Write a Feistal structure in C++

Program should read the number of rounds and key from command line. Convert all input to upper case and remove non-text characters and spaces. If the length of plaintext is not an even number, pad the text with binary zeros. Use a 32-bit block size Use the CBC mode for messages larger than the cipher block size.

Basic algorithm is: The input to each round is split into two blocks of bits. The round function for this round is applied to the right half. The result from the round function is XORed with the left half. The left and right half of the input is swapped and then the right half is replaced with the result of the previous step.