Hello, I'm wanting some help writing a command-line program to encrypt/decrpyt a file or string using a 2048bit key loaded via file (from OpenSSL or whichever). I believe the Bouncy Castle Provider/API is the best to use since there are no limits on strong cryptography and it has been implemented in many books. I have a few e-books on overall Java Crpytography but I've yet to see a program such as what I'm wanting to make. I understand I'll have to import a keyfile, read the file, run it through the algorythim, overwrite the file contents with the cyphertext.

What I'm needing help with:
  • parameter passing throught the command line
  • importing a key/making a RSA 2048bit key
  • passing file contents to the RSA logic
  • getting the cyphertext in a maner it can be written to a file

An example of the program I'm wanting to make can be found on this youtube video I found [ YouTube - My Encryption Program - Text ] (sorry there's music,not my video)

I'm in a Java class but it's still at the basic level and I'm wanting to make something a little more advanced that I can't do on my own. I'm sure a lot of people will ignore this thread thinking "dumb high-school wanna-be programmer" but I've been researching this a lot and haven't found much useful information byond code snipplets from "Beginning Cryptography with Java by David Hook"

I'd appriciate any help you guys can provide :)