Disclaimer

This is a DEVELOPER PREVIEW intended for developers and testers only.

DO NOT RUN THIS CODE ON A PRODUCTION SERVER. IT WILL INSTALL CERTIFICATES SIGNED BY A TEST CA, AND WILL CAUSE CERT WARNINGS FOR USERS.

Browser-trusted certificates will be available in the coming months.

For more information regarding the status of the project, please see https://letsencrypt.org. Be sure to checkout the Frequently Asked Questions (FAQ).

About the Let's Encrypt Client

In short: getting and installing SSL/TLS certificates made easy (watch demo video).

The Let's Encrypt Client is a tool to automatically receive and install X.509 certificates to enable TLS on servers. The client will interoperate with the Let's Encrypt CA which will be issuing browser-trusted certificates for free.

It's all automated:

The tool will prove domain control to the CA and submit a CSR (Certificate Signing Request).
If domain control has been proven, a certificate will get issued and the tool will automatically install it.

All you need to do to sign a single domain is:

user@www:~$ sudo letsencrypt -d www.example.org auth

For multiple domains (SAN) use:

user@www:~$ sudo letsencrypt -d www.example.org -d example.org auth

and if you have a compatible web server (Apache or Nginx), Let's Encrypt can not only get a new certificate, but also deploy it and configure your server automatically!:

user@www:~$ sudo letsencrypt -d www.example.org run

Encrypt ALL the things!

Current Features

web servers supported:
- apache/2.x (tested and working on Ubuntu Linux)
- nginx/0.8.48+ (tested and mostly working on Ubuntu Linux)
- standalone (runs its own webserver to prove you control the domain)
the private key is generated locally on your system
can talk to the Let's Encrypt (demo) CA or optionally to other ACME compliant services
can get domain-validated (DV) certificates
can revoke certificates
adjustable RSA key bitlength (2048 (default), 4096, ...)
optionally can install a http->https redirect, so your site effectively runs https only (Apache only)
fully automated
configuration changes are logged and can be reverted using the CLI
text and ncurses UI
Free and Open Source Software, made with Python.