tools

Tools

A small Go web app built with Gin that provides a browser-based toolkit for:

• TLS certificate generation
• DNS record lookup
• SSL/TLS certificate inspection for a remote URL
• PEM inspection for pasted certificates, CSRs, private keys, and public keys

Requirements

• Go 1.24+
• Optional: Docker

Run locally

Start the app over HTTP on the default port:

go run .

The app listens on PORT if it is set, otherwise it uses 8080.

PORT=9090 go run .

Run with TLS

If both TLS_CERT_FILE and TLS_KEY_FILE are provided, the server starts with HTTPS:

PORT=8443 TLS_CERT_FILE=server.crt TLS_KEY_FILE=server.key go run .

If only one of TLS_CERT_FILE or TLS_KEY_FILE is set, startup fails.

Available tools

TLS Generator

Generate an RSA private key, public key, CSR, and self-signed certificate.

• Supports subject fields like common name, organization, OU, locality, state/province, and country
• Supports DNS SAN entries
• Supports RSA key sizes 2048, 3072, and 4096

DNS Lookup

Look up common DNS records for a hostname:

• A / AAAA
• CNAME
• MX
• NS
• TXT

TSL Check

Enter a URL and the app connects to the remote server over TLS and displays:

• Negotiated TLS version
• Cipher suite
• ALPN protocol
• Leaf certificate PEM
• Parsed certificate chain details

PEM Check

Paste PEM blocks directly into the UI to inspect:

• Certificates
• Certificate signing requests
• RSA private keys
• PKCS#8 private keys
• EC private keys
• Public keys

API endpoints

The UI uses these JSON endpoints:

• POST /api/tls/generate
• POST /api/dns/lookup
• POST /api/tsl/check
• POST /api/pem/check

Test and build

go test ./...
go build ./...

Docker

Build the image manually:

docker build -t bmallenxs/tools:latest .

Or use the helper script:

./publish.sh

The script builds the Docker image with the tag bmallenxs/tools:latest.