Further edDSA clean-up

Remove unused things, and give the EdDSASecurityProviderRegistrar a
PublicKeyFactory.

Author: tomaswolf

sshd-common/src/main/java/org/apache/sshd/common/util/security/bouncycastle/BouncyCastlePublicKeyFactory.java

@@ -25,9 +25,11 @@
 import org.apache.sshd.common.util.security.SecurityUtils;
 import org.bouncycastle.jcajce.interfaces.EdDSAPrivateKey;
 
-public class BouncyCastlePublicKeyFactory implements PublicKeyFactory {
+public final class BouncyCastlePublicKeyFactory implements PublicKeyFactory {
 
-    public BouncyCastlePublicKeyFactory() {
+    public static final PublicKeyFactory INSTANCE = new BouncyCastlePublicKeyFactory();
+
+    private BouncyCastlePublicKeyFactory() {
         super();
     }
 

sshd-common/src/main/java/org/apache/sshd/common/util/security/bouncycastle/BouncyCastleSecurityProviderRegistrar.java

@@ -172,7 +172,7 @@ public boolean isSupported() {
     @Override
     public PublicKey getPublicKey(PrivateKey key) {
         if (isEnabled() && isEdDSASupported() && key.getClass().getPackage().getName().startsWith("org.bouncycastle.")) {
-            return new BouncyCastlePublicKeyFactory().getPublicKey(key);
+            return BouncyCastlePublicKeyFactory.INSTANCE.getPublicKey(key);
         }
         return super.getPublicKey(key);
     }

sshd-common/src/main/java/org/apache/sshd/common/util/security/eddsa/EdDSAPublicKeyFactory.java

@@ -0,0 +1,61 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.sshd.common.util.security.eddsa;
+
+import java.security.GeneralSecurityException;
+import java.security.KeyFactory;
+import java.security.PrivateKey;
+import java.security.PublicKey;
+
+import net.i2p.crypto.eddsa.EdDSAPrivateKey;
+import net.i2p.crypto.eddsa.spec.EdDSAPublicKeySpec;
+import org.apache.sshd.common.util.ValidateUtils;
+import org.apache.sshd.common.util.security.PublicKeyFactory;
+import org.apache.sshd.common.util.security.SecurityUtils;
+
+/**
+ * @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a>
+ */
+public final class EdDSAPublicKeyFactory implements PublicKeyFactory {
+
+    public static final PublicKeyFactory INSTANCE = new EdDSAPublicKeyFactory();
+
+    private EdDSAPublicKeyFactory() {
+        super();
+    }
+
+    @Override
+    public PublicKey getPublicKey(PrivateKey key) {
+        ValidateUtils.checkTrue(SecurityUtils.isEDDSACurveSupported(), SecurityUtils.EDDSA + " not supported");
+        if (!(key instanceof EdDSAPrivateKey)) {
+            return null;
+        }
+
+        EdDSAPrivateKey prvKey = (EdDSAPrivateKey) key;
+        EdDSAPublicKeySpec keySpec = new EdDSAPublicKeySpec(prvKey.getAbyte(), prvKey.getParams());
+        KeyFactory factory;
+        try {
+            factory = SecurityUtils.getKeyFactory(SecurityUtils.ED25519);
+            return factory.generatePublic(keySpec);
+        } catch (GeneralSecurityException e) {
+            return null;
+        }
+    }
+
+}

sshd-common/src/main/java/org/apache/sshd/common/util/security/eddsa/EdDSASecurityProviderRegistrar.java

@@ -134,11 +134,7 @@ protected String effectiveAlgorithm(String originalAlgorithm) {
     public PublicKey getPublicKey(PrivateKey key) {
         if (isEnabled() && isSupported() && "EdDSA".equals(key.getAlgorithm())
                 && key.getClass().getPackage().getName().startsWith("net.i2p.")) {
-            try {
-                return EdDSASecurityProviderUtils.recoverEDDSAPublicKey(key);
-            } catch (GeneralSecurityException e) {
-                return null;
-            }
+            return EdDSAPublicKeyFactory.INSTANCE.getPublicKey(key);
         }
         return super.getPublicKey(key);
     }