SUKU Blockchain Document Authenticator Library

This is the SUKU Blockchain Document Authenticator Library. It can be used to write blockchain proofs (signed hashes) of files to the blockchain. It expects a deployed version of the SUKU Ethereum Node API.

Usage as a library

Note: Before you start, please make sure that you have a deployed version of SUKU Ethereum Node API.

The document authenticator ships as an npm package. It requires the document authenticator smart contract to be deployed to the blockchain.

This package uses SUKU Ethereum Node API Client Lib to connect to an instance of SUKU Ethereum Node API.

NPM Install

@suku/doc-auth-lib is available as an NPM Package.

Use the following command to install the library.

npm i --save @suku/doc-auth-lib

Prep: Contract Deployment

The Doc Authenticator requires a contract that needs to be deployed to the blockchain. If the contract has already been deployed to your network, please skip this section.

If you still need to deploy the contract, you can deploy it manually or use our deploymenty script.

Manual Deployment

To deploy the contract manually, copy the smart contract code from ./blockchain/contracts/Docauth.sol. Use Remix and MetaMask to deploy the contract to your network. Connect remix to the network of your choice. We recommend Ganache for test purposes.

Automatic Deployment

The document authenticator comes with a helper script that allows for flexible deployment.

1. Import the deployment script from the library
2. Use the deployDocAuth(nodeUrl, privateKey) function to deploy the smart contract to your blockchain.
3. As nodeURL use the URL of a running instance of SUKU Ethereum Node API.
4. As privateKey specify a private key that is able to send transactions on the Ethereum node that your API instance is connected to. Make sure that this private key has sufficient gas to send transactions.

import deployDocAuth from '@suku/doc-auth-lib/dist/deploydocauthenticator';

const nodeUrl = "HTTP://xyz"; // SUKU Ethereum Node API instance
const privateKey = "abc"; 

deployDocAuth(nodeUrl,privateKey)
.then( async receipt => {
    logger.info("Contract deployed. Contract address: " + receipt.contractAddress);
});

Importing the library

The import depends on you ECMAScript version.

For ECMAScript <= ES5 (CommonJS require())

const docAuthLibrary = require('@suku/doc-auth-lib');

For ECMAScript >= ES6 (import)

import DocAuthenicator from '@suku/doc-auth-lib';

Adding a Proof

CommonJS Example:

const docAuthLibrary = require('@suku/doc-auth-lib');

let docauth = new docAuthLibrary.default(
        nodeUrl, // SUKU Ethereum Node API instance
        receipt.contractAddress, // contractAddress
        privateKey // private key that is used for signing
    );

let proofReceipt = await docauth.addProof(fileBuffer, uid);
let docHash = proofReceipt.docHash;
let txReceipt = proofReceipt.txReceipt;

Reading a Proof

CommonJS Example:

const docAuthLibrary = require('@suku/doc-auth-lib');

let docauth = new docAuthLibrary.default(
        nodeUrl, // SUKU Ethereum Node API instance
        receipt.contractAddress, // contractAddress
        privateKey // private key that is used for signing
    );

let docProof = docauth.readProof(buffer);