code: def import_certificate(
          ctx, slot, management_key, pin, cert, password, verify):
      
      controller = ctx.obj['controller']
      _ensure_authenticated(ctx, controller, pin, management_key)
  
      data = cert.read()
  
      while True:
          if password is not None:
              password = password.encode()
          try:
              certs = parse_certificates(data, password)
          except (ValueError, TypeError):
              if password is None:
                  password = click.prompt(
                      'Enter password to decrypt certificate',
                      default='', hide_input=True,
                      show_default=False,
                      err=True)
                  continue
              else:
                  password = None
                  click.echo('Wrong password.')
              continue
          break
  
      if len(certs) > 1:
          #  If multiple certs, only import leaf.
          #  Leaf is the cert with a subject that is not an issuer in the chain.
          leafs = get_leaf_certificates(certs)
          cert_to_import = leafs[0]
      else:
          cert_to_import = certs[0]
  
      def do_import(retry=True):
          try:
              controller.import_certificate(
                  slot, cert_to_import, verify=verify,
                  touch_callback=prompt_for_touch)
  
          except KeypairMismatch:
              ctx.fail('This certificate is not tied to the private key in the '
                       '{} slot.'.format(slot.name))
  
          except APDUError as e:
              if e.sw == SW.SECURITY_CONDITION_NOT_SATISFIED and retry:
                  _verify_pin(ctx, controller, pin)
                  do_import(retry=False)
              else:
                  raise
  
      do_import()
docs: Import a X.509 certificate.
  
      Write a certificate to one of the slots on the YubiKey.
  
      \b
      SLOT            PIV slot to import the certificate to.
      CERTIFICATE     File containing the certificate. Use '-' to use stdin.