# MsgLib.db readability and wrapper-path precheck

Date: 2026-07-10

## Question

Why are the copied `MsgLib.db` files not directly readable as SQLite, and what is the safest next path for extracting contact/group display names and richer message metadata?

## Evidence checked

- Existing ignored metadata:
  - `runs/offline-evidence-intake/zyl-qqfile-20260709/metadata/schema-inspection-summary.json`
  - `runs/offline-evidence-intake/zyl-qqfile-20260709/metadata/archive-list.txt`
- New ignored C24 metadata:
  - `runs/offline-evidence-intake/zyl-qqfile-20260709/metadata/c24-msglib-format-precheck.json`
  - `runs/offline-evidence-intake/zyl-qqfile-20260709/metadata/c24-wrapper-string-precheck.json`
- Read-only extracted wrapper candidates under ignored:
  - `runs/offline-evidence-intake/zyl-qqfile-20260709/extracted/c24-wrapper-candidates/`

No raw DB bytes, decrypted messages, or personal values are committed in this note.

## Findings

1. The three inspected `MsgLib.db` copies do not start with SQLite magic and contain no SQLite header within the first 1 MiB sample.
2. The inspected DB samples have high entropy and the same non-SQLite prefix shape across iSphere and IMPP account copies. This strongly suggests a consistent encrypted/wrapped DB format rather than a random corrupt copy.
3. The archive contains standard SQLite libraries, DB abstraction libraries, and a repair tool next to `MsgLib.db`:
   - `System.Data.SQLite.dll`
   - `Utilities.Lib.DBSQLite.dll`
   - `Utilities.Lib.SQLiteInteraction.dll`
   - `Utilities.Lib.SQLiteInteractionBase.dll`
   - `Utilities.Lib.DBBase.dll`
   - `Utilities.Lib.DBModel.dll`
   - `HYHC.IMPP.DAL.dll`
   - `RepairDatabase.exe`
4. String-only static scanning of wrapper candidates shows that `HYHC.IMPP.DAL.dll` and `RepairDatabase.exe` reference message/group DB behavior and candidate table/method names, including:
   - `tblMsgGroupPersonMsg`
   - `ImportOldDataBase`
   - `GetGroupMessaeByID`
   - `GetGroupRecentMsg`
   - `UpdateGroupName`
   - `SelectMsgGroupName`
   - `SelectRecentGroupName`
   - `SaveGroupInfomation`
   - `groupJid`
   - `set_MemberJid`
   - `set_MsgGroupName`
   - `set_MemberName`
   - `get_naturalname`
5. `Utilities.Lib.SQLiteInteraction.dll` exposes `SQLiteConnectionStringBuilder` plus `get_Password` and `set_Password`.
6. `Utilities.Lib.DBModel.dll` exposes configuration concepts such as `IConStrDecryption`, `PasswordPropertyName`, and `DecryptionPropertyName`.
7. `smcrypto-*` and `BouncyCastle.Crypto.dll` are present, but C24 does not prove they are the actual `MsgLib.db` wrapper. They are supporting crypto candidates only.

## Decision

Do not treat `MsgLib.db` as ordinary SQLite.

The best current hypothesis is:

> `MsgLib.db` is an encrypted or wrapped SQLite database opened through the client DB abstraction layer, likely involving `Utilities.Lib.SQLiteInteraction*`, `Utilities.Lib.DBModel`, and `HYHC.IMPP.DAL`.

The next safe implementation path is not direct DB reads. It is static wrapper analysis first:

1. Inspect .NET metadata/IL for the DB wrapper assemblies.
2. Identify how connection strings/password/decryption are supplied.
3. Identify table names and model classes for message, contact, group, member, and display-name fields.
4. Only after that, attempt a read-only schema extraction on copied DB files under ignored paths.

## Next slice

C25 should perform a read-only static .NET wrapper analysis over the extracted candidate assemblies. It should produce table/model/source mappings only, not execute the client and not write to the original DB.

Suggested C25 focus:

- `HYHC.IMPP.DAL.dll`
- `Utilities.Lib.SQLiteInteraction.dll`
- `Utilities.Lib.DBModel.dll`
- `Utilities.Lib.DBSQLite.dll`
- `RepairDatabase.exe`

Expected output:

- candidate table names;
- candidate model/property names for contact/group/message metadata;
- likely connection-string/password/decryption flow;
- decision whether C26 can attempt a copied-DB read-only schema extraction.