Define IRouterWithoutCollisions which Router inherits from

This ensures Router implements most of IRouterWithoutCollisions. It solely
leaves us to confirm Router implements the extensions defined in IRouter.

Cargo.lock

@@ -8724,6 +8724,7 @@ dependencies = [
  "alloy-rpc-client",
  "alloy-rpc-types-eth",
  "alloy-simple-request-transport",
+ "alloy-sol-macro",
  "alloy-sol-macro-expander",
  "alloy-sol-macro-input",
  "alloy-sol-types",

processor/ethereum/router/Cargo.toml

@@ -20,7 +20,9 @@ workspace = true
 group = { version = "0.13", default-features = false }
 
 alloy-core = { version = "0.8", default-features = false }
+
 alloy-sol-types = { version = "0.8", default-features = false }
+alloy-sol-macro = { version = "0.8", default-features = false }
 
 alloy-consensus = { version = "0.3", default-features = false }
 

processor/ethereum/router/build.rs

@@ -26,17 +26,14 @@ fn main() {
     fs::create_dir(&artifacts_path).unwrap();
   }
 
-  build_solidity_contracts::build(
-    &["../../../networks/ethereum/schnorr/contracts", "../erc20/contracts"],
-    "contracts",
-    &artifacts_path,
-  )
-  .unwrap();
-
-  // This cannot be handled with the sol! macro. The Solidity requires an import
+  // This cannot be handled with the sol! macro. The Router requires an import
   // https://github.com/alloy-rs/core/issues/602
   sol(
-    &["../../../networks/ethereum/schnorr/contracts/Schnorr.sol", "contracts/Router.sol"],
+    &[
+      "../../../networks/ethereum/schnorr/contracts/Schnorr.sol",
+      "contracts/IRouter.sol",
+      "contracts/Router.sol",
+    ],
     &(artifacts_path + "/router.rs"),
   );
 }

