Application SSL Certificates

SSL is a cryptographic protocol that provides end-to-end encryption and integrity for all web requests.

Application SSL Certificates

SSL is a cryptographic protocol that provides end-to-end encryption and integrity for all web requests. Apps that transmit sensitive data should enable SSL to ensure all information is transmitted securely.

To enable SSL on a custom domain, e.g.,, use the SSL endpoint.

!!! note drycc certs is only useful for custom domains. Default application domains are SSL-enabled already and can be accessed simply by using https, e.g. (provided that you have installed your wildcard certificate on the routers or on the load balancer).


Because of the unique nature of SSL validation, provisioning SSL for your domain is a multi-step process that involves several third-parties. You will need to:

  1. Purchase an SSL certificate from your SSL provider
  2. Upload the cert to Drycc

Acquire SSL Certificate

Purchasing an SSL cert varies in cost and process depending on the vendor. RapidSSL offers a simple way to purchase a certificate and is a recommended solution. If you’re able to use this provider, see buy an SSL certificate with RapidSSL for instructions.

DNS and Domain Configuration

Once the SSL certificate is provisioned and your cert is confirmed, you must route requests for your domain through Drycc. Unless you’ve already done so, add the domain specified when generating the CSR to your app with:

$ drycc domains:add --type==web -a foo
Adding to foo... done

Add a Certificate

Add your certificate, any intermediate certificates, and private key to the endpoint with the certs:add command.

$ drycc certs:add example-com server.crt server.key
Adding SSL endpoint... done

!!! note The name given to the certificate can only contain a-z (lowercase), 0-9 and hyphens

The Drycc platform will investigate the certificate and extract any relevant information from it such as the Common Name, Subject Alt Names (SAN), fingerprint and more.

This allows for wildcard certificates and multiple domains in the SAN without uploading duplicates.

Add a Certificate Chain

Sometimes, your certificates (such as a self-signed or a cheap certificate) need additional certificates to establish the chain of trust. What you need to do is bundle all the certificates into one file and give that to Drycc. Importantly, your site’s certificate must be the first one:

$ cat server.crt > server.bundle

After that, you can add them to Drycc with the certs:add command:

$ drycc certs:add example-com server.bundle server.key
Adding SSL endpoint... done

Attach SSL certificate to a domain

Certificates are not automagically connected up to domains, instead you will have to attach a certificate to a domain

$ drycc certs:attach example-com

Each certificate can be connected to many domains. There is no need to upload duplicates.

To remove an association

$ drycc certs:detach example-com

Endpoint overview

You can verify the details of your domain’s SSL configuration with drycc certs.

$ drycc certs

     Name     |    Common Name    | SubjectAltName    |         Expires         |   Fingerprint   |   Domains    |   Updated   |   Created
  example-com |   |  | 31 Dec 2017 (in 1 year) | 8F:8E[...]CD:EB | | 30 Jan 2016 | 29 Jan 2016

or by looking at at each certificates detailed information

$ drycc certs:info example-com

=== bar-com Certificate
Common Name(s):
Expires At:         2017-01-14 23:57:57 +0000 UTC
Starts At:          2016-01-15 23:57:57 +0000 UTC
Fingerprint:        7A:CA:B8:50:FF:8D:EB:03:3D:AC:AD:13:4F:EE:03:D5:5D:EB:5E:37:51:8C:E0:98:F8:1B:36:2B:20:83:0D:C0
Subject Alt Name:
Issuer:             /C=US/ST=CA/L=San Francisco/O=Drycc/OU=Engineering/[email protected]
Subject:            /C=US/ST=CA/L=San Francisco/O=Drycc/OU=Engineering/[email protected]

Connected Domains:
Owner:              admin-user
Created:            2016-01-28 19:07:41 +0000 UTC
Updated:            2016-01-30 00:10:02 +0000 UTC

Testing SSL

Use a command line utility like curl to test that everything is configured correctly for your secure domain.

!!! note The -k option flag tells curl to ignore untrusted certificates.

Pay attention to the output. It should print SSL certificate verify ok. If it prints something like common name: (does not match '') then something is not configured correctly.

Enforcing SSL at the Router

To enforce all HTTP requests be redirected to HTTPS, TLS can be enforced at the router level by running

$ drycc tls:force:enable -a foo
Enabling https-only requests for foo... done

Users hitting the HTTP endpoint for the application will now receive a 301 redirect to the HTTPS endpoint.

To disable enforced TLS, run

$ drycc tls:force:disable -a foo
Disabling https-only requests for foo... done

Automated Certificate Management

With Automated Certificate Management (ACM), Drycc automatically manages TLS certificates for apps with Hobby and Professional dynos on the Common Runtime, and for apps in Private Spaces that enable the feature. Certificates handled by ACM automatically renew one month before they expire, and new certificates are created automatically whenever you add or remove a custom domain. All applications with paid dynos include ACM for free. Automated Certificate Management uses Let’s Encrypt, the free, automated, and open certificate authority for managing your application’s TLS certificates. Let’s Encrypt is run for the public benefit by the Internet Security Research Group (ISRG).

To enable ACM with the following command: $ drycc tls:auto:enable -a foo

To disable ACM with the following command: $ drycc tls:auto:disable -a foo

Remove Certificate

You can remove a certificate using the certs:remove command:

$ drycc certs:remove my-cert
Removing Done.

Swapping out certificates

Over the lifetime of an application an operator will have to acquire certificates with new expire dates and apply it to all relevant applications, below is the recommended way to swap out certificates.

Be intentional with certificate names, name them example-com-2017 when possible, where the year signifies the expiry year. This allows for example-com-2018 when a new certificate is purchased.

Assuming all applications are already using example-com-2017 the following commands can be ran, chained together or otherwise:

$ drycc certs:detach example-com-2017
$ drycc certs:attach example-com-2018

This will take care of a singular domain which allows the operator to verify everything went as planned and slowly roll it out to any other application using the same method.


Here are some steps you can follow if your SSL endpoint is not working as you’d expect.

Untrusted Certificate

In some cases when accessing the SSL endpoint, it may list your certificate as untrusted.

If this occurs, it may be because it is not trusted by Mozilla’s list of root CAs. If this is the case, your certificate may be considered untrusted for many browsers.

If you have uploaded a certificate that was signed by a root authority but you get the message that it is not trusted, then something is wrong with the certificate. For example, it may be missing intermediary certificates. If so, download the intermediary certificates from your SSL provider, remove the certificate from Drycc and re-run the certs:add command.