DNSroboCert

Features

DNSroboCert is designed to manageLet’s Encrypt SSL certificates based onDNS challenges.

  • Let’s Encrypt wildcard and regular certificates generation byCertbot using DNS challenges,

  • Integrated automated renewal of almost expired certificates,

  • Standardized API throughLexicon library to insert the DNS challenge with various DNS providers,

  • Centralized YAML configuration file to maintain several certificates and several DNS providerswith configuration validity control,

  • Modification of container configuration without restart,

  • Flexible hooks upon certificate creation/renewal including containers restart, commands in containersor custom hooks,

  • Support forDNS alias mode (see thefollow_cnames option in thecertificate section),

  • Linux, Mac OS X and Windows support, with a particular care for Docker services,

  • Delivered as a standalone application and a Docker image.

Why use DNSroboCert

If you are reading these lines, you certainly want to secure all your services using Let’s Encrypt SSLcertificates, which are free and accepted everywhere.

If you want to secure Web services through HTTPS, there is already plenty of great tools. In the Dockerworld, one can checkTraefik, ornginx-proxy +letsencrypt-nginx-proxy-companion. Basically, theses toolswill allow automated and dynamic generation/renewal of SSL certificates, based on TLS or HTTP challenges,on top of a reverse proxy to encrypt everything through HTTPS.

So far so good, but you may fall in one of the following categories:

  1. You are in a firewalled network, and your HTTP/80 and HTTPS/443 ports are not opened to the outside world.

  2. You want to secure non-Web services (like LDAP, IMAP, POP, etc.) were the HTTPS protocol is of no use.

  3. You want to generate a wildcard certificate, valid for any sub-domain of a given domain.

For the first case, ACME servers need to be able to access your website through HTTP (for HTTP challenges)or HTTPS (for TLS challenges) in order to validate the certificate. With a firewall these two challenges -which are widely used in HTTP proxy approaches - will not be usable: you need to ask a DNS challenge.Please note that traefik embed DNS challenges, but only for few DNS providers.

For the second case, there is no website to use TLS or HTTP challenges, and you should ask a DNS challenge.Of course you could create a “fake” website to validate the domain using a HTTP challenge, and reuse thecertificate on the “real” service. But it is a workaround, and you have to implement a logic to propagatethe certificate, including during its renewal. Indeed, most of the non-Web services will need to berestarted each time the certificate is renewed.

For the last case, the use of a DNS challenge is mandatory. Then the problems concerning certificatespropagation that have been discussed in the second case will also occur.

The solution is a dedicated and specialized tool which handles the creation/renewal of Let’s Encryptcertificates, and ensure their propagation in the relevant services. It is the purpose ofthis project.