modifiers.sol

Overview

This Solidity source file defines an abstract contract Modifiers which centralizes a collection of constants and reusable function modifiers to enforce common access controls, validations, and gas acceptance patterns in the GOSH smart contract ecosystem. The contract inherits from an Errors contract to utilize standardized error codes for revert messages.

The purpose of Modifiers is to provide a consistent and maintainable way to implement permission checks (such as ownership and sender verification), resource constraints (minimum balance or message value), and transaction acceptance across various contracts within the system. This helps reduce code duplication and enhances security by standardizing validation logic.

Constants

The file declares numerous constants used throughout the system, categorized as follows:

• TvmCell Identifiers: Numeric constants identifying different smart contract components, such as m_PopitGame, m_PopCoinWallet, m_PopCoinRoot, etc.

• Deployment Fees: Fixed deployment fees for various contract types, expressed in vmshell units (e.g., FEE_DEPLOY_POPIT_GAME_WALLET, FEE_DEPLOY_POP_COIN_WALLET).

• Balance Thresholds: Constants defining minimum balance requirements for contracts, such as ROOT_BALANCE and CONTRACT_BALANCE.

• Currency and Reward Parameters: Identifiers and timing constants related to currencies and reward periods (e.g., CURRENCIES_ID, RewardPeriod).

• Size and Limit Constants: Parameters controlling limits on queued requests, lifetimes of keys, maximum numbers of factors or cards, and maximum lengths.

• Cryptographic and Bitwise Constants: Values such as BASE_PART and SHIFT used in cryptographic or bit-shifting operations.

• WASM Module Information: Constants specifying the WASM module and function for TLS checking.

These constants are intended for use in various parts of the GOSH ecosystem and provide standardized values that ensure consistency and prevent magic numbers scattered across the codebase.

Contract: Modifiers

The Modifiers contract is an abstract contract extending from Errors, indicating it cannot be instantiated directly but serves as a base for other contracts.

Properties

• versionModifiers: A string indicating the version of this modifiers contract ("1.0.0").

Modifiers

Modifiers are reusable pieces of code that can be attached to functions to enforce certain preconditions or behaviors.

onlyOwnerPubkey(uint256 rootpubkey)

• Purpose: Ensures that the message sender's public key matches the specified rootpubkey.

• Parameters:

  • rootpubkey (uint256): The expected owner's public key.

• Behavior: Reverts with ERR_NOT_OWNER if the sender's public key does not match.

• Usage Example:

  function sensitiveFunction() external onlyOwnerPubkey(ownerPubkey) {
      // function logic
  }
  

onlyOwner

• Purpose: Restricts function access to the contract owner, identified by the contract's public key.

• Behavior: Checks if msg.pubkey() equals tvm.pubkey(). Reverts with ERR_NOT_OWNER if not.

• Usage Example:

  function adminFunction() external onlyOwner {
      // admin-only logic
  }
  

accept

• Purpose: Accepts inbound external messages, allowing the contract to process them.

• Behavior: Calls tvm.accept() before function execution.

• Usage Example:

  function receiveFunds() external accept {
      // logic that requires message acceptance
  }
  

onlyOwnerWallet(optional(address) owner_wallet, uint256 rootpubkey)

• Purpose: Restricts function access to either the owner's public key or the specified owner wallet address.

• Parameters:

  • owner_wallet (optional(address)): Optional address of the owner's wallet.

  • rootpubkey (uint256): Owner's public key.

• Behavior:

  • If the sender's public key is not equal to rootpubkey, it requires:

    • owner_wallet to be present.

    • msg.sender equals owner_wallet.

  • Reverts with ERR_NOT_OWNER on failure.

• Usage Example:

  function updateSettings(optional(address) ownerWallet) external onlyOwnerWallet(ownerWallet, rootPubkey) {
      // update logic
  }
  

onlyOwnerWalletOpt(optional(address) owner_wallet, optional(uint256) rootpubkey)

• Purpose: Similar to onlyOwnerWallet but both owner_wallet and rootpubkey are optional.

• Parameters:

  • owner_wallet (optional(address)): Optional owner wallet address.

