class Net::HTTPHeader::DigestAuthenticator

def authorization_header
  @cnonce = md5(random)
  header = [
    %(Digest username="#{@username}"),
    %(realm="#{@response['realm']}"),
    %(nonce="#{@response['nonce']}"),
    %(uri="#{@path}"),
    %(response="#{request_digest}")
  ]
  header << %(algorithm="#{@response['algorithm']}") if algorithm_present?
  if qop_present?
    header << %(cnonce="#{@cnonce}")
    header << %(qop="#{@response['qop']}")
    header << 'nc=00000001'
  end
  header << %(opaque="#{@response['opaque']}") if opaque_present?
  header
end