processor/ethereum/router/contracts/IRouter.sol

@@ -0,0 +1,152 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.26;
+
+/// @title Serai Router (without functions overriden by selector collisions)
+/// @author Luke Parker <lukeparker@serai.exchange>
+/// @notice Intakes coins for the Serai network and handles relaying batches of transfers out
+interface IRouterWithoutCollisions {
+  /// @notice Emitted when the key for Serai's Ethereum validators is updated
+  /// @param nonce The nonce consumed to update this key
+  /// @param key The key updated to
+  event SeraiKeyUpdated(uint256 indexed nonce, bytes32 indexed key);
+
+  /// @notice Emitted when an InInstruction occurs
+  /// @param from The address which called `inInstruction` and caused this event to be emitted
+  /// @param coin The coin transferred in
+  /// @param amount The amount of the coin transferred in
+  /// @param instruction The Shorthand-encoded InInstruction for Serai to decode and handle
+  event InInstruction(
+    address indexed from, address indexed coin, uint256 amount, bytes instruction
+  );
+
+  /// @notice Emitted when a batch of `OutInstruction`s occurs
+  /// @param nonce The nonce consumed to execute this batch of transactions
+  /// @param messageHash The hash of the message signed for the executed batch
+  event Executed(uint256 indexed nonce, bytes32 indexed messageHash);
+
+  /// @notice Emitted when `escapeHatch` is invoked
+  /// @param escapeTo The address to escape to
+  event EscapeHatch(address indexed escapeTo);
+
+  /// @notice Emitted when coins escape through the escape hatch
+  /// @param coin The coin which escaped
+  event Escaped(address indexed coin);
+
+  /// @notice The contract has had its escape hatch invoked and won't accept further actions
+  error EscapeHatchInvoked();
+  /// @notice The signature was invalid
+  error InvalidSignature();
+  /// @notice The amount specified didn't match `msg.value`
+  error AmountMismatchesMsgValue();
+  /// @notice The call to an ERC20's `transferFrom` failed
+  error TransferFromFailed();
+
+  /// @notice An invalid address to escape to was specified.
+  error InvalidEscapeAddress();
+  /// @notice Escaping when escape hatch wasn't invoked.
+  error EscapeHatchNotInvoked();
+
+  /// @notice Transfer coins into Serai with an instruction
+  /// @param coin The coin to transfer in (address(0) if Ether)
+  /// @param amount The amount to transfer in (msg.value if Ether)
+  /**
+   * @param instruction The Shorthand-encoded InInstruction for Serai to associate with this
+   *   transfer in
+   */
+  // Re-entrancy doesn't bork this function
+  // slither-disable-next-line reentrancy-events
+  function inInstruction(address coin, uint256 amount, bytes memory instruction) external payable;
+
+  /// @notice Execute some arbitrary code within a secure sandbox
+  /**
+   * @dev This performs sandboxing by deploying this code with `CREATE`. This is an external
+   *   function as we can't meter `CREATE`/internal functions. We work around this by calling this
+   *   function with `CALL` (which we can meter). This does forward `msg.value` to the newly
+   *  deployed contract.
+   */
+  /// @param code The code to execute
+  function executeArbitraryCode(bytes memory code) external payable;
+
+  /// @notice Escape coins after the escape hatch has been invoked
