PassChain

Authors: Rob-Jago Flötgen, Florian Liss, Lars Lütjens, Niklas Reiter

Created for blc-psi 2017

Installation

Download

PassChain uses npm as Package Manager, webpack for compilation and React for the frontend. It uses Parity as a client ot interact with the Ethereum Blockchain

Install Parity (one line installer for Mac and Ubuntu) or full installation guideline:

bash <(curl https://get.parity.io -Lk)

Clone the repository into your favorite folder:

$ cd ~/favorite-folder/
$ git clone git@github.com:fkbenjamin/pc-firebase-starter.git passchain

Download dependencies:

$ cd passchain/
$ npm install -g webpack
$ npm install

While developing webpack has to be running in a terminal to continously update the compiled code. To build:

webpack --watch

Files will be build into dist/. To access the dapp from parity, symlink your folder to the parity/apps folder:

Make app visible in Parity

(Source of the following paragraph)

To get Parity to discover your dapp, it needs to be placed into a place that Parity will see it - its local "dapps" directory. We will make a symbolic link for our dapp's dist directory (containing all of the ready-built dapp) in Parity's dapp directory.

Parity's directory structure is different depending on your system. For Mac, Parity's local dapp directory sits at $HOME/Library/Application Support/io.parity.ethereum/dapps, so you'll need to enter:

For Mac systems
ln -s $PWD/dist $HOME/Library/Application\ Support/io.parity.ethereum/dapps/mydapp

For Linux it's $HOME/.local/share/io.parity.ethereum/dapps - in this case you'd want to enter:

# For Linux systems
ln -s $PWD/dist $HOME/.local/share/io.parity.ethereum/dapps/mydapp

For Windows, it's in %APPDATA%/Parity/Ethereum/dapps - here you'd want to enter:

%=For Windows systems=%
mklink /D "%APPDATA%/Parity/Ethereum/dapps/mydapp" "%cd%/dist"

Once you have it linked, you should start (or restart, if already running) Parity and head to the Applications page of Parity Wallet. There you'll see your new dapp.

You should be able to access your Dapp now via Parity on http://127.0.0.1:8180/#/app/firebase-starter

Deploy contract infrastructure

PassChain uses six contracts to store data and to interact with the user. Either you can use the predefined addresses in the code or deploy the contracts by yourself. For deploying the contracts you need to:

$ cd ./contracts/
./contracts$ mkdir out
./contracts$ solc -o out/ --bin --abi --optimize --overwrite Embassy.sol Citizen.sol Nation.sol NameRegistry.sol Immigration.sol

You won't get a feedback but there will be *.abi and *.sol files in the out/ folder. Use these files to deploy each contract to the Blockchain one after another. For example, this can be done using Parity and its contract deploy feature. Alternatively truffle or geth is less userfriendly but feasible choice. This order is recommended to meet the dependencies of the contracts:

1. NameRegistry
2. Storage
3. Citizen
4. Embassy
5. Immigration
6. Nation

Contracts will have links to each other to call their functions so you have to make sure all pointers are correctly set before using the infrastructure.

For further explanation of the contracts' functions and the dependencies please refer to the documentation.

Link contracts to app

If you deployed your own contracts, you need to link them to the App. Open app.jsx in src/client/scripts/app.jsx and change the following lines to your contracts's addresses:

//all contracts
this.contract = parity.bonds.makeContract('0xca16D554f2974F32C16212c6C39e678dA958b50e', abi.getStorageABI()); // v0.6
this.immigration = parity.bonds.makeContract('0x42Da049B7E5c7AAcF5506cE7198b1a7B23070C93', abi.getImmigrationABI()); //v0.8
this.citizen = parity.bonds.makeContract('0x90f8092B9f6E596D8D2937c971D64B93f866dD80', abi.getCitizenABI()); // v0.4
this.nation = parity.bonds.makeContract('0x75e0292B68FaADc14B4Ac64E7ED6D6A1b2706654', abi.getNationABI()); // v0.5
this.embassy = parity.bonds.makeContract('0x13477Ff61aF4337434ACC1df74c31Dff68E368a5', abi.getEmbassyABI()); // v0.7
this.nameresolver = parity.bonds.makeContract('0x53708Ea1EF858086Afcb2E063E5CA7CDF7EC9d76', abi.getNameresolverABI()); // v0.4

The ABI of your contracts have to go into ABI.jsx. Please change the respectives ABIs.

Setup a firebase instance

Some data is not stored on the Ethereum Blockchain as it is simply too expensive to store large amounts of data. This includes the Passports and the Pass pictures. If you do not want to use the default Firebase project for this, you have to create your own Firebase project and add the URL to it to fireclass.jsx.

Running

To execute the project, please run parity. e.g. on the Ropsten Testnet:

$ parity --chain ropsten

Use Ctrl+C to kill Parity.