presto-proxy/src/main/java/io/prestosql/proxy/ProxyResource.java/ProxyResource/loadSharedSecret
class ProxyResource:    private static byte[] loadSharedSecret(File file)
    {
        try {
            return Base64.getMimeDecoder().decode(readAllBytes(file.toPath()));
        }
        catch (IOException | IllegalArgumentException e) {
            throw new RuntimeException("Failed to load shared secret file: " + file, e);
        }
    }