pub unsafe extern "C" fn rsa_pkcs1_encrypt(
    ctx: *mut rsa_context,
    f_rng: Option<unsafe extern "C" fn(arg1: *mut c_void, arg2: *mut c_uchar, arg3: size_t) -> c_int>,
    p_rng: *mut c_void,
    mode: c_int,
    ilen: size_t,
    input: *const c_uchar,
    output: *mut c_uchar
) -> c_int