Bech32

The implementation of the Bech32 encoder and decoder for Ruby.

Bech32 is checksummed base32 format that is used in following Bitcoin address format.

https://github.com/bitcoin/bips/blob/master/bip-0173.mediawiki

Installation

Add this line to your application's Gemfile:

gem 'bech32'

And then execute:

$ bundle

Or install it yourself as:

$ gem install bech32

Usage

Require the Gem:

require 'bech32'

Decode

Decode Bech32-encoded data into hrp part and data part.

hrp, data = Bech32.decode('BC1QW508D6QEJXTDG4Y5R3ZARVARY0C5XW7KV8F3T4')

# hrp is human-readable part of Bech32 format
'bc'

# data is data part of Bech32 format
[0, 14, 20, 15, 7, 13, 26, 0, 25, 18, 6, 11, 13, 8, 21, 4, 20, 3, 17, 2, 29, 3, 12, 29, 3, 4, 15, 24, 20, 6, 14, 30, 22]

Decode Bech32-encoded Segwit address into Bech32::SegwitAddr instance.

addr = 'BC1QW508D6QEJXTDG4Y5R3ZARVARY0C5XW7KV8F3T4'
segwit_addr = Bech32::SegwitAddr.new(addr)

# generate script pubkey
segwit_addr.to_script_pubkey
=> 0014751e76e8199196d454941c45d1b3a323f1433bd6

Advanced

The maximum number of characters of Bech32 defined in BIP-173 is limited to 90 characters. However, LN specification BOLT#11 has no limitation.

To decode data of more than 90 characters, specify max_length at decode as below. (The default value of max_length is 90.)

MAX_INTEGER = 2**31 - 1
Bech32.decode(bechString, MAX_INTEGER)

Note that between length of the addresses and the error-detection capabilities are trade-off.

Encode

Encode Bech32 human-readable part and data part into Bech32 string.

hrp = 'bc'
data = [0, 14, 20, 15, 7, 13, 26, 0, 25, 18, 6, 11, 13, 8, 21, 4, 20, 3, 17, 2, 29, 3, 12, 29, 3, 4, 15, 24, 20, 6, 14, 30, 22]

bech = Bech32.encode(hrp, data)
=> bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4

Encode Segwit script into Bech32 Segwit address.

segwit_addr = Bech32::SegwitAddr.new
segwit_addr.script_pubkey = '0014751e76e8199196d454941c45d1b3a323f1433bd6'

# generate addr
segwit_addr.addr
=> bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4

License

The gem is available as open source under the terms of the MIT License.