This is the directory for Homework Assignment 6, CPSC 467, Fall 2020.

The src directory contains working code for the SnakeOil cryptosystem.
It also contains partial code for a brute force key finder.  However,
two functions needed by analyze.cpp are missing, so it won't compile.

The data directory contains five kinds of files:

1) keyshares is a file of 100 key shares that was used for all of the
   encryptions.
2) The *.enc files are ciphertexts encrypted by SnakeOil using
   keyshares but with different key indices.
3) The *.dat files are byte frequency tables derived from various
   sources.  merrywifes.dat is from the Shakespeare play, "The Merry
   Wifes of Windsor".  ulysses.dat is from the James Joyce novel,
   "Ulysses".  uniform.dat is the uniform distribution.  space.dat has
   only a single sample at position 32, which is the ASCII code for
   space.
4) sample.txt is the plaintext that was encrypted to yield the
   ciphertext sample.enc.  It was encrypted using indices 4 and 31.
5) snakeoil is an executable command that performs SnakeOil encryptions
   and decryptions.  It can also generate a new keyshares file.  See the
   comments at the top of src/snakeoil.hpp for usage information.