Ok. I remembered what the cbc layer was called, but forgot what the other was called.What are you encrypting again?
A file from the CDN? CDN encryption is just AES-128-CBC with the IV being the content ID in the TMD and the key being the decrypted titlekey padded with 0.
An NCCH itself? AES-128-CTR, IVs and keys vary between individual sections (RomFS, ExeFS in its entirety, ExeFS:/.code, exheader).