mpags-cipher

A simple command line tool for encrypting/decrypting text using classical ciphers

Building mpags-cipher

Compilation of mpags-cipher requires the CMake build tool, plus a C++11 compatible compiler (GCC 4.8 or better, Clang 3.4 or better are recommended) and make on a UNIX operating system. Windows platforms with Visual Studio 2015 or better are also expected to work, but not tested.

To build from a clone of this repository, open a terminal window and change directory into that holding this README. Create a build directory in which to run cmake and the build, and change into it:

$ ls
CMakeLists.txt   LICENSE          MPAGSCipher      README.md        mpags-cipher.cpp
$ mkdir ../Build
$ cd ../Build

Run cmake in this directory, pointing it to the directory holding this README, and consequently the top level CMake script for the project:

$ cmake ../<this dir>
... system specific output ...
-- Configuring done
-- Generating done
-- Build files have been written to: ... your build dir path ...
$

The exact output will depend on your system, compiler and build directory location, but you should not see any errors. CMake will generate Makefiles by default on UNIX platforms, so to build, simply run make in the build directory:

$ ls
CMakeCache.txt      CMakeFiles          Makefile            cmake_install.cmake
$ make
... verbose output ...
[100%] Built target mpags-cipher
...
$

Again, the exact output will be system specific, but you should see the mpags-cipher target built without error. The resulting mpags-cipher executable can then be run directly, and provides the following command line options:

$ ./mpags-cipher --help
Usage: mpags-cipher [-i <file>] [-o <file>] [-k <key>] [--encrypt/--decrypt]

Encrypts/Decrypts input alphanumeric text using classical ciphers

Available options:

  -h|--help        Print this help message and exit

  --version        Print version information

  -i FILE          Read text to be processed from FILE
                   Stdin will be used if not supplied

  -o FILE          Write processed text to FILE
                   Stdout will be used if not supplied

  -k KEY           Specify the cipher KEY
                   A null key, i.e. no encryption, is used if not supplied

  --encrypt        Will use the cipher to encrypt the input text (default behaviour)

  --decrypt        Will use the cipher to decrypt the input text

If no input file is supplied, mpags-cipher will wait for user input from the keyboard until RETURN followed by CTRL-D are pressed. It will then echo the input to stdout or write it to the file supplied with the -o option.

To ensure the input text can be used with the character sets known to classical ciphers, it is transliterated using the following rules:

• Alphabetical characters are converted to uppercase
• Digits are translated to their English equivalent words (e.g. '0' -> "ZERO")
• All other characters (punctuation) are discarded

At present only the Caesar Cipher is supported.

Source Code Layout

Under this directory, the code and associated files are organised as follows:

MPAGS-Code
├── README.md             This file, describes the project
├── LICENSE               License file, in our case MIT
├── CMakeLists.txt        CMake build script
├── mpags-cipher.cpp      Main program C++ source file
├── MPAGSCipher           Subdirectory for MPAGSCipher library code
|   └── ProcessCommandLine.cpp
|   └── ProcessCommandLine.hpp
|   └── RunCaesarCipher.cpp
|   └── RunCaesarCipher.hpp
|   └── TransformChar.cpp
|   └── TransformChar.hpp

Copying

mpags-cipher is licensed under the terms of the MIT License. Please see the file LICENSE for full details.