diff --git a/src/java.base/share/classes/com/sun/crypto/provider/AESParameters.java b/src/java.base/share/classes/com/sun/crypto/provider/AESParameters.java
index 4c1c93ceb3c..becda6383b0 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/AESParameters.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/AESParameters.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -44,7 +44,7 @@ import java.security.spec.InvalidParameterSpecException;
  */
 public final class AESParameters extends AlgorithmParametersSpi {
 
-    private BlockCipherParamsCore core;
+    private final BlockCipherParamsCore core;
 
     public AESParameters() {
         core = new BlockCipherParamsCore(AESConstants.AES_BLOCK_SIZE, 4, 8);
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/BlockCipherParamsCore.java b/src/java.base/share/classes/com/sun/crypto/provider/BlockCipherParamsCore.java
index 738b34d3aeb..ece9f8161d1 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/BlockCipherParamsCore.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/BlockCipherParamsCore.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -46,10 +46,10 @@ import javax.crypto.spec.IvParameterSpec;
  *
  */
 final class BlockCipherParamsCore {
-    private int block_size = 0;
+    private final int block_size;
     private byte[] iv = null;
 
-    private int[] moreSizes = null;
+    private final int[] moreSizes;
 
     BlockCipherParamsCore(int blksize, int... moreSizes) {
         block_size = blksize;
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/BlowfishCipher.java b/src/java.base/share/classes/com/sun/crypto/provider/BlowfishCipher.java
index a389340b45a..247ea63f2e6 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/BlowfishCipher.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/BlowfishCipher.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -29,9 +29,7 @@ import java.security.*;
 import java.security.spec.*;
 import java.util.Arrays;
 
-import sun.security.util.*;
 import javax.crypto.*;
-import javax.crypto.spec.*;
 import javax.crypto.BadPaddingException;
 
 /**
@@ -57,7 +55,7 @@ public final class BlowfishCipher extends CipherSpi {
     /*
      * internal CipherCore object which does the real work.
      */
-    private CipherCore core = null;
+    private final CipherCore core;
 
     /**
      * Creates an instance of Blowfish cipher with default ECB mode and
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/BlowfishParameters.java b/src/java.base/share/classes/com/sun/crypto/provider/BlowfishParameters.java
index beb2804c3fd..85bf2e2ea27 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/BlowfishParameters.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/BlowfishParameters.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -44,7 +44,7 @@ import java.security.spec.InvalidParameterSpecException;
 
 public final class BlowfishParameters extends AlgorithmParametersSpi {
 
-    private BlockCipherParamsCore core;
+    private final BlockCipherParamsCore core;
 
     public BlowfishParameters() {
         core = new BlockCipherParamsCore
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/CipherBlockChaining.java b/src/java.base/share/classes/com/sun/crypto/provider/CipherBlockChaining.java
index 4fc5a34b46b..5d756e26847 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/CipherBlockChaining.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/CipherBlockChaining.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -27,7 +27,6 @@ package com.sun.crypto.provider;
 
 import java.security.InvalidKeyException;
 import java.security.ProviderException;
-import java.util.Objects;
 
 import jdk.internal.vm.annotation.IntrinsicCandidate;
 import sun.security.util.ArrayUtil;
@@ -55,7 +54,7 @@ class CipherBlockChaining extends FeedbackCipher  {
     /*
      * output buffer
      */
-    private byte[] k;
+    private final byte[] k;
 
     // variables for save/restore calls
     private byte[] rSave = null;
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/CipherCore.java b/src/java.base/share/classes/com/sun/crypto/provider/CipherCore.java
index 64ce01c53ab..2555448e3c0 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/CipherCore.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/CipherCore.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -57,12 +57,12 @@ final class CipherCore {
     /*
      * internal buffer
      */
-    private byte[] buffer = null;
+    private final byte[] buffer;
 
     /*
      * block size of cipher in bytes
      */
-    private int blockSize = 0;
+    private final int blockSize;
 
     /*
      * unit size (number of input bytes that can be processed at a time)
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/CipherFeedback.java b/src/java.base/share/classes/com/sun/crypto/provider/CipherFeedback.java
index 71e94cc7ffa..00b50b9e8ca 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/CipherFeedback.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/CipherFeedback.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -57,7 +57,7 @@ final class CipherFeedback extends FeedbackCipher {
      * number of bytes for each stream unit, defaults to the blocksize
      * of the embedded cipher
      */
-    private int numBytes;
+    private final int numBytes;
 
