}

    /**
     * Default provider is BouncyCastleProvider.
     * For registering custom provider
     * @see jcifs.util.Crypto#initProvider(Provider)
     * @return Provider
     */
    public static Provider getProvider() {
        if (provider != null) {
            return provider;
        }
        provider = new BouncyCastleProvider();
        return provider;
    }

    /**

import okhttp3.internal.platform.PlatformRegistry
import okhttp3.tls.HandshakeCertificates
import okhttp3.tls.HeldCertificate
import okhttp3.tls.internal.TlsUtil.localhost
import org.bouncycastle.jce.provider.BouncyCastleProvider
import org.bouncycastle.jsse.provider.BouncyCastleJsseProvider
import org.conscrypt.Conscrypt
import org.hamcrest.BaseMatcher
import org.hamcrest.CoreMatchers.anything
import org.hamcrest.Description

    @BeforeAll
    static void setupClass() {
        // Ensure BouncyCastle provider is available for AES-CMAC
        if (Security.getProvider(BouncyCastleProvider.PROVIDER_NAME) == null) {
            Security.addProvider(new BouncyCastleProvider());
        }
    }

    @BeforeEach
    void setup() {
        sessionKey = new byte[16];
        Arrays.fill(sessionKey, (byte) 0xAA);

import okhttp3.tls.HandshakeCertificates
import okhttp3.tls.internal.TlsUtil.localhost
import okhttp3.zstd.Zstd
import okio.ByteString.Companion.toByteString
import org.bouncycastle.jce.provider.BouncyCastleProvider
import org.bouncycastle.jsse.provider.BouncyCastleJsseProvider
import org.conscrypt.Conscrypt
import org.junit.jupiter.api.Assertions.assertEquals
import org.junit.jupiter.api.Assertions.assertFalse