Fixing ASN1Data encoding and decoding

`OpenSSL::ASN1::ASN1Data` encoding and decoding hasn't worked well for
some time:

* it was decoding the value always as a Sequence (when values can be
  strings as well);
* after decoding, the `.tag_class` was always `:CONTEXT_SPECIFIC` (it
  can be `:UNIVERSAL` as well);
* it wasn't correctly encoding `:APPLICATION`-tagged structures;

The tests added verify that the behaviour of these operations now
matchws what CRuby's `openssl` gem does.

Author: HoneyryderChuck

src/main/java/org/jruby/ext/openssl/ASN1.java

@@ -956,7 +956,7 @@ private static RubyString name(final ThreadContext context, IRubyObject value,
     } // ObjectId
 
     static IRubyObject decodeObject(final ThreadContext context,
-        final RubyModule ASN1, final org.bouncycastle.asn1.ASN1Encodable obj)
+        final RubyModule ASN1, final ASN1Encodable obj)
         throws IOException, IllegalArgumentException {
         final Ruby runtime = context.runtime;
 
@@ -1072,22 +1072,47 @@ else if ( obj instanceof DERBMPString ) {
             return ASN1.getClass("ObjectId").newInstance(context, runtime.newString(objId), Block.NULL_BLOCK);
         }
 
-        if (obj instanceof ASN1TaggedObject) {
+
+        if ( obj instanceof ASN1TaggedObject ) {
             final ASN1TaggedObject taggedObj = (ASN1TaggedObject) obj;
-            if (taggedObj.getTagClass() == BERTags.APPLICATION) {
-                IRubyObject tag = runtime.newFixnum( taggedObj.getTagNo() );
-                IRubyObject tag_class = runtime.newSymbol("APPLICATION");
-                final ASN1Sequence sequence = (ASN1Sequence) taggedObj.getBaseUniversal(false, SEQUENCE);
-                @SuppressWarnings("unchecked")
+            // IRubyObject val = decodeObject(context, ASN1, taggedObj.getBaseObject());
+            IRubyObject tag = runtime.newFixnum( taggedObj.getTagNo() );
+            IRubyObject tag_class;
+            switch(taggedObj.getTagClass()) {
+                case BERTags.PRIVATE:
+                  tag_class = runtime.newSymbol("PRIVATE");
+                  break;
+                case BERTags.APPLICATION:
+                  tag_class = runtime.newSymbol("APPLICATION");
+                  break;
+                case BERTags.CONTEXT_SPECIFIC:
+                  tag_class = runtime.newSymbol("CONTEXT_SPECIFIC");
+                  break;
+                default:
+                  tag_class = runtime.newSymbol("UNIVERSAL");
+                  break;
+            }
+
+            try {
+                final ASN1Sequence sequence = (ASN1Sequence) taggedObj.getExplicitBaseObject();
                 final RubyArray valArr = decodeObjects(context, ASN1, sequence.getObjects());
                 return ASN1.getClass("ASN1Data").newInstance(context, new IRubyObject[] { valArr, tag, tag_class }, Block.NULL_BLOCK);
-            } else {
-                IRubyObject val = decodeObject(context, ASN1, taggedObj.getBaseObject());
-                IRubyObject tag = runtime.newFixnum( taggedObj.getTagNo() );
-                IRubyObject tag_class = runtime.newSymbol("CONTEXT_SPECIFIC");
-                final RubyArray valArr = runtime.newArray(val);
-                return ASN1.getClass("ASN1Data").newInstance(context, new IRubyObject[] { valArr, tag, tag_class }, Block.NULL_BLOCK);
+            } catch(ClassCastException e) {
+                final ASN1Encodable taggedBaseObj = taggedObj.getBaseObject();
+                return ASN1.getClass("ASN1Data").newInstance(context, new IRubyObject[] { decodeObject(context, ASN1, taggedBaseObj).callMethod(context, "value"), tag, tag_class }, Block.NULL_BLOCK);
             }
+
+            // if ( obj instanceof DLTaggedObject ) { // isConstructed
+            //     System.out.println("ASN1Data constructive!");
+            //     final ASN1Sequence sequence = (ASN1Sequence) taggedObj.getBaseUniversal(false, SEQUENCE);
+            //     @SuppressWarnings("unchecked")
+            //     final RubyArray valArr = decodeObjects(context, ASN1, sequence.getObjects());
+            //     return ASN1.getClass("ASN1Data").newInstance(context, new IRubyObject[] { valArr, tag, tag_class }, Block.NULL_BLOCK);
+            // } else {
+            //     final ASN1Encodable taggedBaseObj = taggedObj.getBaseObject();
+            //     System.out.println("ASN1Data primitive!");
+            //     return ASN1.getClass("ASN1Data").newInstance(context, new IRubyObject[] { decodeObject(context, ASN1, taggedBaseObj).callMethod(context, "value"), tag, tag_class }, Block.NULL_BLOCK);
+            // }
         }
 
