Function eax_init 

pub unsafe extern "C" fn eax_init(
    eax: *mut eax_state,
    cipher: c_int,
    key: *const c_uchar,
    keylen: c_ulong,
    nonce: *const c_uchar,
    noncelen: c_ulong,
    header: *const c_uchar,
    headerlen: c_ulong,
) -> c_int