Udacity Blockchain Capstone
6. Real State Marketplace - 6.1 Generate OpenSea marketplace - 6.3 List and Purchase on the marketplace
5. Deployed Contracts Info
6. Project Resources

Udacity Blockchain Capstone

The capstone will build upon the knowledge you have gained in the course in order to build a decentralized housing product. You will be minting your own tokens to represent your title to the real estate properties. Before you mint a token, you need to verify your own the property. You will use zk-SNARKs to create a verification system which can prove you have title to the property without revealing that specific information on the property. Once the token has been verified you will place it on a blockchain market place (OpenSea) for others to purchase. The detail steps of the project is as follows:

building of the ERC 721 tokens for the real estate homes
compiling and integrating zokrates into the tokens that is just built

1. PROJECT SPECIFICATION

Capstone: Real Estate Marketplace

1.1 Project Deliverables

CRITERIA	MEETS SPECIFICATIONS	Status
Write Up	Student includes a README to explain how to test their code.	👌
Write Up	Student provides Contract Addresses, Contract Abi's, OpenSea MarketPlace Storefront link's.	👌

1.2 ERC721

CRITERIA	MEETS SPECIFICATIONS	Status
ERC721 Mintable Contract	Student completes the boilerplate ERC721 Mintable Contract in ERC721Mintable.sol	👌
ERC721 Mintable Contract Test Cases	Student writes and passes the test cases in TestERC721Mintable.js	👌
ERC721 Mintable Contract Zokrates Test	Student writes and passes the test cases in 'TestSquareVerifier.js'	👌
ERC721 Mintable Contract Zokrates Test Cases	Student writes and passes the test cases in TestSolnSquareVerifier.js	👌

1.3 Zokrates

CRITERIA	MEETS SPECIFICATIONS	Status
Zokrates program written using DSL	Student completes the Zokrates proof in square.code by adding the variable names in square.code	👌
Zokrates Test Cases	Student completes test contract in SolnSquareVerifier.sol	👌
Zokrates Test Cases	Student writes and passes the test cases in 'TestSolnSquareVerifier.js'	👌

1.4 OpenSea Marketplace

CRITERIA	MEETS SPECIFICATIONS	Status
Market Place	Student list ERC721/ ZoKrates tokens & complete transactions on market place	👌

1.5 Deployment

CRITERIA	MEETS SPECIFICATIONS	Status
Deployment	Student deploys ERC721 contracts with Zokrates integration.	👌

2 Versions

truffle version

Truffle v5.1.66 (core: 5.1.66)
Solidity v0.5.16 (solc-js)
Node v14.15.5
Web3.js v1.2.9

3. Project Steps

Clone the project repository
Explore the code base.
Fill out ERC721 Mintable Contract in ERC721Mintable.sol
Write test cases TestERC721Mintable.js
Compile and pass test cases in TestERC721Mintable.js
Implement Zokrates
1. Using Docker to install and instantiate a Zokrates zkSnarks development environment
2. Completes the Zokrates proof in square.code by adding the variable names in square.code
3. Compile program
4. Trusted setup
5. Compute witness
6. Generate Proof
7. Export Verifier.sol
8. Note: This project uses solidity version 0.5.2 so you will be required to update the code in Verifier.sol accordingly based on the compiler errors you receive
Write a test script to verify the solidity contract generated by Zokrates executed successfully 1. TestSquareVerifier.js
Write test contract for ZK and ERC721 integration 1. SolnSquareVerifier.sol
Compile and pass with TestSolnSquareVerifier.js
Deploy latest contracts generated by Zokrates (a.k.a verifier.sol)
Deploy SolnSquareVerifier contract to Rinkeby network
Mint 10 tokens
Generate OpenSea marketplace
Test and Verify OpenSea with your SolnSquareVerifier tokens
1. List 5 of your tokens on the marketplace
2. Purchase those 5 tokens using a different address
Complete required documentation and submit!

4 Setup

4.1 Install

This repository contains Smart Contract code in Solidity (using Truffle), tests (also using Truffle)

To install, download or clone the repo, then execute:

nvm install 14.15.5
nvm use 14.15.5
npm install -g truffle
npm install
cd eth-contracts/
truffle compile

4.2 GANACHE setup

Download and install Ganache v2.5.4: https://www.trufflesuite.com/ganache

Run Ganache follow the steps:

on Workspace Tab:
- select NEW WORKSPACE - Ethereum
- enter Workspace name: Capstone
- click on ADD PROJECT and add the truffle-config.js file.
on Server Tab:
- change Port number to 8545.
on Accounts and Keys Tab:
- change TOTAL ACCOUNTS TO GENERATE to 5
- change the Mnemonic to depart quit survey faint message service talk spider urge dynamic jewel fancy
- The Mnemonic shall be the same text of the \\eth-contracts\\.secret file contents.
on Chain Tab:
- change the GAS LIMIT to 9999999
Then click on SAVE WORKSPACE button.

