Diamond Proxy Storage Rewrite Tool

This repository exists to correct the effects a known issue in multiple EIP-2535 Diamond proxy implementations.

Issue

The issue in question manifests when a zero-selector is added to a diamond proxy at position 8n + 1. If it is later removed, the diamondCut function treats it as an empty slot rather than a function signature and ignores it, corrupting the storage of the proxy.

Usage

Follow the Development insructions below to setup the Hardhat environment.

Use the included Hardhat tasks to correct the storage of an affected diamond proxy. It is recommended to use the high-level repair task.

yarn run hardhat repair TODO

The repair task consists of multiple component tasks which can be run individually. See the Hardhat help menu for more information.

All tasks make use of the Solidstate hardhat-txn-dot-xyz plugin, which delegates transaction signing to a web browser. This is intended to make it easier for multisig account users to update their diamond proxies.

The following is a description of each of the arguments accepted by the tasks.

Argument	Description
diamond	Address of the diamond proxy with corrupted storage.
proxy	Address of the StorageRewrite contract.
authorizedSender	Address of the account permitted to call the rewrite function on the StorageRewrite contract. Defaults to the EIP-173 owner of the diamond proxy.
storageLayoutSeed	String seed used to calculate slot of storage layout struct, where slot = keccak256(seed)
selectorMappingOffset	Index within the storage struct where the diamond proxy's "selectorSlots" mapping is located.
facetsMappingOffset	Index within the storage struct where the diamond proxy's "facets" mapping is located.
selectorCountOffset	Index within the storage struct where the diamond proxy's total selector count is stored.
slots	JSON array of the data to be written to storage, generated by the storage-calculate-diff task.

The following are storage slot seeds and offset values for known common diamond implementations. Values for other implementations must be calculated manually.

Implementation	storageLayoutSeed	selectorMappingOffset	facetsMappingOffset	selectorCountOffset
Solidstate	solidstate.contracts.storage.DiamondBase	2n	0n	1n
Reference ("diamond-2")	diamond.standard.diamond.storage	1n	0n	2n

Development

Install dependencies via Yarn:

yarn install

Setup Husky to format code on commit:

yarn prepare

Compile contracts via Hardhat:

yarn run hardhat compile

The Hardhat environment relies on the following environment variables. The dotenv package will attempt to read them from the .env and .env.secret files, if they are present.

Key	Description
API_KEY_ETHERSCAN	Etherscan API key for source code verification
NODE_URL_MAINNET	JSON-RPC node URL for mainnet network
PKEY_MAINNET	private key for production use on mainnet network
REPORT_GAS	if true, a gas report will be generated after running tests

Networks

By default, Hardhat uses the Hardhat Network in-process. An additional network, mainnet, is available, and its behavior is determined by the configuration of environment variables.

Testing

Test contracts via Hardhat:

yarn run hardhat test

Activate gas usage reporting by setting the REPORT_GAS environment variable to "true":

REPORT_GAS=true yarn run hardhat test

Generate a code coverage report using solidity-coverage:

yarn run hardhat coverage

Documentation

A static documentation site can be generated using hardhat-docgen:

yarn run hardhat docgen