+  /// @param coin The coin to escape
+  function escape(address coin) external;
+
+  /// @notice Fetch the next nonce to use by an action published to this contract
+  /// return The next nonce to use by an action published to this contract
+  function nextNonce() external view returns (uint256);
+
+  /// @notice Fetch the current key for Serai's Ethereum validator set
+  /// @return The current key for Serai's Ethereum validator set
+  function seraiKey() external view returns (bytes32);
+
+  /// @notice Fetch the address escaped to
+  /// @return The address which was escaped to (address(0) if the escape hatch hasn't been invoked)
+  function escapedTo() external view returns (address);
+}
+
+/// @title Serai Router
+/// @author Luke Parker <lukeparker@serai.exchange>
+/// @notice Intakes coins for the Serai network and handles relaying batches of transfers out
+interface IRouter is IRouterWithoutCollisions {
+  /// @title A signature
+  /// @dev Thin wrapper around `c, s` to simplify the API
+  struct Signature {
+    bytes32 c;
+    bytes32 s;
+  }
+
+  /// @title The type of destination
+  /// @dev A destination is either an address or a blob of code to deploy and call
+  enum DestinationType {
+    Address,
+    Code
+  }
+
+  /// @title A code destination
+  /**
+   * @dev If transferring an ERC20 to this destination, it will be transferred to the address the
+   *   code will be deployed to. If transferring ETH, it will be transferred with the deployment of
+   *   the code. `code` is deployed with CREATE (calling its constructor). The entire deployment
+   *   (and associated sandboxing) must consume less than `gasLimit` units of gas or it will revert.
+   */
+  struct CodeDestination {
+    uint32 gasLimit;
+    bytes code;
+  }
+
+  /// @title An instruction to transfer coins out
+  /// @dev Specifies a destination and amount but not the coin as that's assumed to be contextual
+  struct OutInstruction {
+    DestinationType destinationType;
+    bytes destination;
+    uint256 amount;
+  }
+
+  /// @notice Update the key representing Serai's Ethereum validators
+  /// @dev This assumes the key is correct. No checks on it are performed
+  /// @param signature The signature by the current key authorizing this update
+  /// @param newSeraiKey The key to update to
+  function updateSeraiKey(Signature calldata signature, bytes32 newSeraiKey) external;
+
+  /// @notice Execute a batch of `OutInstruction`s
+  /**
+   * @dev All `OutInstruction`s in a batch are only for a single coin to simplify handling of the
+   *  fee
+   */
+  /// @param signature The signature by the current key for Serai's Ethereum validators
+  /// @param coin The coin all of these `OutInstruction`s are for
+  /// @param fee The fee to pay (in coin) to the caller for their relaying of this batch
+  /// @param outs The `OutInstruction`s to act on
+  function execute(
+    Signature calldata signature,
+    address coin,
+    uint256 fee,
+    OutInstruction[] calldata outs
+  ) external;
+
+  /// @notice Escapes to a new smart contract
+  /// @dev This should be used upon an invariant being reached or new functionality being needed
+  /// @param signature The signature by the current key for Serai's Ethereum validators
+  /// @param escapeTo The address to escape to
+  function escapeHatch(Signature calldata signature, address escapeTo) external;
+}

