class Bitcoin::Mnemonic
Mnemonic
code for generating deterministic keys github.com/bitcoin/bips/blob/master/bip-0039.mediawiki
Constants
- WORD_DIR
Attributes
Public Class Methods
# File lib/bitcoin/mnemonic.rb, line 11 def initialize(language) raise ArgumentError, 'specified language is not supported.' unless Mnemonic.word_lists.include?(language) @language = language end
get support language list
# File lib/bitcoin/mnemonic.rb, line 17 def self.word_lists Dir.glob("#{WORD_DIR}/**.txt").map{|f| f.gsub("#{WORD_DIR}/", '').gsub('.txt', '') } end
Public Instance Methods
calculate entropy checksum @param [String] entropy an entropy with bit string format @return [String] an entropy checksum with bit string format
# File lib/bitcoin/mnemonic.rb, line 63 def checksum(entropy) b = Bitcoin.sha256([entropy].pack('B*')).unpack1('B*') b.slice(0, (entropy.length/32)) end
generate entropy from mnemonic word @param [Array] words the array of mnemonic word. @return [String] an entropy with hex format.
# File lib/bitcoin/mnemonic.rb, line 24 def to_entropy(words) word_master = load_words mnemonic = words.map do |w| index = word_master.index(w.downcase) raise IndexError, 'word not found in words list.' unless index index.to_s(2).rjust(11, '0') end.join entropy = mnemonic.slice(0, (mnemonic.length * 32) / 33) checksum = mnemonic.gsub(entropy, '') raise SecurityError, 'checksum mismatch.' unless checksum == checksum(entropy) [entropy].pack('B*').bth end
generate mnemonic words from entropy. @param [String] entropy an entropy with hex format. @return [Array] the array of mnemonic word.
# File lib/bitcoin/mnemonic.rb, line 40 def to_mnemonic(entropy) raise ArgumentError, 'entropy is empty.' if entropy.nil? || entropy.empty? e = entropy.htb.unpack1('B*') seed = e + checksum(e) mnemonic_index = seed.chars.each_slice(11).map{|i|i.join.to_i(2)} word_master = load_words mnemonic_index.map{|i|word_master[i]} end
generate seed from mnemonic if mnemonic protected with passphrase, specify that passphrase. @param [Array] mnemonic a array of mnemonic word. @param [String] passphrase a passphrase which protects mnemonic. the default value is an empty string. @return [String] seed
# File lib/bitcoin/mnemonic.rb, line 54 def to_seed(mnemonic, passphrase: '') to_entropy(mnemonic) OpenSSL::PKCS5.pbkdf2_hmac(mnemonic.join(' ').downcase, 'mnemonic' + passphrase, 2048, 64, OpenSSL::Digest::SHA512.new).bth end
Private Instance Methods
load word list contents
# File lib/bitcoin/mnemonic.rb, line 71 def load_words File.readlines("#{WORD_DIR}/#{language}.txt").map(&:strip) end