faisal-hameed / private-blockchain

Basic conceptual application for blockchain storage

Private Blockchain Web-Service

This is a simple blockchain web service to store data in private blockchain.

Getting Started

These instructions will get you a copy of the project up and running on your local machine for development and testing purposes. Following technologies are used in this project:

1. Node.js
2. Express framework for web services
3. express-generator, to quickly create an application skeleton.
4. LevelDB to persist blocks
5. crypto-js library to encrypt blocks

Prerequisites

Installing Node and NPM is pretty straightforward using the installer package available from the (Node.js® web site)[https://nodejs.org/en/].

• Test your node installation by typing below command in terminal

node --version

It should return node version e.g. v8.9.4

Running Blockchain web service

• Installing project dependencies

npm install

• Start the application and browse it at : http://localhost:8000
  Note : npm start will invoke ./bin/www script which contains web service startup script

 npm start

APIs

Following APIs are implemented. Use any REST client to test below APIs

---

Utility Functions

1. Generate hash

http://localhost:8000/gateway/hash

Returns SHA256 hash of data

• URL

  /gateway/hash

• Method:

  POST

• Request Body

  {"data":"any type of data in string"}

• Success Response:

  • Code: 200
    Content: {"hash": "3e50d150f89b90f5ddac34b9131380bfed94cf5db8a8de6c8161393b8d5ec5b0"}

• Error Response:

  • Code: 500 Internal Server Error
    Content: {"code":"500","status":"Internal Server Error","message":"data is undefind"}

2. Generate signature

http://localhost:8000/gateway/sign/generate

Generates signature of data by using provided private key

• URL

  /sign/generate

• Method:

  POST

• Request Body

  {"data": "My secret message", "privateKey": "L4ZYGVyypC1riua7f8SBgVrN6bswk7ufNubaSh7NMLJTpWqcSJv3"}

• Success Response:

  • Code: 200
    Content: {"signature":"Hw10mwhAH7RaHD1f+aeMt5AcZQHu2e4+H3cF5QTW+g4qTtZoCATg8UKdSR9pbf/DyhFvfwXyIZ6C7qbOcMBpQkM="}

• Error Response:

  • Code: 500 Internal Server Error
    Content: {"code":"500","status":"Internal Server Error","message":"Missing parameters"}

3. Validate signature

http://localhost:8000/gateway/sign/validate

Validate signature

• URL

  /sign/validate

• Method:

  POST

• Request Body

  {"data" : "My secret message", "walletAddress" : "1CYgQ8wbdWZPGEWgbxZLq5JUe5e1ECWPe7", "signature" : "Hw10mwhAH7RaHD1f+aeMt5AcZQHu2e4+H3cF5QTW+g4qTtZoCATg8UKdSR9pbf/DyhFvfwXyIZ6C7qbOcMBpQkM="}

• Success Response:

  • Code: 200
    Content: {"isValid":true}

• Error Response:

  • Code: 500 Internal Server Error
    Content: {"code":"500","status":"Internal Server Error","message":"Missing parameters"}

Private blockchain

1. Get block

http://localhost:8000/block/{BLOCK_HEIGHT} Returns json data about a single block at height.

• URL

  /block/:height

• Method:

  GET

• URL Params

  Required:

  height=[integer]

• Success Response:

  • Code: 200
    Content: {"hash":"910bb1155fecdc5cf22f4b70f7805186f9f6de8f5c8d2e05f01f222e82cdea9d","height":0,"body":"First block in the chain - Genesis block","time":"1535137099","previousBlockHash":""}

• Error Response:

  • Code: 500 Internal Server Error
    Content: {"code":"500","status":"Internal Server Error","message":"Block with provided height does not exist"}

---

2. Post Block

http://localhost:8000/block

Returns json data of added block

• URL

  /block

• Method:

  POST

• Request Body

  {"body":"block body contents"}

• Success Response:

  • Code: 200
    Content: {"hash":"910bb1155fecdc5cf22f4b70f7805186f9f6de8f5c8d2e05f01f222e82cdea9d","height":0,"body":""New block 1","time":"1535137099","previousBlockHash":"910bb1155fecdc5cf22f4b70f7805186f9f6de8f5c8d2e05f01f222e82cdea9d"}

• Error Response:

  • Code: 500 Internal Server Error
    Content: {"code":"500","status":"Internal Server Error","message":"New block not added"}