Add tests to check that an EdDSAEngine object can be reused with the same key

Author: str4d

test/net/i2p/crypto/eddsa/EdDSAEngineTest.java

@@ -24,9 +24,10 @@
  *
  */
 public class EdDSAEngineTest {
-    static final byte[] ZERO_SEED = Utils.hexToBytes("0000000000000000000000000000000000000000000000000000000000000000");
-    static final byte[] ZERO_PK = Utils.hexToBytes("3b6a27bcceb6a42d62a3a8d02a6f0d73653215771de243a63ac048a18b59da29");
-    static final byte[] ZERO_MSG_SIG = Utils.hexToBytes("94825896c7075c31bcb81f06dba2bdcd9dcf16e79288d4b9f87c248215c8468d475f429f3de3b4a2cf67fe17077ae19686020364d6d4fa7a0174bab4a123ba0f");
+    static final byte[] TEST_SEED = Utils.hexToBytes("0000000000000000000000000000000000000000000000000000000000000000");
+    static final byte[] TEST_PK = Utils.hexToBytes("3b6a27bcceb6a42d62a3a8d02a6f0d73653215771de243a63ac048a18b59da29");
+    static final byte[] TEST_MSG = "This is a secret message".getBytes(Charset.forName("UTF-8"));
+    static final byte[] TEST_MSG_SIG = Utils.hexToBytes("94825896c7075c31bcb81f06dba2bdcd9dcf16e79288d4b9f87c248215c8468d475f429f3de3b4a2cf67fe17077ae19686020364d6d4fa7a0174bab4a123ba0f");
 
     @Rule
     public ExpectedException exception = ExpectedException.none();
@@ -75,16 +76,52 @@ public void testVerifyWrongSigLength() throws Exception {
         //Signature sgr = Signature.getInstance("EdDSA", "I2P");
         Signature sgr = new EdDSAEngine(MessageDigest.getInstance("SHA-512"));
 
-        EdDSAPublicKeySpec pubKey = new EdDSAPublicKeySpec(ZERO_PK,
+        EdDSAPublicKeySpec pubKey = new EdDSAPublicKeySpec(TEST_PK,
                 EdDSANamedCurveTable.getByName("ed25519-sha-512"));
         PublicKey vKey = new EdDSAPublicKey(pubKey);
         sgr.initVerify(vKey);
 
-        byte[] message = "This is a secret message".getBytes(Charset.forName("UTF-8"));
-        sgr.update(message);
+        sgr.update(TEST_MSG);
 
         exception.expect(SignatureException.class);
         exception.expectMessage("signature length is wrong");
         sgr.verify(new byte[] {0});
     }
+
+    @Test
+    public void testSignResetsForReuse() throws Exception {
+        Signature sgr = new EdDSAEngine(MessageDigest.getInstance("SHA-512"));
+        EdDSAParameterSpec spec = EdDSANamedCurveTable.getByName("ed25519-sha-512");
+
+        EdDSAPrivateKeySpec privKey = new EdDSAPrivateKeySpec(TEST_SEED, spec);
+        PrivateKey sKey = new EdDSAPrivateKey(privKey);
+        sgr.initSign(sKey);
+
+        // First usage
+        sgr.update(new byte[] {0});
+        sgr.sign();
+
+        // Second usage
+        sgr.update(TEST_MSG);
+        assertThat("Second sign failed", sgr.sign(), is(equalTo(TEST_MSG_SIG)));
+    }
+
+    @Test
+    public void testVerifyResetsForReuse() throws Exception {
+        //Signature sgr = Signature.getInstance("EdDSA", "I2P");
+        Signature sgr = new EdDSAEngine(MessageDigest.getInstance("SHA-512"));
+
+        EdDSAPublicKeySpec pubKey = new EdDSAPublicKeySpec(TEST_PK,
+                EdDSANamedCurveTable.getByName("ed25519-sha-512"));
+        PublicKey vKey = new EdDSAPublicKey(pubKey);
+        sgr.initVerify(vKey);
+
+        // First usage
+        sgr.update(new byte[] {0});
+        sgr.verify(TEST_MSG_SIG);
+
+        // Second usage
+        sgr.update(TEST_MSG);
+        assertThat("Second verify failed", sgr.verify(TEST_MSG_SIG), is(true));
+    }
 }