Padded AES

For AES Encrypt/Decrypt, I would like to enter a key that is UTF-8 for instance and is shorter than the required key length and it is padded with 0s (NULLs)

There are tools that currently do this however CyberChef does not.
This could potentially be a checkbox on AES Decrypt/Encrypt.

Review the AES Encrypt/Decrypt operation entry points first, especially how key length and UTF-8 input are handled. The issue names no files or tests; locate the relevant implementation and coverage, then verify the proposed option for NULL-padding shorter keys during both encryption and decryption.

Written by the indexing model from the issue text.