* I2CP Client: Generate revocation key of same type as signing key

* i2ptunnel: Only offer Sig options that are available in the JVM
 * LeaseSet: Add check for SigTYpe mismatch
 * SigType: Add isAvailable()

core/java/src/net/i2p/client/RequestLeaseSetMessageHandler.java

@@ -9,6 +9,7 @@ package net.i2p.client;
  *
  */
 
+import java.security.GeneralSecurityException;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 
@@ -25,6 +26,7 @@ import net.i2p.data.PublicKey;
 import net.i2p.data.SessionKey;
 import net.i2p.data.SigningPrivateKey;
 import net.i2p.data.SigningPublicKey;
+import net.i2p.data.SimpleDataStructure;
 import net.i2p.data.i2cp.I2CPMessage;
 import net.i2p.data.i2cp.RequestLeaseSetMessage;
 import net.i2p.util.Log;
@@ -129,9 +131,16 @@ class RequestLeaseSetMessageHandler extends HandlerImpl {
         private final PrivateKey _privKey;
         private final SigningPublicKey _signingPubKey;
         private final SigningPrivateKey _signingPrivKey;
+
         public LeaseInfo(Destination dest) {
             Object encKeys[] = KeyGenerator.getInstance().generatePKIKeypair();
-            Object signKeys[] = KeyGenerator.getInstance().generateSigningKeypair();
+            // must be same type as the Destination's signing key
+            SimpleDataStructure signKeys[];
+            try {
+                signKeys = KeyGenerator.getInstance().generateSigningKeys(dest.getSigningPublicKey().getType());
+            } catch (GeneralSecurityException gse) {
+                throw new IllegalStateException(gse);
+            }
             _pubKey = (PublicKey) encKeys[0];
             _privKey = (PrivateKey) encKeys[1];
             _signingPubKey = (SigningPublicKey) signKeys[0];

core/java/src/net/i2p/crypto/SigType.java

@@ -2,6 +2,7 @@ package net.i2p.crypto;
 
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
+import java.security.Signature;
 import java.security.spec.AlgorithmParameterSpec;
 import java.security.spec.InvalidParameterSpecException;
 import java.util.HashMap;
@@ -159,6 +160,24 @@ public enum SigType {
         }
     }
 
+    /**
+     *  @since 0.9.12
+     *  @return true if supported in this JVM
+     */
+    public boolean isAvailable() {
+        if (DSA_SHA1 == this)
+            return true;
+        try {
+            getParams();
+            Signature.getInstance(getAlgorithmName());
+            getDigestInstance();
+            getHashInstance();
+        } catch (Exception e) {
+            return false;
+        }
+        return true;
+    }
+
     private static final Map<Integer, SigType> BY_CODE = new HashMap<Integer, SigType>();
 
     static {

core/java/src/net/i2p/data/LeaseSet.java

@@ -137,12 +137,23 @@ public class LeaseSet extends DatabaseEntry {
         _encryptionKey = encryptionKey;
     }
 
-    /** @deprecated unused */
+    /**
+     *  The revocation key.
+     *  @deprecated unused
+     */
     public SigningPublicKey getSigningKey() {
         return _signingKey;
     }
 
+    /**
+     *  The revocation key. Unused.
+     *  Must be the same type as the Destination's SigningPublicKey.
+     *  @throws IllegalArgumentException if different type
+     */
     public void setSigningKey(SigningPublicKey key) {
+        if (key != null && _destination != null &&
+            key.getType() != _destination.getSigningPublicKey().getType())
+            throw new IllegalArgumentException("Signing key type mismatch");
         _signingKey = key;
     }