Enhancements and Security Concerns in OpenZeppelin Cairo Contract for StarkNet

[fruitbox12]

🧐 Motivation Improving the OpenZeppelin Cairo contract's Account component on StarkNet is crucial for enhancing security, efficiency, and developer experience. Specific code segments and patterns I have looked at or used where targeted improvements might mitigate potential vulnerabilities, optimize performance, and improve readability. IDK :P

📝 Details Look into a Stricter Caller Verification: As of now ^.^ , the method to prevent unauthorized calls is based on a simple check: assert(sender.is_zero(), Errors::INVALID_CALLER);. This might not be sufficient for all security contexts. Enhancing this check to consider more scenarios can fortify the contract against unauthorized access attempts.

let sender = get_caller_address();
assert(sender.is_zero(), Errors::INVALID_CALLER);
Suggestion: Implement a more robust verification mechanism that accounts for different types of calls and contexts, enhancing the contract's security.

Robust Signature Validation: The function is_valid_signature plays a vital role in ensuring transaction integrity but might be prone to oversights in its current form. Reviewing its logic and potentially incorporating additional checks could prevent exploits.

fn is_valid_signature(
    self: @ComponentState<TContractState>, hash: felt252, signature: Array<felt252>
) -> felt252 {
    if self._is_valid_signature(hash, signature.span()) {
        starknet::VALIDATED
    } else {
        0
    }
}

Suggestion: Enhance the signature validation process with additional safeguards to protect against advanced security threats.

Efficiency and Gas Optimization Optimize Storage Access: Repeated storage operations can be costly. The set_public_key and _set_public_key functions involve multiple reads and writes that could be optimized.

fn set_public_key(ref self: ComponentState<TContractState>, new_public_key: felt252) {
    self.emit(OwnerRemoved { removed_owner_guid: self.Account_public_key.read() });
    self._set_public_key(new_public_key);
}

PLEASE Review and refactor storage access patterns to minimize gas costs, possibly by reducing the number of storage operations or caching values. Code Structure and Readability Enhanced Error Handling: Using string literals for error messages can lead to duplication and larger contract sizes. For instance, const INVALID_CALLER: felt252 = 'Account: invalid caller'; is a pattern seen across different error definitions. Suggestion: Utilize a centralized error handling system with error codes or enums to manage error messages more efficiently.

Documentation Improvements: Expanding comments and documentation within the code can significantly aid understanding and maintainability. For example, detailed explanations for the purpose and usage of functions like execute and is_valid_signature could be more comprehensive. PLEASE Add detailed docstrings and inline comments explaining the logic, parameters, and expected outcomes of functions.

Standardized Naming Conventions: The mix of camelCase and snake_case in variable and function names should be standardized. PLEASE Adopt a consistent naming convention throughout the code to improve clarity and developer experience.

### Tasks
- [ ] https://github.com/OpenZeppelin/cairo-contracts/issues/942