Clojure Compojure Ring and https - https

Question

I'm using Clojure (ring and compojure) to build a web app and I don't know where to start with https. I have a registration and login that will need to be secured, then once they're authenticated they'll need to stay in https.
I can't seem to find a good tutorial on setting up https in general or for a clojure app specifically.
I found this answer: How do you enable https and http->https redirects in ring / compojure
Does that mean I can write my compojure app as if there's no https and have nginx sit in front and take care of all that for me?

Answer 1

Yes, the standard procedure is to have nginx act as a reverse proxy in front of the ring based webapp. This is considered secure and it's easier to maintain because it's more standard. Every clojure based site I know about does it this way.

Answer 2

The reverse proxy approach does seem to be the most common option. However, as an 'experiment' I looked into using just ring, jetty compojure etc with https. It isn't that hard.
First you need to use keytool to generate a self signed certificate and install that into a new keystore. The keytool docs a pretty good and can walk you through this process. Note that if you use a self signed cert, you will need to add an exception rule with most browsers to say that you trust that certificate.
Copy the keystore file created into the root of your project tree
Update the jetty config parameters to specify ssl, ssl-port, keystore file and keystore password.
Add the ring/ring-defaults package to your project.clj
Add the wrap-defaults middleware with the secure-site-defaults configuration option to force https connections i.e. redirect http connections to https.
This is not the setup I would recommend for production use, but I found it simpler than also having to configure ngix when doing development etc. The hardest part was working through the keytool process. However, just following the docs and examples gives you enough provided you don't allow yoruself to be overwhelmed by all the options - just keep it simple.
Something like
keytool -genkeypair \
-keystore $SSL_DIR/$KS_NAME \
-keypass $PASSWORD \
-storepass $PASSWORD \
-keyalg RSA -keysize 2048 \
-alias root \
-ext bc:c \
-dname "$ROOT_CN"
echo "CA Key"
keytool -genkeypair \
-keystore $SSL_DIR/$KS_NAME \
-alias ca \
-ext bc:c \
-keypass $PASSWORD \
-keyalg RSA -keysize 2048 \
-storepass $PASSWORD \
-dname "$CA_CN"
echo "Server Key"
keytool -genkeypair \
-keystore $SSL_DIR/$KS_NAME \
-alias server \
-keypass $PASSWORD \
-storepass $PASSWORD \
-keyalg RSA -keysize 2048 \
-dname "$SERVER_CN"
echo "Root Cert"
keytool -keystore $SSL_DIR/$KS_NAME \
-storepass $PASSWORD \
-alias root \
-exportcert \
-rfc > $SSL_DIR/root.pem
echo "CA Cert"
keytool -storepass $PASSWORD \
-keystore $SSL_DIR/$KS_NAME \
-certreq \
-alias ca | keytool -storepass $PASSWORD \
-keystore $SSL_DIR/$KS_NAME \
-gencert \
-alias root \
-ext BC=0 \
-rfc > $SSL_DIR/ca.pem
echo "Import CA cert"
keytool -keystore $SSL_DIR/$KS_NAME \
-storepass $PASSWORD \
-importcert \
-alias ca \
-file $SSL_DIR/ca.pem
echo "Server Cert"
keytool -storepass $PASSWORD \
-keystore $SSL_DIR/$KS_NAME \
-certreq \
-alias server | keytool -storepass $PASSWORD \
-keystore $SSL_DIR/$KS_NAME \
-gencert \
-alias ca \
-rfc > $SSL_DIR/server.pem
echo "Import Server Cert"
cat $SSL_DIR/root.pem $SSL_DIR/ca.pem $SSL_DIR/server.pem | \
keytool -keystore $SSL_DIR/$KS_NAME \
-storepass $PASSWORD \
-keypass $PASSWORD \
-importcert \
-alias server

Answer 3

Usually application-level code does not care whether it's HTTPS or HTTP. Most often it's provided by application server or a proxy in front of it. If you're familiar, your choices are pretty much the same as in the Java world.
If you're using the Jetty adapter, it has ssl? and ssl-port options. See docs here and related blog post here.
You can run your Ring app in plain HTTP and place a proxy such as Nginx or Apache in front of it. Proxy would implement HTTPS and forward requests as plain HTTP to your app.

Answer 4

Another solution is to try nginx-clojure (http://nginx-clojure.github.io) by which you can deploy ring app on nginx directly. nginx can do https things more efficiently.
Here's an example about nginx.conf
http {
### jvm dynamic library path
jvm_path '/usr/lib/jvm/java-7-oracle/jre/lib/amd64/server/libjvm.so';
### my app jars e.g. clojure-1.5.1.jar , groovy-2.3.4.jar ,etc.
jvm_var my_other_jars 'my_jar_dir/clojure-1.5.1.jar';
### my app classpath, windows user should use ';' as the separator
jvm_options "-Djava.class.path=jars/nginx-clojure-0.3.0.jar:#{my_other_jars}";
server {
listen 80 default deferred;
server_name example.com;
###redirect to https
rewrite ^/(.+) https://example.com/$1 permanent;
}
server {
listen 443 ssl;
server_name example.com;
ssl_certificate /opt/mycert/my-unified.crt;
ssl_certificate_key /opt/mycert/my.key;
location /myapp {
content_handler_name 'my/ringapp';
}
}
}
You can get more details about SSL server configurations from http://nginx.org/en/docs/http/configuring_https_servers.html

Answer 5

You can setup Ring middleware that will force all requests to use SSL. An easy way to do this is to use the ring-defaults library.
From the ring-defaults documentation:
There are four configurations included with the middleware
- api-defaults
- site-defaults
- secure-api-defaults
- secure-site-defaults
...
The "secure" defaults force SSL. Unencrypted HTTP URLs are redirected to the equivlant HTTPS URL, and various headers and flags are sent to prevent the browser sending sensitive information over insecure channels.
Also note:
In order to enable local development without SSL, you can set which ring-defaults set you use based on an environment variable. Environ helps with this.
In order to enable SSL to work behind a load balancer or proxy, you have to set :proxy to true in the ring-defaults map.
Here's the general idea:
(ns my-app
(:require [ring.middleware.defaults :refer :all]
[environ.core :refer [env]]))
(defroutes app-routes
(GET "/" [] "home page"))
(def app
(-> app-routes
(wrap-defaults (if (= (env :environment) "dev")
site-defaults
(assoc secure-site-defaults :proxy true))))
I don't know about nginx, but I have this working for an app deployed to Heroku.

Answer 6

Its very simple. If you want to enable HTTPS support in your web app, just do the following:
Generate a Java KeyStore(.jks) file using a linux tool called keytool.
In the ring map of your project.clj file, add the following:
{
:ssl? true
:ssl-port 8443
:keystore "path to the jks file"
:key-password "the keystore password"
}
Fire up the server. Now your web app is HTTPS enabled.
I had a similar problem while I was trying to test my Sign-In using Social Media code which obviously had to authenticate over HTTPS and this did the trick for me.