ElGamal: Deprecate GENERAL

pgpainless-core/src/main/java/org/pgpainless/algorithm/PublicKeyAlgorithm.java

@@ -34,6 +34,11 @@ public enum PublicKeyAlgorithm {
     EC              (PublicKeyAlgorithmTags.EC),
     ECDH            (PublicKeyAlgorithmTags.ECDH),
     ECDSA           (PublicKeyAlgorithmTags.ECDSA),
+
+    /**
+     * @deprecated see https://tools.ietf.org/html/rfc4880#section-13.8
+     */
+    @Deprecated
     ELGAMAL_GENERAL (PublicKeyAlgorithmTags.ELGAMAL_GENERAL),
     DIFFIE_HELLMAN  (PublicKeyAlgorithmTags.DIFFIE_HELLMAN),
     EDDSA           (PublicKeyAlgorithmTags.EDDSA),

pgpainless-core/src/main/java/org/pgpainless/key/generation/type/elgamal/ElGamal_ENCRYPT.java

@@ -15,18 +15,37 @@
  */
 package org.pgpainless.key.generation.type.elgamal;
 
+import java.security.spec.AlgorithmParameterSpec;
 import javax.annotation.Nonnull;
 
+import org.bouncycastle.jce.spec.ElGamalParameterSpec;
 import org.pgpainless.algorithm.PublicKeyAlgorithm;
+import org.pgpainless.key.generation.type.KeyType;
 
-public class ElGamal_ENCRYPT extends ElGamal_GENERAL {
+public final class ElGamal_ENCRYPT implements KeyType {
 
-    ElGamal_ENCRYPT(@Nonnull ElGamalLength length) {
+    private final ElGamalLength length;
-        super(length);
+
+    private ElGamal_ENCRYPT(@Nonnull ElGamalLength length) {
+        this.length = length;
+    }
+
+    public static ElGamal_ENCRYPT withLength(ElGamalLength length) {
+        return new ElGamal_ENCRYPT(length);
+    }
+
+    @Override
+    public String getName() {
+        return "ElGamal";
     }
 
     @Override
     public PublicKeyAlgorithm getAlgorithm() {
         return PublicKeyAlgorithm.ELGAMAL_ENCRYPT;
     }
+
+    @Override
+    public AlgorithmParameterSpec getAlgorithmSpec() {
+        return new ElGamalParameterSpec(length.getP(), length.getG());
+    }
 }

pgpainless-core/src/main/java/org/pgpainless/key/generation/type/elgamal/ElGamal_GENERAL.java

@@ -22,6 +22,7 @@ import org.bouncycastle.jce.spec.ElGamalParameterSpec;
 import org.pgpainless.algorithm.PublicKeyAlgorithm;
 import org.pgpainless.key.generation.type.KeyType;
 
+@Deprecated
 public class ElGamal_GENERAL implements KeyType {
 
     private final ElGamalLength length;

pgpainless-core/src/test/java/org/pgpainless/encryption_signing/EncryptDecryptTest.java

@@ -68,6 +68,7 @@ public class EncryptDecryptTest {
             "Unfold the imagined happiness that both\n" +
             "Receive in either by this dear encounter.";
 
+    @SuppressWarnings("deprecation")
     @Test
     public void freshKeysRsaToElGamalTest()
             throws PGPException, NoSuchAlgorithmException, InvalidAlgorithmParameterException, IOException {