Open your saved workspace:

4.2 Implement Zokrates

Step	Details
Step 1: Install Docker	docker install
Step 2: Run ZoKrates	`docker run -v <path to your GIT project folder>:/home/zokrates/code -ti zokrates/zokrates /bin/bash`

Step	Details	Output
Step 3: Compile the ZoKrates DSL	`cd code/zokrates/code/square/` `zokrates compile -i square.code`
Step 4: Generate the Trusted Setup	`zokrates setup`
Step 5: Compute Witness	`zokrates compute-witness -a 3 9`
Step 6: Generate Proof	`zokrates generate-proof`
Step 7: Export Verifier	`zokrates export-verifier`

Migrate smart contracts to the locally running blockchain, ganache-cli:

cd eth-contracts/
truffle migrate --reset

This will :

deploy the smart contract artifacts to running Ganache

4.3 Tests

To run truffle tests: In directory eth-contracts/

For all tests:

cd eth-contracts/
truffle test

All 11 tests should pass.

For single file tests:

Test	Output
truffle test test/TestERC721Mintable.js
truffle test test/TestSquareVerifier.js
truffle** test test/TestSolnSquareVerifier.js

4.4 Deploying

truffle migrate --network rinkeby --reset

Output:

4.5 Mint Tokens

Mint 10 tokens using scripts/mint.js

cd scripts
node mint.js

Output:

-------------------------------------------
OWNER_ADDRESS: 0xAC1bAde854beFc9cC81C13F258a4DEe38c4cf91a
tokenId: 1
totalSupplyBefore:  0
Minted item. Transaction: 0xada52609b0337453869efeab8be04e4b58ea5337d3090a8c58c9d1ad42bb7510
-------------------------------------------
OWNER_ADDRESS: 0xAC1bAde854beFc9cC81C13F258a4DEe38c4cf91a
tokenId: 2
totalSupplyBefore:  1
Minted item. Transaction: 0xbd15baa4ff82cad0be2d72a0651f584a962f17bf51b51f37cf6dbc4ff099bac0
-------------------------------------------
OWNER_ADDRESS: 0xAC1bAde854beFc9cC81C13F258a4DEe38c4cf91a
tokenId: 3
totalSupplyBefore:  2
Minted item. Transaction: 0xb59e9288f99435c4fd7f585c3a7c9811bcdbf885b15d106fc40eb09e2560977e
-------------------------------------------
OWNER_ADDRESS: 0xAC1bAde854beFc9cC81C13F258a4DEe38c4cf91a
tokenId: 4
totalSupplyBefore:  3
Minted item. Transaction: 0x6e41b1536c39482fe8ee0c1b8e3cdc0d96d705554fad95ef33576d72023a3fc8
-------------------------------------------
OWNER_ADDRESS: 0xAC1bAde854beFc9cC81C13F258a4DEe38c4cf91a
tokenId: 5
totalSupplyBefore:  4
Minted item. Transaction: 0xbbacc140e8e883844b22157104222e19801887159b6a05ee1e8da6c7bbc57448
-------------------------------------------
OWNER_ADDRESS: 0xAC1bAde854beFc9cC81C13F258a4DEe38c4cf91a
tokenId: 6
totalSupplyBefore:  5
Minted item. Transaction: 0x2161b34fb99361f0f5cdfd4b3ddb0f6357b2d9ccc4f34a10c3d9e080995d965c
-------------------------------------------
OWNER_ADDRESS: 0xAC1bAde854beFc9cC81C13F258a4DEe38c4cf91a
tokenId: 7
totalSupplyBefore:  6
Minted item. Transaction: 0x246922b35a16e9a53a796f4c78b2fc02f3a7824e6262f827afe235c5a62a6d1a
-------------------------------------------
OWNER_ADDRESS: 0xAC1bAde854beFc9cC81C13F258a4DEe38c4cf91a
tokenId: 8
totalSupplyBefore:  7
Minted item. Transaction: 0x422e90914e006bfa7e974389f586434e1d8b6ea2cac8c4ee9c5541aefcd923bf
-------------------------------------------
OWNER_ADDRESS: 0xAC1bAde854beFc9cC81C13F258a4DEe38c4cf91a
tokenId: 9
totalSupplyBefore:  8
Minted item. Transaction: 0x917e204a433521feec51bb70906ee0a37bacf3b60b6380c844e255c3a137cb16
-------------------------------------------
OWNER_ADDRESS: 0xAC1bAde854beFc9cC81C13F258a4DEe38c4cf91a
tokenId: 10
totalSupplyBefore:  9
Minted item. Transaction: 0x3e3b4f7b5b1b5c02d407fc7e71827b88676efb9745dd0d406c66f02d50fac776