     // variables for save/restore calls
     private byte[] registerSave = null;
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/DESCipher.java b/src/java.base/share/classes/com/sun/crypto/provider/DESCipher.java
index 5fdfd32b2b5..ee283441eeb 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/DESCipher.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/DESCipher.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -29,7 +29,6 @@ import java.security.*;
 import java.security.spec.*;
 import java.util.Arrays;
 import javax.crypto.*;
-import javax.crypto.spec.*;
 import javax.crypto.BadPaddingException;
 
 /**
@@ -52,7 +51,7 @@ public final class DESCipher extends CipherSpi {
     /*
      * internal CipherCore object which does the real work.
      */
-    private CipherCore core = null;
+    private final CipherCore core;
 
     /**
      * Creates an instance of DES cipher with default ECB mode and
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/DESParameters.java b/src/java.base/share/classes/com/sun/crypto/provider/DESParameters.java
index a5ae615870b..c825e700a74 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/DESParameters.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/DESParameters.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -44,7 +44,7 @@ import java.security.spec.InvalidParameterSpecException;
 
 public final class DESParameters extends AlgorithmParametersSpi {
 
-    private BlockCipherParamsCore core;
+    private final BlockCipherParamsCore core;
 
     public DESParameters() {
         core = new BlockCipherParamsCore(DESConstants.DES_BLOCK_SIZE);
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/DESedeCipher.java b/src/java.base/share/classes/com/sun/crypto/provider/DESedeCipher.java
index a3599b608cc..3c1f122ae3b 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/DESedeCipher.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/DESedeCipher.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -29,7 +29,6 @@ import java.security.*;
 import java.security.spec.*;
 import java.util.Arrays;
 import javax.crypto.*;
-import javax.crypto.spec.*;
 
 /**
  * This class implements the DESede algorithm (DES-EDE, tripleDES) in
@@ -50,7 +49,7 @@ public sealed class DESedeCipher extends CipherSpi
     /*
      * internal CipherCore object which does the real work.
      */
-    private CipherCore core = null;
+    private final CipherCore core;
 
     /**
      * Creates an instance of DESede cipher with default ECB mode and
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/DESedeCrypt.java b/src/java.base/share/classes/com/sun/crypto/provider/DESedeCrypt.java
index b037c44d86d..496a59b002a 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/DESedeCrypt.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/DESedeCrypt.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2007, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -48,7 +48,8 @@ final class DESedeCrypt extends DESCrypt implements DESConstants {
     private byte[] key1 = null;
     private byte[] key2 = null;
     private byte[] key3 = null;
-    private byte[] buf1, buf2;
+    private final byte[] buf1;
+    private final byte[] buf2;
 
     /*
      * constructor
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/DESedeParameters.java b/src/java.base/share/classes/com/sun/crypto/provider/DESedeParameters.java
index d2bba89b799..879a4d30cd2 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/DESedeParameters.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/DESedeParameters.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -43,7 +43,7 @@ import java.security.spec.InvalidParameterSpecException;
  */
 public final class DESedeParameters extends AlgorithmParametersSpi {
 
-    private BlockCipherParamsCore core;
+    private final BlockCipherParamsCore core;
 
     public DESedeParameters() {
         core = new BlockCipherParamsCore(DESConstants.DES_BLOCK_SIZE);
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/DESedeWrapCipher.java b/src/java.base/share/classes/com/sun/crypto/provider/DESedeWrapCipher.java
index 8ba473e467e..92d25b57a7e 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/DESedeWrapCipher.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/DESedeWrapCipher.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2004, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2004, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -57,7 +57,7 @@ public final class DESedeWrapCipher extends CipherSpi {
     /*
      * internal cipher object which does the real work.
      */
-    private FeedbackCipher cipher;
+    private final FeedbackCipher cipher;
 
     /*
      * iv for (re-)initializing the internal cipher object.
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/DHPrivateKey.java b/src/java.base/share/classes/com/sun/crypto/provider/DHPrivateKey.java
index c08357b37bb..0d5363e866a 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/DHPrivateKey.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/DHPrivateKey.java
@@ -53,7 +53,7 @@ final class DHPrivateKey implements PrivateKey,
     private static final BigInteger PKCS8_VERSION = BigInteger.ZERO;
 
