EVM Validator Contract

Source on GitHub: github.com/Dobprotocol — DOBVALIDATOR/distribution-contracts/contracts/DOBValidator.sol

DOBValidator.sol is the on-chain component of the DobValidator platform. It stores submission hashes and TRUFA scores on EVM chains, providing a permanent, tamper-proof record of asset verification results that anyone can query.

Contract Overview

Property	Value
Contract	DOBValidator.sol
Solidity	^0.8.20
Access Control	OpenZeppelin AccessControl
Key Role	VALIDATOR_ROLE = keccak256("VALIDATOR_ROLE")
Networks	Sepolia, Polygon Amoy, Base Sepolia, Base Mainnet

Access Control

bytes32 public constant VALIDATOR_ROLE = keccak256("VALIDATOR_ROLE");

Role	Permissions
DEFAULT_ADMIN_ROLE	Grant / revoke roles.
VALIDATOR_ROLE	addProject, setProjectApproved.

The constructor grants both roles to the admin address passed in.

TrufaScores Struct

struct TrufaScores {
    uint32 technicalFeasibility;
    uint32 regulatoryCompliance;
    uint32 financialViability;
    uint32 environmentImpact;     // note: environmentImpact, not environmental
    uint32 overallTrufaScore;
}

Each field is uint32, validated to be <= 100 on-chain. The five fields pack into a single 32-byte storage slot.

Project Struct

struct Project {
    bool        exists;
    bool        approved;
    address     addedBy;       // VALIDATOR_ROLE that called addProject
    address     approvedBy;    // VALIDATOR_ROLE that called setProjectApproved
    TrufaScores scores;
    uint256     addedAt;       // block.timestamp on addProject
    uint256     approvedAt;    // block.timestamp on setProjectApproved (0 until approved)
}

mapping(bytes32 => Project) public projects;

Core Functions

addProject

function addProject(bytes32 projectHash) external onlyRole(VALIDATOR_ROLE);

Registers projectHash as a Pending project. Reverts if the hash already exists. Emits:

event ProjectAdded(bytes32 indexed projectHash, address indexed addedBy, uint256 timestamp);

setProjectApproved

function setProjectApproved(bytes32 projectHash, TrufaScores calldata scores) external onlyRole(VALIDATOR_ROLE);

Approves a previously added project and writes its TRUFA scores. Reverts if any score is > 100, the project does not exist, or it is already approved. Emits:

event ProjectApproved(
    bytes32 indexed projectHash,
    address indexed approvedBy,
    uint32 technicalFeasibility,
    uint32 regulatoryCompliance,
    uint32 financialViability,
    uint32 environmentImpact,
    uint32 overallTrufaScore,
    uint256 timestamp
);

getProject / isProjectApproved

function getProject(bytes32 projectHash) external view returns (Project memory);
function isProjectApproved(bytes32 projectHash) external view returns (bool);

getProject reverts if the project hash has never been added.

Two-Step Attestation

The deliberate split lets the validator timestamp a submission as soon as it enters review, then publish scores once the review is complete.

Validator: addProject(0xa635...)
  --> Project { exists: true, approved: false, addedBy: msg.sender, addedAt: now }

Validator: setProjectApproved(0xa635..., {95, 92, 85, 88, 90})
  --> Project { ..., approved: true, approvedBy: msg.sender, scores: {...}, approvedAt: now }

On-Chain Verification (JS)

import { ethers } from 'ethers';

const contract = new ethers.Contract(validatorAddress, abi, provider);
const project  = await contract.getProject(certificateHash);

if (project.exists && project.approved) {
  const s = project.scores;
  console.log('Technical feasibility:', s.technicalFeasibility);
  console.log('Regulatory compliance:', s.regulatoryCompliance);
  console.log('Financial viability:',   s.financialViability);
  console.log('Environment impact:',    s.environmentImpact);
  console.log('Overall TRUFA:',         s.overallTrufaScore);
}

Gas Costs

Function	Approximate gas
addProject	~50k (one new storage slot)
setProjectApproved	~60k (overwrites the packed scores slot)
getProject	view, free off-chain

Deployed Addresses

TODO: verify and fill in. Addresses are deployed via DOBVALIDATOR/distribution-contracts/scripts/deploy.ts per network.

Network	Chain ID	Address
Ethereum Sepolia	11155111	TODO
Polygon Amoy	80002	TODO
Base Sepolia	84532	TODO
Base Mainnet	8453	TODO