Horde ActiveSync Implementation

AI generated on 2025 april 19th

Overview

Horde ActiveSync is a robust implementation of the Microsoft Exchange ActiveSync (EAS) protocol, designed to provide synchronization capabilities between mobile devices and email servers. This implementation supports various EAS protocol versions and provides a flexible framework for integrating with different backend systems.

System Architecture

Core Components

1. ActiveSync Server (Horde_ActiveSync)

   • Main entry point for all ActiveSync operations
   • Handles protocol version negotiation
   • Manages device authentication and state
   • Coordinates between different components

2. Protocol Handlers

   • Supports multiple EAS protocol versions (2.5, 12.0, 12.1, 14.0, 14.1, 16.0)
   • Handles protocol-specific features and requirements
   • Manages version-specific headers and responses

3. State Management

   • Device state persistence
   • Sync state tracking
   • Policy enforcement
   • Device provisioning

4. Data Synchronization

   • Folder hierarchy management
   • Item synchronization
   • Conflict resolution
   • Change tracking

Key Features

• Multi-Protocol Support

  • Supports EAS versions 2.5 through 16.0
  • Automatic version negotiation
  • Backward compatibility

• Security

  • Device authentication
  • Policy enforcement
  • Remote wipe capabilities
  • Certificate validation

• Data Synchronization

  • Email synchronization
  • Calendar synchronization
  • Contact synchronization
  • Task synchronization
  • Notes synchronization

• Device Management

  • Device provisioning
  • Policy enforcement
  • Device state tracking
  • Remote wipe capabilities

Protocol Support

Supported Commands

• Sync
• SendMail
• SmartForward
• SmartReply
• GetAttachment
• GetHierarchy
• CreateCollection
• DeleteCollection
• MoveCollection
• FolderSync
• FolderCreate
• FolderDelete
• FolderUpdate
• MoveItems
• GetItemEstimate
• MeetingResponse
• Search
• Settings
• Ping
• ItemOperations
• Provision
• ResolveRecipients
• ValidateCert

Supported Data Types

• Email
• Contacts
• Calendar
• Tasks
• Notes
• SMS

Integration Points

1. Backend Driver

   • Abstract interface for backend integration
   • Customizable authentication
   • Data access layer

2. State Storage

   • Device state persistence
   • Sync state management
   • Policy storage

3. Logging

   • Flexible logging system
   • Debug capabilities
   • Error tracking

Security Features

1. Authentication

   • User authentication
   • Device authentication
   • Domain support

2. Policy Enforcement

   • Device policies
   • Security policies
   • Remote wipe capabilities

3. Data Protection

   • Secure communication
   • Certificate validation
   • Data encryption

Technical Details

Protocol Versions

• 2.5 (6.5.7638.1)
• 12.0
• 12.1
• 14.0
• 14.1
• 16.0

Data Formats

• WBXML encoding/decoding
• Multipart support
• MIME handling
• Truncation support

Performance Considerations

• Memory usage optimization
• Data truncation options
• Batch processing
• State caching

Integration Guide

Backend Integration

1. Implement Horde_ActiveSync_Driver_Base
2. Configure authentication
3. Implement data access methods
4. Set up state storage

Configuration

1. Set up logging
2. Configure protocol versions
3. Set security policies
4. Configure device management

Best Practices

1. Security

   • Implement proper authentication
   • Enforce device policies
   • Monitor device access

2. Performance

   • Optimize data access
   • Implement proper caching
   • Monitor resource usage

3. Maintenance

   • Regular state cleanup
   • Monitor device connections
   • Update security policies

Dependencies

• PHP 7.0 or higher
• Horde Framework
• WBXML support
• SSL/TLS support

License

This software is licensed under the GPLv2 license. See the LICENSE file for details.