Debian 8.6, Proxy guacamole via Apache2 using HTTPS and Fail2Ban

In my previous article I explained how to install guacamole on Debian 8.6, in this article I cover how to publish this over https using Apache2, as well as using fail2ban and ufw in an attempt to protect the service.

First, install required pre-reqs:

apt-get install apache2 libapache2-mod-proxy-html

Now, we will modify the tomcat8 config

vi /etc/tomcat8/server.xml

Uncomment and modify the AJP/1.3 line accordingly:

 <Connector port="8009" protocol="AJP/1.3"
    redirectPort="8443" />

Now restart tomcat8:

systemctl restart tomcat8.service

Now for Apache2 configuration. Firstly you’ll need to enable the following modules using a2enmod:

a2enmod proxy
a2enmod proxy_http
a2enmod proxy_wstunnel
a2enmod log_config
a2enmod ssl

Now for SSL configuration; generate your private key and CSR (yo can then process these with an external, third-part CA such as StartSSL – which is free.

openssl req -newkey rsa:2048 -keyout guac.key -out guac.csr

I’m now assuming you now have the following files:

  1. Root certificate bundle for your CA (.crt from third-part CA)
  2. Public key for your certificate (.crt from third-part CA)
  3. Private key for your certificate (.key file form OpenSSL command)

We’ll now copy these files to /etc/apache2/ssl:

mkdir /etc/apache2/ssl
cp 1_root_bundle.crt /etc/apache2/ssl
cp /etc/apache2/ssl
cp guac.key /etc/apache2/ssl

Note, your .key file (private key) likely has a passphrase, you’ll want to remove this otherwise you’ll have to manually enter this when Apache2 loads:

openssl rsa -in guac.key -out guac-nopass.key

Now, protect those files!

chmod 600 /etc/apache2/ssl/*

Create a root directory for the new HTTPS site and enable mod_ssl:

mkdir /srv/www-guacamole

Now, we’ll configure the site definition in Apache2

vi /etc/apache2/sites-available/guacamole.conf

Contents as below – make sure you change the URL in bold – note the HTTPS definition uses IP address, not hostname. See this URL for more details, but by using hostname you will receive the following errors:

SSL received a record that exceeded the maximum permissible length. Error code: SSL_ERROR_RX_RECORD_TOO_LONG remote client

    # Redirect traffic from 80 to 443, and also from / to /guacamole/
    Redirect permanent /
    Redirect permanent /guacamole

    # Redirect traffic from / to /guacamole/        
    Redirect permanent /
    SSLEngine on
    SSLProtocol all -SSLv2 -SSLv3
    SSLCertificateFile /etc/apache2/ssl/
    SSLCertificateKeyFile /etc/apache2/ssl/guac.key
    SSLCertificateChainFile /etc/apache2/ssl/1_root_bundle.crt
    DocumentRoot /srv/www-guacamole	
    <Location /guacamole/>
        Order allow,deny
        Allow from all
        ProxyPass http://localhost:8080/guacamole/ max=20 flushpackets=on
        ProxyPassReverse http://localhost:8080/guacamole/
        SetEnvIf Request_URI "^/guacamole/tunnel" dontlog
    <Location /guacamole/websocket-tunnel>
        Order allow,deny
        Allow from all
        ProxyPass ws://localhost:8080/guacamole/websocket-tunnel
        ProxyPassReverse ws://localhost:8080/guacamole/websocket-tunnel
CustomLog /var/log/apache2/guac.log common env=!dontlog

Next we need to enable this site using a2ensite:

a2ensite guacamole.conf

Now, restart Apache2:

systemctl restart apache2

Next, configure Apache2 to load on boot:

systemctl enable apache2

You’ll now be able to access your guacamole instance by using the URL: https://<your chosen url>

Now for the fail2ban installation and configuration – first download and install fail2ban:

cd ~
git clone
cd fail2ban
python install
cp files/debian-initd /etc/init.d/fail2ban
systemctl daemon-reload
cp /etc/fail2ban/jail.conf /etc/fail2ban/jail.local

No we’ll enable the guacamole by editing /etc/fail2ban/jail.local

vi /etc/fail2ban/jail.local

# Add a new line "enabled = true" under [guacamole]
enabled = true
port     = http,https
logpath  = /var/log/tomcat*/catalina.out

# Now save and close /etc/fail2ban/jail.local

# Prevent local network from banning - change as per your setup
sed -i "s|ignoreip = ::1|ignoreip = ::1|" /etc/fail2ban/jail.local

Lastly for fail2ban config, we need to adjust the regexthat detects failures – as per this site (where I found this fix!).

vi /etc/fail2ban/filter.d/guacamole.conf

# change this incorrect regex: failregex = ^.*\nWARNING: Authentication attempt from <HOST> for user "[^"]*" failed\.$ to this:

failregex = \bAuthentication attempt from \[<HOST>(?:,.*)?\] for user ".*" failed\.

Now, enable fail2ban to start on boot

systemctl enable fail2ban

Home straight now… ufw config. The commands below are specifically designed for the solution outlined in this post – please review and consider rules that apply to your environment. If you lose access to your server it’s not my fault!

# Install Uncomplicated Firewall
apt-get install ufw

# Allow HTTPS from to guacamole/apache2 server
ufw allow from to port 443
# Allow HTTP from local LAN (for redirect only)
ufw allow from to port 80
# Enable Firewall
ufw enable



5 replies on “Debian 8.6, Proxy guacamole via Apache2 using HTTPS and Fail2Ban”

Hi, I’m trying to get this working on my test guacamole install, but no luck. I’m just interested on the https side of things ATM I’m lost with the certificates where do you get those two .crt’s also on the apache2 config it thought me an error with your config saying there is a virtual host not closed, and I think there is, looks like you have the last two lines duplicated. Im trying to get this working with apache as I failed to get it working (https) on tomcat8.

Thanks for the heads-up ref the Apache config. You were right, I had duplicated the last two lines w/ copy and paste. So, I have moved all of my config to NGINX. SSL certificate info can be found here (also works with Apache, but you will need to change the config): plus, initial config/ setup :

If you continue with Apache, use “Let’s Encrypt” to generate the two crt files.

No problem, Thanks for getting back to be on the certificate side of things, I was via proxie route because I wasn’t managing to get tomcat/catalina to work with HTTPS/SSL I have managed to get this working now, so no need for proxies at the time being.
Thanks and Regards

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