N2100 How To Extract Or Recreate Thecus Firmware

Thecus supply encrypted firmware updates for their devices. It may be useful or necessary for you to extract this to investigate or manipulate its contents. To do this you will need to have openssl installed on a Linux machine. Currently you can obtain firmware for the N1200 from the following locations:


 * The Thecus beta downloads area
 * Official Thecus downloads area

Thecus have encoded the updates using openssl with the DES algorithm using 7A9816A4C275D557 as the password.

Decrypt Firmware
After downloading n2100upgrade.2.1.03.1.bin for example, run the following command:

openssl enc -d -des -in n2100upgrade.2.1.03.1.bin -out n2100upgrade.2.1.03.1.tar.gz -K 7A9816A4C275D557 -iv 0 -nosalt -nopad

This will leave the n2100upgrade.2.1.03.1.tar.gz file in your current directory which you can extract with:

tar -xzf n2100upgrade.2.1.03.1.tar.gz

Re-Encrypt Firmware
If you have assembled a custom update into the file MY_UPDATE.tar.gz run the following command to encrypt it:

openssl enc -e -des -out n2100upgrade.2.1.03.1.bin -in MY_UPDATE.tar.gz -K 7A9816A4C275D557 -iv 0 -nosalt

You will now have your modified update in the n2100upgrade.2.1.03.1.bin file in your current directory.