fix: Handle serialization and deserialization of bigint/bytestring wh…

…en length > 64 (#398)

* fix: Handle serialization and deserialization of bigint as ByteString

* chore: Remove encodeAsByteString() and only handle BS to BigInt decoding

* fix: #399 Handle encoding/decoding of BigInt and ByteString when length > 64

common/src/main/java/com/bloxbean/cardano/client/common/cbor/custom/ChunkedByteString.java

@@ -0,0 +1,26 @@
+package com.bloxbean.cardano.client.common.cbor.custom;
+
+import co.nstant.in.cbor.model.ByteString;
+
+import java.util.List;
+
+/**
+ * This class is used to represent a ByteString which is chunked into multiple byte arrays. Each chunk length is less than or equal to 64 bytes
+ * This is used in PlutusData serialization/deserialization when the byte array is greater than 64 bytes and need to be chunked.
+ * For more details, how chunking is done in Cardano, refer the below link
+ * https://github.com/IntersectMBO/plutus/blob/441b76d9e9745dfedb2afc29920498bdf632f162/plutus-core/plutus-core/src/PlutusCore/Data.hs#L243
+ */
+public class ChunkedByteString extends ByteString {
+    private List<byte[]> chunks;
+
+    public ChunkedByteString(List<byte[]> chunks) {
+        super(new byte[0]);
+        this.chunks = chunks;
+        setChunked(true);
+    }
+
+    public List<byte[]> getChunks() {
+        return chunks;
+    }
+
+}

common/src/main/java/com/bloxbean/cardano/client/common/cbor/custom/CustomByteStringEncoder.java

@@ -0,0 +1,34 @@
+package com.bloxbean.cardano.client.common.cbor.custom;
+
+import co.nstant.in.cbor.CborEncoder;
+import co.nstant.in.cbor.CborException;
+import co.nstant.in.cbor.encoder.ByteStringEncoder;
+import co.nstant.in.cbor.model.ByteString;
+import co.nstant.in.cbor.model.MajorType;
+import co.nstant.in.cbor.model.SimpleValue;
+
+import java.io.OutputStream;
+import java.util.List;
+
+/**
+ * A custom ByteStringEncoder impl to handle serialization of {@link ChunkedByteString} in PlutusData.
+ */
+public class CustomByteStringEncoder extends ByteStringEncoder {
+    public CustomByteStringEncoder(CborEncoder encoder, OutputStream outputStream) {
+        super(encoder, outputStream);
+    }
+
+    @Override
+    public void encode(ByteString byteString) throws CborException {
+        if (byteString instanceof ChunkedByteString) {
+            List<byte[]> chunks = ((ChunkedByteString) byteString).getChunks();
+            this.encodeTypeChunked(MajorType.BYTE_STRING);
+            for (byte[] chunk : chunks) {
+                this.encode(new ByteString(chunk));
+            }
+            this.encoder.encode(SimpleValue.BREAK);
+        } else {
+            super.encode(byteString);
+        }
+    }
+}

common/src/main/java/com/bloxbean/cardano/client/common/cbor/custom/CustomCborEncoder.java

@@ -2,23 +2,24 @@
 
 import co.nstant.in.cbor.CborEncoder;
 import co.nstant.in.cbor.CborException;
-import co.nstant.in.cbor.model.DataItem;
-import co.nstant.in.cbor.model.Map;
-import co.nstant.in.cbor.model.SimpleValue;
-import co.nstant.in.cbor.model.Tag;
+import co.nstant.in.cbor.model.*;
 
 import java.io.OutputStream;
 
+import static co.nstant.in.cbor.model.MajorType.BYTE_STRING;
 import static co.nstant.in.cbor.model.MajorType.MAP;
 
 /**
  * A custom CborEncoder impl to handle serialization of {@link SortedMap} when canonical cbor is set in CborEncoder level.
  * This class exists to handle the scenario where a Map's key is already sorted by the caller, so
  * encoder doesn't need to sort it again even if canonical = true.
+ *
+ * It is also used to handle chunked ByteStrings in PlutusData serialization/deserialization.
  */
 public class CustomCborEncoder extends CborEncoder {
 
     private CustomMapEncoder customMapEncoder;
+    private CustomByteStringEncoder chunkByteStringEncoder;
 
     /**
      * Initialize a new encoder which writes the binary encoded data to an
@@ -29,6 +30,7 @@ public class CustomCborEncoder extends CborEncoder {
     public CustomCborEncoder(OutputStream outputStream) {
         super(outputStream);
         this.customMapEncoder = new CustomMapEncoder(this, outputStream);
+        this.chunkByteStringEncoder = new CustomByteStringEncoder(this, outputStream);
     }
 
