class Bitcoin::ExtKey
BIP32 Extended private key
Constants
- MASTER_FINGERPRINT
- MAX_DEPTH
Attributes
Public Class Methods
import private key from Base58
private key address
# File lib/bitcoin/ext_key.rb, line 163 def self.from_base58(base58) ExtKey.parse_from_payload(ExtPubkey.validate_base58(base58)) end
generate master key from seed. @params [String] seed a seed data with hex format.
# File lib/bitcoin/ext_key.rb, line 23 def self.generate_master(seed) ext_key = ExtKey.new ext_key.depth = ext_key.number = 0 ext_key.parent_fingerprint = MASTER_FINGERPRINT l = Bitcoin.hmac_sha512('Bitcoin seed', seed.htb) left = l[0..31].bth.to_i(16) raise 'invalid key' if left >= CURVE_ORDER || left == 0 ext_key.key = Bitcoin::Key.new(priv_key: l[0..31].bth, key_type: Bitcoin::Key::TYPES[:compressed]) ext_key.chain_code = l[32..-1] ext_key end
# File lib/bitcoin/ext_key.rb, line 143 def self.parse_from_payload(payload) buf = StringIO.new(payload) ext_key = ExtKey.new ext_key.ver = buf.read(4).bth # version raise ArgumentError, Errors::Messages::INVALID_BIP32_VERSION unless ExtKey.support_version?(ext_key.ver) ext_key.depth = buf.read(1).unpack1('C') ext_key.parent_fingerprint = buf.read(4).bth ext_key.number = buf.read(4).unpack1('N') if ext_key.depth == 0 raise ArgumentError, Errors::Messages::INVALID_BIP32_FINGERPRINT unless ext_key.parent_fingerprint == ExtKey::MASTER_FINGERPRINT raise ArgumentError, Errors::Messages::INVALID_BIP32_ZERO_INDEX if ext_key.number > 0 end raise ArgumentError, Errors::Messages:: INVALID_BIP32_ZERO_DEPTH if ext_key.parent_fingerprint == ExtKey::MASTER_FINGERPRINT && ext_key.depth > 0 ext_key.chain_code = buf.read(32) raise ArgumentError, Errors::Messages::INVALID_BIP32_PRIV_PREFIX unless buf.read(1).bth == '00' # 0x00 ext_key.key = Bitcoin::Key.new(priv_key: buf.read(32).bth, key_type: Bitcoin::Key::TYPES[:compressed]) ext_key end
check whether version
is supported version bytes.
# File lib/bitcoin/ext_key.rb, line 181 def self.support_version?(version) p = Bitcoin.chain_params [p.bip49_privkey_p2wpkh_p2sh_version, p.bip84_privkey_p2wpkh_version, p.extended_privkey_version].include?(version) end
get version bytes from purpose' value.
# File lib/bitcoin/ext_key.rb, line 168 def self.version_from_purpose(purpose) v = purpose - Bitcoin::HARDENED_THRESHOLD case v when 49 Bitcoin.chain_params.bip49_privkey_p2wpkh_p2sh_version when 84 Bitcoin.chain_params.bip84_privkey_p2wpkh_version else Bitcoin.chain_params.extended_privkey_version end end
Public Instance Methods
# File lib/bitcoin/ext_key.rb, line 139 def ==(other) to_payload == other.to_payload end
get address
# File lib/bitcoin/ext_key.rb, line 73 def addr ext_pubkey.addr end
derive new key @param [Integer] number a child index @param [Boolean] harden whether hardened key or not. If true, 2^31 is added to number
. @return [Bitcoin::ExtKey] derived new key.
# File lib/bitcoin/ext_key.rb, line 96 def derive(number, harden = false) number += Bitcoin::HARDENED_THRESHOLD if harden new_key = ExtKey.new new_key.depth = depth + 1 raise IndexError, 'Depth over 255.' if new_key.depth > MAX_DEPTH new_key.number = number new_key.parent_fingerprint = fingerprint if number > (Bitcoin::HARDENED_THRESHOLD - 1) data = [0x00].pack('C') << key.priv_key.htb << [number].pack('N') else data = key.pubkey.htb << [number].pack('N') end l = Bitcoin.hmac_sha512(chain_code, data) left = l[0..31].bth.to_i(16) raise 'invalid key' if left >= CURVE_ORDER child_priv = (left + key.priv_key.to_i(16)) % CURVE_ORDER raise 'invalid key ' if child_priv >= CURVE_ORDER new_key.key = Bitcoin::Key.new( priv_key: child_priv.to_even_length_hex.rjust(64, '0'), key_type: key_type) new_key.chain_code = l[32..-1] new_key.ver = version new_key end
get ExtPubkey
from priv_key
# File lib/bitcoin/ext_key.rb, line 36 def ext_pubkey k = ExtPubkey.new k.depth = depth k.number = number k.parent_fingerprint = parent_fingerprint k.chain_code = chain_code k.pubkey = key.pubkey k.ver = priv_ver_to_pub_ver k end
get fingerprint
# File lib/bitcoin/ext_key.rb, line 83 def fingerprint identifier.slice(0..7) end
whether hardened key.
# File lib/bitcoin/ext_key.rb, line 88 def hardened? number >= Bitcoin::HARDENED_THRESHOLD end
# File lib/bitcoin/ext_key.rb, line 68 def hash160 Bitcoin.hash160(pub) end
get key identifier
# File lib/bitcoin/ext_key.rb, line 78 def identifier Bitcoin.hash160(key.pubkey) end
get key type defined by BIP-178 using version.
# File lib/bitcoin/ext_key.rb, line 127 def key_type v = version case v when Bitcoin.chain_params.bip49_privkey_p2wpkh_p2sh_version Bitcoin::Key::TYPES[:p2wpkh_p2sh] when Bitcoin.chain_params.bip84_privkey_p2wpkh_version Bitcoin::Key::TYPES[:p2wpkh] when Bitcoin.chain_params.extended_privkey_version Bitcoin::Key::TYPES[:compressed] end end
get private key(hex)
# File lib/bitcoin/ext_key.rb, line 59 def priv key.priv_key end
convert privkey version to pubkey version
# File lib/bitcoin/ext_key.rb, line 187 def priv_ver_to_pub_ver case version when Bitcoin.chain_params.bip49_privkey_p2wpkh_p2sh_version Bitcoin.chain_params.bip49_pubkey_p2wpkh_p2sh_version when Bitcoin.chain_params.bip84_privkey_p2wpkh_version Bitcoin.chain_params.bip84_pubkey_p2wpkh_version else Bitcoin.chain_params.extended_pubkey_version end end
get public key(hex)
# File lib/bitcoin/ext_key.rb, line 64 def pub key.pubkey end
Base58
encoded extended private key
# File lib/bitcoin/ext_key.rb, line 54 def to_base58 ExtPubkey.encode_base58(to_hex) end
serialize extended private key
# File lib/bitcoin/ext_key.rb, line 48 def to_payload version.htb << [depth].pack('C') << parent_fingerprint.htb << [number].pack('N') << chain_code << [0x00].pack('C') << key.priv_key.htb end
get version bytes using serialization format
# File lib/bitcoin/ext_key.rb, line 121 def version return ExtKey.version_from_purpose(number) if depth == 1 ver ? ver : Bitcoin.chain_params.extended_privkey_version end