Open the Etherscan and check the Tokens generated by address owner: Ribas Tokens link

6. Real State Marketplace

The goal of this project to create a decentralized house listing service. The real estate properties are represented by ERC721 tokens. We are using the zk-SNARKs toolbox from ZoKrates to establish a verification mechanism before minting each tokens. Finally, the tokens are listed and able for exchange on the blockchain market place OpenSea. On OpenSea, you can buy or sell any of these items through a smart contract, meaning that no central authority ever holds custody of your items.

6.1 Generate OpenSea marketplace

Open the the Ribas token Marketplace link

6.3 List and Purchase on the marketplace

Test and Verify OpenSea with your SolnSquareVerifier tokens List 5 of your tokens on the marketplace Purchase those 5 tokens using a different address

5. Deployed Contracts Info

Contract Address on Rinkeby Network

Contract Name	Contract Address
Migrations	0xbc9d7Df93c36C50dcfd7Ad4F2cd1d63233e35E94
Verifier	0x579E1C26e1BaF3BD0Ab2396b5BB14E110F876355
SolnSquareVerifier	0x7968e940c8b66A7D9468752DFd8aAb1C75f395C6

Contract Abi's

Just open the \eth-contracts\build\contracts\SolnSquareVerifier.json file and get abi:

"abi": [
    {
      "inputs": [
        {
          "internalType": "string",
          "name": "name",
          "type": "string"
        },
        {
          "internalType": "string",
          "name": "symbol",
          "type": "string"
        }
      ],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "constructor"
    },
    {
      "anonymous": false,
      "inputs": [
        {
          "indexed": true,
          "internalType": "address",
          "name": "owner",
          "type": "address"
        },
        {
          "indexed": true,
          "internalType": "address",
          "name": "approved",
          "type": "address"
        },
        {
          "indexed": true,
          "internalType": "uint256",
          "name": "tokenId",
          "type": "uint256"
        }
      ],
      "name": "Approval",
      "type": "event"
    },
    {
      "anonymous": false,
      "inputs": [
        {
          "indexed": true,
          "internalType": "address",
          "name": "owner",
          "type": "address"
        },
        {
          "indexed": true,
          "internalType": "address",
          "name": "operator",
          "type": "address"
        },
        {
          "indexed": false,
          "internalType": "bool",
          "name": "approved",
          "type": "bool"
        }
      ],
      "name": "ApprovalForAll",
      "type": "event"
    },
    {
      "anonymous": false,
      "inputs": [
        {
          "indexed": false,
          "internalType": "address",
          "name": "newOwner",
          "type": "address"
        }
      ],
      "name": "OwnershipTransfered",
      "type": "event"
    },
    {
      "anonymous": false,
      "inputs": [
        {
          "indexed": false,
          "internalType": "address",
          "name": "account",
          "type": "address"
        }
      ],
      "name": "Paused",
      "type": "event"
    },
    {
      "anonymous": false,
      "inputs": [
        {
          "indexed": false,
          "internalType": "uint256",
          "name": "index",
          "type": "uint256"
        },
        {
          "indexed": false,
          "internalType": "address",
          "name": "wallet",
          "type": "address"
        }
      ],
      "name": "SolutionAdded",
      "type": "event"
    },
    {
      "anonymous": false,
      "inputs": [
        {
          "indexed": false,
          "internalType": "uint256",
          "name": "index",
          "type": "uint256"
        },
        {
          "indexed": false,
          "internalType": "address",
          "name": "wallet",
          "type": "address"
        }
      ],
      "name": "TokenMint",
      "type": "event"
    },
    {
      "anonymous": false,
      "inputs": [
        {
          "indexed": false,
          "internalType": "address",
          "name": "to",
          "type": "address"
        },
        {
          "indexed": false,
          "internalType": "uint256",
          "name": "tokenId",
          "type": "uint256"
        }
      ],
      "name": "TokenMinted",
      "type": "event"
    },
    {
      "anonymous": false,
      "inputs": [
        {
          "indexed": true,
          "internalType": "address",
          "name": "from",
          "type": "address"
        },
        {
          "indexed": true,
          "internalType": "address",
          "name": "to",
          "type": "address"
        },
        {
          "indexed": true,
          "internalType": "uint256",
          "name": "tokenId",
          "type": "uint256"
        }
      ],
      "name": "Transfer",
      "type": "event"
    },
    {
      "anonymous": false,
      "inputs": [
        {
          "indexed": false,
          "internalType": "address",
          "name": "account",
          "type": "address"
        }
      ],
      "name": "Unpaused",
      "type": "event"
    },
    {
      "constant": false,
      "inputs": [
        {
          "internalType": "bytes32",
          "name": "_myid",
          "type": "bytes32"
        },
        {
          "internalType": "string",
          "name": "_result",
