Dart Requires Chilkat v11.0.0+

HTTPS Server Certificate Require Hostname Match

See more HTTP Examples

Demonstrates and explains the RequireHostnameMatch property. Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // The RequireHostnameMatch property was added in Chilkat v11.0.0
  // to ensure the URL's hostname matches at least one of the server certificate SAN's (Subject Alternative Names)
  // 
  // In actuality, it is the SNI hostname that must match.  If the SNI hostname is not explicitly set,
  // then Chilkat uses the hostname from the URL as the SNI hostname.

  // Here's an example using chilkatsoft.com
  // The SSL server certificate for chilkatsoft.com has 2 Subject Alternative Names:
  // 
  // 1) DNS Name: *.chilkatsoft.com
  // 2) DNS Name: chilkatsoft.com
  // 
  // See Explaining the SNI Hostname in TLS

  final http = CkHttp();

  http.requireHostnameMatch = true;

  // This should succeed because "www.chilkatsoft.com" matches the SAN entry "*.chilkatsoft.com"
  var html = http.quickGetStr('https://www.chilkatsoft.com/helloWorld.html');
  print('1) Succeeded: ${http.lastMethodSuccess}');

  // At the time of writing this example, the IP address for chilkatsoft.com is 3.101.18.47
  // If we send the request using the IP address, it will fail because the IP address is does 
  // not match any of the SAN entries in the server certificate.
  html = http.quickGetStr('https://3.101.18.47/helloWorld.html');
  print('2) Succeeded: ${http.lastMethodSuccess}');

  // However, it will succeed if we explicitly set the SNI hostname.
  http.sniHostname = 'www.chilkatsoft.com';
  html = http.quickGetStr('https://3.101.18.47/helloWorld.html');
  print('3) Succeeded: ${http.lastMethodSuccess}');

  // Remove our explicit SNI hostname.
  http.sniHostname = '';

  // Now let's try wrong.host.badssl.com
  // The SSL server certificate for badssl.com has 2 Subject Alternative Names:
  // 
  // 1) DNS Name: *.badssl.com
  // 2) DNS Name: badssl.com

  // The domain wrong.host.badssl.com will fail the RequireHostnameMatch because
  // the wildcarded domain SAN entry only extends 1 level deep.  
  html = http.quickGetStr('https://wrong.host.badssl.com/');
  print('4) Succeeded: ${http.lastMethodSuccess}');

  // The expected output is:
  // 1) Succeeded: True
  // 2) Succeeded: False
  // 3) Succeeded: True
  // 4) Succeeded: False
}