Rock Paper Scissors

Summary

The Game struct in the Rock Paper Scissors contract contains 16 storage variables, risking "Stack Too Deep" errors during compilation and inefficient gas usage. The EVM has a 16-slot stack limit, and large structs such as this causes the contract compilation failure.

Vulnerability Details

Impact

• Compilation Failures: Solidity throws Stack too deep errors when compiling the contract

  CompilerError: Stack too deep. Try compiling with `--via-ir` or removing local variables.

• Increased gas costs for players

• Storage inefficiencies

Tools Used

• Remix IDE: Confirmed compilation error

Recommendations

• Split the Struct

  struct GameConfig {

  address playerA;

  address playerB;

  uint256 bet;

  uint256 timeoutInterval;

  uint256 totalTurns;

  }

  ​

  struct GameState {

  uint256 currentTurn;

  bytes32 commitA;

  bytes32 commitB;

  Move moveA;

  Move moveB;

  uint8 scoreA;

  uint8 scoreB;

  GameState status;

  }

  ​

  struct GameTiming {

  uint256 revealDeadline;

  uint256 creationTime;

  uint256 joinDeadline;

  }

  ​

  mapping(uint256 => GameConfig) public gameConfigs;

  mapping(uint256 => GameState) public gameStates;

  mapping(uint256 => GameTiming) public gameTimings;

The oversized Game struct poses compilation risks and gas inefficiencies. Splitting the struct is the most robust solution, while --via-ir offers a temporary workaround. Recommended actions:

• Short-term: Enable via_ir for deployment.

• Long-term: Refactor into smaller structs (Solution 1).