removed use of ElGamalPublicKey (reduce portability issues)

Author: dghgit

pg/src/main/java/org/bouncycastle/openpgp/operator/jcajce/JcaPGPKeyConverter.java

@@ -76,7 +76,6 @@
 import org.bouncycastle.jcajce.util.DefaultJcaJceHelper;
 import org.bouncycastle.jcajce.util.NamedJcaJceHelper;
 import org.bouncycastle.jcajce.util.ProviderJcaJceHelper;
-import org.bouncycastle.jce.interfaces.ElGamalPublicKey;
 import org.bouncycastle.math.ec.ECCurve;
 import org.bouncycastle.math.ec.ECPoint;
 import org.bouncycastle.math.ec.rfc7748.X25519;
@@ -560,8 +559,8 @@ private BCPGKey getPublicBCPGKey(int algorithm, PGPAlgorithmParameters algorithm
             case PublicKeyAlgorithmTags.ELGAMAL_ENCRYPT:
             case PublicKeyAlgorithmTags.ELGAMAL_GENERAL:
             {
-                ElGamalPublicKey egK = (ElGamalPublicKey) pubKey;
-                return new ElGamalPublicBCPGKey(egK.getParameters().getP(), egK.getParameters().getG(), egK.getY());
+                DHPublicKey egK = (DHPublicKey) pubKey;
+                return new ElGamalPublicBCPGKey(egK.getParams().getP(), egK.getParams().getG(), egK.getY());
             }
             case PublicKeyAlgorithmTags.DSA:
             {

prov/src/main/java/org/bouncycastle/jce/interfaces/ElGamalPublicKey.java

@@ -4,6 +4,9 @@
 
 import javax.crypto.interfaces.DHPublicKey;
 
+/**
+ * @deprecated just use DHPublicKey.
+ */
 public interface ElGamalPublicKey
     extends ElGamalKey, DHPublicKey
 {