module JWT::SecurityUtils

def raw_to_asn1(signature, private_key)
  byte_size = (private_key.group.degree + 7) / 8
  sig_bytes = signature[0..(byte_size - 1)]
  sig_char = signature[byte_size..-1] || ''
  OpenSSL::ASN1::Sequence.new([sig_bytes, sig_char].map { |int| OpenSSL::ASN1::Integer.new(OpenSSL::BN.new(int, 2)) }).to_der
end