I am new to Linux. I want to customize/write a device driver for USB storage device that can manipulate on the data before writing it to the USB device. Can someone help me by providing samples or pointers to the USB source code which I can modify to my requirement.

Also please guide me through how to install the driver and get it running. Thanks in advance!!

The source code is available online, from many different places, all easily found through Google (like http://www.kernel.org/ and http://www.linux.org/).

Since you're already a developer, you already know how to write code, compile it, and make a working module. To load it, just type "modprobe <your module name>".

Thanks for the reply. I am actually new to linux. I want to know if if it is possible to write a driver in C++ or is there already a USB storage device driver written in C++ which I can refer to. I tried searching in google but couldn't find anything relevant.

Yes, and I gave you two links to the source code. There is tons of source code available with an easy Google search, and you can probably find source code for your particular distro on the installation media/repositories already.

USB storage has been supported already for years.

I did some googling and found few source code for USB driver. My requirement is to enrypt/decrypt the data that is written to the USB driver. I have the code for this. I thought of plugging this in the USB driver. I read that the USB driver runs in the kernel mode. Is it possible to do the encryption/decryption from the driver code?

PS: I dont prefer to write a wrapper for the driver and use a special application to write data to the disk. I could use the legacy way of writing to the disk with encryption achieved at the device driver level.