cipher

Command line tool for simple encryption ciphers

Usage

The command interface is simple: you provide an encryption method, a passkey, and an option filename for input or output files.

If no filename for input is given, stdin is used. If no filename for output is given, stdout is used.

Run with -h for more details.

Example 1:

File: hello.txt

HELLOWORLD

Run the cipher program with a Vigenère cipher, take input from hello.txt and output to stdout:

cipher -m vigenere -k KEY hello.txt

Output:

RIJVSUYVJN

Example 2:

Use input from stdin to encrypt then decrypt the same text with Caesar:

echo "MYSUPERSECRETSTUFF" | cipher -m caesar -k B | cipher -m caesar -k Z

Output:

MYSUPERSECRETSTUFF

Supported ciphers are:

• Caesar cipher (and by extension ROT13)
• Vigenère cipher
• Rail fence cipher
• Scytale cipher

Building and Installing

Dependencies

The following programs/libraries are needed to build from source and run the unit tests:

• C++ compiler (such as g++)
• python
• make
• cmake
• googletest (aka gtest)

You can install the dependencies with the following command:

On Ubuntu:

sudo apt-get update
sudo apt-get install build-essential cmake libgtest-dev python

Building with Make

This project uses CMake to generate the build system. Included in the repository is a script to automate the CMake generation process (see build.sh)

To build the project:

# 1. Clone the repository:
git clone https://github.com/padinadrian/cipher.git

# 2. Run the generation script:
cd cipher
chmod +x build.sh
./build.sh

#3. Run make to build all:
cd build
make

#4. To install at /usr/local/bin/cipher (optional):
sudo make install

This will place both the cipher program and the unit tests in the bin folder at bin/cipher and bin/cipher_tests respectively. By running the make install command you can also install cipher to your application path so that it can be used from the command line from anywhere.

Running unit tests

The unit tests for cipher use gtest, which needs to be installed separately (see Dependencies above).

You can run the tests directly from the build folder:

bin/cipher_tests

Or, you can also use this convenience script which automatically rebuilds the tests before running:

./run_tests.sh

Future work

Future features:

• Installation instructions
• Support for direct decryption
• Read key from file

Future ciphers

• Rail fence
• Caesar
• Vigenere
• Scytale
• Columnar

Future bugfixes

• Change -p option to -k, and change PASSWORD to CIPHERKEY