Tests: add tests for hmac

test/python/test_instructions.py

@@ -339,3 +339,15 @@ def test_sign_message(
         assert tx_hash == tx.hash, \
             f"Expected hash {tx.hash.hex()} but got {tx_hash.hex()}"
         account.check_signature(signature, bytes(tx))
+
+
+@pytest.mark.parametrize("account", [DEFAULT_ACCOUNT])
+def test_hmac(
+        account: Account,
+        client: TezosClient) -> None:
+    """Test the HMAC instruction."""
+
+    message = bytes.fromhex("0123456789abcdef")
+    data = client.hmac(account, message)
+    hmac = bytes.fromhex("dde436940ab1602029a49dc77e6263b633fa3567c4d8479820d4f77072369ac1")
+    assert data == hmac, f"No expected {hmac.hex()} but got {data.hex()}"

test/python/utils/client.py

@@ -325,3 +325,17 @@ def sign_message_with_hash(self,
             data[:Message.HASH_SIZE],
             data[Message.HASH_SIZE:]
         )
+
+    def hmac(self,
+             account: Account,
+             message: bytes) -> bytes:
+        """Send the HMAC instruction."""
+
+        data: bytes = b''
+        data += bytes(account.path)
+        data += message
+
+        return self._exchange(
+            ins=Ins.HMAC,
+            sig_scheme=account.sig_scheme,
+            payload=data)