Make private fields final

src/main/java/com/hierynomus/sshj/transport/IdentificationStringParser.java

@@ -28,7 +28,7 @@ public class IdentificationStringParser {
     private final Logger log;
     private final Buffer.PlainBuffer buffer;
 
-    private byte[] EXPECTED_START_BYTES = new byte[] {'S', 'S', 'H', '-'};
+    private final byte[] EXPECTED_START_BYTES = new byte[] {'S', 'S', 'H', '-'};
 
     public IdentificationStringParser(Buffer.PlainBuffer buffer) {
 	this(buffer, LoggerFactory.DEFAULT);

src/main/java/com/hierynomus/sshj/transport/cipher/BlockCiphers.java

@@ -121,11 +121,11 @@ public static Factory TripleDESCBC() {
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<Cipher> {
 
-        private int keysize;
-        private String cipher;
-        private String mode;
-        private String name;
-        private int ivsize;
+        private final int keysize;
+        private final String cipher;
+        private final String mode;
+        private final String name;
+        private final int ivsize;
 
         /**
          * @param ivsize

src/main/java/com/hierynomus/sshj/transport/cipher/GcmCiphers.java

@@ -33,12 +33,12 @@ public static Factory AES256GCM() {
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<Cipher> {
 
-        private int keysize;
-        private int authSize;
-        private String cipher;
-        private String mode;
-        private String name;
-        private int ivsize;
+        private final int keysize;
+        private final int authSize;
+        private final String cipher;
+        private final String mode;
+        private final String name;
+        private final int ivsize;
 
         /**
          * @param ivsize

src/main/java/com/hierynomus/sshj/transport/cipher/StreamCiphers.java

@@ -40,10 +40,10 @@ public static Factory Arcfour256() {
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<Cipher> {
 
-        private int keysize;
-        private String cipher;
-        private String mode;
-        private String name;
+        private final int keysize;
+        private final String cipher;
+        private final String mode;
+        private final String name;
 
         /**
          * @param keysize The keysize used in bits.

src/main/java/com/hierynomus/sshj/transport/kex/DHG.java

@@ -28,8 +28,8 @@
  *
  */
 public class DHG extends AbstractDHG {
-    private BigInteger group;
-    private BigInteger generator;
+    private final BigInteger group;
+    private final BigInteger generator;
 
     public DHG(BigInteger group, BigInteger generator, Digest digest) {
         super(new DH(), digest);

src/main/java/com/hierynomus/sshj/transport/kex/DHGroups.java

@@ -68,10 +68,10 @@ public static DHGroups.Factory Group18SHA512() {
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<KeyExchange> {
 
-        private String name;
-        private BigInteger group;
-        private BigInteger generator;
-        private Factory.Named<Digest> digestFactory;
+        private final String name;
+        private final BigInteger group;
+        private final BigInteger generator;
+        private final Factory.Named<Digest> digestFactory;
 
         public Factory(String name, BigInteger group, BigInteger generator, Named<Digest> digestFactory) {
             this.name = name;

src/main/java/com/hierynomus/sshj/transport/mac/Macs.java

@@ -71,10 +71,10 @@ public static Factory HMACSHA2512Etm() {
 
     public static class Factory implements net.schmizz.sshj.common.Factory.Named<MAC> {
 
-        private String name;
-        private String algorithm;
-        private int bSize;
-        private int defBSize;
+        private final String name;
+        private final String algorithm;
+        private final int bSize;
+        private final int defBSize;
         private final boolean etm;
 
         public Factory(String name, String algorithm, int bSize, int defBSize, boolean etm) {

src/main/java/com/hierynomus/sshj/transport/verification/KnownHostMatchers.java

@@ -57,7 +57,7 @@ public interface HostMatcher {
     }
 
     private static class EquiHostMatcher implements HostMatcher {
-        private String host;
+        private final String host;
 
         public EquiHostMatcher(String host) {
             this.host = host;

src/main/java/net/schmizz/sshj/connection/channel/ChannelOutputStream.java

@@ -37,7 +37,7 @@ public final class ChannelOutputStream extends OutputStream implements ErrorNoti
     private final DataBuffer buffer = new DataBuffer();
     private final byte[] b = new byte[1];
 
-    private AtomicBoolean closed;
+    private final AtomicBoolean closed;
     private SSHException error;
 
     private final class DataBuffer {

src/main/java/net/schmizz/sshj/signature/SignatureECDSA.java

@@ -77,7 +77,7 @@ public String getName() {
 
     }
 
-    private String keyTypeName;
+    private final String keyTypeName;
 
     public SignatureECDSA(String algorithm, String keyTypeName) {
         super(algorithm, keyTypeName);

src/main/java/net/schmizz/sshj/signature/SignatureRSA.java

@@ -87,7 +87,7 @@ public String getName() {
 
     }
 
-    private KeyType keyType;
+    private final KeyType keyType;
 
 
     public SignatureRSA(String algorithm, KeyType keyType, String name) {

src/main/java/net/schmizz/sshj/transport/kex/ECDHNistP.java

@@ -25,7 +25,7 @@
 
 public class ECDHNistP extends AbstractDHG {
 
-    private String curve;
+    private final String curve;
 
     /** Named factory for ECDHNistP key exchange */
     public static class Factory521

src/main/java/net/schmizz/sshj/transport/verification/OpenSSHKnownHosts.java

@@ -475,7 +475,7 @@ public String getComment() {
     }
 
     public static class BadHostEntry implements KnownHostEntry {
-        private String line;
+        private final String line;
 
         public BadHostEntry(String line) {
             this.line = line;

src/main/java/net/schmizz/sshj/userauth/keyprovider/PuTTYKeyFile.java

@@ -101,7 +101,7 @@ public boolean isEncrypted() throws IOException {
         throw new IOException(String.format("Unsupported encryption: %s", encryption));
     }
 
-    private Map<String, String> payload = new HashMap<String, String>();
+    private final Map<String, String> payload = new HashMap<String, String>();
 
     /**
      * For each line that looks like "Xyz: vvv", it will be stored in this map.

src/main/java/net/schmizz/sshj/xfer/scp/ScpCommandLine.java

@@ -71,7 +71,7 @@ String escapedPath(String path) {
         }
     }
 
-    private LinkedHashMap<Arg, String> arguments = new LinkedHashMap<Arg, String>();
+    private final LinkedHashMap<Arg, String> arguments = new LinkedHashMap<Arg, String>();
     private String path;
 
     ScpCommandLine() {