added null test for ContextParameterSpec

Author: dghgit

prov/src/main/java/org/bouncycastle/jcajce/provider/asymmetric/util/BaseDeterministicOrRandomSignature.java

@@ -34,14 +34,14 @@ public abstract class BaseDeterministicOrRandomSignature
     protected BaseDeterministicOrRandomSignature(String name)
     {
         super(name);
-        this.originalSpec = null;
+        this.originalSpec = ContextParameterSpec.EMPTY_CONTEXT_SPEC;
     }
 
     final protected void engineInitVerify(PublicKey publicKey)
         throws InvalidKeyException
     {
         verifyInit(publicKey);
-        paramSpec = null;
+        paramSpec = ContextParameterSpec.EMPTY_CONTEXT_SPEC;
         isInitState = true;
         reInit();
     }
@@ -53,7 +53,7 @@ final protected void engineInitSign(
         throws InvalidKeyException
     {
         signInit(privateKey, null);
-        paramSpec = null;
+        paramSpec = ContextParameterSpec.EMPTY_CONTEXT_SPEC;
         isInitState = true;
         reInit();
     }
@@ -64,7 +64,7 @@ final protected void engineInitSign(
         throws InvalidKeyException
     {
         signInit(privateKey, random);
-        paramSpec = null;
+        paramSpec = ContextParameterSpec.EMPTY_CONTEXT_SPEC;
         isInitState = true;
         reInit();
     }

prov/src/main/java/org/bouncycastle/jcajce/spec/ContextParameterSpec.java

@@ -7,6 +7,8 @@
 public class ContextParameterSpec
     implements AlgorithmParameterSpec
 {
+    public static ContextParameterSpec EMPTY_CONTEXT_SPEC = new ContextParameterSpec(new byte[0]);
+
     private final byte[] context;
 
     public ContextParameterSpec(byte[] context)

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

@@ -529,6 +529,12 @@ public void testHashMLDSAKATSig()
         sig.update(msg, 0, msg.length);
 
         assertTrue(sig.verify(genS));
+
+        AlgorithmParameters algP = sig.getParameters();
+
+        ContextParameterSpec cSpec = algP.getParameterSpec(ContextParameterSpec.class);
+
+        assertTrue(Arrays.areEqual(new byte[0], cSpec.getContext()));
     }
 
     public void testHashMLDSAKATSigWithContext()