---

<a name="tlsv13_only"></a>
#### ¹ TLSv1.3 Only

Cipher suites that are only available with TLSv1.3.

<a name="http2_naughty"></a>
#### ² HTTP/2 Cipher Suite Denylist

Cipher suites that are [discouraged for use][http2_denylist] with HTTP/2. OkHttp includes them because better suites are not commonly available. For example, none of the better cipher suites listed above shipped with Android 4.4 or Java 7.

public class CachedCipherTest {

    @Test
    public void testEncryptDecryptBytes() {
        final CachedCipher cipher = new CachedCipher();
        cipher.setKey("mySecretKey");

        final byte[] original = "Hello World".getBytes();
        final byte[] encrypted = cipher.encrypt(original);
        final byte[] decrypted = cipher.decrypt(encrypted);

        assertThat(encrypted, is(not(original)));

        return new HMACT64(key);
    }

    /**
     * Get an RC4 cipher instance initialized with the specified key.
     * @param key the encryption key
     * @return RC4 cipher in encryption mode
     */
    public static Cipher getArcfour(final byte[] key) {
        try {
            final Cipher c = Cipher.getInstance("RC4");
            c.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(key, "RC4"));
            return c;

	testCases := []struct {
		content       string
		expectedErr   bool
		expectedValue string
	}{
		{
			"value\n",
			false,
			"value",
		},
		{
			" \t\n Hello, Gophers \n\t\r\n",
			false,
			"Hello, Gophers",
		},
	}

	for _, testCase := range testCases {
		t.Run("", func(t *testing.T) {
			tmpfile, err := os.CreateTemp(t.TempDir(), "testfile")
			if err != nil {
				t.Error(err)
			}

        IvParameterSpec ivSpec = new IvParameterSpec(iv);

        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivSpec);
        byte[] encrypted = cipher.doFinal(plaintext);

        cipher.init(Cipher.DECRYPT_MODE, keySpec, ivSpec);
        byte[] decrypted = cipher.doFinal(encrypted);

        // Then
        assertNotNull(encrypted);

        byte[] keybytes = key.getEncoded();
        Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
        cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(keybytes, "AES"), new IvParameterSpec(ZERO_IV, 0, ZERO_IV.length));
        if (constant.length != cipher.getBlockSize()) {
            constant = expandNFold(constant, cipher.getBlockSize());
        }
        byte[] enc = constant;

        SMBUtil.writeInt2(this.ciphers != null ? this.ciphers.length : 0, dst, dstIndex);
        dstIndex += 2;

        if (this.ciphers != null) {
            for (final int cipher : this.ciphers) {
                SMBUtil.writeInt2(cipher, dst, dstIndex);
                dstIndex += 2;
            }
        }
        return dstIndex - start;
    }

    /**
     * {@inheritDoc}
     *

        SecretKeySpec dataKey = new SecretKeySpec(dataHmac, KerberosConstants.RC4_ALGORITHM);

        cipher = Cipher.getInstance(KerberosConstants.RC4_ALGORITHM);
        cipher.init(Cipher.DECRYPT_MODE, dataKey);

        int plainDataLength = data.length - KerberosConstants.CHECKSUM_SIZE;
        byte[] plainData = cipher.doFinal(data, KerberosConstants.CHECKSUM_SIZE, plainDataLength);

            secureRandom.nextBytes(iv);

            // Setup cipher
            Cipher cipher = Cipher.getInstance(ENCRYPTION_ALGORITHM);
            GCMParameterSpec gcmSpec = new GCMParameterSpec(GCM_TAG_SIZE, iv);
            cipher.init(Cipher.ENCRYPT_MODE, masterKey, gcmSpec);

            // Encrypt
            byte[] ciphertext = cipher.doFinal(plaintextBytes);

            // Combine IV and ciphertext

   * order for a socket to be compatible the enabled cipher suites and protocols must intersect.
   *
   * For cipher suites, at least one of the [required cipher suites][cipherSuites] must match the
   * socket's enabled cipher suites. If there are no required cipher suites the socket must have at
   * least one cipher suite enabled.
   *