     /**
@@ -40,18 +42,25 @@ public CustomCborEncoder(OutputStream outputStream) {
      *                       an problem with the {@link OutputStream}.
      */
     public void encode(DataItem dataItem) throws CborException {
-        //If Map type, handle it here. Otherwise, delegates to default implementation in CborEncoder
+        if (dataItem == null) {
+            dataItem = SimpleValue.NULL;
+        }
+
+        //If Map type or ByteString, handle it here. Otherwise, delegates to default implementation in CborEncoder
         if (dataItem.getMajorType().equals(MAP)) {
-            if (dataItem == null) {
-                dataItem = SimpleValue.NULL;
+            if (dataItem.hasTag()) {
+                Tag tagDi = dataItem.getTag();
+                encode(tagDi);
             }
 
+            customMapEncoder.encode((Map) dataItem);
+        } else if (dataItem.getMajorType().equals(BYTE_STRING)) {
             if (dataItem.hasTag()) {
                 Tag tagDi = dataItem.getTag();
                 encode(tagDi);
             }
 
-            customMapEncoder.encode((Map) dataItem);
+            chunkByteStringEncoder.encode((ByteString) dataItem);
         } else {
             super.encode(dataItem);
         }

plutus/src/main/java/com/bloxbean/cardano/client/plutus/spec/BigIntPlutusData.java

@@ -1,10 +1,8 @@
 package com.bloxbean.cardano.client.plutus.spec;
 
-import co.nstant.in.cbor.model.DataItem;
-import co.nstant.in.cbor.model.NegativeInteger;
+import co.nstant.in.cbor.model.*;
 import co.nstant.in.cbor.model.Number;
-import co.nstant.in.cbor.model.UnsignedInteger;
-import com.bloxbean.cardano.client.exception.CborDeserializationException;
+import com.bloxbean.cardano.client.common.cbor.custom.ChunkedByteString;
 import com.bloxbean.cardano.client.exception.CborSerializationException;
 import com.bloxbean.cardano.client.plutus.spec.serializers.BigIntDataJsonDeserializer;
 import com.bloxbean.cardano.client.plutus.spec.serializers.BigIntDataJsonSerializer;
@@ -14,6 +12,8 @@
 
 import java.math.BigInteger;
 
+import static com.bloxbean.cardano.client.plutus.util.Bytes.getChunks;
+
 @Getter
 @AllArgsConstructor
 @NoArgsConstructor
@@ -24,13 +24,33 @@
 public class BigIntPlutusData implements PlutusData {
     private BigInteger value;
 
-    public static BigIntPlutusData deserialize(Number numberDI) throws CborDeserializationException {
+    public static BigIntPlutusData deserialize(Number numberDI) {
         if (numberDI == null)
             return null;
 
         return new BigIntPlutusData(numberDI.getValue());
     }
 
+    public static BigIntPlutusData deserialize(ByteString byteString) {
+        if (byteString == null)
+            return null;
+
+        var tag = byteString.getTag();
+        if (tag != null) {
+            switch ((int) tag.getValue()) {
+                case BIG_UINT_TAG:
+                    return BigIntPlutusData.of(new BigInteger(1, byteString.getBytes()));
+                case BIG_NINT_TAG:
+                    return BigIntPlutusData.of(MINUS_ONE.subtract(new BigInteger(1, byteString.getBytes())));
+                default:
+                    throw new IllegalArgumentException("Invalid tag for BigIntPlutusData");
+            }
+        } else {
+            throw new IllegalArgumentException("Missing tag for BigIntPlutusData");
+        }
+    }
+
+
     public static BigIntPlutusData of(int i) {
         return new BigIntPlutusData(BigInteger.valueOf(i));
     }
@@ -47,13 +67,33 @@ public static BigIntPlutusData of(BigInteger b) {
     public DataItem serialize() throws CborSerializationException {
         DataItem di = null;
         if (value != null) {
-            if (value.compareTo(BigInteger.ZERO) == 0 || value.compareTo(BigInteger.ZERO) == 1) {
-                di = new UnsignedInteger(value);
+            if (value.bitLength() <= BYTES_LIMIT) {
+                if (value.signum() >= 0) {
+                    di = new UnsignedInteger(value);
+                } else {
+                    di = new NegativeInteger(value);
+                }
             } else {
-                di = new NegativeInteger(value);
+                byte[] bytes = value.toByteArray();
+                if (value.signum() < 0) {
+                    bytes = negateBytes(bytes);
+                    di = new ChunkedByteString(getChunks(bytes, BYTES_LIMIT));
+                    di.setTag(BIG_NINT_TAG);
+                } else {
+                    di = new ChunkedByteString(getChunks(bytes, BYTES_LIMIT));
+                    di.setTag(BIG_UINT_TAG);
+                }
             }
         }
 
         return di;
     }
+
+    private byte[] negateBytes(byte[] bytes) {
+        for (int i = 0; i < bytes.length; i++) {
+            bytes[i] = (byte) ~bytes[i];
+        }
+        return bytes;
+    }
+
 }

plutus/src/main/java/com/bloxbean/cardano/client/plutus/spec/BytesPlutusData.java

