Class: Tapyrus::ExtPubkey

Inherits:
Object
  • Object
show all
Includes:
HexConverter
Defined in:
lib/tapyrus/ext_key.rb

Overview

BIP-32 Extended public key

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from HexConverter

#to_hex

Instance Attribute Details

#chain_code ⇒ Object

Returns the value of attribute chain_code.



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# File 'lib/tapyrus/ext_key.rb', line 216

def chain_code
  @chain_code
end

#depth ⇒ Object

Returns the value of attribute depth.



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# File 'lib/tapyrus/ext_key.rb', line 214

def depth
  @depth
end

#number ⇒ Object

Returns the value of attribute number.



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# File 'lib/tapyrus/ext_key.rb', line 215

def number
  @number
end

#parent_fingerprint ⇒ Object

Returns the value of attribute parent_fingerprint.



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# File 'lib/tapyrus/ext_key.rb', line 218

def parent_fingerprint
  @parent_fingerprint
end

#pubkey ⇒ Object

hex format



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# File 'lib/tapyrus/ext_key.rb', line 217

def pubkey
  @pubkey
end

#ver ⇒ Object

Returns the value of attribute ver.



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# File 'lib/tapyrus/ext_key.rb', line 213

def ver
  @ver
end

Class Method Details

.encode_base58(hex) ⇒ String

Generate Base58 encoded key from BIP32 payload with hex format.

Parameters:

  • hex (String) —

    BIP32 payload with hex format.

Returns:

  • (String) —

    Base58 encoded extended key.



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# File 'lib/tapyrus/ext_key.rb', line 262

def self.encode_base58(hex)
  Base58.encode(hex + Tapyrus.calc_checksum(hex))
end

.from_base58(address) ⇒ Object

import pub key from Base58 private key address



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# File 'lib/tapyrus/ext_key.rb', line 339

def self.from_base58(address)
  ExtPubkey.parse_from_payload(ExtPubkey.validate_checksum(address))
end

.parse_from_payload(payload) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/tapyrus/ext_key.rb', line 316

def self.parse_from_payload(payload)
  buf = StringIO.new(payload)
  ext_pubkey = ExtPubkey.new
  ext_pubkey.ver = buf.read(4).bth # version
  raise ArgumentError, Errors::Messages::INVALID_BIP32_VERSION unless ExtPubkey.support_version?(ext_pubkey.ver)
  ext_pubkey.depth = buf.read(1).unpack("C").first
  ext_pubkey.parent_fingerprint = buf.read(4).bth
  ext_pubkey.number = buf.read(4).unpack("N").first
  if ext_pubkey.depth == 0
    unless ext_pubkey.parent_fingerprint == ExtKey::MASTER_FINGERPRINT
      raise ArgumentError, Errors::Messages::INVALID_BIP32_FINGERPRINT
    end
    raise ArgumentError, Errors::Messages::INVALID_BIP32_ZERO_INDEX if ext_pubkey.number > 0
  end
  if ext_pubkey.parent_fingerprint == ExtKey::MASTER_FINGERPRINT && ext_pubkey.depth > 0
    raise ArgumentError, Errors::Messages::INVALID_BIP32_ZERO_DEPTH
  end
  ext_pubkey.chain_code = buf.read(32)
  ext_pubkey.pubkey = Tapyrus::Key.new(pubkey: buf.read(33).bth).pubkey
  ext_pubkey
end

.support_version?(version) ⇒ Boolean

check whether version is supported version bytes.

Returns:

  • (Boolean) 


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# File 'lib/tapyrus/ext_key.rb', line 366

def self.support_version?(version)
  p = Tapyrus.chain_params
  [p.bip49_pubkey_p2wpkh_p2sh_version, p.bip84_pubkey_p2wpkh_version, p.extended_pubkey_version].include?(version)
end

.validate_checksum(base58) ⇒ String

Validate address checksum and return payload.

Parameters:

  • BIP32 (String) —

    Base58 address

Returns:

  • (String) —

    BIP32 payload with binary format

Raises:

  • (ArgumentError) 


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# File 'lib/tapyrus/ext_key.rb', line 346

def self.validate_checksum(base58)
  raw = Base58.decode(base58)
  raise ArgumentError, Errors::Messages::INVALID_CHECKSUM unless Tapyrus.calc_checksum(raw[0...-8]) == raw[-8..-1]
  raw[0...-8].htb
end

.version_from_purpose(purpose) ⇒ Object

get version bytes from purpose' value.



