Function aes_ctr_apply 

pub fn aes_ctr_apply(
    sek: &[u8],
    salt: &[u8; 16],
    pkt_seq_no: u32,
    data: &mut [u8],
) -> Result<()>

Available on crate feature crypto only.

AES-CTR encrypt/decrypt one data packet’s payload in place (draft-sharabayko-srt-01 §6.2.2/§6.3.2). CTR mode is its own inverse — EncryptedPayload = AES_CTR_Encrypt(SEK, IV, UnencryptedPayload) and DecryptedPayload = AES_CTR_Encrypt(SEK, IV, EncryptedPayload) are the same operation (XOR with the same keystream), so this one function serves both directions.

sek selects AES-128/192/256 by its length (16/24/32 bytes); salt and pkt_seq_no feed packet_counter. No padding is applied or expected — CTR is a stream cipher (§6.1.1).

Errors

Error::InvalidField if sek.len() is not 16, 24, or 32.