Update to the new CCV specs

.github/workflows/run-tests.yml

@@ -10,7 +10,7 @@ on:
 
 jobs:
   test:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     container: bigspider/bitcoin_matt
     steps:
       - name: Prepare Configuration File
@@ -20,24 +20,32 @@ jobs:
       - name: Run MATT-enabled bitcoind
         run: |
           bitcoind -regtest --daemon
+      - name: Set up dependencies
+        run: |
+          apt-get update
+          apt-get install -y libssl-dev libffi-dev
+          apt-get install -y python3-venv
       - name: Set up Python
         uses: actions/setup-python@v2
         with:
           python-version: '3.10'
       - name: Clone
         uses: actions/checkout@v4
-      - name: Install pip and pytest
+      - name: Install dependencies
         run: |
-          apt-get update
-          apt-get install -y python3-pip
+          python -m venv venv
+          source venv/bin/activate
+          pip install --upgrade pip
           pip install -r requirements-dev.txt
-      - name: Install pymatt
-        run: |
           pip install .
+        shell: bash
       - name: Create test wallet
         run: bash ./examples/init.sh
       - name: Run tests and capture output
-        run: pytest -vv
+        run: |
+          source venv/bin/activate
+          pytest -vv
+        shell: bash
       - name: Upload test output as artifact
         uses: actions/upload-artifact@v4
         with:

matt/contracts.py

@@ -1,3 +1,5 @@
+import hashlib
+
 from abc import ABC, abstractmethod
 from dataclasses import dataclass
 from enum import Enum
@@ -11,6 +13,19 @@
 from .btctools.segwit_addr import encode_segwit_address
 
 
+def tweak_embed_data(key: bytes, data: bytes) -> Optional[Tuple[bytes, Optional[bool]]]:
+    """
+    Tweaks a key with the sha256 hash of the data, returning the tweaked key and whether the result had to be negated.
+    If the data is empty, the key is returned as is.
+    """
+
+    if len(data) == 0:
+        return key, None
+
+    data_tweak = hashlib.sha256(key + data).digest()
+    return tweak_add_pubkey(key, data_tweak)
+
+
 class AbstractContract:
     pass
 
@@ -317,9 +332,7 @@ def get_taptree_merkle_root(self) -> bytes:
         return self.get_tr_info(b'\0'*32).merkle_root
 
     def get_tr_info(self, data: bytes) -> TaprootInfo:
-        assert len(data) == 32
-
-        internal_pubkey, _ = tweak_add_pubkey(self.naked_internal_pubkey, data)
+        internal_pubkey, _ = tweak_embed_data(self.naked_internal_pubkey, data)
 
         return script.taproot_construct(internal_pubkey, self.get_scripts())