trying to extract django session manually

extract_session.py

from django.conf import settings

import base64
import json
from django.core.management.base import BaseCommand
from django.core.signing import Signer, BadSignature
from django.conf import settings


class Command(BaseCommand):
    help = "Extract and decode session data from django_session table or session ID string."

    def add_arguments(self, parser):
        """
        コマンド引数を定義する
        """
        pass
        # parser.add_argument(
        #     "session_data",
        #     type=str,
        #     help="Raw session data string from the Django session table",
        # )
        # parser.add_argument(
        #     "--secret",
        #     type=str,
        #     default=None,
        #     help="Optional secret key for manual unsigned verification (default: Django SECRET_KEY)",
        # )

    def handle(self, *args, **options):
        session_data = "eyJudW0iOjB9:1tkbpN:Z-LnQJetmMWEDEiwCAD-FthyF2EvtsUTg4CZkjP0O2Q"
        # session_data = options["session_data"]
        # secret_key = options["secret"]  # SECRET_KEYを指定可能
        # secret_key = settings.SECRET_KEY  # SECRET_KEYを指定可能

        # if not secret_key:
        #     from django.conf import settings
        #
        #     secret_key = settings.SECRET_KEY
        print(f"SECRET_KEY: {settings.SECRET_KEY}")
        secret_key = settings.SECRET_KEY

        try:
            decoded_data = self.extract_session_data(session_data, secret_key)
            self.stdout.write(self.style.SUCCESS("Decoded session data:"))
            self.stdout.write(json.dumps(decoded_data, indent=2, ensure_ascii=False))
        except ValueError as e:
            self.stderr.write(self.style.ERROR(f"Error decoding session data: {e}"))

    def extract_session_data(self, session_data, secret_key):
        """
        セッションデータを抽出し、署名の確認とデコードを行う
        """
        # `:`で右から1回だけ分割し、署名を分離
        if ":" not in session_data:
            raise ValueError("Invalid session format: missing ':' separator")
        value, sig = session_data.rsplit(":", 1)
        self.stdout.write(f"1. Value: {value}")
        self.stdout.write(f"2. Signature: {sig}")

        # 署名を検証
        signer = Signer(key=secret_key)
        try:
            unsigned_value = signer.unsign(f"{value}:{sig}")  # データ+署名全体の検証
        except BadSignature as e:
            raise ValueError(f"Invalid signature: {e}")
        self.stdout.write("3. Signature verification successful!")

        # Base64デコード（パディング補正後）
        try:
            decoded_data = base64.b64decode(self.fix_base64_padding(unsigned_value))
        except base64.binascii.Error as e:
            raise ValueError(f"Error in Base64 decoding: {e}")
        self.stdout.write(f"4. Decoded base64 data: {decoded_data}")

        # JSONデコード
        try:
            session_dict = json.loads(decoded_data.decode("utf-8"))
        except json.JSONDecodeError as e:
            raise ValueError(f"Error decoding session as JSON: {e}")
        self.stdout.write("5. Successfully decoded JSON!")

        return session_dict

    @staticmethod
    def fix_base64_padding(encoded_data):
        """
        Base64パディングを修正（文字数が4の倍数になるよう補正）
        """
        missing_padding = len(encoded_data) % 4
        if missing_padding != 0:
            encoded_data += "=" * (4 - missing_padding)
        return encoded_data


# class Command(BaseCommand):
#     help = "Extract and decode session data from django_session table"
#
#     def handle(self, *args, **options):
#         print(f"SESSION_COOKIE_NAME: {settings.SESSION_COOKIE_NAME}")
#         print(f"SECRET_KEY: {settings.SECRET_KEY}")
#         # セッションデータの確認対象（仮のテストデータ）
#         session_data = ".eJxVjMsOwiAURP-FtSHA5SEu3fsN5F4eUjWQlHZl_HfbpAtdzpwz82YB16WGdeQ5TIldmGSn344wPnPbQXpgu3cee1vmifiu8IMOfuspv66H-3dQcdRtTRRROCu01-6MQNaDLUJriaIYoiRUQSJQEgz46LQtBbTZQrE-Kojs8wXWvjdh:1tkcFa:S3ACKYM5m3OV0Xefq3ctkEzVgfxLcL1aIBkoDoT82uw"  # django_sessionテーブルから取得した値
#
#         # セッションデータのデコード
#         try:
#             session_dict = extract_session_data(session_data)
#             self.stdout.write(f"Decoded session data: {session_dict}")
#         except ValueError as e:
#             self.stderr.write(f"Error: {e}")

現在未完成です