🛡️ Web Security Guard

🌟 Overview

Web Security Guard (web-security-guard) is a zero-dependency, high-performance security automation suite and interactive Web Security Studio (design influenced by Material 3). Built for developers, DevOps engineers, and autonomous AI coding agents, it eliminates the complexity of securing modern web applications against Cross-Site Scripting (XSS), Clickjacking, MIME confusion, and supply chain tampering.

                  ┌───────────────────────────────────────────────┐
                  │          Web Security Studio UI               │
                  │   Material 3 Influenced  •  0-100 Grade Gauge │
                  └───────────────────────┬───────────────────────┘
                                          │
        ┌───────────────────┬─────────────┴───────┬───────────────────┐
        ▼                   ▼                     ▼                   ▼
┌───────────────┐   ┌───────────────┐     ┌───────────────┐   ┌───────────────┐
│ Live Auditor  │   │ CSP Level 3   │     │  SRI Engine   │   │   WCAG 2.2    │
│ Headers & SSR │   │ Nonces & Next │     │ Hashes & Tag  │   │ Color Contrast│
│ 10+ Vectors   │   │ Multi-Platform│     │ Auto-Inject   │   │ CB Simulation │
└───────┬───────┘   └───────┬───────┘     └───────┬───────┘   └───────┬───────┘
        │                   │                     │                   │
        └───────────────────┼─────────────────────┼───────────────────┘
                            ▼                     ▼
                  ┌───────────────────────────────────────────────┐
                  │        Model Context Protocol (MCP) Hub       │
                  │  Claude Desktop • Cursor • Cline • Zed • CLI  │
                  └───────────────────────────────────────────────┘

Related MCP server: Sekrd Security Scanner

🚀 Key Features

1. 🛡️ Multi-Vector Security Header Auditor

• Audits live websites or response headers against OWASP Top 10 and modern web security guidelines.

• Computes an animated 0–100 Security Grade Gauge ($A+, A, B, C, D, F$).

• Evaluates:

  • Strict-Transport-Security (HSTS duration, subdomains, preloading).

  • Content-Security-Policy Level 3.

  • X-Frame-Options & CSP frame-ancestors.

  • X-Content-Type-Options: nosniff.

  • Referrer-Policy, Permissions-Policy, COOP, COEP, CORP.

  • RFC 6265bis Cookie Hardening (Secure, HttpOnly, SameSite, __Host- prefixes).

  • Information Leakage detection (Server, X-Powered-By).

2. 🔒 CSP Level 3 Policy Builder & Framework Exporter

• Interactive synthesis of modern 'strict-dynamic' policies with per-request cryptographic nonces.

• Eliminates vulnerable domain allowlists.

• Generates 1-click drop-in configurations for:

  • Next.js 14/15 App Router (middleware.ts)

  • Nginx (nginx.conf)

  • Vercel (vercel.json)

  • Netlify (_headers and netlify.toml)

  • Cloudflare Workers

  • Apache (.htaccess)

  • Express.js (helmet)

3. 🧬 Subresource Integrity (SRI) Hasher & HTML Injector

• Computes SHA-256, SHA-384, and SHA-512 base64 digests for local files or remote CDN bundles.

• Automated HTML Batch Injector parses raw HTML and inserts integrity and crossorigin="anonymous" tags to protect against supply-chain attacks.

4. 🎨 WCAG 2.2 Color Contrast & Color Blindness Simulator

• Exact relative luminance ($L = 0.2126 R + 0.7152 G + 0.0722 B$) calculation.

• Live compliance validation for WCAG AA Normal (4.5:1), AA Large (3:1), UI Components (3:1), and AAA Normal (7:1).

• Integrated matrix transformation simulation for Protanopia, Deuteranopia, Tritanopia, and Achromatopsia.

5. 🔑 High-Fidelity Secret Leakage & API Key Scanner

• Audits HTML, JS, JSON, and source bundles for 25+ exposed credential types.

• Detects AWS keys, GitHub PATs, Stripe keys, OpenAI/Anthropic tokens, Slack webhooks, Twilio SIDs, SendGrid keys, private RSA/EC keys, database connection strings, and JWTs.

• Computes Shannon entropy per token to filter false positives and auto-redacts sensitive substrings (sk_live_...4a2f).

6. 📦 Supply Chain, Script Integrity & Mixed Content Auditor

• Scans web documents for third-party <script>, <link>, <iframe>, <form>, and <a> elements.

• Detects missing Subresource Integrity (integrity="sha384-...") on external CDNs.

• Blocks Mixed Content (RFC 6797) HTTP assets on HTTPS origins and alerts on unpinned CDN releases (@latest).

• Flags Reverse Tabnabbing (target="_blank" without rel="noopener noreferrer") and insecure form POST endpoints.

7. 🤖 AI Agent Model Context Protocol (MCP) Hub

• Out-of-the-box MCP server compatible with Claude Desktop, Cursor AI, Cline, Roo Code, and Zed Editor.

