[Question][Hw2] About CBC block size

[JaejunHan]

Name: Jaejun Han

I'm curious about block size of CBC in hw2.

In a template code (main.ml), a block has 2 bytes which is depicted in this comment.
(* 1 block = 2 bytes = 16 bits *)

However, assuming block size as 2 got a wrong answer when executing './aes enc test/key.txt test/iv.txt test/helloworld.txt' in a terminal.

After modifying my code to have block size as same as key or iv, this problem is solved for helloworld.txt. This is because in this case, iv and key block has 3 bytes including new line character, not 2 bytes.
Therefore, I'm curious whether the block size of CBC is determined by key's size(num of bytes for a key).
Also, if key size and iv size are differenct, what should be padded? The iv or the key?