WeChat v4.1.1.4 Linux Flatpak: "file is not a database

[hupeipei125]

WeChat v4.1.1.4 Linux Flatpak: wx sessions returns "file is not a database"

Environment

Item	Value
WeChat version	4.1.1.4 (Flatpak, com.tencent.WeChat)
OS	Debian 12 (LXD container)
wx-cli version	0.3.0
Install method	npm install -g @jackwener/wx-cli

Steps to reproduce

1. Install WeChat via Flatpak on Linux
2. Launch WeChat with QT_SCALE_FACTOR=1.5 (otherwise QR code renders split on Xvfb)
3. Scan QR code to log in
4. WeChat data directory structure (WeChat v4 uses db_storage/ instead of Msg/):

xwechat_files/
├── wxid_xxx_4433/
│   ├── db_storage/
│   │   ├── message/
│   │   │   ├── message_0.db       (26 MB)
│   │   │   ├── message_fts.db     (52 MB)
│   │   │   └── message_resource.db
│   │   ├── session/
│   │   │   └── session.db         (69 KB)
│   │   ├── contact/
│   │   │   └── contact.db         (2 MB)
│   │   └── ...

5. Create symlinks to match expected structure:

ln -sfn db_storage/message message
ln -sfn db_storage/session session
ln -sfn db_storage/contact contact

6. Keys extracted from /proc/<pid>/mem using x'<64hex><32hex>' pattern — 15 keys found, salts match all database files correctly.

7. all_keys.json created with matched enc_key + salt pairs.

Expected behavior

wx sessions should list recent chat sessions.

Actual behavior

$ HOME=/home/agent wx sessions
启动 wx-daemon...
错误: file is not a database

Daemon log shows:

[daemon] DB_DIR: .../wxid_xxx_4433
[daemon] 密钥数量: 2
[cache] 全量解密 session/session.db (0ms)
[daemon] 预热完成，联系人 0 个

The cached "decrypted" DB has correct SQLite magic header (SQLite format 3\0) but bytes 16+ are garbage (invalid page size 6806, etc.).

Manual verification

• AES-256-CBC decryption of session.db page 1 with extracted key produces valid SQLite format 3\0 magic but garbage after byte 16 — confirming key extraction is correct but decryption parameters may differ for v4 Flatpak.
• Same issue with message_0.db (26 MB).
• sqlcipher CLI with PRAGMA key = "x'<key>'" also returns "file is not a database".

Additional context

• Similar to issue 查询公众号推送(wx biz-articles )偶尔提示 错误: file is not a database #84 ("file is not a database" for biz-articles)
• WeChat v4 uses db_storage/ directory structure (not traditional Msg/)
• Database files have WAL files (session.db-wal, message_0.db-wal, etc.)
• SQLCipher page size: 4096, RESERVE_SIZE: 80

Workaround attempted

• Manual Python decryption with cryptography library (AES-256-CBC, matching wx-cli's decrypt_page logic)
• sqlcipher CLI with various PRAGMA settings
• All produce same result: correct magic header, garbage data