Combined Policies

Overview

This policy allows you to customize a tailored security blanket for your protocol, unique to your protocol's business offering. This is a common best practice through which security is seen as a multi-layered onion, where each layer protects against different attack vectors.

Protected Attack Vector

Based on your configuration, this policy will allow you to protect against any number of attack vectors, by combining them in different orders and configurations.

How It Works

1. When a transaction reaches this policy, it goes through the list of configured policy combinations.

2. Once all policies finished executing and inspecting the incoming transactions, the policy checks if the combined results matches any of the configured combinations.

3. If a matching combination exist, the transaction will be allowed to go through. Otherwise, it will be reverted.

Setup Instructions

1. Deploy your own version of this policy (see Source Code).

2. Call the setConsumersStatuses() method to configure which consumers are allowed to interact with this policy.

3. Call the setFirewall() method to set which Firewall is allowed to use this policy.

4. Call the setAllowedCombinations() method to set what policies combinations you want this policy to work with.

5. Add the newly deployed policy to the Firewall (you can do this Globally or Per-Method, see Policy Administration).

6. That's it!

Properties

Name	Type	Description
firewallAddress	address	the address of the Firewall that can use this policy
allowedCombinationHashes	bytes32[]	the list of allowed policies combinations (hashed)
isAllowedCombination	mapping (bytes32 => bool)	a mapping between combination hashes and their status (true or false)
approvedConsumer	mapping (address => bool)	a mapping of allowed consumers
policies	addresses[]	a list of policy addresses
currentResults	bool[][]	a matrix of inspection results, used throughout the execution of the configured policies

Methods

setConsumersStatuses()

function setConsumersStatuses(address[] calldata consumers, bool[] calldata statuses)

Callable only by the policy owner. Sets which consumers are allowed to use this policy.

Parameter Name	Type	Description
consumers	address[] calldata	a list of consumers for which we're setting the statuses
statuses	bool[] calldata	a list of statuses to approve / disapprove the corresponding consumers

setFireall()

function setFirewall(address _firewallAddress)

Callable only by the policy owner. Sets the Firewall that can use this policy.

Parameter Name	Type	Description
_firewallAddress	address	the address of the Firewall to set

setAllowedCombinations()

function setAllowedCombinations(address[] calldata _policies, bool[][] calldata _allowedCombinations)

Callable only by the policy owner. Sets the policies combinations that the policy will use.

Parameter Name	Type	Description
_policies	address[] calldata	a list of addresses for the policies we want to configure combinations for
_allowedCombinations	bool[][]	a matrix of combinations for allowed policies the row length must match the length of the _policies array each row represents a combination policies that need to pass in order to allow the transaction to go through

Security Lifecycle

This policy runs during both the Firewall's Pre Execution and the Post Execution hooks.

Source Code

On our GitHub repository: CombinedPoliciesPolicy.sol