  • rootpubkey (optional(uint256)): Optional owner public key.

• Behavior:

  • If rootpubkey is provided, requires msg.pubkey() equals rootpubkey.

  • Otherwise, requires owner_wallet to be present and msg.sender equals owner_wallet.

  • Reverts with ERR_NOT_OWNER if conditions are not met.

• Usage Example:

  function privilegedAction(optional(address) ownerWallet, optional(uint256) rootPubkey) external onlyOwnerWalletOpt(ownerWallet, rootPubkey) {
      // privileged logic
  }
  

onlyOwnerAddress(address addr)

• Purpose: Permits access only if the sender's address matches the specified addr.

• Parameters:

  • addr (address): The authorized sender address.

• Behavior: Reverts with ERR_NOT_OWNER if msg.sender is not addr.

• Usage Example:

  function restrictedCall() external onlyOwnerAddress(authorizedAddress) {
      // restricted logic
  }
  

minValue(uint128 val)

• Purpose: Ensures the inbound message value is at least val.

• Parameters:

  • val (uint128): Minimum allowed value.

• Behavior: Reverts with ERR_LOW_VALUE if msg.value < val.

• Usage Example:

  function payableFunction() external minValue(1000000) {
      // logic requiring minimum value
  }
  

senderIs(address sender)

• Purpose: Restricts function calls to a specific sender address.

• Parameters:

  • sender (address): Expected sender address.

• Behavior: Reverts with ERR_INVALID_SENDER if msg.sender is not sender.

• Usage Example:

  function onlyFromTrusted() external senderIs(trustedAddress) {
      // logic
  }
  

minBalance(uint128 val)

• Purpose: Requires the contract balance to be above a certain threshold.

• Parameters:

  • val (uint128): Minimum required balance.

• Behavior: Reverts with ERR_LOW_BALANCE if address(this).balance ≤ val + 1 vmshell.

• Usage Example:

  function criticalOperation() external minBalance(5000000) {
      // operation requiring sufficient contract balance
  }
  

Important Implementation Details

• The contract uses require statements with custom error codes defined in the inherited Errors contract to enforce access control and validation.

• The contract utilizes optional types for owner wallet addresses and public keys, allowing flexible authorization checks depending on the presence or absence of these parameters.

• The accept modifier calls tvm.accept(), which is necessary in TON-based smart contracts to accept inbound messages and allow processing.

• Constants related to deployment fees (FEE_DEPLOY_*) and balance thresholds (ROOT_BALANCE, CONTRACT_BALANCE) suggest this contract plays a role in managing resource constraints for deploying and operating various components in the GOSH ecosystem.

• The public key and address checks help secure function calls, preventing unauthorized interactions.

Interactions with Other Parts of the System

• This file imports "./structs/structs.sol" and "./errors.sol". The Errors contract provides error codes used in require statements, ensuring standardized revert messages across contracts.

• Contracts that inherit from Modifiers gain access to these modifiers and constants, enabling them to enforce consistent authorization and validation without redefining these rules.

• The Modifiers contract is likely used across multiple smart contracts, such as wallets (PopCoinWallet), token roots (PopCoinRoot), games (PopitGame), multifactor authentication modules (MvMultifactor), indexers, and boost components, as suggested by the constants naming.

• The constants related to WASM modules and TLS checking indicate possible integration with external verification or cryptographic modules.

• This contract helps coordinate security and operational constraints within the broader system by providing foundational building blocks for other contracts.

Mermaid Diagram: Contract Structure

classDiagram
class Modifiers {
+string versionModifiers
+modifier onlyOwnerPubkey()
+modifier onlyOwner()
+modifier accept()
+modifier onlyOwnerWallet()
+modifier onlyOwnerWalletOpt()
+modifier onlyOwnerAddress()
+modifier minValue()
+modifier senderIs()
+modifier minBalance()
}
Modifiers --|> Errors

The diagram illustrates the Modifiers contract inheriting from Errors and lists the available modifiers and the versionModifiers property. This structure reflects how Modifiers serves as a base for access control and validation in the system.