processor/ethereum/router/contracts/Router.sol

@@ -1,12 +1,12 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 pragma solidity ^0.8.26;
 
-// TODO: MIT licensed interface
-
 import "IERC20.sol";
 
 import "Schnorr.sol";
 
+import "IRouter.sol";
+
 /*
   The Router directly performs low-level calls in order to fine-tune the gas settings. Since this
   contract is meant to relay an entire batch of transactions, the ability to exactly meter
@@ -24,7 +24,7 @@ import "Schnorr.sol";
 /// @title Serai Router
 /// @author Luke Parker <lukeparker@serai.exchange>
 /// @notice Intakes coins for the Serai network and handles relaying batches of transfers out
-contract Router {
+contract Router is IRouterWithoutCollisions {
   /**
    * @dev The next nonce used to determine the address of contracts deployed with CREATE. This is
    *   used to predict the addresses of deployed contracts ahead of time.
@@ -51,151 +51,141 @@ contract Router {
   /// @dev The address escaped to
   address private _escapedTo;
 
-  /// @title The type of destination
-  /// @dev A destination is either an address or a blob of code to deploy and call
-  enum DestinationType {
-    Address,
-    Code
-  }
-
-  /// @title A code destination
-  /**
-   * @dev If transferring an ERC20 to this destination, it will be transferred to the address the
-   *   code will be deployed to. If transferring ETH, it will be transferred with the deployment of
-   *   the code. `code` is deployed with CREATE (calling its constructor). The entire deployment
-   *   (and associated sandboxing) must consume less than `gasLimit` units of gas or it will revert.
-   */
-  struct CodeDestination {
-    uint32 gasLimit;
-    bytes code;
-  }
-
-  /// @title An instruction to transfer coins out
-  /// @dev Specifies a destination and amount but not the coin as that's assumed to be contextual
-  struct OutInstruction {
-    DestinationType destinationType;
-    bytes destination;
-    uint256 amount;
-  }
-
-  /// @title A signature
-  /// @dev Thin wrapper around `c, s` to simplify the API
-  struct Signature {
-    bytes32 c;
-    bytes32 s;
-  }
-
-  /// @notice Emitted when the key for Serai's Ethereum validators is updated
-  /// @param nonce The nonce consumed to update this key
-  /// @param key The key updated to
-  event SeraiKeyUpdated(uint256 indexed nonce, bytes32 indexed key);
-
-  /// @notice Emitted when an InInstruction occurs
-  /// @param from The address which called `inInstruction` and caused this event to be emitted
-  /// @param coin The coin transferred in
-  /// @param amount The amount of the coin transferred in
-  /// @param instruction The Shorthand-encoded InInstruction for Serai to decode and handle
-  event InInstruction(
-    address indexed from, address indexed coin, uint256 amount, bytes instruction
-  );
-
-  /// @notice Emitted when a batch of `OutInstruction`s occurs
-  /// @param nonce The nonce consumed to execute this batch of transactions
-  /// @param messageHash The hash of the message signed for the executed batch
-  event Executed(uint256 indexed nonce, bytes32 indexed messageHash);
-
-  /// @notice Emitted when `escapeHatch` is invoked
-  /// @param escapeTo The address to escape to
-  event EscapeHatch(address indexed escapeTo);
-
-  /// @notice Emitted when coins escape through the escape hatch
-  /// @param coin The coin which escaped
-  event Escaped(address indexed coin);
-
-  /// @notice The contract has had its escape hatch invoked and won't accept further actions
-  error EscapeHatchInvoked();
-  /// @notice The signature was invalid
-  error InvalidSignature();
-  /// @notice The amount specified didn't match `msg.value`
-  error AmountMismatchesMsgValue();
-  /// @notice The call to an ERC20's `transferFrom` failed
-  error TransferFromFailed();
-
-  /// @notice An invalid address to escape to was specified.
-  error InvalidEscapeAddress();
-  /// @notice Escaping when escape hatch wasn't invoked.
-  error EscapeHatchNotInvoked();
-
-  /**
-   * @dev Updates the Serai key at the end of the current function. Executing at the end of the
-   *   current function allows verifying a signature with the current key. This does not update
-   *   `_nextNonce`
-   */
+  /// @dev Updates the Serai key. This does not update `_nextNonce`
   /// @param nonceUpdatedWith The nonce used to update the key
   /// @param newSeraiKey The key updated to
-  modifier updateSeraiKeyAtEndOfFn(uint256 nonceUpdatedWith, bytes32 newSeraiKey) {
-    // Run the function itself
-    _;
-
-    // Update the key
+  function _updateSeraiKey(uint256 nonceUpdatedWith, bytes32 newSeraiKey) private {
     _seraiKey = newSeraiKey;
     emit SeraiKeyUpdated(nonceUpdatedWith, newSeraiKey);
   }
 
