Bech32

The implementation of the Bech32/Bech32m 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

Bech32m is checksummed base32m format that is used in following Bitcoin address format.

https://github.com/bitcoin/bips/blob/master/bip-0350.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, spec = 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]

# spec is whether Bech32::Encoding::BECH32 or Bech32::Encoding::BECH32M

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, Bech32::Encoding::BECH32)
=> 'bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4'

Segwit

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'

Encode Segwit script into Bech32 Segwit address.

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

# generate addr
segwit_addr.addr
=> 'bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4'

Nostr

Supports encoding/decoding of Nostr's NIP-19 entities.

# Decode bare entity
bech32 = 'npub10elfcs4fr0l0r8af98jlmgdh9c8tcxjvz9qkw038js35mp4dma8qzvjptg'
entity = Bech32::Nostr::NIP19.parse(bech32)
entity.hrp
=> 'npub'
entity.data
=> '7e7e9c42a91bfef19fa929e5fda1b72e0ebc1a4c1141673e2794234d86addf4e'

# Decode tlv entity
bech32 = 'nprofile1qqsrhuxx8l9ex335q7he0f09aej04zpazpl0ne2cgukyawd24mayt8gpp4mhxue69uhhytnc9e3k7mgpz4mhxue69uhkg6nzv9ejuumpv34kytnrdaksjlyr9p'
entity = Bech32::Nostr::NIP19.parse(bech32)
entity.hrp
=> 'nprofile'
entity.entries[0].value
=> '3bf0c63fcb93463407af97a5e5ee64fa883d107ef9e558472c4eb9aaaefa459d'
entity.entries[1].value
=> 'wss://r.x.com'

# Encode bare entity
entity = Bech32::Nostr::BareEntity.new('npub', '7e7e9c42a91bfef19fa929e5fda1b72e0ebc1a4c1141673e2794234d86addf4e')
entity.encode
=> 'npub10elfcs4fr0l0r8af98jlmgdh9c8tcxjvz9qkw038js35mp4dma8qzvjptg'

# Encode tlv entity
entry_relay = Bech32::Nostr::TLVEntry.new(Bech32::Nostr::TLVEntity::TYPE_RELAY, 'wss://relay.nostr.example')
entry_author = Bech32::Nostr::TLVEntry.new(Bech32::Nostr::TLVEntity::TYPE_AUTHOR, '97c70a44366a6535c145b333f973ea86dfdc2d7a99da618c40c64705ad98e322')
entity = Bech32::Nostr::TLVEntity.new(Bech32::Nostr::NIP19::HRP_EVENT, [entry_relay, entry_author])
entity.encode
=> 'nevent1qyvhwumn8ghj7un9d3shjtnwdaehgu3wv4uxzmtsd3jsygyhcu9ygdn2v56uz3dnx0uh865xmlwz675emfsccsxxguz6mx8rygstv78u'

CLI

After installing the gem, the bech32 command will be available. Encoding and decoding features are also available in the cli.

Encode

The encode command takes HRP, data, and type (bech32 or bech32m) as arguments and outputs a bech32/bech32m string.

$ bech32 encode genesis 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 bech32
genesis1qyfe883hey6jrgj2xvk5g3dfmfqfzm7a4wez4pd2krf7ltsxffd6u6nrvjvv0uzda6whtuhzscj72zuj6udkmknakfn0anc07gaya2303dnngu3sxqctqvg5v7nw0fvkwqce7auqkxv3sj5j7e8d6vu4zy5qlssvffxqccxqcfgwc98zenr3qrzk5msfgkvjnj0ejpl8zunedeqhvajry08ueg99ynwgd2sdntrq22gensffcj03r3yjv4cv4j20ee8vujxve3fssj2demyvknzwe3glqt6t954vknpdvurthpc9fpex7t97nvqryeqpjrpscap6q0zvfpgv3nxzpy6wmx24k9xcu35vuatm5zvn7t084ec7tlw2gh0av9xwumwkv02hats66l5hkwd55rwkm2q8fsd4zvqwpvqqqqtdc6rp

Note: data must be converted from 8-bit to 5-bit units.

Decode

The decode command takes bech32/bech32m string as arguments and outputs HRP, data, and type.

$ bech32 decode genesis1qyfe883hey6jrgj2xvk5g3dfmfqfzm7a4wez4pd2krf7ltsxffd6u6nrvjvv0uzda6whtuhzscj72zuj6udkmknakfn0anc07gaya2303dnngu3sxqctqvg5v7nw0fvkwqce7auqkxv3sj5j7e8d6vu4zy5qlssvffxqccxqcfgwc98zenr3qrzk5msfgkvjnj0ejpl8zunedeqhvajry08ueg99ynwgd2sdntrq22gensffcj03r3yjv4cv4j20ee8vujxve3fssj2demyvknzwe3glqt6t954vknpdvurthpc9fpex7t97nvqryeqpjrpscap6q0zvfpgv3nxzpy6wmx24k9xcu35vuatm5zvn7t084ec7tlw2gh0av9xwumwkv02hats66l5hkwd55rwkm2q8fsd4zvqwpvqqqqtdc6rp
HRP: genesis
DATA: 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
TYPE: bech32

If bech32 string has segwit hrp, it will also output witness version and witness program:

$ bech32 decode bc1pw508d6qejxtdg4y5r3zarvary0c5xw7kw508d6qejxtdg4y5r3zarvary0c5xw7kt5nd6y
HRP: bc
DATA: 010e140f070d1a001912060b0d081504140311021d030c1d03040f1814060e1e160e140f070d1a001912060b0d081504140311021d030c1d03040f1814060e1e16
TYPE: bech32m
WITNESS VERSION: 1
WITNESS PROGRAM: 751e76e8199196d454941c45d1b3a323f1433bd6751e76e8199196d454941c45d1b3a323f1433bd6

If bech32 string has NIP-19 hrp, it will also output NIP-19 entry:

$ bech32 decode nprofile1qqsrhuxx8l9ex335q7he0f09aej04zpazpl0ne2cgukyawd24mayt8gpp4mhxue69uhhytnc9e3k7mgpz4mhxue69uhkg6nzv9ejuumpv34kytnrdaksjlyr9p
HRP: nprofile
DATA: 00001003171c0606071f051906111114001e17190f090f051d19120f1502011d02011f0f13190a18081c16041d0e0d0a151b1d040b07080101151b17061c191a051c1717040b1318051911161e1b080102151b17061c191a051c1716081a13020c0519121c1c1b010c111516040b13030d1d1610
TYPE: bech32
NIP19 Entities:
  special: 3bf0c63fcb93463407af97a5e5ee64fa883d107ef9e558472c4eb9aaaefa459d
  relay: wss://r.x.com
  relay: wss://djbas.sadkb.com

Note: DATA is data without bit conversion. When used, the DATA must be converted from 5-bit to 8-bit and padded as necessary.

License

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