If you just want a for a tool that uses keys.txt in Citra style, here’s a clean feature outline :
Without these keys, Citra cannot interpret the encrypted headers or game content, leading to load errors. The keys inside aes_keys.txt act as a bridge, allowing the software to perform the same cryptographic functions as the original 3DS hardware. citra aes keystxt top
Citra can only run "decrypted" ROMs (which are rare today). Most standard ROMs are encrypted and will fail to boot. If you just want a for a tool that uses keys
Citra looks for this file in specific folders depending on your operating system. citra aes keystxt top