Free SSL/TLS Certificates

Automatic Certificate Management Environment (ACME)

Automatic Certificate Management Environment - Wikiwand
RFC 8555 - Automatic Certificate Management Environment (ACME)
An In-Depth Symbolic Security Analysis of the ACME Standard formal proof

How It Works - Let's Encrypt
Challenge Types - Let's Encrypt
Multi-Perspective Validation Improves Domain Validation Security - Let's Encrypt

http-01

Server visits http://<domain.name>/.well-known/acme-challenge/<TOKEN>

dns-01

A Technical Deep Dive: Securing the Automation of ACME DNS Challenge Validation | Electronic Frontier Foundation
dns-01-challenge · GitHub Topics plugin for certbots

Automating Let's Encrypt Certificate Renewal using DNS Challenge Type — Chariot Solutions

Dynamic DNS updates on Hostinger server by API:

curl https://developers.hostinger.com/api/dns/v1/zones/<domain.name> \ --request PUT \ --header 'Content-Type: application/json' \ --header 'Authorization: Bearer <API_KEY>' \ --data '{ "overwrite": true, "zone": [ { "name": "_acme-challenge", "records": [ { "content": "<TOKEN>" } ], "ttl": 300, "type": "TXT" } ] }'

tls-alpn-01

RFC 8737 - Automated Certificate Management Environment (ACME) TLS Application-Layer Protocol Negotiation (ALPN) Challenge Extension

Let's Encrypt

Let's Encrypt
How It Works
Technology
letsencrypt

Let's Debug
Let's Encrypt Status

The CA's Role in Fighting Phishing and Malware - Let's Encrypt - Free SSL/TLS Certificates

Automatic HTTPS — Caddy Documentation

Rate Limits - Let's Encrypt - Free SSL/TLS Certificates
Staging Environment - Let's Encrypt - Free SSL/TLS Certificates
https://acme-staging-v02.api.letsencrypt.org/directory

Let's Encrypt the web with Jacob Hoffman-Andrews (Changelog Interviews #243)

Let's Encrypt Demo - YouTube
Let’s Encrypt Your Docker Dan’s Trial & Errno
Docker, Nginx & Letsencrypt: Easy & Secure Reverse Proxy
How to setup your website for that sweet, sweet HTTPS with Docker, Nginx, and letsencrypt
SSL with Docker Swarm, Let's Encrypt and Nginx
Nginx and Let’s Encrypt with Docker in Less Than 5 Minutes
How To Secure a Containerized Node Application with Let's Encrypt | DigitalOcean
Enabling HTTPS with Let's Encrypt on Docker - BROS - Medium
Generate free SSL certificates with Docker and LetsEncrypt | Tit Petrič
How to Set Up Free SSL Certificates from Let's Encrypt using Docker and Nginx

nginx-proxy/acme-companion: Automated ACME SSL certificate generation for nginx-proxy
linuxserver/docker-swag: Nginx webserver and reverse proxy with php support and a built-in Certbot (Let's Encrypt) client. It also contains fail2ban for intrusion prevention.
JonasAlfredsson/docker-nginx-certbot: Automatically create and renew website certificates for free using the Let's Encrypt certificate authority.

Two domains on one droplet with one SSL certificate | DigitalOcean
How To Secure Nginx with Let's Encrypt on Ubuntu 16.04 | DigitalOcean

如何免费的让网站启用 HTTPS | | 酷壳 - CoolShell
Complete guide to configure SSL on Nginx with Let's Encrypt (Ubuntu/Centos/RHEL) - LinuxTechLab
Let's Encrypt with HAProxy
Let's Encrypt on Raspberry Pi
adventures in haproxy: tcp, tls, https, ssh, openvpn
Setting up HTTPS on Nginx using Let’s Encrypt – Frederik Banke – Medium with Docker and certbot
How to configure Nginx with free Let’s Encrypt SSL certificate on Debian or Ubuntu Linux

Clients

integrating Let's Encrypt client into a private DNS server is cool

ACME Client Implementations - Let's Encrypt
draft-aaron-acme-profiles-01 - Automated Certificate Management Environment (ACME) Profiles Extension

Certbot docs previously letsencrypt/letsencrypt-auto
User Guide — Certbot.documentation
certbot/certbot: Certbot is EFF's tool to obtain certs from Let's Encrypt and (optionally) auto-enable HTTPS on your server. It can also act as a client for any other CA that uses the ACME protocol.

zerossl/zerossl-bot: The repository for the ZeroSSL certbot wrapper

Lego :: Let’s Encrypt client and ACME library written in Go.
go-acme/lego: Let's Encrypt/ACME client and library written in Go Used in Caddy

diafygi/acme-tiny: A tiny script to issue and renew TLS certs from Let's Encrypt

acme-client

kelunik/acme-client: Let's Encrypt / ACME client written in PHP for the CLI.

Enabling free SSL on Hostinger shared hosting | Kenrick's Notes
iamshreeram/php-ssl-installer: Installing SSL certificate in hostinger

php bin/acme issue --domains [colon-separated domain names] --path [colon-separated full path to domain root]

acme.sh

acmesh-official/acme.sh: A pure Unix shell script implementing ACME client protocol
LetsEncrypt SSL cert on GoDaddy Shared Hosting with No Root and No nc --deploy, then add cron jobs

acme.sh --issue -d $DOMAIN -w /home/wwwroot/$DOMAIN
# acme.sh --deploy -d example.com --deploy-hook cpanel_uapi
~/.acme.sh/$DOMAIN/$DOMAIN.cer  # cert
~/.acme.sh/$DOMAIN/$DOMAIN.key  # private key

~/.acme.sh/acme.sh --cron --home ~/.acme.sh --force 2>&1 >> ~/.acme.sh/cronlog.txt

Cloudflare

How to Get a FREE SSL Certificate with Hostinger - YouTube

create Cloudflare account
point to a domain with records
enable Let's Encrypt

CloudFlare Protection on Hostinger
For 1 CloudFlare Protection plan, you can only use it for 1 website/domain and all its subdomains as long as the domain/website is pointed to us.
We use Cloudflare’s free plan here at Hostinger. It does provide you with these features:

DDoS attack mitigation
Global Content Delivery Network (CDN)

The main differences between using Cloudflare with Hostinger directly with and Cloudflare.com are:

DNS zone can be fully managed from Hostinger side – so you don’t need to worry about updating DNS Records in different places: all of your domain’s DNS management will be in one place
All main setting of Cloudflare can be found in hPanel – so changing security level will only take a few clicks
One time activation fee – and Cloudflare will secure your domain and all of your subdomains as long as your domain is hosted with us 💜