Posted on Apr 4, 2021

Get SSL Cert At Let's Encrypt

#dart #dartlang #certbot #letsencrypt

In the previous document I created an Http Server without SSL.

In this time, I explain to how to get ssl cert from let's encrypt.

Install certbot

I used certbot to communicate Let'sEncrypt.

$ apt-get install certbot -y

HttpServer For Certbot

Certbot's generate a file for acme-challege under '${WebRoot}/.well-known/acme-challenge/' folder.

and get request 'http://${HOST}/.well-known/acme-challenge/xxx'

bin/main.dart

Write a Code at Dart.

import 'dart:io' as io;

const String cerbotWebRootPath = "/var/www/html";

void main(List<String> arguments) async {
  try {
    print("start bind");
    var httpServer = await io.HttpServer.bind("0.0.0.0", 80);
    print("binded");
    await for (var request in httpServer) {
      try {
        print("receive requested ${request.uri}");
        if (request.uri.path.startsWith("/.well-known/")) {
          var acmeChallengeFilePath = "" +
              cerbotWebRootPath +
              request.uri.path.replaceAll(RegExp("\\?.*"), "");
          acmeChallengeFilePath = acmeChallengeFilePath.replaceAll("/..", "/");
          var acmeChallengeFile = io.File(acmeChallengeFilePath);
          var acmeChallengeData = await acmeChallengeFile.readAsString();
          request.response.write(acmeChallengeData);
          request.response.close();
        }
        request.response.write("Hello");
        request.response.close();
      } catch (e, s) {
        print("${e}");
        print("${s}");
      }
    }
  } catch (e, s) {
    print("${e}");
    print("${s}");
  }
}

update server

$ dart2native ./bin/main.dart
$ mv bin/main.exe /opt/main.exe
$ systemctl restart darthelloserver

and, execute certbot at webroot mode

$ certbot certonly --webroot -w /var/www/html -d tetorica.net -m kyorohiro@gmail.com
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Plugins selected: Authenticator webroot, Installer None
Obtaining a new certificate
Performing the following challenges:
http-01 challenge for tetorica.net
Using the webroot path /var/www/html for all unmatched domains.
Waiting for verification...
Cleaning up challenges

IMPORTANT NOTES:
 - Congratulations! Your certificate and chain have been saved at:
   /etc/letsencrypt/live/tetorica.net/fullchain.pem
   Your key file has been saved at:
   /etc/letsencrypt/live/tetorica.net/privkey.pem
   Your cert will expire on 2021-07-02. To obtain a new or tweaked
   version of this certificate in the future, simply run certbot
   again. To non-interactively renew *all* of your certificates, run
   "certbot renew"
 - If you like Certbot, please consider supporting our work by:

   Donating to ISRG / Let's Encrypt:   https://letsencrypt.org/donate
   Donating to EFF:                    https://eff.org/donate-le