Gem::Security::Policy#check_root

# File tmp/rubies/ruby-3.1.3/lib/rubygems/security/policy.rb, line 129
def check_root(chain, time)
  raise Gem::Security::Exception, "missing signing chain" unless chain

  root = chain.first

  raise Gem::Security::Exception, "missing root certificate" unless root

  raise Gem::Security::Exception,
        "root certificate #{root.subject} is not self-signed " +
        "(issuer #{root.issuer})" if
    root.issuer != root.subject

  check_cert root, root, time
end