If you have Filezilla installed in Windows XP delete the following user specific file:

\Documents and Settings\UserName\Application Data\FileZilla\trustedcerts.xml

Replace “UserName” with the username of the user account that was running the Filezilla program when the SSL certificates were saved.

If you have Filezilla installed in Vista delete the following file:

C:\Program Files (x86)\FileZilla\Trusted Certs.dat

Change “C:\Program Files (x86)\FileZilla\” to the directory you installed Filezilla to if you did not go with the default installation location.

SSL Certificate

If you encounter the error

net.sf.portecle.crypto.CryptoException: Could not load keystore as type PKCS12

while trying to open an OpenSSL created PKCS12 type keystore file, that means you need to install the Java Unlimited Strength Jurisdiction Policy files into your JAVA runtime environment. Due to U.S. export restrictions, practically all JAVA runtime environments are crippled such that they cannot utilize high encryption algorithms. You must manually install the “Unlimited Strength Jurisdiction Policy” files from the JAVA homepage and install them into your JAVA runtime environment.

You can download the “Unlimited Strength Jurisdiction Policy” files from the official JAVA download site: http://java.sun.com/javase/downloads/

Usually the policy files are installed into the ./lib/security subdirectory of your JAVA runtime environment directory.

Command to recursively chmod only directories:

find . -type d -exec chmod 755 {} \;

How to recursively set the execute bit on every directory:

chmod -R a+X *

The +X flag sets the execute bit on directories only

How to recursively chmod only files:

find . -type f -exec chmod 644 {} \;

How to recursively chmod only PHP files (only for PHP files with the extension .php):

find . -type f -name '*.php' -exec chmod 644 {} \;

You can change the “.php” in the line above to whatever file extension that you want.

NX Server is a commercial application released by the company NoMachine. It allows you to connect to your Linux server similar to how you would connect to a Windows computer using remote desktop. NoMachine offers a free version of the product which has a restriction of only allowing 2 simultaneous connections to the server. NX Server runs over SSH so you don’t need to open any other ports on your firewall other than the port for the SSH service.

It is considered a good security practice to change the default port the SSH service listens on. When you change this port it breaks the NX Server service since it expects the SSH service to be running on the default port of 22. You can fix NX Server by modyfing the following file:

/usr/NX/etc/server.cfg

Set the following settings in the file:

SSHDPort = "22"

SSHDAuthPort = "22"

Change “22″ to whatever port your SSH service is now listening on. You’ll then need to restart the NX Server service to put the changes into effect:

/etc/init.d/nxserver restart

NOTE: The instructions above were tested on a Linux Red Hat 5 server.