In this assignment you'll write a program that encrypts the alphabetic letters in a file using the Vigenre cipher. Your program will take two command line parameters containing the names of the file storing the encryption key and the file to be encrypted. The program must generate output to the console (terminal) screen as specified below.

Command Line Parameters

1. Your program must compile and run from the command line.

2. Input the required file names as command line parameters. Your program may NOT prompt the user to enter the file names. The first parameter must be the name of the encryption key file, as described below. The second parameter must be the name of the file to be encrypted, as also described below. The sample run command near the end of this document contains an example of how the parameters will be entered.

3. Your program should open the two files, echo the processed input to the screen, make the necessary calculations, and then output the ciphertext to the console (terminal) screen in the format described below.

Note: If the plaintext file to be encrypted doesn't have the proper number (512) of alphabetic characters, pad the last block as necessary with the letter 'X'. Make sure that all the input characters are lower case only.

Encryption Key File Format The encryption key is plain text that may contain upper and lower case letters, numbers, and other text. The input must be stripped of all non-alphabetic characters. Please note that the input text must be converted to contiguous lower case letters to simplify the encryption process.

Format of the File to be Encrypted The file to be encrypted can be any valid text file with no more than 512 letters in it. (Thus, it's safe to store all characters in the file in a character array of size 512, including any padding characters.) Please note that the input text file will also generally have punctuation, numbers, special characters, and whitespace in it, which should be ignored. You should also ignore whether a letter is uppercase or lowercase in the input file. Thus, you should treat A and a the same in your program. In order to simply the encryption, all letters should be converted to lower case letters. In the event the plaintext input file is less than 512 characters, pad the input file with a lowercase x until the 512 character input buffer is full.

Output Format The program must output the following to the console (terminal) screen: 1. Echo the unmodified input key file 2. Echo the unmodified input plaintext file 3. Ciphertext output produced from running the cipher against the input plaintext file. The ciphertext output portion should consist of only lowercase letters in rows of exactly 80 letters per row, except for the last row, which may possibly have fewer. These characters should correspond to the ciphertext produced by encrypting all the letters in the input file. Please note that only the alphabetic letters in the input plaintext file will be encrypted. All other characters should be ignored.

Program Notes and Hints Your program must read in an input plaintext file that may contain uppercase letters, lowercase letters and non-letter characters. Your program must distinguish between these three groups so that only the letters get encrypted. All non-letter characters in the file are simply skipped and not counted as part of the plaintext. Please note that although both upper case and lower case letters will be encrypted, your program should convert an upper case input letter to the corresponding lower case letter, i.e., it should convert an A to an a.

1) Write a section of code or function that reads only the upper and lower case letters in the input file into an char array of size 512, storing only the appropriate lowercase letters in the character array. 2) Write a section of code or function that takes as input the array from section 1 and the encryption key and produces an array of ciphertext storing only lowercase letters. 3) Write a section of code or function that takes as input the array storing the ciphertext and outputs it to the screen in the format specified. Additional functions or code will be needed to echo the input key and plaintext files.

Sample Key File1 I think and think for months and years. Ninety-nine times, the conclusion is false. The hundredth time I am right. Albert Einstein Imagination is more important than knowledge. For knowledge is limited, whereas imagination embraces the entire world, stimulating progress, giving birth to evolution. Albert Einstein

Sample Plaintext File2 Fall in love with some activity, and do it! Nobody ever figures out what life is all about, and it doesn't matter. Explore the world. Nearly everything is really interesting if you go into it deeply enough. Work as hard and as much as you want to on the things you like to do the best. Don't think about what you want to be, but what you want to do. Keep up some kind of a minimum with other things so that society doesn't stop you from doing anything at all. - Richard Feynman

Corresponding Encrypted Output File ntstvxlbyxdqgrxcdqopmpnigbyrdugvbasumqgrzxzrmynyiuchvhbsbzvnwnsldptisbnnqumwwvxa zxuafkmxlqpwpvvmlmjgkplammrrgrvxzmgpazuzwzqpzcriamxyefdvbctjbuylczxgceehhkttqpva czlzkyorwhszpatlnsfcqueezfuyefmassampvxdwervqhcxcvemwquiyshvwlvuvobuoosruvnhacoe shcknneussxfcgoaeblwndiadtbghrmrzzdjaardpfdbiyqieazczabruwglxzflagnwucgjlnkwqvml ddzwwgawaicbfyikvflamvgmegzobnrbxrepzvuaezqnqytunnqflkfpjlobfjmloqxkqqexkhkltiba dbclohkltibadbfpifjfqbatebobxpfjxdfkxqflkbjyoxzbpqebbkqfobtloiapqfjrixqfkdmoldob ppdfsfkdyfoqeqlbslirqflkxiyboqbf

