Module: Lightning::Invoice

Defined in:

lib/lightning/invoice.rb,
lib/lightning/invoice/version.rb,
lib/lightning/invoice/routing_info.rb

Defined Under Namespace

Classes: Message, RoutingInfo

Constant Summary

PREFIX =

'lnbc'

MAX_LENGTH =

2 ** 64

VERSION =

"0.1.2"

Class Method Summary

• .buffer_to_word(buffer) ⇒ Object
• .convert(data, inbits, outbits, padding) ⇒ Object
• .int_to_array(i, bits = 5, padding = 2) ⇒ Object
• .parse(str) ⇒ Object
• .parse_human_readable(human) ⇒ Object
• .to_bytes(data) ⇒ Object
• .to_int(data) ⇒ Object
• .word_to_buffer(data) ⇒ Object

Class Method Details

.buffer_to_word(buffer) ⇒ Object

# File 'lib/lightning/invoice.rb', line 186

def self.buffer_to_word(buffer)
  words = convert(buffer.unpack('C*'), 8, 5, true)
  return words
end

.convert(data, inbits, outbits, padding) ⇒ Object

# File 'lib/lightning/invoice.rb', line 191

def self.convert(data, inbits, outbits, padding)
  value = 0
  bits = 0
  max = (1 << outbits) - 1

  result = []
  n = data.length
  n.times do |i|
    value = (value << inbits) | data[i]
    bits += inbits
    while bits >= outbits
      bits -= outbits
      result << ((value >> bits) & max)
    end
  end

  if padding && bits > 0
    result << ((value << (outbits - bits)) & max)
  end

  return result
end

.int_to_array(i, bits = 5, padding = 2) ⇒ Object

# File 'lib/lightning/invoice.rb', line 220

def self.int_to_array(i, bits = 5, padding = 2)
  array = []
  return [0] if i.nil? || i == 0
  while i > 0
    array << (i & (2**bits - 1))
    i = (i / (2**bits)).to_i
  end
  if padding > array.size
    array += [0] * (padding - array.size)
  end
  array.reverse
end

.parse(str) ⇒ Object

# File 'lib/lightning/invoice.rb', line 111

def self.parse(str)
  human, data_part = Bech32.decode(str, MAX_LENGTH)
  return nil unless human
  prefix, amount, multiplier = parse_human_readable(human)
  message = Message.new
  message.prefix = prefix
  message.amount = amount.to_i if !amount&.empty?
  message.multiplier = multiplier
  message.timestamp = to_int(data_part[0...7])
  tags = data_part[7...data_part.size - 104]
  index = 0
  if tags
    while index < tags.size
      type = tags[index]
      data_length = (tags[index + 1].to_i << 5) + tags[index + 2].to_i
      data = tags[index + 3 ... index + 3 + data_length]
      bytes = to_bytes(data)
      index += 3 + data_length
      case type
      when 1
        message.payment_hash = bytes[0...64].pack("C*").bth
      when 13
        message.description = bytes.pack("C*").force_encoding('utf-8')
      when 19
        message.pubkey = bytes[0...66].pack("C*").bth
      when 23
        message.description_hash = bytes[0...64].pack("C*").bth
      when 6
        message.expiry = to_int(data)
      when 24
        message.min_final_cltv_expiry = to_int(data)
      when 9
        address = to_bytes(data[1..-1])
        hex = address.pack("C*").unpack("H*").first
        case data[0]
        when 0
          message.fallback_address = Bitcoin::Script.to_p2wpkh(hex).addresses.first
        when 17
          message.fallback_address = Bitcoin.encode_base58_address(hex, Bitcoin.chain_params.address_version)
        when 18
          message.fallback_address = Bitcoin.encode_base58_address(hex, Bitcoin.chain_params.p2sh_version)
        else
        end
      when 3
        offset = 0
        while offset < bytes.size
          message.routing_info << Lightning::Invoice::RoutingInfo.new(
            bytes[offset...offset + 33].pack("C*").bth,
            bytes[offset + 33...offset + 41].pack("C*").bth,
            to_int(bytes[offset + 41...offset + 45]),
            to_int(bytes[offset + 45...offset + 49]),
            to_int(bytes[offset + 49...offset + 51])
          )
          offset += 51
        end
      else
      end
    end
  end
  sig = data_part[data_part.size - 104..-1]
  if sig
    message.signature = word_to_buffer(sig).bth
  end
  message
end

.parse_human_readable(human) ⇒ Object

# File 'lib/lightning/invoice.rb', line 177

def self.parse_human_readable(human)
  human.scan(/^([a-zA-Z]+)(\d*)([munp]?)$/)&.first
end

.to_bytes(data) ⇒ Object

# File 'lib/lightning/invoice.rb', line 233

def self.to_bytes(data)
  buf = []
  (data.size * 5).times do |i|
    loc5 = (i / 5).to_i
    loc8 = i >> 3
    if i % 8 == 0
      buf[loc8] = 0
    end
    buf[loc8] |= ((data[loc5] >> (4 - (i % 5))) & 1) << (7 - (i % 8))
  end
  if data.size % 8 != 0
    buf = buf[0...-1]
  end
  buf
end

.to_int(data) ⇒ Object

# File 'lib/lightning/invoice.rb', line 214

def self.to_int(data)
  data.inject(0) do |i, sum|
    sum + (i << 5)
  end
end

.word_to_buffer(data) ⇒ Object

# File 'lib/lightning/invoice.rb', line 181

def self.word_to_buffer(data)
  buffer = convert(data, 5, 8, false)
  return buffer.pack("C*")
end