     // the private key
-    private BigInteger x;
+    private final BigInteger x;
 
     // the key bytes, without the algorithm information
     private byte[] key;
@@ -68,7 +68,7 @@ final class DHPrivateKey implements PrivateKey,
     private final BigInteger g;
 
     // the private-value length (optional)
-    private int l;
+    private final int l;
 
     /**
      * Make a DH private key out of a private value <code>x</code>, a prime
@@ -161,6 +161,8 @@ final class DHPrivateKey implements PrivateKey,
             // Private-value length is OPTIONAL
             if (params.data.available() != 0) {
                 this.l = params.data.getInteger();
+            } else {
+                this.l = 0;
             }
             if (params.data.available() != 0) {
                 throw new InvalidKeyException("Extra parameter data");
@@ -170,7 +172,9 @@ final class DHPrivateKey implements PrivateKey,
             // privateKey
             //
             this.key = val.data.getOctetString();
-            parseKeyBits();
+
+            DerInputStream in = new DerInputStream(this.key);
+            this.x = in.getBigInteger();
 
             this.encodedKey = encodedKey.clone();
         } catch (IOException | NumberFormatException e) {
@@ -271,16 +275,6 @@ final class DHPrivateKey implements PrivateKey,
         }
     }
 
-    private void parseKeyBits() throws InvalidKeyException {
-        try {
-            DerInputStream in = new DerInputStream(this.key);
-            this.x = in.getBigInteger();
-        } catch (IOException e) {
-            throw new InvalidKeyException(
-                "Error parsing key encoding: " + e.getMessage(), e);
-        }
-    }
-
     /**
      * Calculates a hash code value for the object.
      * Objects that are equal will also have the same hashcode.
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/DHPublicKey.java b/src/java.base/share/classes/com/sun/crypto/provider/DHPublicKey.java
index 7a0607f1227..47727c432a6 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/DHPublicKey.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/DHPublicKey.java
@@ -49,7 +49,7 @@ javax.crypto.interfaces.DHPublicKey, Serializable {
     private static final long serialVersionUID = 7647557958927458271L;
 
     // the public key
-    private BigInteger y;
+    private final BigInteger y;
 
     // the key bytes, without the algorithm information
     private byte[] key;
@@ -64,10 +64,10 @@ javax.crypto.interfaces.DHPublicKey, Serializable {
     private final BigInteger g;
 
     // the private-value length (optional)
-    private int l;
+    private final int l;
 
     // Note: this OID is used by DHPrivateKey as well.
-    static ObjectIdentifier DH_OID =
+    static final ObjectIdentifier DH_OID =
             ObjectIdentifier.of(KnownOIDs.DiffieHellman);
 
     /**
@@ -153,6 +153,8 @@ javax.crypto.interfaces.DHPublicKey, Serializable {
             // Private-value length is OPTIONAL
             if (params.data.available() != 0) {
                 this.l = params.data.getInteger();
+            } else {
+                this.l = 0;
             }
             if (params.data.available() != 0) {
                 throw new InvalidKeyException("Extra parameter data");
@@ -162,7 +164,10 @@ javax.crypto.interfaces.DHPublicKey, Serializable {
              * Parse the key
              */
             this.key = derKeyVal.data.getBitString();
-            parseKeyBits();
+
+            DerInputStream in = new DerInputStream(this.key);
+            this.y = in.getBigInteger();
+
             if (derKeyVal.data.available() != 0) {
                 throw new InvalidKeyException("Excess key data");
             }
@@ -263,16 +268,6 @@ javax.crypto.interfaces.DHPublicKey, Serializable {
         return sb.toString();
     }
 
-    private void parseKeyBits() throws InvalidKeyException {
-        try {
-            DerInputStream in = new DerInputStream(this.key);
-            this.y = in.getBigInteger();
-        } catch (IOException e) {
-            throw new InvalidKeyException(
-                "Error parsing key encoding: " + e.toString());
-        }
-    }
-
     /**
      * Calculates a hash code value for the object.
      * Objects that are equal will also have the same hashcode.
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/EncryptedPrivateKeyInfo.java b/src/java.base/share/classes/com/sun/crypto/provider/EncryptedPrivateKeyInfo.java
index cfeb66c62c6..698a5711356 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/EncryptedPrivateKeyInfo.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/EncryptedPrivateKeyInfo.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -44,10 +44,10 @@ import sun.security.util.*;
 final class EncryptedPrivateKeyInfo {
 
