joeho888 / bitcoin-address-generator

Bitcoin Address Generator

Bitcoin Address Generator

A Web Application generate two types of Bitcoin Address

1. Hierarchical Deterministic Segregated Witness Address (HD Segwit)
2. Multiple Signature P2SH Address (MultiSig P2SH)

URL: https://naughty-hawking-10f012.netlify.com/

Table of Contents

1. Hierarchical Deterministic Segregated Witness Address (HD SegWit) Generator
2. Multiple Signature P2SH Address (MultiSig P2SH) Generator
3. How Seed & Compressed Public Key are generated
4. Getting Started
5. Folder Structure
6. Reference

Hierarchical Deterministic Segregated Witness Address (HD SegWit) Generator

Input: Seed (seed: Buffer, required, between 128 and 512 bits), Path (path: string, required, something like m/123/456'/789, ' denotes hardened child key)

path(m/i_0/i_1/i_2/.../i_L) can be interpreted as [i_0, i_1, i_2, ..., i_L], where i_k is the child key is number with/without ' (denoting hardened child key).

Denote i_-1 as Master Private Key

Output: HD SegWit Address in P2WPKH format

Steps:

1. Generate I from HMAC-SHA512(Key = "Bitcoin seed", Data = seed)
2. Get [IL, IR] from spliting I into two parts, IL denotes the private key, IR denotes the chaincode
3. For each child key notation (i_k),

• Create I from HMAC-SHA512(0x00 || i_k-1 || k) for hardened child key or I from HMAC-SHA512(i_k-1 || k) for normal child key
• Get [IL_k, IR_k] from spliting I into two parts, IL denotes the private key, IR denotes the chaincode for kth child key
• Get new child private Key from (IL_k + PrivateKey_k-1) (mod n)
• Return [PrivateKey_k, IR_k]

4. Obtain the [PrivateKey_L, IR_L]
5. Generate the correspond PublicKey_L from Step 4's PrivateKey_L
6. Covnert PublicKey_L to base32, base32PublicKey_L
7. Generate DataPart from [WitnessVersion] + [base32PublicKey_L], I uses 0 for WitnessVersion
8. Generate P2WPKH Address by applying Bech32 on DataPart with human-readable part, "bc" for mainnet, and "tb" for testnet

Remark:

1. SegWit is a standard to fix Nonintentional malleability and increase Transaction Per Second in Bitcoin, it does not enforce any address format, though there are a few native address format for SegWit (e.g. P2WPKH and P2WPKH nested in P2SH). This generator only support P2WPKH
2. I convert source code from Javascript to Typescript in Step 8
3. I reference and rewrite partial part of code from source code on step 3 to step 6
4. I write Step 1, 2 and 7 solely

Multiple Signature P2SH Address (MultiSig P2SH) Generator

Input: Compressed Public Keys (pubKeys: Buffer, required), Amount of signatures required to release the coins (m: number, required) Output: MultiSig P2SH Bitcoin Address & Corresponding Redeem Script

Steps:

1. Generate Redeem Script Opcodes from pubKeys & m, something like {OP_2 [pubkey1] [pubkey2] [pubkey3] OP_3 OP_CHECKMULTISIG}
2. Compile the Redeem Script Opcodes to Reedeem Script, i.e. convert Redeem Script Opcodes to buffer
3. Obtain hash by applying hash160 on Reedeem Script
4. Prepend character 5 to hash to obtain new payload
5. Apply Base58check on new payload

Remark:

1. I extract and convert source code from Javascript to Typescript in Step 2
2. Rewrite step 1 from BitcoinJS (bitcoinjs-lib), https://github.com/bitcoinjs/bitcoinjs-lib
3. Write steps 3,4,5 solely

How Seed & Compressed Public Key are generated

This web app has built-in seed generation and compressed public key generation for HD SegWit Generator and MultiSig P2SH Generator separately. It uses Crypto, a Node JS built-in module, to create 32 byte (randomByte) randomly.

1. randomByte is used as seed in HD SegWit Generator
2. randomByte serves as a private key and used to create corresponding compressed public key in MultiSig P2SH Generator

P.S. Due to time constraint, I do not create a canvas which allows user to draw something on it at this moment, the data can be used for creating an entropy for replacing randomByte.

Getting Started

Install Dependencies

npm install

Start Web App

npm start

Test

npm test

Folder Structure

.
├── public                            # Static Files
│   ├── image                         # Image Folder
│   │   ├── home                      # Home Page Image
├── src                               # Source Code
│   ├── components                    # Components
│   ├── ├── Footer                    # Universal Footer   
│   ├── ├── HDGenerator               # HD SegWit Generator 
│   ├── ├── Header                    # Universal Header   
│   ├── ├── Home                      # Home   
│   ├── ├── MultiSigGenerator         # MultiSig P2SH Generator   
│   ├── constant                      # Constants
│   ├── ├── HDGenerator               # HD SegWit Constant  
│   ├── ├── MultiSigGenerator         # MultiSig P2SH Constant   
│   ├── utils                         # Helper Functions
│   ├── ├── Common                    # Used by other scopes of helper functions  
│   ├── ├── HD                        # HD SegWit Helper Function  
│   ├── ├── MultiSig                  # MultiSig P2SH Helper Function  

Remark: .spec.ts or .spec.tsx files are Test Suites

Reference

HD SegWit

1. Hierarchical Deterministic Standard (BIP-32): https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki
2. Segregated Witness Standard (BIP-141)https://github.com/bitcoin/bips/blob/master/bip-0141.mediawiki
3. Segregated Witness Address Standard (BIP-173): https://github.com/bitcoin/bips/blob/master/bip-0173.mediawiki#Segwit_address_format
4. Another Web App generating BIP32 Address: http://bip32.org/
5. Another Web App generating BIP32 Public Key & P2WPKH (Pay to Witness Public Key Hash): https://iancoleman.io/bip39/
6. Segwit Address Generator (Step by Step): https://bc-2.jp/tools/bech32demo/index.html

MultiSig P2SH

1. M-of-N Standard Transactions(BIP-11): https://github.com/bitcoin/bips/blob/master/bip-0011.mediawiki
2. Pay to Script Hash Standard (BIP-16): https://github.com/bitcoin/bips/blob/master/bip-0016.mediawiki
3. BitcoinJS Source Code: https://github.com/bitcoinjs/bitcoinjs-lib