DocumentEngine (ERC-1643)

This project has not been audited yet, please use at your own risk. For any questions, please contact [email protected].

The DocumentEngine is an external contract to manage documents through ERC-1643, a standard proposition to manage document on-chain. This standard is notably used by ERC-1400 from Polymath.

The documentEngine is planned to be used by other smart contract,e.g CMTAT token, to store documents on their behalf.

The ERC-1643 defines a document with three attributes:

• A short name (represented as a bytes32)
• A generic URI (represented as a string) that could point to a website or other document portal.
• The hash of the document contents associated with it on-chain.

A smart contract needs only to implement two functions from this standard, available in the interface IERC1643 to get the documents from the documentEngine.

interface IERC1643 {
function getDocument(bytes32 _name) external view returns (string memory , bytes32, uint256);
function getAllDocuments() external view returns (bytes32[] memory);
}

Use an external contract for your smart contract provides two advantages:

• Reduce code size of your smart contract
• Allow to manage documents for several different smart contracts

Warning:

Since this engine allows to set documents for several different smart contracts, the functions to set documents take one supplementary arguments than defined in the ERC-1643.

IERC1643

function setDocument(bytes32 _name, string _uri, bytes32 _documentHash) external;

DocumentEngine

function setDocument(address smartContract,bytes32 name_,string memory uri_, bytes32 documentHash_)

Schema

Inheritance

Graph

Surya Description Report

Contracts Description Table

Contract	Type	Bases
└	Function Name	Visibility	Mutability	Modifiers
DocumentEngine	Implementation	IERC1643, DocumentEngineInvariant, AccessControl
└		Public ❗️	🛑	NO❗️
└	setDocument	Public ❗️	🛑	onlyRole
└	removeDocument	External ❗️	🛑	onlyRole
└	batchSetDocuments	External ❗️	🛑	onlyRole
└	batchSetDocuments	External ❗️	🛑	onlyRole
└	batchRemoveDocuments	External ❗️	🛑	onlyRole
└	batchRemoveDocuments	External ❗️	🛑	onlyRole
└	getDocument	External ❗️		NO❗️
└	getDocument	External ❗️		NO❗️
└	getAllDocuments	External ❗️		NO❗️
└	getAllDocuments	External ❗️		NO❗️
└	hasRole	Public ❗️		NO❗️
└	_getDocument	Internal 🔒
└	_removeDocumentName	Internal 🔒	🛑
└	_removeDocument	Internal 🔒	🛑
└	_setDocument	Internal 🔒	🛑

Legend

Symbol	Meaning
🛑	Function can modify state
💵	Function is payable

Gasless support (ERC-2771)

The DocumentEngine supports client-side gasless transactions using the Gas Station Network (GSN) pattern, the main open standard for transfering fee payment to another account than that of the transaction issuer. The contract uses the OpenZeppelin contract ERC2771ContextUpgradeable, which allows a contract to get the original client with _msgSender() instead of the fee payer given by msg.sender while allowing upgrades on the main contract (see Deployment via a proxy above).

At deployment, the parameter forwarder inside the constructor has to be set with the defined address of the forwarder. Please note that the forwarder can not be changed after deployment.

Please see the OpenGSN documentation for more details on what is done to support GSN in the contract.

Dependencies

The toolchain includes the following components, where the versions are the latest ones that we tested:

• Foundry
• Solidity 0.8.26 (via solc-js)
• OpenZeppelin Contracts (submodule) v5.0.2
• Tests
  • CMTAT v2.5.0-rc0
  • OpenZeppelin Contracts Upgradeable(submodule) v5.0.2

Tools

Prettier

npx prettier --write --plugin=prettier-plugin-solidity 'src/**/*.sol'

Slither

slither .  --checklist --filter-paths "openzeppelin-contracts|test|CMTAT|forge-std" > slither-report.md

Surya

See ./doc/script

Foundry

Foundry is a blazing fast, portable and modular toolkit for Ethereum application development written in Rust.

Foundry consists of:

• Forge: Ethereum testing framework (like Truffle, Hardhat and DappTools).
• Cast: Swiss army knife for interacting with EVM smart contracts, sending transactions and getting chain data.
• Anvil: Local Ethereum node, akin to Ganache, Hardhat Network.
• Chisel: Fast, utilitarian, and verbose solidity REPL.

Documentation

https://book.getfoundry.sh/

Usage

Coverage

$ forge coverage --report lcov && genhtml lcov.info --branch-coverage --output-dir coverage

Gas report

$ forge test --gas-report

Build

$ forge build

Test

$ forge test

Format

$ forge fmt

Gas Snapshots

$ forge snapshot

Anvil

$ anvil

Deploy

$ forge script script/Counter.s.sol:CounterScript --rpc-url <your_rpc_url> --private-key <your_private_key>

Cast

$ cast <subcommand>

Help

$ forge --help
$ anvil --help
$ cast --help

Intellectual property

The code is copyright (c) Capital Market and Technology Association, 2018-2024, and is released under Mozilla Public License 2.0.