@@ -1,8 +1,7 @@
 package com.bloxbean.cardano.client.plutus.spec;
 
-import co.nstant.in.cbor.model.ByteString;
-import co.nstant.in.cbor.model.DataItem;
-import co.nstant.in.cbor.model.UnicodeString;
+import co.nstant.in.cbor.model.*;
+import com.bloxbean.cardano.client.common.cbor.custom.ChunkedByteString;
 import com.bloxbean.cardano.client.exception.CborDeserializationException;
 import com.bloxbean.cardano.client.exception.CborSerializationException;
 import com.bloxbean.cardano.client.plutus.spec.serializers.BytesDataJsonDeserializer;
@@ -13,6 +12,8 @@
 
 import java.nio.charset.StandardCharsets;
 
+import static com.bloxbean.cardano.client.plutus.util.Bytes.getChunks;
+
 @Getter
 @AllArgsConstructor
 @NoArgsConstructor
@@ -38,11 +39,16 @@ public static BytesPlutusData of(String str) {
         return new BytesPlutusData(str.getBytes(StandardCharsets.UTF_8));
     }
 
+    //https://github.com/IntersectMBO/plutus/blob/441b76d9e9745dfedb2afc29920498bdf632f162/plutus-core/plutus-core/src/PlutusCore/Data.hs#L243
     @Override
     public DataItem serialize() throws CborSerializationException {
         DataItem di = null;
         if (value != null) {
-            di = new ByteString(value);
+            if (value.length <= BYTES_LIMIT) {
+                di = new ByteString(value);
+            } else { //More than 64, chunk it
+                di = new ChunkedByteString(getChunks(value, BYTES_LIMIT));
+            }
         }
 
         return di;

plutus/src/main/java/com/bloxbean/cardano/client/plutus/spec/PlutusData.java

@@ -13,7 +13,15 @@
 import com.fasterxml.jackson.annotation.JsonIgnore;
 import lombok.NonNull;
 
+import java.math.BigInteger;
+
 public interface PlutusData {
+    int BIG_UINT_TAG = 2;
+    int BIG_NINT_TAG = 3;
+    BigInteger MINUS_ONE = BigInteger.valueOf(-1);
+
+    int BYTES_LIMIT = 64;
+
 
 //    plutus_data = ; New
 //    constr<plutus_data>
@@ -41,7 +49,13 @@ static PlutusData deserialize(DataItem dataItem) throws CborDeserializationExcep
         if (dataItem instanceof Number) {
             return BigIntPlutusData.deserialize((Number) dataItem);
         } else if (dataItem instanceof ByteString) {
-            return BytesPlutusData.deserialize((ByteString) dataItem);
+            var tag = dataItem.getTag();
+            if (tag != null &&
+                    (tag.getValue() == BIG_UINT_TAG || tag.getValue() == BIG_NINT_TAG)){
+                return BigIntPlutusData.deserialize((ByteString) dataItem);
+            } else {
+                return BytesPlutusData.deserialize((ByteString) dataItem);
+            }
         }  else if (dataItem instanceof UnicodeString) {
             return BytesPlutusData.deserialize(((UnicodeString) dataItem));
         } else if (dataItem instanceof Array) {

plutus/src/main/java/com/bloxbean/cardano/client/plutus/util/Bytes.java

@@ -1,8 +1,10 @@
 package com.bloxbean.cardano.client.plutus.util;
 
 import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.List;
 
-class Bytes {
+public class Bytes {
     public static byte[] concat(byte[]... arrays) {
         int totalLength = 0;
         for (byte[] array : arrays) {
@@ -16,4 +18,19 @@ public static byte[] concat(byte[]... arrays) {
 
         return byteBuffer.array();
     }
+
+    public static List<byte[]> getChunks(byte[] b, int maxChunkSize) {
+        List<byte[]> result = new ArrayList<>();
+
+        ByteBuffer buffer = ByteBuffer.wrap(b);
+
+        while (buffer.remaining() > 0) {
+            int chunkSize = Math.min(buffer.remaining(), maxChunkSize);
+            byte[] chunk = new byte[chunkSize];
+            buffer.get(chunk);
+            result.add(chunk);
+        }
+
+        return result;
+    }
 }