          "type": "string"
        }
      ],
      "name": "__callback",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function"
    },
    {
      "constant": false,
      "inputs": [
        {
          "internalType": "bytes32",
          "name": "_myid",
          "type": "bytes32"
        },
        {
          "internalType": "string",
          "name": "_result",
          "type": "string"
        },
        {
          "internalType": "bytes",
          "name": "_proof",
          "type": "bytes"
        }
      ],
      "name": "__callback",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function"
    },
    {
      "constant": true,
      "inputs": [],
      "name": "_owner",
      "outputs": [
        {
          "internalType": "address",
          "name": "",
          "type": "address"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function"
    },
    {
      "constant": false,
      "inputs": [
        {
          "internalType": "address",
          "name": "to",
          "type": "address"
        },
        {
          "internalType": "uint256",
          "name": "tokenId",
          "type": "uint256"
        }
      ],
      "name": "approve",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function"
    },
    {
      "constant": true,
      "inputs": [
        {
          "internalType": "address",
          "name": "owner",
          "type": "address"
        }
      ],
      "name": "balanceOf",
      "outputs": [
        {
          "internalType": "uint256",
          "name": "",
          "type": "uint256"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function"
    },
    {
      "constant": true,
      "inputs": [],
      "name": "baseTokenURI",
      "outputs": [
        {
          "internalType": "string",
          "name": "",
          "type": "string"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function"
    },
    {
      "constant": true,
      "inputs": [
        {
          "internalType": "uint256",
          "name": "tokenId",
          "type": "uint256"
        }
      ],
      "name": "getApproved",
      "outputs": [
        {
          "internalType": "address",
          "name": "",
          "type": "address"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function"
    },
    {
      "constant": true,
      "inputs": [],
      "name": "getOwner",
      "outputs": [
        {
          "internalType": "address",
          "name": "",
          "type": "address"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function"
    },
    {
      "constant": true,
      "inputs": [
        {
          "internalType": "address",
          "name": "owner",
          "type": "address"
        },
        {
          "internalType": "address",
          "name": "operator",
          "type": "address"
        }
      ],
      "name": "isApprovedForAll",
      "outputs": [
        {
          "internalType": "bool",
          "name": "",
          "type": "bool"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function"
    },
    {
      "constant": false,
      "inputs": [
        {
          "internalType": "address",
          "name": "to",
          "type": "address"
        },
        {
          "internalType": "uint256",
          "name": "tokenId",
          "type": "uint256"
        }
      ],
      "name": "mint",
      "outputs": [
        {
          "internalType": "bool",
          "name": "",
          "type": "bool"
        }
      ],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function"
    },
    {
      "constant": true,
      "inputs": [],
      "name": "name",
      "outputs": [
        {
          "internalType": "string",
          "name": "",
          "type": "string"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function"
    },
    {
      "constant": true,
      "inputs": [
        {
          "internalType": "uint256",
          "name": "tokenId",
          "type": "uint256"
        }
      ],
      "name": "ownerOf",
      "outputs": [
        {
          "internalType": "address",
          "name": "",
          "type": "address"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function"
    },
    {
      "constant": false,
      "inputs": [],
      "name": "pause",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function"
    },
    {
      "constant": false,
      "inputs": [
        {
          "internalType": "address",
          "name": "from",
          "type": "address"
        },
        {
          "internalType": "address",
          "name": "to",
          "type": "address"
        },
        {
          "internalType": "uint256",
          "name": "tokenId",
          "type": "uint256"
        }
      ],
      "name": "safeTransferFrom",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function"
    },
    {
      "constant": false,
      "inputs": [
        {
          "internalType": "address",
          "name": "from",
          "type": "address"
        },
        {
          "internalType": "address",
          "name": "to",
          "type": "address"
        },
        {
          "internalType": "uint256",
          "name": "tokenId",
          "type": "uint256"
        },
        {
          "internalType": "bytes",
          "name": "_data",
          "type": "bytes"
        }
      ],
      "name": "safeTransferFrom",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function"