         if ( obj instanceof ASN1Sequence ) {
@@ -1384,29 +1409,59 @@ ASN1Encodable toASN1(final ThreadContext context) {
 
         final ASN1TaggedObject toASN1TaggedObject(final ThreadContext context) {
             final int tag = getTag(context);
+            final RubyModule ASN1 = _ASN1(context.runtime);
+
+            IRubyObject val = callMethod(context, "value");
+            final IRubyObject tagClass = callMethod(context, "tag_class");
+            ASN1Encodable obj;
+            int berTag;
 
-            final IRubyObject val = callMethod(context, "value");
             if ( val instanceof RubyArray ) {
                 final RubyArray arr = (RubyArray) val;
-                if ( arr.size() > 1 ) {
-                    ASN1EncodableVector vec = new ASN1EncodableVector();
-                    for ( final IRubyObject obj : arr.toJavaArray() ) {
-                        ASN1Encodable data = ((ASN1Data) obj).toASN1(context);
-                        if ( data == null ) break; vec.add( data );
+
+                if ( arr.size() >= 1 ) {
+                    ByteArrayOutputStream bytes = new ByteArrayOutputStream( );
+
+                    for ( final IRubyObject o : arr.toJavaArray() ) {
+                        try {
+                            bytes.write(((RubyString) o).getBytes());
+                        } catch (IOException e) {
+                            throw new IllegalStateException(e.getMessage());
+                        } catch(ClassCastException e) {
+                            throw context.runtime.newTypeError(e.getMessage());
+                        }
                     }
-                    return new DERTaggedObject(isExplicitTagging(), tag, new DERSequence(vec));
-                }
-                else if ( arr.size() == 1 ) {
-                    ASN1Encodable data = ((ASN1Data) arr.entry(0)).toASN1(context);
-                    return new DERTaggedObject(isExplicitTagging(), tag, data);
-                }
-                else {
+                    obj = new DEROctetString(bytes.toByteArray());
+                } else {
                     throw new IllegalStateException("empty array detected");
                 }
+            } else {
+                try {
+                    obj = new DEROctetString(((RubyString) val).getBytes());
+                } catch(ClassCastException e) {
+                    throw context.runtime.newTypeError("no implicit conversion of " + val.getMetaClass().getName() + " into String");
+                }
             }
-            return new DERTaggedObject(isExplicitTagging(), tag, ((ASN1Data) val).toASN1(context));
+
+            switch(tagClass.toString()) {
+                case "PRIVATE":
+                  berTag = BERTags.PRIVATE;
+                  break;
+                case "APPLICATION":
+                  berTag = BERTags.APPLICATION;
+                  break;
+                case "CONTEXT_SPECIFIC":
+                  berTag = BERTags.CONTEXT_SPECIFIC;
+                  break;
+                default:
+                  berTag = BERTags.UNIVERSAL;
+                  break;
+            }
+
+            return new DERTaggedObject(isExplicitTagging(), berTag, tag, obj);
         }
 
+
         @JRubyMethod
         public IRubyObject to_der(final ThreadContext context) {
             try {