams {
+    /// @notice value to approve
+    uint256 value;
+    /// @notice signature expiration time
+    uint256 deadline;
+    /// @notice v,r,s components of a signature
+    uint8 v;
+    bytes32 r;
+    bytes32 s;
+  }
+
   event Cooldown(address indexed user, uint256 amount);
 
   event MaxSlashablePercentageChanged(uint256 newPercentage);
@@ -35,6 +53,44 @@ interface IStakeToken is IERC4626 {
 
   function MIN_ASSETS_REMAINING() external returns (uint256);
 
+  function METADEPOSIT_TYPEHASH() external view returns (bytes32);
+
+  function METAREDEEM_TYPEHASH() external view returns (bytes32);
+
+  /**
+   * @dev Mints shares Vault shares to receiver by depositing exactly amount of underlying tokens, gasless
+   * @param owner address of funds owner
+   * @param receiver address of funds receiver
+   * @param assets amount of underlying to deposit
+   * @param deadline The permit execution deadline
+   * @param permit The v,r,s components together with value and deadline of permit packed into PermitParams, can be empty
+   * @param sigParams The v,r,s components of the signed message packed into SignatureParams
+   */
+  function metaDeposit(
+    address owner,
+    address receiver,
+    uint256 assets,
+    uint256 deadline,
+    PermitParams calldata permit,
+    SignatureParams calldata sigParams
+  ) external returns (uint256);
+
+  /**
+   * @dev Burns exactly shares from owner and sends assets of underlying tokens to receiver, gasless
+   * @param owner address of funds owner
+   * @param receiver address of funds receiver
+   * @param shares value of shares to burn
+   * @param deadline The permit execution deadline
+   * @param sigParams The v,r,s components of the signed message packed into SignatureParams
+   */
+  function metaRedeem(
+    address owner,
+    address receiver,
+    uint256 shares,
+    uint256 deadline,
+    SignatureParams calldata sigParams
+  ) external returns (uint256);
+
   /**
    * @dev Redeems shares, and stop earning rewards
    * @param to Address to redeem to
@@ -48,22 +104,6 @@ interface IStakeToken is IERC4626 {
    */
   function cooldown() external;
 
-  /**
-   * @dev Allows staking a certain amount of STAKED_TOKEN with gasless approvals (permit)
-   * @param amount The amount to be staked
-   * @param deadline The permit execution deadline
-   * @param v The v component of the signed message
-   * @param r The r component of the signed message
-   * @param s The s component of the signed message
-   */
-  function stakeWithPermit(
-    uint256 amount,
-    uint256 deadline,
-    uint8 v,
-    bytes32 r,
-    bytes32 s
-  ) external;
-
   /**
    * @dev Returns the current exchange rate
    * @return exchangeRate as 18 decimal precision uint216

tests/Pause.t.sol

@@ -36,12 +36,14 @@ contract Pause is StakeTestBase {
     stakeToken.deposit(0, user);
   }
 
-  function test_stakeWithPermit_should_revert() external {
+  function test_metaDeposit_should_revert() external {
     _setPaused(true);
 
+    IStakeToken.PermitParams memory permit;
+    IStakeToken.SignatureParams memory sigParams;
+
     vm.expectRevert(PausableUpgradeable.EnforcedPause.selector);
-    vm.prank(user);
-    stakeToken.stakeWithPermit(0, 0, 0, bytes32(0), bytes32(0));
+    stakeToken.metaDeposit(address(0), address(0), 0, 0, permit, sigParams);
   }
 
   function test_redeem_should_revert() external {