   /// @notice The constructor for the relayer
   /// @param initialSeraiKey The initial key for Serai's Ethereum validators
-  constructor(bytes32 initialSeraiKey) updateSeraiKeyAtEndOfFn(0, initialSeraiKey) {
+  constructor(bytes32 initialSeraiKey) {
     // Nonces are incremented by 1 upon account creation, prior to any code execution, per EIP-161
     // This is incompatible with any networks which don't have their nonces start at 0
     _smartContractNonce = 1;
 
-    // We consumed nonce 0 when setting the initial Serai key
+    // Set the Serai key
+    _updateSeraiKey(0, initialSeraiKey);
+
+    // We just consumed nonce 0 when setting the initial Serai key
     _nextNonce = 1;
 
     // We haven't escaped to any address yet
     _escapedTo = address(0);
   }
 
-  /// @dev Verify a signature
-  /// @param message The message to pass to the Schnorr contract
-  /// @param signature The signature by the current key for this message
-  function verifySignature(bytes32 message, Signature calldata signature) private {
+  /**
+   * @dev
+   *   Verify a signature of the calldata, placed immediately after the function selector. The
+   *   calldata should be signed with the nonce taking the place of the signature's commitment to
+   *   its nonce, and the signature solution zeroed.
+   */
+  function verifySignature()
+    private
+    returns (uint256 nonceUsed, bytes memory message, bytes32 messageHash)
+  {
     // If the escape hatch was triggered, reject further signatures
     if (_escapedTo != address(0)) {
       revert EscapeHatchInvoked();
     }
-    // Verify the signature
-    if (!Schnorr.verify(_seraiKey, message, signature.c, signature.s)) {
+
+    message = msg.data;
+    uint256 messageLen = message.length;
+    /*
+      function selector, signature
+
+      This check means we don't read memory, and as we attempt to clear portions, write past it
+      (triggering undefined behavior).
+    */
+    if (messageLen < 68) {
       revert InvalidSignature();
     }
+
+    // Read _nextNonce into memory as the nonce we'll use
+    nonceUsed = _nextNonce;
+
+    // Declare memory to copy the signature out to
+    bytes32 signatureC;
+    bytes32 signatureS;
+
+    // slither-disable-next-line assembly
+    assembly {
+      // Read the signature (placed after the function signature)
+      signatureC := mload(add(message, 36))
+      signatureS := mload(add(message, 68))
+
+      // Overwrite the signature challenge with the nonce
+      mstore(add(message, 36), nonceUsed)
+      // Overwrite the signature response with 0
+      mstore(add(message, 68), 0)
+
+      // Calculate the message hash
+      messageHash := keccak256(add(message, 32), messageLen)
+    }
+
+    // Verify the signature
+    if (!Schnorr.verify(_seraiKey, messageHash, signatureC, signatureS)) {
+      revert InvalidSignature();
+    }
+
     // Set the next nonce
     unchecked {
-      _nextNonce++;
+      _nextNonce = nonceUsed + 1;
+    }
+
+    /*
+      Advance the message past the function selector, enabling decoding the arguments. Ideally, we'd
+      also advance past the signature (to simplify decoding arguments and save some memory). This
+      would transfrom message from:
+
+        message (pointer)
+               v
+               ------------------------------------------------------------
+               | 32-byte length | 4-byte selector | Signature | Arguments |
+               ------------------------------------------------------------
+
+      to:
+
+                 message (pointer)
+                        v
+        ----------------------------------------------
+        | Junk 68 bytes | 32-byte length | Arguments |
+        ----------------------------------------------
+
+      Unfortunately, doing so corrupts the offsets defined within the ABI itself. We settle for a
+      transform to:
+
+                message (pointer)
+                       v
+        ---------------------------------------------------------
+        | Junk 4 bytes | 32-byte length | Signature | Arguments |
+        ---------------------------------------------------------
+    */
+    // slither-disable-next-line assembly
+    assembly {
+      message := add(message, 4)
+      mstore(message, sub(messageLen, 4))
     }
   }
 
   /// @notice Update the key representing Serai's Ethereum validators
-  /// @dev This assumes the key is correct. No checks on it are performed
-  /// @param newSeraiKey The key to update to
-  /// @param signature The signature by the current key authorizing this update
-  function updateSeraiKey(bytes32 newSeraiKey, Signature calldata signature)
-    external
-    updateSeraiKeyAtEndOfFn(_nextNonce, newSeraiKey)
-  {
+  /**
+   * @dev This assumes the key is correct. No checks on it are performed.
+   *
+   *  The hex bytes are to cause a collision with `IRouter.updateSeraiKey`.
+   */
+  // @param signature The signature by the current key authorizing this update
+  // @param newSeraiKey The key to update to
+  function updateSeraiKey5A8542A2() external {
+    (uint256 nonceUsed, bytes memory args,) = verifySignature();
     /*
-      This DST needs a length prefix as well to prevent DSTs potentially being substrings of each
-      other, yet this is fine for our well-defined, extremely-limited use.
-
-      We don't encode the chain ID as Serai generates independent keys for each integration. If
-      Ethereum L2s are integrated, and they reuse the Ethereum validator set, we would use the
-      existing Serai key yet we'd apply an off-chain derivation scheme to bind it to specific
-      networks. This also lets Serai identify EVMs per however it wants, solving the edge case where
-      two instances of the EVM share a chain ID for whatever horrific reason.
-
-      This uses encodePacked as all items present here are of fixed length.
+      We could replace this with a length check (if we don't simply assume the calldata is valid as
+      it was properly signed) + mload to save 24 gas but it's not worth the complexity.
     */
-    bytes32 message = keccak256(abi.encodePacked("updateSeraiKey", _nextNonce, newSeraiKey));
-    verifySignature(message, signature);
+    (,, bytes32 newSeraiKey) = abi.decode(args, (bytes32, bytes32, bytes32));
+    _updateSeraiKey(nonceUsed, newSeraiKey);
   }
 
