From 0e1766a7093480b484e8e9f25b2e5d1bc4977b12 Mon Sep 17 00:00:00 2001
From: Craig Raw <craigraw@gmail.com>
Date: Wed, 28 Feb 2024 10:26:44 +0200
Subject: [PATCH] support parsing of op_checksigadd and taproot control block

---
 .../sparrowwallet/drongo/protocol/ScriptChunk.java | 14 ++++++++++++--
 .../drongo/protocol/ScriptOpCodes.java             |  2 ++
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/main/java/com/sparrowwallet/drongo/protocol/ScriptChunk.java b/src/main/java/com/sparrowwallet/drongo/protocol/ScriptChunk.java
index bf05d97..1592df8 100644
--- a/src/main/java/com/sparrowwallet/drongo/protocol/ScriptChunk.java
+++ b/src/main/java/com/sparrowwallet/drongo/protocol/ScriptChunk.java
@@ -11,6 +11,7 @@ import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
 import java.util.Objects;
+import java.util.stream.IntStream;
 
 import static com.sparrowwallet.drongo.protocol.ScriptOpCodes.*;
 
@@ -150,7 +151,7 @@ public class ScriptChunk {
             return false;
         }
 
-        if(isSignature() || isPubKey()) {
+        if(isSignature() || isPubKey() || isTaprootControlBlock()) {
             return false;
         }
 
@@ -180,13 +181,22 @@ public class ScriptChunk {
             return false;
         }
 
-        return ECKey.isPubKeyCanonical(data);
+        return ECKey.isPubKeyCanonical(data) && !IntStream.range(0, data.length).mapToObj(i -> data[i]).allMatch(b -> b == 0);
     }
 
     public ECKey getPubKey() {
         return ECKey.fromPublicOnly(data);
     }
 
+    public boolean isTaprootControlBlock() {
+        if(data == null || data.length == 0 || (data.length - 1) % 32 != 0) {
+            return false;
+        }
+
+        //Test for BIP341 leaf version and both parity options
+        return ((data[0] & 0xff) == 0xc0 || (data[0] & 0xff) == 0xc1);
+    }
+
     public byte[] toByteArray() {
         ByteArrayOutputStream stream = new ByteArrayOutputStream();
         try {
diff --git a/src/main/java/com/sparrowwallet/drongo/protocol/ScriptOpCodes.java b/src/main/java/com/sparrowwallet/drongo/protocol/ScriptOpCodes.java
index 0b7e9c0..7623706 100644
--- a/src/main/java/com/sparrowwallet/drongo/protocol/ScriptOpCodes.java
+++ b/src/main/java/com/sparrowwallet/drongo/protocol/ScriptOpCodes.java
@@ -161,6 +161,7 @@ public class ScriptOpCodes {
     public static final int OP_NOP8 = 0xb7;
     public static final int OP_NOP9 = 0xb8;
     public static final int OP_NOP10 = 0xb9;
+    public static final int OP_CHECKSIGADD = 0xba;
     public static final int OP_INVALIDOPCODE = 0xff;
 
     private static final Map<Integer, String> opCodeNameMap;
@@ -269,6 +270,7 @@ public class ScriptOpCodes {
         opCodeNameMap.put(OP_CHECKSIGVERIFY, "CHECKSIGVERIFY");
         opCodeNameMap.put(OP_CHECKMULTISIG, "CHECKMULTISIG");
         opCodeNameMap.put(OP_CHECKMULTISIGVERIFY, "CHECKMULTISIGVERIFY");
+        opCodeNameMap.put(OP_CHECKSIGADD, "CHECKSIGADD");
         opCodeNameMap.put(OP_NOP1, "NOP1");
         opCodeNameMap.put(OP_CHECKLOCKTIMEVERIFY, "CHECKLOCKTIMEVERIFY");
         opCodeNameMap.put(OP_CHECKSEQUENCEVERIFY, "CHECKSEQUENCEVERIFY");