Sample Run Command C or C++ program:

prompt> ./a.out key1.txt plainText1.txt Java program: prompt> java vigenere key1.txt plainText1.txt 1 This is k2.txt in the homework 1 ZIP file. 2 This is p2.txt in the homework 1 ZIP file. Grading Rubric The total possible score for this program is 100 points. The following point values will be deducted for the reasons stated: [ -100 points ] Your program does not successfully compile from the command line with one of these commands: C program: prompt> gcc o vigenere vigenere.c C++ program: prompt> g++ o vigenere vigenere.cpp Java program: prompt> javac vigenere.java Note: If you are submitting a Java program, the class file must be named vigenere.java and the class name must be vigenere. [-100 point] The program does not accept input file names from the command line. [ -90 points ] Your program does not run from the command line without error or produces no output. [ -70 points ] The program compiles, runs, and outputs the key matrix and input file, but crashes thereafter or produces no encryption output. [ -50 points ] The program compiles, runs, echoes the inputs, and generates encryption output, but the encryption output is incorrect (ignoring case) and it is not formatted correctly (not all letters or not all lowercase or not 80 letters per line). [ -25 points ] The program compiles, runs, echoes the inputs, generates encryption output, and the encryption output is correct (ignoring case), but it is formatted incorrectly (not all letters or not all lowercase or not 80 letters per line). [ -25 points ] The program compiles, runs, echoes the inputs, and generates encryption output, but the encryption output is incorrect (ignoring case) although it is formatted correctly (all lowercase letters, 80 letters per line). [ no deductions ] The program compiles, runs, echoes the inputs, generates encryption output, the encryption output is correct (ignoring case), and it is formatted correctly (all lowercase letters, 80 letters per line). Sample inputs & outputs There are three commands and their resultant output shown below. They are: cat k1.txt cat p1.txt ./a.out k1.txt p1.txt These commands and their output are described below. A couple of things to note, this is the text output from a session on Eustis and the prompt begins with the login NID followed by the terminal ID and the current working directory. Each of the cases below are in the same working directory hw1 in the $HOME directory, indicated by the ~ character. NID@termID:~/hw1$ cat k1.txt (catalogs the first key file) bbbbbbbbb bbbbbbbbb bbbbbbbbb bbbbbbbbb bbbbbbbbb bbbbbbbbb bbbbbbbbb bbbbbbbbb NID@termID:~/hw1$ cat p1.txt (catalogs the first plaintext file) "If you find that you're spending almost all your time on theory, start turning some attention to practical things; it will improve your theories. If you find that you're spending almost all your time on practice, start turning some attention to theoretical things; it will improve your practice." - Donald Knuth NID@termID:~/hw1$ ./a.out k1.txt p1.txt (encrypts the key/plaintext files) Vigenere Key: bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb Plaintext: ifyoufindthatyourespendingalmostallyourtimeontheorystartturningsomeattentiontopr acticalthingsitwillimproveyourtheoriesifyoufindthatyourespendingalmostallyourtim eonpracticestartturningsomeattentiontotheoreticalthingsitwillimproveyourpractice donaldknuthxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Ciphertext: jgzpvgjoeuibuzpvsftqfoejohbmnptubmmzpvsujnfpouifpsztubsuuvsojohtpnfbuufoujpoupqs bdujdbmuijohtjuxjmmjnqspwfzpvsuifpsjftjgzpvgjoeuibuzpvsftqfoejohbmnptubmmzpvsujn fpoqsbdujdftubsuuvsojohtpnfbuufoujpoupuifpsfujdbmuijohtjuxjmmjnqspwfzpvsqsbdujdf epobmelovuiyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyNID@termID:~/cis3360/hw1/sum2018$ Each of the four key & plaintext files are included in the ZIP file for this assignment. ALSO note that the test file hw1Test.sh runs all four plaintext and key files thru your vigenere code. It can be invoked using the command ./hw1Test.sh vigenere.cpp. (The filenames extension should match the source code, that is .c fo C, .cpp for C++, and .java for Java.)