@stowprotocol/stow-js

StowJS

Quickstart

const Web3 = require("web3");
const Stow = require("@stowprotocol/stow-js");

const web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:7545"));

const stow = new Stow(web3);

// get the deployed contracts
const { _, users, records, permissions } = await stow.getContractInstances();

Installation

You can install using npm:

npm i @stowprotocol/stow-js

or add inject the library onto the window using a script tag:

<script type="text/javascript" src="https://cdn.jsdelivr.net/npm/@stowprotocol/stow-js-script-tag@0.3.0/dist/index.min.js"></script>

Building

npm run build

The compiled library is generated in lib, which you can require by typing require('./lib')

Setting up a Dev Environment

New to ethereum and/or Stow? Head over to our resources page to learn more about the protocol and how to set up your ethereum development environment.

API Documentation

Constructor

new Stow(web3 [, options])

Parameters

1. Object - An instantiated web3 API object
2. Object - (Optional) Constructor options

• hubAddress: String - Address of the StowHub. If not specified, library will use the address of the latest version of the contract deployed on the network.
• tokenAddress:String - Address of the StowToken. If not specified, library will use the address of the latest version of the contract deployed on the network.

Example

const Web3 = require("web3");
const Stow = require("@stowprotocol/stow-js");
const web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:7545"));
const stow = new Stow(web3);

stow.getContractInstances

stow.getContractInstances();

Gets Stow contract instances, wrapped in truffle contract.

Returns

Promise<Object> - A promise when resolved returns an object with truffle Contract instances.

• _hub: Object - DO NOT USE - INTERNAL - StowHub truffle contract instance
• users: Object - StowUsers truffle contract instance
• records: Object - StowRecords truffle contract instance
• permissions: Object - StowPermissions truffle contract instance

Example

stow.getContractInstances().then(instances => {
  let users = instances.users;
  let records = instances.records;
  let permissions = instances.permissions;
});

stow.getRecord

stow.getRecord(dataHash);

Gets a record from Stow by data hash

Parameters

1. String - The data hash, hex-encoded, 0x prefixed

Returns

Promise<Object> - A promise when resolved returns an instance of Record class.

• owner: String - Hex-encoded record owner address
• metadataHash: String - Hex-encoded metadata hash
• sigCount: Object - A bignumber object, the signature count
• irisScore: Object - A bignumber object, the IRIS score
• dataUri: String - URI of the data
• timestamp: Date - The timestamp when the record is added to Stow

stow.getAttestation

stow.getAttestation(dataHash, attesterAddress);

Gets the attestation of the data

Parameters

1. String - The data hash, hex-encoded, 0x prefixed
2. String - The address of the attester

Returns

Promise<Boolean> - A promise when resolved returns true if the record is attested by the specified attester.

stow.getPermission

stow.getPermission(dataHash, viewerAddress);

Gets the permission information of a record

Parameters

1. String - The data hash, hex-encoded, 0x prefixed
2. String - The address of the data viewer

Returns

Promise<Object> - A promise when resolved returns a Stow Permission object.

• canAccess: Boolean - True if the specified viewer is allowed to access the record
• dataUri: String - The data URI of the shared record

---

Append data to Stow

In order to append data to Stow, your web3 instance need to be able to sign with the private key of the owner of the data.

stow.addRecordWithReward

stow.addRecordWithReward(dataHash, metadata, dataUri, ethParams);

Add record to Stow and receive a small reward of stow tokens. This requires an optional parameter to be set in the constructor as follows:

new Stow(web3, (tokenAddress: 0x4cdfbdec0aa003116bf030f249a8a7285cd6a184))

Parameters

1. String - The data hash. Hash of the plain text data + metadata
2. Object - The metadata of the record. Click here to read more about the metadata
3. String - The dataUri, link to the data (eg. the IPFS hash)
4. Object - The ethParams, ethereum account params. (The object need to contain the key 'from')

Returns

Promise<Record> - A promise when resolved returns the record object that was stored.

stow.addRecord

stow.addRecord(dataHash, metadata, dataUri, ethParams);

Add record to Stow

Parameters

1. String - The data hash. Hash of the plain text data + metadata
2. Object - The metadata of the record. Click here to read more about the metadata
3. String - The dataUri, link to the data (eg. the IPFS hash)
4. Object - The ethParams, ethereum account params. (The object need to contain the key 'from')

Returns

Promise<Record> - A promise when resolved returns the record object that was stored.

