module ECDSA::Format::PointOctetString

Public Class Methods

decode(string, group, allow_hybrid: false) click to toggle source
# File lib/tapyrus/ext/ecdsa.rb, line 15
def self.decode(string, group, allow_hybrid: false)
  string = string.dup.force_encoding('BINARY')

  raise ECDSA::Format::DecodeError, 'Point octet string is empty.' if string.empty?

  case string[0].ord
  when 0
    check_length string, 1
    return group.infinity
  when 2
    decode_compressed string, group, 0
  when 3
    decode_compressed string, group, 1
  when 4
    decode_uncompressed string, group
  when 6..7
    unless allow_hybrid
      raise ECDSA::Format::DecodeError, 'Unrecognized start byte for point octet string: 0x%x' % string[0].ord
    end
    decode_uncompressed string, group if allow_hybrid
  else
    raise ECDSA::Format::DecodeError, 'Unrecognized start byte for point octet string: 0x%x' % string[0].ord
  end
end