     // the "encryptionAlgorithm" field
-    private AlgorithmId algid;
+    private final AlgorithmId algid;
 
     // the "encryptedData" field
-    private byte[] encryptedData;
+    private final byte[] encryptedData;
 
     // the ASN.1 encoded contents of this class
     private byte[] encoded;
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/GHASH.java b/src/java.base/share/classes/com/sun/crypto/provider/GHASH.java
index 8a1a086e433..b7aaf6059d5 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/GHASH.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/GHASH.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -124,7 +124,7 @@ final class GHASH implements Cloneable, GCM {
 
     // hashtable subkeyHtbl holds 2*9 powers of subkeyH computed using
     // carry-less multiplication
-    private long[] subkeyHtbl;
+    private final long[] subkeyHtbl;
 
     // buffer for storing hash
     private final long[] state;
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/GaloisCounterMode.java b/src/java.base/share/classes/com/sun/crypto/provider/GaloisCounterMode.java
index 03b481af6c2..686fe384707 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/GaloisCounterMode.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/GaloisCounterMode.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -74,8 +74,8 @@ import jdk.internal.vm.annotation.IntrinsicCandidate;
  * @since 1.8
  */
 abstract class GaloisCounterMode extends CipherSpi {
-    static int DEFAULT_IV_LEN = 12; // in bytes
-    static int DEFAULT_TAG_LEN = 16; // in bytes
+    private static final int DEFAULT_IV_LEN = 12; // in bytes
+    private static final int DEFAULT_TAG_LEN = 16; // in bytes
     // In NIST SP 800-38D, GCM input size is limited to be no longer
     // than (2^36 - 32) bytes. Otherwise, the counter will wrap
     // around and lead to a leak of plaintext.
@@ -98,7 +98,7 @@ abstract class GaloisCounterMode extends CipherSpi {
 
     private boolean initialized = false;
 
-    SymmetricCipher blockCipher;
+    final SymmetricCipher blockCipher;
     // Engine instance for encryption or decryption
     private GCMEngine engine;
     private boolean encryption = true;
@@ -106,7 +106,7 @@ abstract class GaloisCounterMode extends CipherSpi {
     // Default value is 128bits, this is in bytes.
     int tagLenBytes = DEFAULT_TAG_LEN;
     // Key size if the value is passed, in bytes.
-    int keySize;
+    private final int keySize;
     // Prevent reuse of iv or key
     boolean reInit = false;
     byte[] lastKey = EMPTY_BUF;
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/ISO10126Padding.java b/src/java.base/share/classes/com/sun/crypto/provider/ISO10126Padding.java
index 19fb961681a..902d302cac4 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/ISO10126Padding.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/ISO10126Padding.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -38,7 +38,7 @@ import javax.crypto.ShortBufferException;
  */
 final class ISO10126Padding implements Padding {
 
-    private int blockSize;
+    private final int blockSize;
 
     ISO10126Padding(int blockSize) {
         this.blockSize = blockSize;
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/JceKeyStore.java b/src/java.base/share/classes/com/sun/crypto/provider/JceKeyStore.java
index ca6c0a56ea8..fcc450387af 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/JceKeyStore.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/JceKeyStore.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -99,7 +99,7 @@ public final class JceKeyStore extends KeyStoreSpi {
      * Private keys and certificates are stored in a hashtable.
      * Hash entries are keyed by alias names.
      */
-    private Hashtable<String, Object> entries = new Hashtable<String, Object>();
+    private final Hashtable<String, Object> entries = new Hashtable<>();
 
     /**
      * Returns the key associated with the given alias, using the given
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/KeyProtector.java b/src/java.base/share/classes/com/sun/crypto/provider/KeyProtector.java
index 44c7a1f6432..eadc032b36a 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/KeyProtector.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/KeyProtector.java
@@ -78,7 +78,7 @@ final class KeyProtector {
 
     // the password used for protecting/recovering keys passed through this
     // key protector
-    private char[] password;
+    private final char[] password;
 
