Pound Root Jail & HTTPS Configuration

]project-open[ installations under Linux usually include Pound  as a "reverse proxy" in order to allow multiple ]po[ instances to run on a single physical server. Usually, there is one "projop" production server, a "stage" staging server and a "dev" development server.

Pound Configuration

The Pound configuration file "pound.cfg" is usually located in the /etc/pound/ directory. Here is an example for Pound version 2.2:

# *****************************************************
# /etc/pound/pound.cfg
# *****************************************************

User            "nobody"
Group           "nobody"
RootJail        "/var/pound"
LogLevel        2

ListenHTTP
        Address 0.0.0.0
        Port    80
End

# "Stage" is running on 8001
Service
        HeadRequire "Host:.*stage.*"
        BackEnd
                Address localhost
                Port    8001
                TimeOut 600
        End
End

# By default show the "projop" production server
Service
        BackEnd
                Address localhost
                Port    8000
                TimeOut 600
        End
End­

"Chroot" Root Jail Configuration

Please note the "RootJail" line in the configuration above. This line tells the pound daemon process to change the root of its filesystem to /var/pound (instead of "/"). This way, the Pound process will not be able to access the rest of the system in case it should get hacked (which we haven't seen yet in more then 6 years working with Pound...).

Here is the structure of the the /var/pound directory:

# find /var/pound/
/var/pound/
/var/pound/etc
/var/pound/etc/hosts
/var/pound/etc/resolv.conf
/var/pound/dev
/var/pound/dev/urandom
/var/pound/lib

• ­/var/pound/dev/random:
  Pound needs this "device" in order to create random numbers. To create the "device" please enter (as root):
  

  # mknod /var/pound/dev/random c 1 8
  

• /var/pound/etc/resolv.conf:
  Pound needs the IP address(!) of the nameserver for logging etc. The file contains the following two lines:
  

  search localdomain
  nameserver <your_nameserver_ip_address>

• /var/lib/libgcc_s.so.1:
  This is a copy (not a symbolic link!) of the system library with the same name.
  

Please make sure that the entire /var/pound/ tree is owned and writable by root only, but readable for user/group "nobody".

Pound is capable to log error messages to the SysLog (/var/log/messages normally) even if it is running in a root jail. So please watch this file for any additional error messages.

Pound HTTPS Configuration

The following steps will guide you through the generation of a self-signed certificate for your ]project-open[ server.

During the process you will create:

• server.key: This is a 1024 bit random string ("private key") that uniquely identifies your server
• server.csr: This is a "Certificate Signing Request" file. You can send this to a Certificate Authorities (CA), or sign it yourself.
• server.crt: This is a "certificate" that certifies that server.key belongs to you.
• server.pem: This is the file that Pound needs to work correctly. A PEM file is a bundle of a the "server.key" priviate key and a certificate.
  

1. Generate an RSA private key for the server:
   openssl genrsa -out server.key 1024
   
   
2. Remove the passphrase from the key. Please make sure that nobody will have access to this file except for you. Otherwise the security of your server is at risk:
   cp server.key server.key.org
   openssl rsa -in server.key.org -out server.key
   
   
3. Create the Certificate Signing Request file, or CSR:
   openssl req -new -key server.key -out server.csr
   You will have to provide certain information for your CSR. Here are some sample values for ]project-open[:
   
   Country Name (2 letter code) [GB]: ES
   State or Province Name (full name) [Berkshire]: Catalonia
   Locality Name (eg, city) [Newbury]: Barcelona
   Organization Name (eg, company) [My Company Ltd]: Project Open Business Solutions S.L.
   Organizational Unit Name (eg, section) []:
   Common Name (eg, your name or your server's hostname) []: www.project-open.org
   Email Address []:webmaster@project-open.com
   A challenge password []:
   An optional company name []:
   
   
4. Now you could go to some Certificate Authority in the Web (for example: http://www.instantssl.com/ currently offers free certificates for 90 days) and sign your key there. As a result, you will receive a "certificate" file that you can save as "server.crt".
   
   
5. As an alternative you can sign the key yourself.
   The server.crt certificate will be technically valid. However, your browser will show a security warning if it encounters such a self-signed certificate:
   openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt
   
   
6. Verify your certificat. The following command should output some data, and not an error message:
   openssl x509 -in server.crt -text


7. Create a PEM file:
   openssl x509 -in server.crt -out server.pem
openssl rsa -in server.key >> server.pem
   ­
   
8. Now you can add a HTTPS listener configuration to your pound.cfg configuration file:
   ListenHTTPS
  Address 0.0.0.0
  Port    443
  Cert    "/etc/pound/server.pem"
End
   Older versions of Pound (<2.2) may require a different listener configuration, please consult the man-page of your installed version of Pound.

   

The new configuration will be come active after restarting Pound (/etc/init.d/pound restart).

You can execute "netstat -nlp" to list all network connections. In the upper part your should see something like this:

...
tcp        0      0 0.0.0.0:8000                0.0.0.0:*                   LISTEN      24804/nsd
tcp        0      0 0.0.0.0:80                  0.0.0.0:*                   LISTEN      375/pound
...
tcp        0      0 0.0.0.0:443                 0.0.0.0:*                   LISTEN      375/pound
...­

• ­ 0.0.0.0:8000: This is the AOLserver itself
• 0.0.0.0:80: This is Pound listening for unincrypted HTTP connections
• 0.0.0.0.443: This is the Pound HTTPS listener.
  

Pound will write any errors into /var/log/messages.

Configuring ]project-open[ for Pound HTTPS

If you implement HTTPS via Pound, ]project-open[ will need a special parameter in order to deal correctly with "redirects". This is necessary because ]project-open[ receives connections from Pound on a normal HTTP port, instead of HTTPS. So ]po[ will by default use the HTTP port when redirecting a user.

To circumvent this problem, please go to Admin -> Parameters -> intranet-core and change the parameter UtilCurrentLocationRedirect to "https://your.server.com/".

Disable Unencrypted Connections

After going through the steps above, your AOLserver is still listening for unencrypted HTTP connections on port 8000 (example) on the IP address "0.0.0.0". To disable unencrypted connections please configure your computer's package filter ("firewall") to filter port 8000, or tell AOLserver to listen on a local connection only by modifying the configuration in ~/etc/config.tcl to: 'set address "127.0.0.1"'.