Implement hashCode() and equals() fully

- Add hashCode() and equals() everywhere it was missing, so we can test keys for
  equality: Curve, EdDSAParameterSpec, EdDSAPrivateKey, and EdDSAPublicKey
- Speedup for GroupElement.equals()

Signed-off-by: str4d <[email protected]>

Author: zzz

src/net/i2p/crypto/eddsa/EdDSAPrivateKey.java

@@ -3,6 +3,7 @@
 import java.security.PrivateKey;
 import java.security.spec.InvalidKeySpecException;
 import java.security.spec.PKCS8EncodedKeySpec;
+import java.util.Arrays;
 
 import net.i2p.crypto.eddsa.math.GroupElement;
 import net.i2p.crypto.eddsa.spec.EdDSANamedCurveTable;
@@ -80,7 +81,6 @@ public String getFormat() {
      *  @return 49 bytes for Ed25519, null for other curves
      */
     public byte[] getEncoded() {
-        // TODO no equals() implemented in spec, but it's essentially a singleton
         if (!edDsaSpec.equals(EdDSANamedCurveTable.getByName(EdDSANamedCurveTable.CURVE_ED25519_SHA512)))
             return null;
         int totlen = 17 + seed.length;
@@ -179,4 +179,20 @@ public GroupElement getA() {
     public byte[] getAbyte() {
         return Abyte;
     }
+
+    @Override
+    public int hashCode() {
+        return Arrays.hashCode(seed);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (o == this)
+            return true;
+        if (!(o instanceof EdDSAPrivateKey))
+            return false;
+        EdDSAPrivateKey pk = (EdDSAPrivateKey) o;
+        return Arrays.equals(seed, pk.getSeed()) &&
+               edDsaSpec.equals(pk.getParams());
+    }
 }

src/net/i2p/crypto/eddsa/EdDSAPublicKey.java

@@ -3,6 +3,7 @@
 import java.security.PublicKey;
 import java.security.spec.InvalidKeySpecException;
 import java.security.spec.X509EncodedKeySpec;
+import java.util.Arrays;
 
 import net.i2p.crypto.eddsa.math.GroupElement;
 import net.i2p.crypto.eddsa.spec.EdDSANamedCurveTable;
@@ -65,7 +66,6 @@ public String getFormat() {
      *  @return 47 bytes for Ed25519, null for other curves
      */
     public byte[] getEncoded() {
-        // TODO no equals() implemented in spec, but it's essentially a singleton
         if (!edDsaSpec.equals(EdDSANamedCurveTable.getByName(EdDSANamedCurveTable.CURVE_ED25519_SHA512)))
             return null;
         int totlen = 15 + Abyte.length;
@@ -146,4 +146,20 @@ public GroupElement getNegativeA() {
     public byte[] getAbyte() {
         return Abyte;
     }
+
+    @Override
+    public int hashCode() {
+        return Arrays.hashCode(Abyte);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (o == this)
+            return true;
+        if (!(o instanceof EdDSAPublicKey))
+            return false;
+        EdDSAPublicKey pk = (EdDSAPublicKey) o;
+        return Arrays.equals(Abyte, pk.getAbyte()) &&
+               edDsaSpec.equals(pk.getParams());
+    }
 }

src/net/i2p/crypto/eddsa/math/Curve.java

@@ -67,4 +67,23 @@ public GroupElement createPoint(byte[] P, boolean precompute) {
             ge.precompute(true);
         return ge;
     }
+
+    @Override
+    public int hashCode() {
+        return f.hashCode() ^
+               d.hashCode() ^
+               I.hashCode();
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (o == this)
+            return true;
+        if (!(o instanceof Curve))
+            return false;
+        Curve c = (Curve) o;
+        return f.equals(c.getField()) &&
+               d.equals(c.getD()) &&
+               I.equals(c.getI());
+    }
 }

src/net/i2p/crypto/eddsa/math/FieldElement.java

@@ -2,6 +2,9 @@
 
 import java.io.Serializable;
 
+/**
+ * Note: concrete subclasses must implement hashCode() and equals()
+ */
 public abstract class FieldElement implements Serializable {
     private static final long serialVersionUID = 1239527465875676L;
 
@@ -55,4 +58,6 @@ public FieldElement divide(FieldElement val) {
     public abstract FieldElement invert();
 
     public abstract FieldElement pow22523();
+
+    // Note: concrete subclasses must implement hashCode() and equals()
 }

src/net/i2p/crypto/eddsa/math/GroupElement.java

@@ -714,6 +714,8 @@ public int hashCode() {
 
     @Override
     public boolean equals(Object obj) {
+        if (obj == this)
+            return true;
         if (!(obj instanceof GroupElement))
             return false;
         GroupElement ge = (GroupElement) obj;

src/net/i2p/crypto/eddsa/spec/EdDSAParameterSpec.java

@@ -57,4 +57,23 @@ public ScalarOps getScalarOps() {
     public GroupElement getB() {
         return B;
     }
+
+    @Override
+    public int hashCode() {
+        return hashAlgo.hashCode() ^
+               curve.hashCode() ^
+               B.hashCode();
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (o == this)
+            return true;
+        if (!(o instanceof EdDSAParameterSpec))
+            return false;
+        EdDSAParameterSpec s = (EdDSAParameterSpec) o;
+        return hashAlgo.equals(s.getHashAlgorithm()) &&
+               curve.equals(s.getCurve()) &&
+               B.equals(s.getB());
+    }
 }