Gem::Commands::CertCommand#open_cert

# File tmp/rubies/ruby-3.4.1/lib/rubygems/commands/cert_command.rb, line 85
def open_cert(certificate_file)
  check_openssl
  OpenSSL::X509::Certificate.new File.read certificate_file
rescue Errno::ENOENT
  raise Gem::OptionParser::InvalidArgument, "#{certificate_file}: does not exist"
rescue OpenSSL::X509::CertificateError
  raise Gem::OptionParser::InvalidArgument,
    "#{certificate_file}: invalid X509 certificate"
end