Decred sighash and signing.

basicswap/interface/dcr/script.py

@@ -0,0 +1,39 @@
+# -*- coding: utf-8 -*-
+
+# Copyright (c) 2024 tecnovert
+# Distributed under the MIT software license, see the accompanying
+# file LICENSE or http://www.opensource.org/licenses/mit-license.php.
+
+
+OP_0 = 0x00
+OP_DATA_1 = 0x01
+OP_1NEGATE = 0x4f
+OP_1 = 0x51
+OP_PUSHDATA1 = 0x4c
+OP_PUSHDATA2 = 0x4d
+OP_PUSHDATA4 = 0x4e
+
+
+def push_script_data(data_array: bytearray, data: bytes) -> None:
+    len_data: int = len(data)
+
+    if len_data == 0 or (len_data == 1 and data[0] == 0):
+        data_array += bytes((OP_0,))
+        return
+    if len_data == 1 and data[0] <= 16:
+        data_array += bytes((OP_1 - 1 + data[0],))
+        return
+    if len_data == 1 and data[0] == 0x81:
+        data_array += bytes((OP_1NEGATE,))
+        return
+
+    if len_data < OP_PUSHDATA1:
+        data_array += bytes(((OP_DATA_1 - 1) + len_data,))
+    elif len_data <= 0xff:
+        data_array += bytes((OP_PUSHDATA1, len_data))
+    elif len_data <= 0xffff:
+        data_array += bytes((OP_PUSHDATA2,)) + len_data.to_bytes(2, 'little')
+    else:
+        data_array += bytes((OP_PUSHDATA4,)) + len_data.to_bytes(4, 'little')
+
+    data_array += data