• 12 registered tools including sec_scan_secrets, sec_audit_supply_chain, sec_audit_isolation, sec_audit_site, sec_generate_csp, and sec_check_contrast.

8. ⚡ Multi-Platform Hardening Exporter

• 1-click .zip bundle export containing pre-configured security files for your entire infrastructure stack.

📦 Installation & Quickstart

Option A: Run via uvx (Zero Install)

# Start the Web Security Studio UI
uvx web-security-guard serve --port 8080 --open

# Audit a live URL directly from CLI
uvx web-security-guard audit https://example.com

Option B: Install via pip

pip install web-security-guard

💻 CLI Usage

# 1. Audit a live website with interactive report
web-sec-guard audit https://google.com

# 2. Audit and output machine-readable JSON
web-sec-guard audit https://example.com --format json

# 3. Generate Level 3 CSP for Next.js App Router
web-sec-guard csp --preset strict_nonce --export nextjs

# 4. Compute Subresource Integrity for CDN script
web-sec-guard sri https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/js/bootstrap.bundle.min.js

# 5. Check WCAG 2.2 Color Contrast
web-sec-guard contrast --fg "#1a73e8" --bg "#ffffff"

# 6. Scan files or bundles for leaked API keys, tokens & credentials
web-sec-guard secrets ./dist/bundle.js

# 7. Audit third-party script supply chain, SRI & mixed content
web-sec-guard supply ./index.html

# 8. Launch Web Security Studio Web UI
web-sec-guard serve --host 127.0.0.1 --port 8080 --open

🐍 Python SDK

from web_security_guard import (
    SecurityAuditEngine,
    CSPBuilderEngine,
    SRIEngine,
    WCAGContrastEngine,
)

# 1. Run live audit
audit = SecurityAuditEngine.fetch_and_audit("https://example.com")
print(f"Grade: {audit['grade']} (Score: {audit['score']}/100)")

# 2. Build CSP Level 3 policy
csp_data = CSPBuilderEngine.generate({"preset": "strict_nonce"})
print("Next.js Middleware:\n", csp_data["frameworks"]["nextjs"])

# 3. Compute SRI hash
sri = SRIEngine.hash_content_or_url(url="https://cdn.example.com/app.js")
print("SRI Tag:", sri["script_tag"])

# 4. Evaluate WCAG 2.2 Contrast
contrast = WCAGContrastEngine.evaluate("#1a73e8", "#ffffff")
print(f"Ratio: {contrast['ratio_formatted']} | AA: {contrast['wcag_aa_normal']}")

# 5. Scan assets for leaked API keys & credentials
from web_security_guard import scan_secrets
secret_report = scan_secrets('const key = "sk-ant-api03-1234567890abcdef1234567890abcdef";')
print(f"Secrets Found: {secret_report.total_findings}, Clean: {secret_report.clean}")

# 6. Audit supply chain & subresource integrity
from web_security_guard import audit_supply_chain
supply_report = audit_supply_chain('<script src="http://insecure.com/script.js"></script>')
print(f"Supply Chain Grade: {supply_report.grade}, Score: {supply_report.supply_chain_score}/100")

🤖 MCP Client Configuration for AI Agents

Add web-security-guard to your AI editor or Claude Desktop config:

{
  "mcpServers": {
    "web-security-guard": {
      "command": "uvx",
      "args": ["web-security-guard", "mcp"]
    }
  }
}

Detailed guides for Cursor, Cline, Zed, and Claude Desktop are available in docs/MCP_GUIDE.md.

📚 Documentation & Reference Examples

• 🔒 CSP Level 3 Best Practices: Deep dive into 'strict-dynamic', nonces, and bypassing allowlist pitfalls.

• 📋 Multi-Platform Deployment Matrix: Framework configurations for Next.js, Vercel, Netlify, Nginx, Cloudflare, Express, and Apache.

• 🤖 MCP Integration Guide: Complete tool signatures and prompt scenarios for LLM agents.

• 📁 Production Reference Examples:

  • nextjs-app-router/: Next.js 14/15 edge middleware with crypto nonces.

  • vercel-headers/: Hardened vercel.json.

  • netlify-headers/: Production _headers and netlify.toml.

  • nginx-hardening/: TLS 1.3, rate-limiting, and security headers nginx.conf.

  • cdn-sri-html/: HTML5 document with SHA-384 Subresource Integrity.

  • mcp-clients/: Agent configs for Claude, Cursor, Cline, and Zed.

🧪 Testing & CI

# Run unit tests with pytest
PYTHONPATH=src pytest tests/ -v

All 15 GitHub Actions test matrix jobs run on Python 3.9 through 3.13 on Ubuntu, macOS, and Windows.

📄 License

Licensed under the Apache License, Version 2.0. See LICENSE for details.