Using HTTPS with fortrabbit

Criminals and goverment agencies are trying to read your Apps communication. Better serve all requests over HTTPS for extended privacy.

TLDR; Free and zero-config SSL certificates for all domains are provided, nothing you have to take care of. Read on if you want to learn about advanced options.


HTTPS is Hyper Text Transfer Protocol over Transport Layer Security. It is used to secure the data transport between a client (browser) and a server. HTTPS is based on TLS (Transport Layer Security), which is the successor to the still better known SSL (Secure Sockets Layer).

Current browsers show a green lock in the address bar if the connection is over HTTPS, the certificate could be verified and if the certificate is still valid. Google is promoting "https everywhere" (snakeoil), your SEO pagerank might benefit from using HTTPS.

HTTPS options on fortrabbit

As part of security efforts our aim is to give you secure, still easy-to-use and affordable options. Available with all Apps on fortrabbit:

1. Piggyback HTTPS

That's the most easiest and most obvious way to quickly run your App on https. You can already access your App URL using HTTPS. For example: https://{{app-name}} Use this URL for testing or if a custom domain is not important to you.

2. Automatic HTTPS

Let's Encrypt is a free certificate authority and can be used to generate free certificates for custom domains. The Automatic HTTPS feature is included for all fortrabbit Apps: All domains correctly added and routed will receive an SSL certificate by Let's Encrypt, no configuration or extra setup required. The certs will also be renewed automatically. This option does not work for wildcard domains (yet).

3. Custom HTTPS

Bring your own certificate: There are various use-cases to mandate a custom certificate, for example if you plan on using wildcard domains or need a green browser bar with your name > using a higher trusted commercial certificate.

How use Custom HTTPS

The roadmap to setup TLS custom reads like so:

  1. have an external domain registered with your fortrabbit App
  2. create a key and a certificate request locally (see below)
  3. using the certificate request: purchase an TLS/SSL cert from a third party CA
  4. (book the TLS component for your App in the Dashboard) < Pro App only
  5. upload your key and cert(s) to the Dashboard
  6. route all your (sub)domains to your App

Create a new key and certificate

To obtain a certificate, you first must create a certificate signing request (CSR). With the newly generated CSR, you can go to an external certificate vendor, which will issue a certificate for you. For Mac/Linux you can use openssl from the the command line like so:

openssl req -new -nodes -keyout {{app-name}}.key -out {{app-name}}.csr -newkey rsa:2048
# Generating a 2048 bit RSA private key
# ..........................................................................................++
# .............................................+++
# writing new private key to '{{app-name}}.key'
# -----
# You are about to be asked to enter information that will be incorporated
# into your certificate request.
# What you are about to enter is what is called a Distinguished Name or a DN.
# There are quite a few fields but you can leave some blank
# For some fields there will be a default value,
# If you enter '.', the field will be left blank.
# -----
# Country Name (2 letter code) [AU]:DE
# State or Province Name (full name) [Some-State]:Berlin
# Locality Name (eg, city) []:Berlin
# Organization Name (eg, company) [Internet Widgits Pty Ltd]:fortrabbit
# Organizational Unit Name (eg, section) []:Website
# Common Name (e.g. server FQDN or YOUR name) []
# Email Address []
# -----
# Please enter the following 'extra' attributes
# to be sent with your certificate request
# A challenge password []:
# An optional company name []

# Update key format
openssl rsa -in {{app-name}}.key -out {{app-name}}.rsa.key

Do not enter a password! Also: if you plan on using www.yourdomain.tld, don't miss the www. in the "Common Name"! When you have a wildcard domain, use *domain.tld as the Common Name.

Checking your CSR

You can decode the created CSR file to make sure did it correctly. Run this in your local Terminal:

openssl req -in yourcsr.csr -noout -text

Substitute yourcsr.csr with your file. Or just use an online tool, like this one.

Convert an existing key to RSA format

If you already have a private key and it begins with ----BEGIN PRIVATE KEY---- you need to convert it to the RSA format, using:

openssl rsa -in {{app-name}}.key -out {{app-name}}.rsa.key
# writing RSA key

The RSA format is required by our TLS implementation.

Finding the right Certificate Authority provider

Unsure from where to book your certificate? Most Certificate Authority provider look slightly dusty, but they do the job: namecheap SSL certs, DigiCert, Thawte, GeoTrust, SSLs. We have NO business relations here.

Renewing certificates

Remember that certificates are usually only valid for one year. So you need to re-purchase a new certificate from your provider and re-install it with your App, when using Custom HTTPS . The steps are the same as described above.


The following practical tips on how to deal with HTTPS are applying to all TLS options on fortrabbit:

Redirect all requests to HTTPS

It is recommended to forward all requests to the secure line, so no more "http://", only "https://". See an example here.

Secure your domain with a CAA record

A Certification Authority Authorization (CAA) is a DNS record to specify which certificate authorities (CAs) are allowed to issue certificates for a domain. It's an extra security layer, so that now one else can intercept any certificates by wrong authorities. There is no integration here on fortrabbit needed. See if your DNS / domain provider supports CAA entries, set the according identifying domain name. When you are using our free Let's Encrypt certs, see this article on how to set it up. Mind that already existing CAA entries can also become a problem when trying to issue new certificates.

Troubleshooting TLS

Sometimes it just doesn't work as supposed to. Don't panic. You can of course always ask us for support. Here are some things you can do on your own:

Review certificates in the browser

To debug TLS, it's often helpful a certificate in the browser. In Chrome and Firefox you can:

  1. open https://www.{{domain}}.com/ < make sure to use https not http
  2. click on the lock icon
  3. click on the "certificate" to reveal the cert

You see a certificate warning

You visit your Apps domain under the https:// address and the browser throws an error that the certificate can't be verified. If you expect the cert in the browser, you see that the cert is issued for * not for your domain.

This can happen, when the domain is brand new and the cert is not YET installed (can take up to 24 hours). In this case, please wait a little.

This can also happen, when your domain is not routed to fortrabbit (YET), only domains that are already routed to fortrabbit will receive a Let's Encrypt cert. Please see the domain settings in the Dashboard.

There are also other edge cases when this can happen and is not resolving on it's own. One case is, that your domain has set CAA records (see above) with DNS.

Cert is installed but browser bar is not green

In most cases this is due to "mixed content", which means, the cert is installed and everything is working, but your website is requesting external resources over non-secure addresses (http). Check the source code of your website and find and replace all http: requests. You can use https:// instead or you just leave out the protocol entirely like so: //. The last method will use whatever has been used before, so that works especially well, with different environments, for instance when your local development machine doesn't have TLS.

It's not working with Internet Explorer 8 or older

Sorry, IE8 is not supported any more. All our TLS implementations are based on SNI.

Solve SSL verification errors

This is the fix for verification errors when using ssl_verify. If you are receiving an error like the following:

error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed

You need to set the capath as well. Assuming you are using PHP streams, it would look like this:

$context = stream_context_create();
stream_context_set_option($context, 'ssl', 'verify_peer', true);
stream_context_set_option($context, 'ssl', 'capath', '/etc/ssl/certs'); # <<< that's the one
stream_context_set_option($context, 'ssl', 'allow_self_signed', false);

$fp = stream_socket_client("thedomain.tld:443", $errno, $errstr, 5, STREAM_CLIENT_CONNECT, $context);
# ..
if (stream_socket_enable_crypto($fp, true, STREAM_CRYPTO_METHOD_SSLv3_CLIENT) === false) {
    die("Failed to verify certificate");

For cURL, the option CURLOPT_CAPATH needs to be set to /etc/ssl/certs.

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