在Go中验证国际域名的最佳方法

Question

What is the best way to validate international domain names in Go?

https://golang.org/pkg/net/?m=all#isDomainName

https://golang.org/src/net/dnsclient.go?s=3444:3476#L109

Maybe copying this function which isn't exported from net package?

We need to validate domains like icaan.org and example.(special characters)

EDIT: IDN https://en.wikipedia.org/wiki/Internationalized_domain_name

Already using govalidator which fails to validate IDN's as it doesn't handle unicode characters https://github.com/asaskevich/govalidator/blob/master/validator.go

Here are some examples of IDN's

• https://evertpot.com/internationalized-domain-names-are-you-ready/
• http://مثال.إختبار - Arabic.
• http://例子.测试 - Chinese (simplified)
• http://例子.測試 - Chinese (traditional)
• http://παράδειγμα.δοκιμή - greek
• http://उदाहरण.परीक्षा Hindi
• http://例え.テスト - Japanese
• http://실례.테스트 - Korean
• http://مثال.آزمایشی - Persian
• http://пример.испытание - Russian

Just seen the reference to punycode.

Though all these punycode's are in the public suffix list https://publicsuffix.org/list/public_suffix_list.dat

:(

Answer 1

One possible approach is to use the builtin functions url.Parse(string) and url.Hostname() along with a regular expression to match sequences of Unicode letters/numbers/marks separated by dots (as represented in the sample data set).

For example:

var domainNamePattern = regexp.MustCompile(`^([\p{L}\p{M}\p{N}_%+-]+\.)+[\p{L}\p{M}\p{N}]+$`)

func main() {
  ss := []string{
    `https://evertpot.com/internationalized-domain-names-are-you-ready/`,
    `http://bogus!.com`,
    `https://foo1.bar2.com.gah.zip/`,
    `http://مثال.إختبار`,
    `http://例子.测试`,
    `http://例子.測試`,
    `http://παράδειγμα.δοκιμή`,
    `http://उदाहरण.परीक्षा`,
    `http://例え.テスト`,
    `http://실례.테스트`,
    `http://مثال.آزمایشی`,
    `http://пример.испытание`,
  }

  for _, s := range ss {
    u, err := url.Parse(s)
    if err != nil || !domainNamePattern.MatchString(u.Hostname()) {
      bogusPart := s
      if err == nil {
        bogusPart = u.Hostname()
      }
      fmt.Printf("ERROR: invalid URL or hostname %q
", bogusPart)
      continue
    }
    fmt.Printf("OK: hostname=%q
", u.Hostname())
  }
}

// OK: hostname="evertpot.com"
// ERROR: invalid URL or hostname "bogus!.com"
// OK: hostname="foo1.bar2.com.gah.zip"
// OK: hostname="مثال.إختبار"
// OK: hostname="例子.测试"
// OK: hostname="例子.測試"
// OK: hostname="παράδειγμα.δοκιμή"
// OK: hostname="उदाहरण.परीक्षा"
// OK: hostname="例え.テスト"
// OK: hostname="실례.테스트"
// OK: hostname="مثال.آزمایشی"
// OK: hostname="пример.испытание"

Of course, more care should be taken to build the regular expression in such a way that it conforms to any relevant specifications, but this example should be a good starting point.