ERASUREJS : SDK for Erasure Protocol

ErasureJS module comprises of:

1. ErasureClient for creating and getting Users,Feeds,Posts,Agreements,Escrows
2. Core Erasure modules : ErasureFeed,ErasurePost,ErasureAgreements,ErasureEscrows
3. ErasureGraph : for querying Erasure Protocol graph and listening to events

• Use ethers.js for wallet and provider

Usage

const {ErasureClient,ErasureGraph,ErasureFeed,ErasurePost,ErasureAgreement,ErasureEscrow,ErasureUtils} = require("erasure-js)

Config variables for constructors

• wallet : Implemented using ethers.js wallet module, which can be converted from JSON key file, private ket, mnemonic, or web3 wallet.
  • To learn more check out Ethers Docs
• provider: Implemented using ethers.js module, which can be converted from web3Provider
• ipfs : Default = infura node, format : {host:"",port:"",protocol:"https"}
• network (optional) : only used in development env
• graph : default to ErasureGraph of provider's network, can passed in custom local graph for development

Version :

ErasureGraph supports both protocol version 1.0.1 and 1.2.0

const {VERSION_V1,VERSION_V2,MAINNET,RINKEBY} = ErasureUtils
const client = new ErasureClient({version=VERSION_V2})
const graph = new ErasureGraph({version=VERSION_V1,network=MAINNET})

• If no version and network is specified, defaults are : RINKEBY, VERSION_V2

ErasureClient Only support protocol version 1.2.0

• Future development will be added if requested

Contents

• Erasure Client
• Erasure User
• Erasure Template
• Erasure Feed
• Erasure Agreement
• Erasure Escrow
• Erasure Graph Client
• In development

---

ErasureClient

const client = new ErasureClient({wallet=null, provider=null, ipfs=null:{host:string,post:string,protocol:string},graph=null:string})

• Note :
  • If no wallet is specified, a new ethers wallet will be created (when you just want to read data)
  • If no provider is specified, mainnet provider from infura will be provided

METHODS:

• await client.createUser() -> ErasureUser
• await client.createFeed() -> ErasureFeed
• await client.getFeed(address) -> ErasureFeed
• await client.getPost({proofHash,feedAddress}) -> ErasurePost
• await client.createAgreement() -> ErasureAgreement
• await client.getAgreement(address) ->ErasureAgreement
• await client.createEscrow() -> ErasureEscrow
• await client.getEscrow(address) -> ErasureEscrow

Get data from Registry contract

Users

• await client.getAllUsers()
• await client.getUsersCount()
• await client.getPaginatedUsers(start,end)
• await client.getUserData(address)

Feeds

• await client.getAllFeeds()
• await client.getFeedsCount()
• await client.getPaginatedFeeds(start,end)

Agreements

• await client.getAllAgreements()
• await client.getAgreementsCount()
• await client.getPaginatedAgreements(start,end)

Escrows

• await client.getAllEscrows()
• await client.getEscrowsCount()
• await client.getPaginatedEscrows(start,end)

ErasureUser:

const erasureUser = new ErasureUser({wallet,provider,ipfs,graph})

create and register user

const [keypair,confirmedTx] = await erasureUser.createAndRegisterUser({msg,salt=null})

+ How it works:
    1. Create new asym keypair
    2. Upload pubkey to Erasure_User registry
    3. @return keypair

Remove user:

await erasureUser.removeUser()

Getters:

await client.getUserData(address)

Template

Methods:

• await owner()
• await setMetadata(data)
• await denounceOperator()
• await transferOperator(address)
• await operator()
• address - instance's address
• contract - Contract object

ErasureFeed

• (extends Template)

const feed = new ErasureFeed({address,wallet,provider,ipfs,graph})

Create new post:

await feed.createPost(rawData)

+ How It works:    
    1. Create symkey
    2. Encrypt rawData with symkey
    3. Create metadata object:
    {
        address: this.wallet.address,
        rawDataIpfsHash
        symkeyIpfsHash
        encryptedIpfsHash
    }
    4. Upload metadata's multihash digest form to feeds as proofhash
    5. Upload metadata and encryptedData to IPFS

• await feed.reveal() : Reveal all posts
• await feed.getAllEscrows() : Get all Escrows
• await feed.offerBuy() : Create escrow for this feed as buyer
• await feed.offerSell() : Create escrow for this feed as seller
• await feed.offerAsOperator() : create esrow for this feed as operator
• Template Methods

Getters

• Get status of feed (if revealed) : await feed.status()
• Template Methods

ErasurePost :

const post = new ErasurePost({feedAddress,proofHash})

Reveal Post :

const success:bool = await post.reveal({symKey})

+  How it works:
    1. Get the latest post(== proofHash == ipfs path of metadata) of feed from graph
    2. Get metadata from ipfs path
    3. Validate symkey and rawData
    4. Upload symkey and rawData to IPFS 

• await post.offerSell(): Create escrow as seller
• await post.offerBuy() : Create escrow as buyer
• await post.offerAsOperator() : Create escrow as operator

Getters:

• await post.status() : Get status if revealed
• await post.owner()
• await post.proofHash()
• await post.getEscrows() : Get all Escrows that transact this post

ErasureEscrow :

const escrow = new ErasureEscrow({address,wallet,provider,ipfs,graph})

METHODS

Buyer:

• await escrow.depositPayment(amount)
• await escrow.cancel()
• await escrow.timeout()
• await escrow.retrieveDataFromSeller()
  • How it works:
    1. Get dataSubmitted of this escrow from the graph
    2. Decrypt data submitted -> symkey
    3. Get Metadata( multihash digest form of metadata) from the escrow
    4. Get metadata from IPfS
    5. Get encrypted data from metadata.encryptedDataHash
    6. Decrypt data with symKey

Seller

• await escrow.depositStake(amount)
• await escrow.finalize()
• await escrow.cancel()
• await escrow.deliverKey({symKey)
  • How it works:
    1. Get Buyer's pubkey from escrow
    2. Encrypt symKey with Buyer's pubkey
    3. Submit the new encrypted symKey to escrow contract

GETTERS

• await escrow.getAgreement() : Get ErasureAgreement obj of this escrow
• await escrow.buyer()
• await escrow.owner()
• await escrow.seller()
• await escrow.status()
• await escrow.data()

ErasureAgreement

const agreement = new ErasureAgreement({address,wallet,provider,ipfs,graph})

METHODS

• await agreement.reward(amount)
• await agreement.punish(amount)
• await agreement.releaseStake()
• await agreement.timeout()
• await agreement.cancel()
• await agreement.retrieveStake() (countdown)

GETTERS

• await agreement.staker()
• await agreement.counterparty()
• await agreement.owner()
• await agreement.status()
• await escrow.data()

Erasure Graph

const {ErasureGraph} = require("erasureJs")
const erasureGraph = new ErasureGraph({network:ErasureUtils.RINKEBY,version:ErasureUtils.VERSION_V2}) 

• Network :
  • mainnet or rinkery for accessing Erasure graph public node
  • ganache for local node (require having a graph node locally and run deploy graph)
• Queries available

In development

Listening to subscriptions

• If no events array is passed in, client will listen to all events

erasureGraph.startListening(events=null,cb) 

Query the graph

erasrureGraph.query(queryName=null,eventName,opts:Obj,returnData:String)

COMING SOON : Details of all queries available

Development

• yarn
• yarn ganache
• yarn test