Function Hacl_Chacha20Poly1305_256_aead_decrypt 

pub unsafe extern "C" fn Hacl_Chacha20Poly1305_256_aead_decrypt(
    k: *mut u8,
    n: *mut u8,
    aadlen: u32,
    aad: *mut u8,
    mlen: u32,
    m: *mut u8,
    cipher: *mut u8,
    mac: *mut u8,
) -> u32