    },
    {
      "constant": false,
      "inputs": [
        {
          "internalType": "address",
          "name": "to",
          "type": "address"
        },
        {
          "internalType": "bool",
          "name": "approved",
          "type": "bool"
        }
      ],
      "name": "setApprovalForAll",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function"
    },
    {
      "constant": false,
      "inputs": [
        {
          "internalType": "bool",
          "name": "set",
          "type": "bool"
        }
      ],
      "name": "setter",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function"
    },
    {
      "constant": true,
      "inputs": [
        {
          "internalType": "bytes4",
          "name": "interfaceId",
          "type": "bytes4"
        }
      ],
      "name": "supportsInterface",
      "outputs": [
        {
          "internalType": "bool",
          "name": "",
          "type": "bool"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function"
    },
    {
      "constant": true,
      "inputs": [],
      "name": "symbol",
      "outputs": [
        {
          "internalType": "string",
          "name": "",
          "type": "string"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function"
    },
    {
      "constant": true,
      "inputs": [
        {
          "internalType": "uint256",
          "name": "index",
          "type": "uint256"
        }
      ],
      "name": "tokenByIndex",
      "outputs": [
        {
          "internalType": "uint256",
          "name": "",
          "type": "uint256"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function"
    },
    {
      "constant": true,
      "inputs": [
        {
          "internalType": "address",
          "name": "owner",
          "type": "address"
        },
        {
          "internalType": "uint256",
          "name": "index",
          "type": "uint256"
        }
      ],
      "name": "tokenOfOwnerByIndex",
      "outputs": [
        {
          "internalType": "uint256",
          "name": "",
          "type": "uint256"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function"
    },
    {
      "constant": true,
      "inputs": [
        {
          "internalType": "uint256",
          "name": "tokenId",
          "type": "uint256"
        }
      ],
      "name": "tokenURI",
      "outputs": [
        {
          "internalType": "string",
          "name": "",
          "type": "string"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function"
    },
    {
      "constant": true,
      "inputs": [],
      "name": "totalSupply",
      "outputs": [
        {
          "internalType": "uint256",
          "name": "",
          "type": "uint256"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function"
    },
    {
      "constant": false,
      "inputs": [
        {
          "internalType": "address",
          "name": "from",
          "type": "address"
        },
        {
          "internalType": "address",
          "name": "to",
          "type": "address"
        },
        {
          "internalType": "uint256",
          "name": "tokenId",
          "type": "uint256"
        }
      ],
      "name": "transferFrom",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function"
    },
    {
      "constant": false,
      "inputs": [
        {
          "internalType": "address",
          "name": "newOwner",
          "type": "address"
        }
      ],
      "name": "transferOwnership",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function"
    },
    {
      "constant": false,
      "inputs": [],
      "name": "unpause",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function"
    },
    {
      "constant": false,
      "inputs": [
        {
          "internalType": "uint256",
          "name": "index",
          "type": "uint256"
        },
        {
          "internalType": "address",
          "name": "wallet",
          "type": "address"
        }
      ],
      "name": "addSolution",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function"
    },
    {
      "constant": false,
      "inputs": [
        {
          "internalType": "uint256[2]",
          "name": "a",
          "type": "uint256[2]"
        },
        {
          "internalType": "uint256[2][2]",
          "name": "b",
          "type": "uint256[2][2]"
        },
        {
          "internalType": "uint256[2]",
          "name": "c",
          "type": "uint256[2]"
        },
        {
          "internalType": "uint256[2]",
          "name": "inputs",
          "type": "uint256[2]"
        },
        {
          "internalType": "uint256",
          "name": "index",
          "type": "uint256"
        },
        {
          "internalType": "address",
          "name": "wallet",
          "type": "address"
        }
      ],
      "name": "mintNFT",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function"
    }
  ]

OpenSea MarketPlace Storefront link's

Ribas token Marketplace link: https://testnets.opensea.io/assets/ribas-token
Marketplace Seller: https://testnets.opensea.io/accounts/0xac1bade854befc9cc81c13f258a4dee38c4cf91a
Marketplace Buyer: https://testnets.opensea.io/accounts/0xea3624c7da9c50fc15a75c85441ac1ff60bb4263

lucribas / blockchain-capstone Goto Github PK

blockchain-capstone's Introduction