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

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

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

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