     /**
      * {@systemProperty jdk.jceks.iterationCount} property indicating the
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/OAEPParameters.java b/src/java.base/share/classes/com/sun/crypto/provider/OAEPParameters.java
index fd609c9f74e..9d724728893 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/OAEPParameters.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/OAEPParameters.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -56,9 +56,9 @@ public final class OAEPParameters extends AlgorithmParametersSpi {
     private String mdName;
     private MGF1ParameterSpec mgfSpec;
     private byte[] p;
-    private static ObjectIdentifier OID_MGF1 =
+    private static final ObjectIdentifier OID_MGF1 =
             ObjectIdentifier.of(KnownOIDs.MGF1);
-    private static ObjectIdentifier OID_PSpecified =
+    private static final ObjectIdentifier OID_PSpecified =
             ObjectIdentifier.of(KnownOIDs.PSpecified);
 
     public OAEPParameters() {
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/OutputFeedback.java b/src/java.base/share/classes/com/sun/crypto/provider/OutputFeedback.java
index 7b518836cd1..aa56144f090 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/OutputFeedback.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/OutputFeedback.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -45,18 +45,18 @@ final class OutputFeedback extends FeedbackCipher {
     /*
      * output buffer
      */
-    private byte[] k = null;
+    private final byte[] k;
 
     /*
      * register buffer
      */
-    private byte[] register = null;
+    private final byte[] register;
 
     /*
      * number of bytes for each stream unit, defaults to the blocksize
      * of the embedded cipher
      */
-    private int numBytes;
+    private final int numBytes;
 
     // variables for save/restore calls
     private byte[] registerSave = null;
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/PBEKeyFactory.java b/src/java.base/share/classes/com/sun/crypto/provider/PBEKeyFactory.java
index d37f0e763ad..02451e536c6 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/PBEKeyFactory.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/PBEKeyFactory.java
@@ -46,7 +46,7 @@ import java.util.Set;
  */
 abstract class PBEKeyFactory extends SecretKeyFactorySpi {
 
-    private String type;
+    private final String type;
     private static final HashSet<String> validTypes;
 
     /**
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/PBES1Core.java b/src/java.base/share/classes/com/sun/crypto/provider/PBES1Core.java
index f8972b13343..68b1771d7d9 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/PBES1Core.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/PBES1Core.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -43,10 +43,9 @@ import javax.crypto.spec.*;
 final class PBES1Core {
 
     // the encapsulated DES cipher
-    private CipherCore cipher;
-    private MessageDigest md;
-    private int blkSize;
-    private String algo = null;
+    private final CipherCore cipher;
+    private final MessageDigest md;
+    private final String algo;
     private byte[] salt = null;
     private int iCount = 10;
 
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/PBES2Parameters.java b/src/java.base/share/classes/com/sun/crypto/provider/PBES2Parameters.java
index 1661acc434d..fb3dfa00148 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/PBES2Parameters.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/PBES2Parameters.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -92,15 +92,15 @@ import sun.security.util.*;
  */
 abstract class PBES2Parameters extends AlgorithmParametersSpi {
 
-    private static ObjectIdentifier pkcs5PBKDF2_OID =
+    private static final ObjectIdentifier pkcs5PBKDF2_OID =
             ObjectIdentifier.of(KnownOIDs.PBKDF2WithHmacSHA1);
-    private static ObjectIdentifier pkcs5PBES2_OID =
+    private static final ObjectIdentifier pkcs5PBES2_OID =
             ObjectIdentifier.of(KnownOIDs.PBES2);
-    private static ObjectIdentifier aes128CBC_OID =
+    private static final ObjectIdentifier aes128CBC_OID =
             ObjectIdentifier.of(KnownOIDs.AES_128$CBC$NoPadding);
-    private static ObjectIdentifier aes192CBC_OID =
+    private static final ObjectIdentifier aes192CBC_OID =
             ObjectIdentifier.of(KnownOIDs.AES_192$CBC$NoPadding);
-    private static ObjectIdentifier aes256CBC_OID =
+    private static final ObjectIdentifier aes256CBC_OID =
             ObjectIdentifier.of(KnownOIDs.AES_256$CBC$NoPadding);
 
     // the PBES2 algorithm name
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/PBEWithMD5AndDESCipher.java b/src/java.base/share/classes/com/sun/crypto/provider/PBEWithMD5AndDESCipher.java
index 5034434024d..a60656b3cd2 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/PBEWithMD5AndDESCipher.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/PBEWithMD5AndDESCipher.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -43,7 +43,7 @@ import javax.crypto.*;
 public final class PBEWithMD5AndDESCipher extends CipherSpi {
 
