class Aws::S3::EncryptionV2::EncryptHandler

def apply_encryption_cipher(context, cipher)
  io = context.params[:body] || ''
  io = StringIO.new(io) if io.is_a? String
  context.params[:body] = IOEncrypter.new(cipher, io)
  context.params[:metadata] ||= {}
  context.params[:metadata]['x-amz-unencrypted-content-length'] = io.size
  if context.params.delete(:content_md5)
    raise ArgumentError, 'Setting content_md5 on client side '\
      'encrypted objects is deprecated.'
  end
  context.http_response.on_headers do
    context.params[:body].close
  end
end