Append data using Stow Js in the browser

If you are using a Stow Js in the browser you can create the Stow instance with the web3 object from Metamask and append a record the following way:

Example

const Stow = require("@stowprotocol/stow-js");
const stow = new Stow(web3);

const dataHash = "0xcc85fc3d763b9a1d83e4386b37b4b0f3daf9881638ba8b7db0c501c417acb689";
const metadata = {
    dataFormat: "json",
    domain: "social media",
    storage: "IPFS",
    encryptionScheme: "x25519-xsalsa20-poly1305",
    encryptionPublicKey: "hQYhHJpzZH/tGhz1wtqSjkL17tJSnEEC4yVGyNTHNQY=",
    stowjsVersion: "0.1.4",
    providerName: "SocialMedia",
    providerEthereumAddress: "0x349e31e92027f86b0ffeb5cd5e07003c7f229872",
    keywords: [ "socialmedia", "friends list", "people" ],
    creationDate: new Date(Date.UTC(96, 1, 2, 3, 4, 5))
};
const dataUri = "QmSg3jCiroFERczWdpFJUau5CofHfMKCSm5vZXSzn7sZGW";
const ethParams = {
    from: "0xb717d7adf0d19f5f48bb7ff0030e30fcd19eed72", gas: 500000, gasPrice: 20000000000
};

const record = await stow.addRecord(dataHash, metadata, dataUri, ethParams);

In the example above the dataUri is the IPFS Hash where the file was stored.

Append data using Stow Js outside of the browser

In order to add a file you need to generate a web3 instance that can handle the private keys of the owner of the file.

Example

const Stow = require("@stowprotocol/stow-js");
const HDWalletProvider = require('truffle-hdwallet-provider');

// HERE YOU NEED TO ADD THE PRIVATE KEYS OF THE OWNERS
const privKeys = [privkey1, privkey2, ...]
                  
// HERE YOU NEED TO ADD THE PROVIDER, YOU COULD GET AND INFURA KEY AND PUT IT BELOW 
// OR USE ANY ETH PROVIDER
const provider = 'https://ropsten.infura.io/INFURA_KEY'
const hdWalletProvider = new HDWalletProvider(privKeys, provider);
const web3 = new Web3(hdWalletProvider);

const stow = new Stow(web3);

const dataHash = "0xcc85fc3d763b9a1d83e4386b37b4b0f3daf9881638ba8b7db0c501c417acb689";
const metadata = {
    dataFormat: "json",
    domain: "social media",
    storage: "IPFS",
    encryptionScheme: "x25519-xsalsa20-poly1305",
    encryptionPublicKey: "hQYhHJpzZH/tGhz1wtqSjkL17tJSnEEC4yVGyNTHNQY=",
    stowjsVersion: "0.1.4",
    providerName: "SocialMedia",
    providerEthereumAddress: "0x349e31e92027f86b0ffeb5cd5e07003c7f229872",
    keywords: [ "socialmedia", "friends list", "people" ],
    creationDate: new Date(Date.UTC(96, 1, 2, 3, 4, 5))
};
const dataUri = "QmSg3jCiroFERczWdpFJUau5CofHfMKCSm5vZXSzn7sZGW";
const ethParams = {
    from: "0xb717d7adf0d19f5f48bb7ff0030e30fcd19eed72", gas: 500000, gasPrice: 20000000000
};

const record = await stow.addRecord(dataHash, metadata, dataUri, ethParams);

Attest data on Stow

Attest data on Stow means sign a record and verify that contain legitimate and correct information.

stow.signRecord

stow.signRecord(dataHash, ethParams);

Attest a record to Stow

Parameters

1. String - The data hash, hex-encoded, 0x prefixed
2. Object - The ethParams, ethereum account params. (The object need to contain the key 'from')

Returns

Promise<Attestation> - A promise when resolved returns the Attestation that was added.

Example

const Stow = require("@stowprotocol/stow-js");
const stow = new Stow(web3);

const dataHash = "0xcc85fc3d763b9a1d83e4386b37b4b0f3daf9881638ba8b7db0c501c417acb689";
const ethParams = {
    from: "0xb717d7adf0d19f5f48bb7ff0030e30fcd19eed72", gas: 500000, gasPrice: 20000000000
};

const attestation = await stow.signRecord(dataHash, ethParams);

---

Record class

An instance of Record class is returned when stow.getRecord is called and promise resolved.

Members

• owner: String - Hex-encoded record owner address
• metadataHash: String - Hex-encoded metadata hash
• sigCount: Object - A bignumber object, the signature count
• irisScore: Object - A bignumber object, the IRIS score
• dataUri: String - URI of the data
• timestamp: Date - The timestamp when the record is added to Stow

record.getAttestation

record.getAttestation(attesterAddress);

Gets the attestation of the data

Parameters

1. String - The address of the attester

Returns

Promise<Boolean> - A promise when resolved returns true if the record is attested by the specified attester.

