This repo holds a c rewrite of a cipher program that I wrote in high school. My original code was not easy to follow or understandable for that matter. I also am using this to learn more about how the command line is parsed in C, as well as how to write to files.
Please don't use this for anything important. All it does is encrypt said string with a vigerene cipher using a given keyword, and optinally can reverse the word.
I'd like to make it use the message for encryption too.
Currently there are some bugs when trying to decrypt encrypted messages; I get the wrong result it seems.
NOTE One limitation of the program in it's current state is that it can only encrypt messages that consist of solely capital letters. There is no support for lowercase letters or any other character on the keyboard.
- update the command line parsing to handle spaces
- support reading in a message from standard in
- make
- c89 compiler
To build, run make
If you want to encrypt a message with a specfic key, run:
./ciph -kKEY -mYOURMESSAGE -e
If you want to decrypt a message that uses a specific key, run:
./ciph -kKEY -mENCMESSAGE -d
Optionally, you can include the -oOUTFILE to save the result into a file
because by default, it is printed to stdout.
NOTE: Right now decryption is in a half working state. Some keys it will work while others don't. This is an issue I am working to solve.
Decryption is now working.
If you want to reverse the message as well, you can add the -r flag, and it will
reverse the input string.