lab.johlem.net

Security reference platform — cheatsheets, tools, compliance resources.

French cybersecurity provider index for SMEs — Cyber PME scheme.

Luxembourg electronic network coverage maps and open data.

Dynamic map aggregating Luxembourg open data — transport, EV charging, infrastructure.

Mapping Luxembourg public cadastral and property open data.

Shared coffee cost tracker — log drinks, split bag costs, settle monthly balances.

Build Content-Security-Policy headers with visual interface and presets.

Score vulnerabilities using the official CVSS v3.1 methodology with Base, Temporal, and Environmental metrics.

Decode SSL/TLS certificates to view subject, issuer, validity, and extensions.

Scan package.json, requirements.txt, or composer.json for known CVEs via OSV.dev API.

Analyze email headers for phishing indicators, spoofing, and security threats.

Check SPF, DKIM, and DMARC records to validate email authentication.

Analyze iptables, UFW, and nftables rules for anomalies, shadowed rules, and overly permissive configurations.

Grade HTTP security headers A+ to F with per-header analysis, scoring, and fix recommendations.

Remove EXIF and metadata from images before sharing. Strip GPS, camera info, and identifying data.

Analyze URLs, domains, and content for phishing indicators and typosquatting.

Analyze SSL/TLS certificates with trust score, expiration alerts, and legitimacy indicators.

Analyze USB device lists from lsusb, PowerShell, or CSV exports to identify risky devices like potential BadUSB.

Decode QR codes from images — extract URLs with defanged copy for safe sharing in tickets and chat.

QRadar AQL query builder and reference for SOC analysts.

Safely defang and refang malicious indicators for secure SOC sharing.

Paste or import IOCs, link to incidents and systems, pivot between related objects, and export as CSV or STIX 2.1.

Build interactive incident timelines from log snippets with automatic timestamp normalization and JSON export.

Safely anonymize IPs, emails, JWT tokens, session IDs, and API keys in log snippets before sharing.

Interactive decision tree for SOC log triage with SIEM query templates and MITRE ATT&CK references.

Fast offline search across ATT&CK Enterprise techniques with detection guidance and SIEM cross-links.

Search and filter 30 SIEM query templates across QRadar AQL, Splunk SPL, and Microsoft Sentinel KQL.

Interactive decision trees for alert triage with QRadar AQL and Microsoft Defender KQL queries.

Generate professional security operations response emails and ticket descriptions from 100+ templates.

Aggregated security news, CVEs, and threat intel from 40+ sources (CISA, NVD, CERTs, vendors).

Build Sigma detection rules visually with live YAML preview and export to Splunk SPL, QRadar AQL, and Sentinel KQL.

Searchable database of 1000+ compliance specifications from NIST 800-53, DORA, GDPR, NIS2, and CRA frameworks.

Interactive DORA self-assessment covering all five pillars with Luxembourg CSSF specifics and exportable gap report.

Generate NIS2, DORA, and GDPR incident report templates with regulatory deadlines and severity classification.

Calculate IP ranges, subnets, and network addressing for infrastructure planning.

Map DNS infrastructure with visual network graphs, subdomain discovery, and ASN lookup.

Look up A, AAAA, MX, TXT, NS, CNAME, and SOA records for any domain with TTL and export.

Check if domain names are available across multiple TLDs using RDAP lookups.

Geolocate any IP address, view your browser fingerprint, and detect VPN/proxy usage with privacy analysis.

Analyze IPv4/IPv6 addresses with binary representation and range detection.

Look up MAC address vendor/manufacturer from OUI database.

Define, visualize, and validate authorized network flows between zones with matrix view and policy checks.

Look up network port information, security status, and common usage.

Look up domain registration information using RDAP (registrar, dates, nameservers).

Encrypt and decrypt text with AES-256-GCM using Web Crypto API and PBKDF2 key derivation.

Encode, decode, and detect text encodings: Hex, Binary, URL, HTML, Unicode, Base64, and more.

Generate, verify, and identify cryptographic hashes (MD5, SHA-256, SHA-512, bcrypt, and more).

Decode and analyze JSON Web Tokens for security issues and debugging.

Generate strong passwords, analyze strength with entropy and cracking time, and hash with bcrypt.

Generate Ed25519 and RSA SSH key pairs, analyze public keys with fingerprint and security assessment.

Generate and verify Time-based One-Time Passwords (RFC 6238) with provisioning URI builder.

Extract EXIF metadata from images client-side. GPS coordinates, camera info, timestamps for OSINT and forensics.

Generate professional Rules of Engagement and Scope documents for penetration testing and security assessments.

Assess LinkedIn profile exposure risk from an attacker perspective. Score identity leaks, job details, and posting behavior.

Create Apache .htaccess files with security, caching, and rewrite rules.

Parse CSV/TSV data and convert to JSON, SQL, HTML, or Markdown tables.

Compare two texts with side-by-side diff and unified format output.

Build HTTP requests and export as cURL, fetch, Python, PHP, and more.

Complete searchable reference of HTTP response status codes with descriptions and use cases.

Validate, format, and convert between JSON, YAML, and PHP array syntax with syntax highlighting and tree view.

Extract and list all links from any webpage with filtering and export options.

Look up MIME types by file extension for correct Content-Type headers.

Write Markdown with live preview and export as HTML or Markdown file.

Test Apache mod_rewrite rules and see URL transformations.

Generate realistic random test data: emails, usernames, IPs, domains, paths, MACs, UUIDs, and more.

Test regular expressions with highlighting, pattern library, and ReDoS protection.

Parse and analyze robots.txt files with URL testing and validation.

Format, beautify, and minify SQL queries with syntax highlighting.

Validate Apache and Nginx configuration syntax with best-practice checks.

Convert text between camelCase, snake_case, kebab-case, PascalCase, and more.

Strip HTML, remove diacritics, normalize whitespace, trim BOMs, fix line endings, and remove invisible characters.

Analyze text for word count, readability scores, and keyword density.

Parse URLs into components, encode/decode, and build URLs from parts.

Parse browser user agent strings to extract browser, OS, and device information.

Generate ASCII art text banners for MOTD, scripts, and terminal displays.

Complete ASCII character reference with decimal, hex, octal, and binary values.

Convert between number bases with step-by-step explanations and arithmetic.

Convert colors between HEX, RGB, HSL, CMYK with WCAG contrast checker.

Parse cron expressions, see next run times, and build schedules visually.

Generate favicons from text, emojis, or solid colors in multiple sizes.

Create .ics calendar event files compatible with Apple Calendar, Google Calendar, Outlook, and Thunderbird.

Generate placeholder text for design mockups in various formats and lengths.

Convert meeting times across timezones with business hours visualization and calendar export.

Convert text, hex, UUIDs, and hashes to NATO phonetic alphabet for clear verbal communication.

Generate QR codes for URLs, WiFi, contacts, and more with custom colors.

Paste output from uptime, free, df, top, or PowerShell to get CPU, RAM, disk, and IO health analysis.

Convert Unix timestamps to human-readable dates and vice versa, with batch conversion and timezone support.

Generate and validate UUIDs (v1, v4) with bulk generation support.

Calculate Unix/Linux file permissions (chmod) with visual editor.