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# File 'lib/tapyrus/ext_key.rb', line 353

def self.version_from_purpose(purpose)
  v = purpose - Tapyrus::HARDENED_THRESHOLD
  case v
  when 49
    Tapyrus.chain_params.bip49_pubkey_p2wpkh_p2sh_version
  when 84
    Tapyrus.chain_params.bip84_pubkey_p2wpkh_version
  else
    Tapyrus.chain_params.extended_pubkey_version
  end
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/tapyrus/ext_key.rb', line 312

def ==(other)
  to_payload == other.to_payload
end

#addr ⇒ Object

get address



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# File 'lib/tapyrus/ext_key.rb', line 234

def addr
  key.to_p2pkh
end

#derive(number) ⇒ Object

derive child key



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# File 'lib/tapyrus/ext_key.rb', line 272

def derive(number)
  new_key = ExtPubkey.new
  new_key.depth = depth + 1
  new_key.number = number
  new_key.parent_fingerprint = fingerprint
  raise "hardened key is not support" if number > (Tapyrus::HARDENED_THRESHOLD - 1)
  data = pub.htb << [number].pack("N")
  l = Tapyrus.hmac_sha512(chain_code, data)
  left = l[0..31].bth.to_i(16)
  raise "invalid key" if left >= CURVE_ORDER
  l_priv = ECDSA::Format::IntegerOctetString.encode(left, 32)
  p1 = Tapyrus::Key.new(priv_key: l_priv.bth, key_type: Tapyrus::Key::TYPES[:uncompressed]).to_point
  p2 = Tapyrus::Key.new(pubkey: pubkey, key_type: key_type).to_point
  new_key.pubkey = (p1 + p2).to_hex
  new_key.chain_code = l[32..-1]
  # A depth 1 key derives its version bytes from the purpose, see #version.
  new_key.ver = new_key.depth == 1 ? nil : version
  new_key
end

#fingerprint ⇒ Object

get fingerprint



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# File 'lib/tapyrus/ext_key.rb', line 250

def fingerprint
  identifier.slice(0..7)
end

#hardened? ⇒ Boolean

whether hardened key.

Returns:

  • (Boolean) 


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# File 'lib/tapyrus/ext_key.rb', line 267

def hardened?
  number >= Tapyrus::HARDENED_THRESHOLD
end

#hash160 ⇒ Object 



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# File 'lib/tapyrus/ext_key.rb', line 229

def hash160
  Tapyrus.hash160(pub)
end

#identifier ⇒ Object

get key identifier



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# File 'lib/tapyrus/ext_key.rb', line 245

def identifier
  Tapyrus.hash160(pub)
end

#key ⇒ Tapyrus::Key

get key object

Returns:



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# File 'lib/tapyrus/ext_key.rb', line 240

def key
  Tapyrus::Key.new(pubkey: pubkey, key_type: key_type)
end

#key_type ⇒ Object

get key type defined by BIP-178 using version.



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# File 'lib/tapyrus/ext_key.rb', line 300

def key_type
  v = version
  case v
  when Tapyrus.chain_params.bip49_pubkey_p2wpkh_p2sh_version
    Tapyrus::Key::TYPES[:p2wpkh_p2sh]
  when Tapyrus.chain_params.bip84_pubkey_p2wpkh_version
    Tapyrus::Key::TYPES[:p2wpkh]
  when Tapyrus.chain_params.extended_pubkey_version
    Tapyrus::Key::TYPES[:compressed]
  end
end

#master? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/tapyrus/ext_key.rb', line 371

def master?
  depth == 0 && number == 0 && parent_fingerprint == "00000000"
end

#pub ⇒ Object 



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# File 'lib/tapyrus/ext_key.rb', line 225

def pub
  pubkey
end

#to_base58 ⇒ Object

Base58 encoded extended pubkey



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# File 'lib/tapyrus/ext_key.rb', line 255

def to_base58
  ExtPubkey.encode_base58(to_hex)
end

#to_payload ⇒ Object

serialize extended pubkey



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# File 'lib/tapyrus/ext_key.rb', line 221

def to_payload
  version.htb << [depth].pack("C") << parent_fingerprint.htb << [number].pack("N") << chain_code << pub.htb
end

#version ⇒ Object

get version bytes using serialization format



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# File 'lib/tapyrus/ext_key.rb', line 293

def version
  return ver if ver
  return ExtPubkey.version_from_purpose(number) if depth == 1
  Tapyrus.chain_params.extended_pubkey_version
end