gen-key.rb

#!/usr/bin/ruby
# encoding: utf-8
# Created: 2013-04-19 17:51:52 +0300 by ice

# Generates beautiful bitcoin address

STDOUT.sync = true
%w{
openssl
benchmark
}.each { |r| require r}
exit if __FILE__ != $0

def sha256 str
  OpenSSL::Digest::SHA256.hexdigest str
end

def rmd160 str
  OpenSSL::Digest::RIPEMD160.hexdigest str
end

def pack str
  [str].pack "H*"
end

def to_58 hex
  # Bitcoin variant of Base58 encoding
  code_string = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"
  x = hex.to_i(16)
  output_string = ''

  while x > 0
    x, rem = x.divmod 58
    output_string << code_string[rem]
  end

  # For every leading zero byte add '1'
  if (l_zeros = hex[/^0+/])
    (l_zeros.size/2).times { output_string << code_string[0] }
  end

  output_string.reverse
end

def to_WIF hex
  # Converts private key from hex form to Wallet Import Format

  # Prepend with 0x80
  ekey = "80#{hex}"

  # Double hash
  dh = sha256(pack(sha256(pack(ekey))))

  checksum = dh[0, 8] # First 4 bytes is the checksum

  to_58(ekey << checksum)
end

def gen_key
  data = []

  # 0 - Private ECDSA Key
  key = OpenSSL::PKey::EC.new("secp256k1")
  key.generate_key
  data << key.private_key

  #1 - Public ECDSA Key
  data << key.public_key.to_bn.to_s(16)

  #2 - SHA-256 hash of 1
  data << sha256(pack(data[1]))

  #3 - RIPEMD-160 Hash of 2
  data << rmd160(pack(data[2]))

  #4 - Adding network bytes to 3
  data << "00" + data[3]

  #5 - SHA-256 hash of 4
  data << sha256(pack(data[4]))

  #6 - SHA-256 hash of 5
  data << sha256(pack(data[5]))

  #7 - First four bytes of 6
  data << data[6][0, 8]

  #8 - Adding 7 at the end of 4
  data << data[4] + data[7]

  #9 - Base58 encoding of 8
  data << to_58(data[8])

  data.values_at(0, 9)
end

if (arg = $*.first)
  raise 'Unallowed symbols: [0OIl]' if arg[/[0OIl]/]
  pattern = eval(arg)
else
  puts "Usage: ruby ./gen-key.rb '/^1regex/i'"
  exit
end

loop do
  sec, addr = gen_key
  if addr =~ pattern
    puts addr
    puts "importprivkey #{to_WIF(sec.to_s(16))}"
    exit
  end
end