     // the encapsulated DES cipher
-    private PBES1Core core;
+    private final PBES1Core core;
 
     /**
      * Creates an instance of this cipher, and initializes its mode (CBC) and
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/PBEWithMD5AndTripleDESCipher.java b/src/java.base/share/classes/com/sun/crypto/provider/PBEWithMD5AndTripleDESCipher.java
index 16784afc897..41a1b3ca7fa 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/PBEWithMD5AndTripleDESCipher.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/PBEWithMD5AndTripleDESCipher.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -53,7 +53,7 @@ import javax.crypto.*;
  */
 public final class PBEWithMD5AndTripleDESCipher extends CipherSpi {
 
-    private PBES1Core core;
+    private final PBES1Core core;
 
     /**
      * Creates an instance of this cipher, and initializes its mode (CBC) and
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/PBKDF2KeyImpl.java b/src/java.base/share/classes/com/sun/crypto/provider/PBKDF2KeyImpl.java
index 8e85221f4bb..a02ce2d1551 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/PBKDF2KeyImpl.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/PBKDF2KeyImpl.java
@@ -63,7 +63,7 @@ final class PBKDF2KeyImpl implements javax.crypto.interfaces.PBEKey {
     private final char[] passwd;
     private final byte[] salt;
     private final int iterCount;
-    private byte[] key;
+    private final byte[] key;
 
     // The following fields are not Serializable. See writeReplace method.
     private final transient Mac prf;
@@ -93,6 +93,7 @@ final class PBKDF2KeyImpl implements javax.crypto.interfaces.PBEKey {
         // Convert the password from char[] to byte[]
         byte[] passwdBytes = getPasswordBytes(this.passwd);
 
+        byte[] key = null;
         try {
             this.salt = keySpec.getSalt();
             if (salt == null) {
@@ -111,7 +112,7 @@ final class PBKDF2KeyImpl implements javax.crypto.interfaces.PBEKey {
                 throw new InvalidKeySpecException("Key length is negative");
             }
             this.prf = Mac.getInstance(prfAlgo, SunJCE.getInstance());
-            this.key = deriveKey(prf, passwdBytes, salt, iterCount, keyLength);
+            key = deriveKey(prf, passwdBytes, salt, iterCount, keyLength);
         } catch (NoSuchAlgorithmException nsae) {
             // not gonna happen; re-throw just in case
             throw new InvalidKeySpecException(nsae);
@@ -122,7 +123,7 @@ final class PBKDF2KeyImpl implements javax.crypto.interfaces.PBEKey {
             }
         }
         // Use the cleaner to zero the key when no longer referenced
-        final byte[] k = this.key;
+        final byte[] k = this.key = key;
         final char[] p = this.passwd;
         cleaner = CleanerFactory.cleaner().register(this,
                 () -> {
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/PKCS5Padding.java b/src/java.base/share/classes/com/sun/crypto/provider/PKCS5Padding.java
index 191d7308eba..7b3850bd556 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/PKCS5Padding.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/PKCS5Padding.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -38,7 +38,7 @@ import java.util.Arrays;
  */
 final class PKCS5Padding implements Padding {
 
-    private int blockSize;
+    private final int blockSize;
 
     PKCS5Padding(int blockSize) {
         this.blockSize = blockSize;
diff --git a/src/java.base/share/classes/com/sun/crypto/provider/PrivateKeyInfo.java b/src/java.base/share/classes/com/sun/crypto/provider/PrivateKeyInfo.java
index 2ea5220ed2e..cf4d1a15dbd 100644
--- a/src/java.base/share/classes/com/sun/crypto/provider/PrivateKeyInfo.java
+++ b/src/java.base/share/classes/com/sun/crypto/provider/PrivateKeyInfo.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -53,10 +53,10 @@ final class PrivateKeyInfo {
     private static final BigInteger VERSION = BigInteger.ZERO;
 
     // the private-key algorithm
-    private AlgorithmId algid;
+    private final AlgorithmId algid;
 
     // the private-key value
-    private byte[] privkey;
+    private final byte[] privkey;
 
     /**
      * Constructs a PKCS#8 PrivateKeyInfo from its ASN.1 encoding.