Crypto: Change X25519 key classes from Java keys to I2P keys,

in prep for new crypto (Proposal 144)
Add EncType
Fix PrivateKey constructor w/ EncType
Add support to KeyGenerator

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

@@ -10,7 +10,10 @@ package net.i2p.crypto;
 public enum EncAlgo {
 
     ELGAMAL("ElGamal"),
-    EC("EC");
+    EC("EC"),
+
+    /** @since 0.9.38 */
+    ECIES("ECIES");
 
     private final String name;
 

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

@@ -6,6 +6,7 @@ import java.util.HashMap;
 import java.util.Locale;
 import java.util.Map;
 
+import static net.i2p.crypto.x25519.spec.X25519Spec.X25519_SPEC;
 import net.i2p.data.Hash;
 import net.i2p.data.SimpleDataStructure;
 
@@ -36,7 +37,13 @@ public enum EncType {
     EC_P384(2, 96, 48, EncAlgo.EC, "EC/None/NoPadding", ECConstants.P384_SPEC, "0.9.20"),
 
     /**  Pubkey 132 bytes; privkey 66 bytes; */
-    EC_P521(3, 132, 66, EncAlgo.EC, "EC/None/NoPadding", ECConstants.P521_SPEC, "0.9.20");
+    EC_P521(3, 132, 66, EncAlgo.EC, "EC/None/NoPadding", ECConstants.P521_SPEC, "0.9.20"),
+
+    /**
+     *  Pubkey 32 bytes; privkey 32 bytes
+     *  @since 0.9.38
+     */
+    ECIES_X25519(4, 32, 32, EncAlgo.ECIES, "EC/None/NoPadding", X25519_SPEC, "0.9.38");
 
 
 

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

@@ -31,6 +31,8 @@ import java.util.Arrays;
 import java.util.ArrayList;
 import java.util.Collection;
 
+import com.southernstorm.noise.crypto.x25519.Curve25519;
+
 import net.i2p.I2PAppContext;
 import net.i2p.crypto.eddsa.EdDSAPrivateKey;
 import net.i2p.crypto.eddsa.EdDSAPublicKey;
@@ -173,20 +175,38 @@ public final class KeyGenerator {
         return keys;
     }
 
-    /** Convert a PrivateKey to its corresponding PublicKey
+    /**
+     * Convert a PrivateKey to its corresponding PublicKey.
+     * As of 0.9.38, supports EncTypes
+     *
      * @param priv PrivateKey object
      * @return the corresponding PublicKey object
      * @throws IllegalArgumentException on bad key
      */
     public static PublicKey getPublicKey(PrivateKey priv) {
-        BigInteger a = new NativeBigInteger(1, priv.toByteArray());
-        BigInteger aalpha = CryptoConstants.elgg.modPow(a, CryptoConstants.elgp);
-        PublicKey pub = new PublicKey();
-        try {
-            pub.setData(SigUtil.rectify(aalpha, PublicKey.KEYSIZE_BYTES));
-        } catch (InvalidKeyException ike) {
-            throw new IllegalArgumentException(ike);
+        EncType type = priv.getType();
+        byte[] data;
+        switch (type) {
+          case ELGAMAL_2048:
+            BigInteger a = new NativeBigInteger(1, priv.toByteArray());
+            BigInteger aalpha = CryptoConstants.elgg.modPow(a, CryptoConstants.elgp);
+            try {
+                data = SigUtil.rectify(aalpha, PublicKey.KEYSIZE_BYTES);
+            } catch (InvalidKeyException ike) {
+                throw new IllegalArgumentException(ike);
+            }
+            break;
+
+          case ECIES_X25519:
+            data = new byte[32];
+            Curve25519.eval(data, 0, priv.getData(), null);
+            break;
+
+          default:
+            throw new IllegalArgumentException("Unsupported algorithm");
+
         }
+        PublicKey pub = new PublicKey(type, data);
         return pub;
     }
 

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

@@ -0,0 +1,28 @@
+package net.i2p.crypto;
+
+import net.i2p.data.PrivateKey;
+import net.i2p.data.PublicKey;
+
+/**
+ * Same as java.security.KeyPair, but with I2P keys
+ *
+ * @since 0.9.38
+ */
+public class KeyPair {
+
+    private final PublicKey pub;
+    private final PrivateKey priv;
+
+    public KeyPair(PublicKey publicKey, PrivateKey privateKey) {
+        pub = publicKey;
+        priv = privateKey;
+    }
+
+    public PublicKey getPublic() {
+        return pub;
+    }
+
+    public PrivateKey getPrivate() {
+        return priv;
+    }
+}

core/java/src/net/i2p/crypto/x25519/spec/X25519Spec.java

@@ -0,0 +1,9 @@
+package net.i2p.crypto.x25519.spec;
+
+import java.security.spec.AlgorithmParameterSpec;
+
+public class X25519Spec implements AlgorithmParameterSpec {
+
+    public static final X25519Spec X25519_SPEC = new X25519Spec();
+
+}

core/java/src/net/i2p/crypto/x25519/spec/package.html

@@ -0,0 +1,7 @@
+<html><body>
+<p>
+   AlgorithmParameterSpec for X25519.
+</p><p>
+   Since 0.9.38.
+</p>
+</body></html>

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

@@ -53,8 +53,11 @@ public class PrivateKey extends SimpleDataStructure {
      *  @since 0.9.38
      */
     public PrivateKey(EncType type, byte data[]) {
-        super(data);
+        super();
         _type = type;
+        if (data == null)
+            throw new IllegalArgumentException("Data must be specified");
+        _data = data;
     }
 
     /** constructs from base64