pub unsafe extern "C" fn rsa_rsaes_pkcs1_v15_decrypt(
    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,
    olen: *mut size_t,
    input: *const c_uchar,
    output: *mut c_uchar,
    output_max_len: size_t
) -> c_int