The recommended and legal way to get aes_keys.txt is by dumping the keys from your own 3DS console. This process typically involves using homebrew software designed for the 3DS.
The Nintendo 3DS uses to protect its software from piracy and unauthorized use. Every game (ROM) you dump from your console is typically encrypted. Citra Aes Keys.txt Download
This can happen if the keys inside your text file are outdated, corrupted, or formatted incorrectly. The recommended and legal way to get aes_keys
The only method endorsed by the original Citra developers for obtaining AES keys is to dump them directly from your own, Nintendo 3DS console. This ensures you are legally using your own console's unique keys. Every game (ROM) you dump from your console
These are game files that have already had their encryption stripped away using a hacked 3DS console. Decrypted files do not require Citra to have an external aes_keys.txt file. The Legality of Downloading aes_keys.txt
Downloading these files from unverified online sources carries significant risks: