BlazorFrame 2.1.0

BlazorFrame

A security-first Blazor iframe component with automatic resizing, cross-frame messaging, and comprehensive Content Security Policy integration.

Features

• Security-First Design - Built-in origin validation, message filtering, and sandbox isolation
• Content Security Policy - Comprehensive CSP integration with fluent configuration API
• Cross-Frame Messaging - Secure postMessage communication with validation
• Sandbox Support - Multiple security levels from permissive to paranoid isolation
• Environment-Aware - Different configurations for development vs production
• Automatic Resizing - Smart height adjustment based on iframe content

Documentation

Complete Documentation

• Quick Start Guide

• Security Features

  • Configuration Validation
  • Sandbox

• Configuration Guide

• Real-world Examples

• API Reference

• Troubleshooting

🚀 Quick Start

Installation

dotnet add package BlazorFrame

Basic Usage

@using BlazorFrame


<BlazorFrame Src="https://example.com" />


<BlazorFrame Src="https://widget.example.com"
            SecurityOptions="@securityOptions"
            OnValidatedMessage="HandleMessage"
            OnSecurityViolation="HandleViolation" />

@code {
    private readonly MessageSecurityOptions securityOptions = new MessageSecurityOptions()
        .ForProduction()        // Strict security settings
        .WithBasicSandbox()     // Enable iframe sandboxing
        .RequireHttps();        // Enforce HTTPS transport
        
    private Task HandleMessage(IframeMessage message)
    {
        Console.WriteLine($"Received message from {message.Origin}: {message.Data}");
        return Task.CompletedTask;
    }

    private Task HandleViolation(IframeMessage violation)
    {
        Console.WriteLine($"Security violation: {violation.ValidationError}");
        return Task.CompletedTask;
    };
}

Configuration Examples

// Development environment - relaxed security
var devOptions = new MessageSecurityOptions()
    .ForDevelopment()
    .WithPermissiveSandbox();

// Production environment - strict security
var prodOptions = new MessageSecurityOptions()
    .ForProduction()
    .WithStrictSandbox()
    .ValidateAndThrow();

// Payment widgets - maximum security
var paymentOptions = new MessageSecurityOptions()
    .ForPaymentWidget();

Content Security Policy

<BlazorFrame Src="https://widget.example.com"
            CspOptions="@cspOptions"
            OnCspHeaderGenerated="HandleCspGenerated" />

@code {
    private readonly CspOptions cspOptions = new CspOptions()
        .ForProduction()
        .AllowFrameSources("https://widget.example.com")
        .WithScriptNonce("secure-nonce-123");
        
    private Task HandleCspGenerated(CspHeader cspHeader)
    {
        // Apply CSP header to HTTP response
        // HttpContext.Response.Headers.Add(cspHeader.HeaderName, cspHeader.HeaderValue);
        return Task.CompletedTask;
    }
}

Security Features

Sandbox Security Levels

Message Validation

All iframe messages are automatically validated for:

• Origin verification - Ensures messages come from allowed domains
• Content validation - JSON structure and size limits
• Security filtering - Blocks malicious patterns and script injection
• Custom validation - Extensible validation pipeline

Demo

Interactive Demo - Try different security configurations live

Requirements

• .NET 8.0 or later
• Blazor Server or Blazor WebAssembly
• Modern browser with ES6 modules support

Browser Support

• Chrome 91+
• Firefox 90+
• Safari 15+
• Edge 91+

Support

• Issues: GitHub Issues
• Discussions: GitHub Discussions
• NuGet: BlazorFrame Package

License

This project is licensed under the MIT License.

Built with ❤️ for the Blazor community