   /// @notice Transfer coins into Serai with an instruction
@@ -355,28 +345,23 @@ contract Router {
   /// @notice Execute a batch of `OutInstruction`s
   /**
    * @dev All `OutInstruction`s in a batch are only for a single coin to simplify handling of the
-   *  fee
+   *  fee.
+   *
+   *  The hex bytes are to cause a function selector collision with `IRouter.execute`.
    */
-  /// @param coin The coin all of these `OutInstruction`s are for
-  /// @param fee The fee to pay (in coin) to the caller for their relaying of this batch
-  /// @param outs The `OutInstruction`s to act on
-  /// @param signature The signature by the current key for Serai's Ethereum validators
+  // @param signature The signature by the current key for Serai's Ethereum validators
+  // @param coin The coin all of these `OutInstruction`s are for
+  // @param fee The fee to pay (in coin) to the caller for their relaying of this batch
+  // @param outs The `OutInstruction`s to act on
   // Each individual call is explicitly metered to ensure there isn't a DoS here
   // slither-disable-next-line calls-loop
-  function execute(
-    address coin,
-    uint256 fee,
-    OutInstruction[] calldata outs,
-    Signature calldata signature
-  ) external {
-    // Verify the signature
-    // This uses `encode`, not `encodePacked`, as `outs` is of variable length
-    // TODO: Use a custom encode in verifySignature here with assembly (benchmarking before/after)
-    bytes32 message = keccak256(abi.encode("execute", _nextNonce, coin, fee, outs));
-    verifySignature(message, signature);
+  function execute4DE42904() external {
+    (uint256 nonceUsed, bytes memory args, bytes32 message) = verifySignature();
+    (,, address coin, uint256 fee, IRouter.OutInstruction[] memory outs) =
+      abi.decode(args, (bytes32, bytes32, address, uint256, IRouter.OutInstruction[]));
 
     // TODO: Also include a bit mask here
-    emit Executed(_nextNonce, message);
+    emit Executed(nonceUsed, message);
 
     /*
       Since we don't have a re-entrancy guard, it is possible for instructions from later batches to
@@ -389,9 +374,9 @@ contract Router {
     // slither-disable-next-line reentrancy-events
     for (uint256 i = 0; i < outs.length; i++) {
       // If the destination is an address, we perform a direct transfer
-      if (outs[i].destinationType == DestinationType.Address) {
+      if (outs[i].destinationType == IRouter.DestinationType.Address) {
         /*
-          This may cause a revert if the destination isn't actually a valid address. Serai is
+          This may cause a revert  if the destination isn't actually a valid address. Serai is
           trusted to not pass a malformed destination, yet if it ever did, it could simply re-sign a
           corrected batch using this nonce.
         */
@@ -415,7 +400,8 @@ contract Router {
           erc20TransferOut(nextAddress, coin, outs[i].amount);
         }
 
-        (CodeDestination memory destination) = abi.decode(outs[i].destination, (CodeDestination));
+        (IRouter.CodeDestination memory destination) =
+          abi.decode(outs[i].destination, (IRouter.CodeDestination));
 
         /*
           Perform the deployment with the defined gas budget.
@@ -438,10 +424,19 @@ contract Router {
   }
 
   /// @notice Escapes to a new smart contract
-  /// @dev This should be used upon an invariant being reached or new functionality being needed
-  /// @param escapeTo The address to escape to
-  /// @param signature The signature by the current key for Serai's Ethereum validators
-  function escapeHatch(address escapeTo, Signature calldata signature) external {
+  /**
+   * @dev This should be used upon an invariant being reached or new functionality being needed.
+   *
+   * The hex bytes are to cause a collision with `IRouter.escapeHatch`.
+   */
+  // @param signature The signature by the current key for Serai's Ethereum validators
+  // @param escapeTo The address to escape to
+  function escapeHatchDCDD91CC() external {
+    // Verify the signature
+    (, bytes memory args,) = verifySignature();
+
+    (,, address escapeTo) = abi.decode(args, (bytes32, bytes32, address));
+
     if (escapeTo == address(0)) {
       revert InvalidEscapeAddress();
     }
@@ -454,10 +449,6 @@ contract Router {
       revert EscapeHatchInvoked();
     }
 
