Struct KeyBlock 

pub struct KeyBlock<'a> {
    pub key_type: u8,
    pub encrypted_key: &'a [u8],
    pub kcv: [u8; 3],
    pub clear_key_len: u8,
}

One encrypted key block plus its KCV (built from backend output). The encrypted key already borrows (&[u8]) — no alloc here.

Fields

key_type: u8

encrypted_key: &'a [u8]

kcv: [u8; 3]

clear_key_len: u8

Plaintext key length in bytes (16/24/32 for AES). Emitted as the AES clear-key-length byte (Amendment D §7.2); ignored for 3DES blocks. This differs from encrypted_key.len() for AES-192 (24-byte key, 32-byte ciphertext).