Zip Encrypt Ftp Backups

Didier Stevens did it again with a pretty useful tool that could be used for backups that should be placed on another server on the internet. This is great if you want to separate site or operating system backups from the running server to avoid that both are not recoverable after a crash.

ZIPEncryptFTP is a C# command-line program, you will need the .NET 2.0 framework runtime to run it. It will write to the Application eventlog, so you need to run it the first time with administrator privileges, to register ZIPEncryptFTP with the eventlog.

To use the program you will have to use the command line. If you wanted for instance to backup the contents of the directory c:\temp, use the password:test to encrypt the folder(s) with AES and upload it to the ftp 192.168.1.100 with the username test and the password pass you would do the following:

ZIPEncryptFTP /directory:c:\test /password:test /url:ftp://192.168.1.100 /ftpuser:test /ftppassword:pass

You can add more than one directory by simply adding another /directory parameter to ZipEncryptFtp.

You can use ZipEncryptFtp to encrypt the data again but it needs to be retrieved with a ftp program before. To decode the file you need to use the following command:

ZIPEncryptFTP /password:test /infile:test /outfile:test.zip

Everything is done in memory, no temporary (ZIP) files are created. The ZIP file is created and encrypted in memory.

The password is converted to a 256 bit key, and the initialization vector is generated at random. The effect of this is that encrypting the same file twice will yield 2 completely different encrypted files.