added processing for old LMS private keys.

Author: dghgit

core/src/main/java/org/bouncycastle/pqc/crypto/lms/HSSPrivateKeyParameters.java

@@ -121,7 +121,16 @@ else if (src instanceof byte[])
             try // 1.5 / 1.6 compatibility
             {
                 in = new DataInputStream(new ByteArrayInputStream((byte[])src));
-                return getInstance(in);
+                try
+                {
+                    return getInstance(in);
+                }
+                catch (Exception e)
+                {
+                    // old style single LMS key.
+                    LMSPrivateKeyParameters lmsKey = LMSPrivateKeyParameters.getInstance(src);
+                    return new HSSPrivateKeyParameters(lmsKey, lmsKey.getIndex(), lmsKey.getIndex() + lmsKey.getUsagesRemaining());
+                }
             }
             finally
             {

prov/src/test/java/org/bouncycastle/pqc/jcajce/provider/test/LMSTest.java

@@ -34,6 +34,9 @@ public class LMSTest
     private static final byte[] nestedPublicKey = Base64.decode("MFAwDQYLKoZIhvcNAQkQAxEDPwAEPAAAAAEAAAAFAAAAAa3sRFhG3xQtT/xfuJJswgV80jvx/sFlYxteNrZ0hheITiUL/bJ8wJpphIpoSB/E9g==");
     private static final byte[] nestedPrivateKey = Base64.decode("MIG6AgEBMA0GCyqGSIb3DQEJEAMRBGcEZQAAAAEAAAAAAAAAAQAAAAAAAAAAAAAAAAAAACAAAAAAAAAAAAUAAAABrexEWEbfFC1P/F+4kmzCBQAAAAAAAAAgAAAAIO01yI+Hj7eX+P2clcPDW0SzllJ4uzQt1JenbcllHpQngT0AAAAAAQAAAAUAAAABrexEWEbfFC1P/F+4kmzCBXzSO/H+wWVjG142tnSGF4hOJQv9snzAmmmEimhIH8T2");
 
+    private static byte[] lmsPublicEnc = Base64.decode("MFAwDQYLKoZIhvcNAQkQAxEDPwAEPAAAAAEAAAAFAAAAAXjGRFXZMjGgOKA/sHWwYWNl6eTf5nI+RcEvlnIKQHQXpxNDreZCkeFm6x9CBN4YlA==");
+    private static byte[] lmsPrivateEnc = Base64.decode("MIGhAgEBMA0GCyqGSIb3DQEJEAMRBE4ETAAAAAEAAAAAAAAABQAAAAF4xkRV2TIxoDigP7B1sGFjAAAAAAAAACAAAAAghIRA7xa5TChn4+0KIh1LvGLp14alEkmcz3m3v7kTiBeBPQAAAAABAAAABQAAAAF4xkRV2TIxoDigP7B1sGFjZenk3+ZyPkXBL5ZyCkB0F6cTQ63mQpHhZusfQgTeGJQ=");
+
     public void setUp()
     {
         if (Security.getProvider(BouncyCastleProvider.PROVIDER_NAME) == null)
@@ -42,6 +45,20 @@ public void setUp()
         }
     }
 
+    public void testLmsOldKeyEncoding()
+        throws Exception
+    {
+        PKCS8EncodedKeySpec lmsPrivateKeySpec = new PKCS8EncodedKeySpec(lmsPrivateEnc);
+        X509EncodedKeySpec lmsPublicKeySpec = new X509EncodedKeySpec(lmsPublicEnc);
+
+        KeyFactory kFact = KeyFactory.getInstance("LMS", "BC");
+
+        PrivateKey lmsPrivateKey = kFact.generatePrivate(lmsPrivateKeySpec);
+        PublicKey lmsPublicKey = kFact.generatePublic(lmsPublicKeySpec);
+
+        trySigning(new KeyPair(lmsPublicKey, lmsPrivateKey));
+    }
+
     public void testKeyPairGenerators()
         throws Exception
     {