-    // Verify the signature
-    bytes32 message = keccak256(abi.encodePacked("escapeHatch", _nextNonce, escapeTo));
-    verifySignature(message, signature);
-
     _escapedTo = escapeTo;
     emit EscapeHatch(escapeTo);
   }

processor/ethereum/router/src/lib.rs

@@ -28,10 +28,25 @@ use serai_client::networks::ethereum::Address as SeraiAddress;
 #[expect(clippy::all)]
 #[expect(clippy::ignored_unit_patterns)]
 #[expect(clippy::redundant_closure_for_method_calls)]
-mod _abi {
+mod _irouter_abi {
+  alloy_sol_macro::sol!("contracts/IRouter.sol");
+}
+
+#[rustfmt::skip]
+#[expect(warnings)]
+#[expect(needless_pass_by_value)]
+#[expect(clippy::all)]
+#[expect(clippy::ignored_unit_patterns)]
+#[expect(clippy::redundant_closure_for_method_calls)]
+mod _router_abi {
   include!(concat!(env!("OUT_DIR"), "/serai-processor-ethereum-router/router.rs"));
 }
-use _abi::Router as abi;
+
+mod abi {
+  pub use super::_router_abi::IRouterWithoutCollisions::*;
+  pub use super::_router_abi::IRouter::*;
+  pub use super::_router_abi::Router::constructorCall;
+}
 use abi::{
   SeraiKeyUpdated as SeraiKeyUpdatedEvent, InInstruction as InInstructionEvent,
   Executed as ExecutedEvent,
@@ -309,26 +324,37 @@ impl Router {
 
   /// Get the message to be signed in order to update the key for Serai.
   pub fn update_serai_key_message(nonce: u64, key: &PublicKey) -> Vec<u8> {
-    ("updateSeraiKey", U256::try_from(nonce).expect("couldn't convert u64 to u256"), key.eth_repr())
-      .abi_encode_packed()
+    abi::updateSeraiKeyCall::new((
+      abi::Signature { c: U256::try_from(nonce).unwrap().into(), s: U256::ZERO.into() },
+      key.eth_repr().into(),
+    ))
+    .abi_encode()
   }
 
   /// Construct a transaction to update the key representing Serai.
   pub fn update_serai_key(&self, public_key: &PublicKey, sig: &Signature) -> TxLegacy {
     TxLegacy {
       to: TxKind::Call(self.1),
-      input: abi::updateSeraiKeyCall::new((public_key.eth_repr().into(), sig.into()))
-        .abi_encode()
-        .into(),
-      gas_limit: 40748 * 120 / 100,
+      input: abi::updateSeraiKeyCall::new((
+        abi::Signature::from(sig),
+        public_key.eth_repr().into(),
+      ))
+      .abi_encode()
+      .into(),
+      gas_limit: 40_889 * 120 / 100,
       ..Default::default()
     }
   }
 
   /// Get the message to be signed in order to execute a series of `OutInstruction`s.
   pub fn execute_message(nonce: u64, coin: Coin, fee: U256, outs: OutInstructions) -> Vec<u8> {
-    ("execute".to_string(), U256::try_from(nonce).unwrap(), coin.address(), fee, outs.0)
-      .abi_encode_sequence()
+    abi::executeCall::new((
+      abi::Signature { c: U256::try_from(nonce).unwrap().into(), s: U256::ZERO.into() },
+      coin.address(),
+      fee,
+      outs.0,
+    ))
+    .abi_encode()
   }
 
