Add encode command to user space

[alach2]

Description:
Implement an encode command that takes in a file to encrypt in the sha256 scheme. I would need to build out the sha256 library in order to use it in my encode command.

Proposed Changes:
Update user space with an encode process that uses the sha256 library that I also added into the user space. I will create functionality that reads in a file and updates each character with the proper sha256 conversion. I will update the Makefile to add the encode feature. When ran, the user will call encode [filename] and that file will now be encoded with the cryptic hash function.

Future Development:
I would add the counterpart decode command to undo the encoded files. I could also add different styles of encoding, like -s for sha256, -h for hex, -b for base64, etc. This would allow the user to have more options, creativity, and control with encoding files.

[malensek]

This sounds good. You can use a public domain implementation of the sha256 algorithm, so the extra features are a nice touch to make this a bit more of a challenge.

IIRC there was a sha1 implementation last semester that had some pretty big limitations, so you may want to look at that and could possibly use your encoding styles as a separate library that both utilities could use.

[geoweb999]

I'll be happy to do one of the student code reviews