# JWT Authentication Fix for OnlyOffice Docs 7.1+

## Problem

The error you encountered:

```
[ERROR] nodeJS - auth missing required parameter document.key (since 7.1 version)
```

And the Chinese error dialog: "错误 - 文档安全令牌的格式不正确" (Document security token format is incorrect)

## Root Cause

Starting with OnlyOffice Docs version 7.1, when JWT authentication is enabled on the server, the entire configuration object must be signed with a JWT token. Simply passing a pre-generated JWT token as a separate field is not sufficient.

According to the [ONLYOFFICE signature documentation](https://api.onlyoffice.com/docs/docs-api/additional-api/signature/), the token must:

1. Be generated using the JWT secret key configured on the server
2. Include the entire configuration object (including `document.key` and all other parameters)
3. Use the HS256 algorithm

## Changes Made

### 1. Added JWT Package

**File: `pubspec.yaml`**

Added `dart_jsonwebtoken: ^2.14.1` to properly sign JWT tokens.

```yaml
dependencies:
  flutter:
    sdk: flutter
  crypto: ^3.0.7
  webview_flutter: ^4.13.0
  webview_flutter_android: ^4.10.10
  webview_flutter_wkwebview: ^3.0.0
  dart_jsonwebtoken: ^2.14.1  # NEW
```

### 2. Updated OnlyOfficeViewer Widget

**File: `lib/onlyoffice_viewer.dart`**

**Changed parameter name:**
- ❌ Old: `final String? token;`
- ✅ New: `final String? jwtSecret;`

**Updated JWT signing logic:**

```dart
// Sign the entire config with JWT if secret is provided
if (widget.jwtSecret != null && widget.jwtSecret!.isNotEmpty) {
  final jwt = JWT(config);
  final token = jwt.sign(SecretKey(widget.jwtSecret!), algorithm: JWTAlgorithm.HS256);
  config['token'] = token;
}
```

The key difference: Instead of just adding a pre-made token to the config, we now:
1. Create a JWT from the **entire config object**
2. Sign it with the **secret key** using HS256 algorithm
3. Add the resulting signed token to the config

### 3. Updated Example App

**File: `example/lib/main.dart`**

```dart
// Old:
static const String jwtToken = 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...';

// New:
static const String jwtSecret = '6Yr6DGoVV3ACS6GtVgdH453mXxLftd6Q';

// Usage:
OnlyOfficeViewer(
  onlyOfficeServerUrl: onlyOfficeServerUrl,
  fileUrl: currentDoc.url,
  jwtSecret: jwtSecret,  // Pass the secret, not a pre-made token
)
```

### 4. Updated Tests

**File: `test/onlyoffice_viewer_unit_test.dart`**

- Updated all test cases to use `jwtSecret` instead of `token`
- Added new test to verify JWT token generation and validation
- Updated TestHelper to match the real implementation

## How to Use

### For Your Server Configuration

You need to provide the **JWT secret** that matches your OnlyOffice server configuration. This secret is configured in your OnlyOffice server's `local.json`:

```json
{
  "services": {
    "CoAuthoring": {
      "secret": {
        "inbox": {
          "string": "YOUR_SECRET_HERE"
        },
        "outbox": {
          "string": "YOUR_SECRET_HERE"
        }
      },
      "token": {
        "enable": {
          "browser": true,
          "request": {
            "inbox": true,
            "outbox": true
          }
        }
      }
    }
  }
}
```

### Example Usage

```dart
OnlyOfficeViewer(
  onlyOfficeServerUrl: 'https://document.23544.com/',
  fileUrl: 'https://example.com/document.pptx',
  jwtSecret: '6Yr6DGoVV3ACS6GtVgdH453mXxLftd6Q', // Your server's JWT secret
)
```

## What Gets Signed

The JWT token now contains the entire configuration object:

```dart
{
  'document': {
    'fileType': 'pptx',
    'key': 'sha256_hash_of_url',
    'title': 'document.pptx',
    'url': 'https://example.com/document.pptx',
  },
  'documentType': 'slide',
  'editorConfig': {
    'mode': 'view',
    'lang': 'zh-CN'
  },
  'type': 'mobile',
}
```

This entire object is signed with HS256 algorithm using your secret, and the resulting JWT is added as the `token` field.

## Security Note

⚠️ **Never commit your JWT secret to version control!** 

Store it securely:
- Use environment variables
- Use secure configuration management
- Use encrypted secret storage

## References

- [ONLYOFFICE Signature Documentation](https://api.onlyoffice.com/docs/docs-api/additional-api/signature/)
- [JWT.io - Introduction to JSON Web Tokens](https://jwt.io/introduction)

## Testing

All tests pass successfully:

```bash
flutter test test/onlyoffice_viewer_unit_test.dart
# ✅ All 20 tests passed!
```