   /// Construct a transaction to execute a batch of `OutInstruction`s.
@@ -336,9 +362,11 @@ impl Router {
     let outs_len = outs.0.len();
     TxLegacy {
       to: TxKind::Call(self.1),
-      input: abi::executeCall::new((coin.address(), fee, outs.0, sig.into())).abi_encode().into(),
+      input: abi::executeCall::new((abi::Signature::from(sig), coin.address(), fee, outs.0))
+        .abi_encode()
+        .into(),
       // TODO
-      gas_limit: 100_000 + ((200_000 + 10_000) * u128::try_from(outs_len).unwrap()),
+      gas_limit: (45_501 + ((200_000 + 10_000) * u128::try_from(outs_len).unwrap())) * 120 / 100,
       ..Default::default()
     }
   }

processor/ethereum/router/src/tests/mod.rs

@@ -10,7 +10,7 @@ use alloy_sol_types::SolCall;
 
 use alloy_consensus::TxLegacy;
 
-use alloy_rpc_types_eth::BlockNumberOrTag;
+use alloy_rpc_types_eth::{BlockNumberOrTag, TransactionReceipt};
 use alloy_simple_request_transport::SimpleRequest;
 use alloy_rpc_client::ClientBuilder;
 use alloy_provider::RootProvider;
@@ -22,6 +22,18 @@ use ethereum_deployer::Deployer;
 
 use crate::{Coin, OutInstructions, Router};
 
+#[test]
+fn selector_collisions() {
+  assert_eq!(
+    crate::_irouter_abi::IRouter::executeCall::SELECTOR,
+    crate::_router_abi::Router::execute4DE42904Call::SELECTOR
+  );
+  assert_eq!(
+    crate::_irouter_abi::IRouter::updateSeraiKeyCall::SELECTOR,
+    crate::_router_abi::Router::updateSeraiKey5A8542A2Call::SELECTOR
+  );
+}
+
 pub(crate) fn test_key() -> (Scalar, PublicKey) {
   loop {
     let key = Scalar::random(&mut OsRng);
@@ -154,8 +166,16 @@ async fn test_erc20_in_instruction() {
   todo!("TODO")
 }
 
-async fn publish_outs(key: (Scalar, PublicKey), nonce: u64, coin: Coin, fee: U256, outs: OutInstructions) -> TransactionReceipt {
-  let msg = Router::execute_message(nonce, coin, fee, instructions.clone());
+async fn publish_outs(
+  provider: &RootProvider<SimpleRequest>,
+  router: &Router,
+  key: (Scalar, PublicKey),
+  nonce: u64,
+  coin: Coin,
+  fee: U256,
+  outs: OutInstructions,
+) -> TransactionReceipt {
+  let msg = Router::execute_message(nonce, coin, fee, outs.clone());
 
   let nonce = Scalar::random(&mut OsRng);
   let c = Signature::challenge(ProjectivePoint::GENERATOR * nonce, &key.1, &msg);
@@ -163,10 +183,10 @@ async fn publish_outs(key: (Scalar, PublicKey), nonce: u64, coin: Coin, fee: U25
 
   let sig = Signature::new(c, s).unwrap();
 
-  let mut tx = router.execute(coin, fee, instructions, &sig);
+  let mut tx = router.execute(coin, fee, outs, &sig);
   tx.gas_price = 100_000_000_000u128;
   let tx = ethereum_primitives::deterministically_sign(&tx);
-  ethereum_test_primitives::publish_tx(&provider, tx).await
+  ethereum_test_primitives::publish_tx(provider, tx).await
 }
 
 #[tokio::test]
@@ -182,7 +202,7 @@ async fn test_eth_address_out_instruction() {
   ethereum_test_primitives::fund_account(&provider, router.address(), amount).await;
 
   let instructions = OutInstructions::from([].as_slice());
-  let receipt = publish_outs(key, 1, Coin::Ether, fee, instructions);
+  let receipt = publish_outs(&provider, &router, key, 1, Coin::Ether, fee, instructions).await;
   assert!(receipt.status());
   println!("empty execute used {} gas:", receipt.gas_used);