feat: add CLI command to download and cache the RB6 db key from the w…

…eb (#64)

Pyrekordbox tries to download the key from projects that have hard-coded the key (see issue #77). If the download was successful it writes it to the cache file.

README.md

@@ -244,6 +244,13 @@ from pyrekordbox import Rekordbox6Database
 write_db6_key_cache("<insert key here>")  # call once
 db = Rekordbox6Database()
 ````
+The command line interface of ``pyrekordbox`` also
+provides a command for downloading the key from known sources and writing it to the
+cache file:
+````shell
+> python -m pyrekordbox download-key
+````
+
 
 ## 💡 File formats
 

docs/source/tutorial/db6.md

@@ -56,6 +56,12 @@ from pyrekordbox import Rekordbox6Database
 write_db6_key_cache("<insert key here>")  # call once
 db = Rekordbox6Database()
 ````
+The command line interface of ``pyrekordbox`` also
+provides a command for downloading the key from known sources and writing it to the
+cache file:
+````shell
+> python -m pyrekordbox download-key
+````
 
 
 

pyrekordbox/__main__.py

@@ -3,8 +3,29 @@
 # Date:   2023-08-15
 
 import os
+import re
 import sys
 import shutil
+import urllib.request
+from pyrekordbox.config import write_db6_key_cache, _cache_file
+
+# fmt: off
+KEY_SOURCES = [
+    {
+        "url": r"https://raw.githubusercontent.com/mganss/CueGen/19878e6eb3f586dee0eb3eb4f2ce3ef18309de9d/CueGen/Generator.cs",  # noqa: E501
+        "regex": re.compile(
+            r'((.|\n)*)Config\.UseSqlCipher.*\?.*"(?P<dp>.*)".*:.*null',
+            flags=re.IGNORECASE | re.MULTILINE
+        )
+    },
+    {
+        "url": r"https://raw.githubusercontent.com/dvcrn/go-rekordbox/8be6191ba198ed7abd4ad6406d177ed7b4f749b5/cmd/getencryptionkey/main.go",  # noqa: E501
+        "regex": re.compile(
+            r'((.|\n)*)fmt\.Print\("(?P<dp>.*)"\)',
+            flags=re.IGNORECASE | re.MULTILINE)
+    }
+]
+# fmt: on
 
 
 class WorkingDir:
@@ -124,12 +145,39 @@ def install_pysqlcipher(
             print(f"Could not remove temporary directory '{tmpdir}'!")
 
 
+def download_db6_key():
+    dp = ""
+    for source in KEY_SOURCES[1:]:
+        url = source["url"]
+        regex = source["regex"]
+        print(f"Looking for key: {url}")
+
+        res = urllib.request.urlopen(url)
+        data = res.read().decode("utf-8")
+        match = regex.match(data)
+        if match:
+            dp = match.group("dp")
+            break
+    if dp:
+        print(f"Found key, updating cache file {_cache_file}")
+        write_db6_key_cache(dp)
+    else:
+        print("No key found in the online sources.")
+
+
 def main():
     from argparse import ArgumentParser
 
     parser = ArgumentParser("pyrekordbox")
     subparsers = parser.add_subparsers(dest="command")
 
+    # Download Rekordbx 6 database key command
+    subparsers.add_parser(
+        "download-key",
+        help="Download the Rekordbox 6 database key from the internet "
+        "and write it to the cache file.",
+    )
+
     # Install pysqlcipher3 command (Windows only)
     install_parser = subparsers.add_parser(
         "install-sqlcipher",
@@ -164,7 +212,9 @@ def main():
 
     # Parse args and handle command
     args = parser.parse_args(sys.argv[1:])
-    if args.command == "install-sqlcipher":
+    if args.command == "download-key":
+        download_db6_key()
+    elif args.command == "install-sqlcipher":
         if sys.platform == "win32":
             install_pysqlcipher(
                 args.tmpdir, args.cryptolib, args.fixquote, install=not args.buildonly