Add Dogecoin wallet extraction script

docs/changes.txt

@@ -134,6 +134,7 @@
 - Help: show supported hash-modes only with -hh
 - Makefile: prevent make failure with Apple Silicon in case of partial rebuild
 - Rules: Rename best64.rule to best66.rule and remove the unknown section from it
+- Tools: Added new dogechain2hashcat.py extraction script.
 
 * changes v6.2.5 -> v6.2.6
 

tools/dogechain2hashcat.py

@@ -0,0 +1,45 @@
+#!/usr/bin/env python3
+
+#
+# Author......: See docs/credits.txt
+# License.....: MIT
+#
+
+import json
+from argparse import ArgumentParser
+from base64 import b64decode, b64encode
+
+
+if __name__ == "__main__":
+    # prepare parser and parse args
+    parser = ArgumentParser(description="dogechain2hashcat extraction tool")
+    parser.add_argument("path", type=str, help="path to dogechain wallet")
+    args = parser.parse_args()
+
+    try:
+        # open wallet file
+        with open(args.path) as file:
+            wallet = json.load(file)
+        # verify basic fields
+        if ("pbkdf2_iterations" not in wallet) or ("payload" not in wallet) or ("salt" not in wallet):
+            parser.error("Unsupported wallet format")
+        # variant
+        if ("cipher" not in wallet) or (wallet["cipher"].upper() == "AES-CBC"):
+            variant = 0
+        elif wallet["cipher"].upper() == "AES-GCM":
+            variant = 1
+        else:
+            parser.error("Unsupported wallet cipher variant")
+        # iterations
+        iterations = wallet["pbkdf2_iterations"]
+        # payload
+        payload = b64decode(wallet["payload"])
+        payload = payload[:240]  # payload length must be equal to 320
+        payload = b64encode(payload)
+        payload = payload.decode()
+        # salt
+        salt = wallet["salt"]
+        # print
+        print("$dogechain$" + "*".join([str(variant), str(iterations), payload, salt]))
+    except IOError as e:
+        parser.error(e.strerror.lower())