Example

let dataHash =
  "0x174e6ab7cf9a53497cff763d0743258f5d5014cb20ae08c7ec22bf50f5d5e326";
let attester = "0xac07bea81fe26b379de0e4327f1a6ecd0875edfc";
stow
  .getRecord(dataHash)
  .then(record => record.getAttestation(attester))
  .then(attested => {
    if (attested) {
      // ...
    } else {
      // ...
    }
  });

record.getPermission

record.getPermission(viewerAddress);

Gets the permission information of a record

Parameters

1. String - The address of the data viewer

Returns

Promise<Object> - A promise when resolved returns a Stow Permission object.

• canAccess: Boolean - True if the specified viewer is allowed to access the record
• dataUri: String - The data URI of the shared record

record.decryptData

record.decryptData(privKey, uriResolver);

Gets the plaintext data of the record

Parameters

1. String - The private key to decrypt the data
2. (String) => (String) - A function to resolve the data URI. The parameter is the string data URI. The function should return the plaintext data.

Returns

String - The plaintext data

Example

let privKey =
  "0x5230a384e9d271d59a05a9d9f94b79cd98fcdcee488d1047c59057046e128d2b";
stow
  .decryptData(privKey, dataUri => {
    // assume data URI is HTTP URL here
    return fetch(dataUri).then(res => {
      return res.arrayBuffer();
    });
  })
  .then(plainText => {
    console.log(plainText.toString());
  });

record.decryptPermissioned

record.decryptPermissioned(viewerAddress, privKey, uriResolver)

Gets the plaintext data of a permissioned copy of the record

Parameters

1. String - The address of viewer
2. String - The private key to decrypt the data of the permissioned copy. Note that this is the key controlled by the viewer, not the record owner.
3. (String) => (Promise<String>) - A function to resolve the data URI. The parameter is the string data URI. The function should return the encrypted data..

Returns

String - The plaintext data

record.verifyData

record.verifyData(plaintext);

Verifies the hash of the data against the one in Stow.

Parameters

1. String - The plaintext data to be verified

Returns

Boolean - True if hash matches

record.reencryptData

record.reencryptData(pubKey, privKey, uriResolver);

Re-encrypts the data to another public key

Parameters

1. String - Public key to re-encrypt the data to
2. String - Private key to decrypt the record data. This should be a key controlled by the record owner
3. (String) => (String) - A function to resolve the data URI. The parameter is the string data URI. The function should return the encrypted data.

Returns

String - The re-encrypted data

---

Attestation class

Members

• attester: String - Hex-encoded attester address
• dataHash: String - Hex-encoded data hash

---

Utility functions

Stow.util.encrypt

Stow.util.encrypt(pubKeyTo, plaintext)

Encrypts a message.

Parameters

1. String - The public key to encrypt the data
2. String - The plaintext data

Returns

String - The encrypted data, which includes the IV, ephemeral public key, MAC, and ciphertext.

Example

let pubKey =
  "0xb1f26f98d374540eac3d31208f13a3935318e228207084c9ee32d741ff1ad2341af4ac9658aba4a254bf1dc6451b3c08524febba5273bec227c73e25cd376387";
let encrypted = Stow.util.encrypt(pubKey, "foo");
console.log(encrypted.toString("hex"));

Stow.util.decrypt

Stow.util.decrypt(privKey, ciphertext);

Decrypts a message encrypted by Stow.util.encrypt.

Parameters

1. String - The private key to decrypt the data.
2. String - The encrypted data, which includes the IV, ephemeral public key, MAC, and ciphertext.

Returns

String - The decrypted plaintext

Example

let encrypted =
  "0xbf18f1b6eb4b748b18cc3bd4a8d47f5f045766a445431dd918a43d6ca7871bdf7acd2214dce02a508a97f173f0697e781cf3cbf1b2d6fc0dcce940cdcef0aab443469773eb672b04117d4cb36336891aa98cd21f07d994b756f456f52db2b26a316fdbaaf87f52a638e0ad4d4280b63ec6447befdc97ecf07117bfc9eb8f8a073f";
let privKey =
  "0x5230a384e9d271d59a05a9d9f94b79cd98fcdcee488d1047c59057046e128d2b";
let plaintext = Stow.util.decrypt(privKey, encrypted).toString();
// plaintext is 'foo'