certificate-transparency

What problem does it solve?

Certificate Transparency (CT) logs often reveal how a domain is actually used in the wild, but manually searching and extracting subject alternative names (SANs) is time-consuming and error-prone.

Core Features & Use Cases

• Query CT logs for certificates: Retrieves certificate records from crt.sh for a target domain and collects issuer and validity metadata.
• Extract and validate SAN-based subdomains: Splits and deduplicates SAN entries to produce a clean list of unique subdomains for reconnaissance.
• Detect naming patterns and wildcard usage: Infers internal conventions via regex patterns and flags wildcard certificate scopes to highlight potential security exposure.
• Use Case: Find previously unknown subdomains and infer environment/service naming conventions for a given domain to support security review and asset inventory.

Quick Start

Use the skill to analyze certificates for example.com and return unique subdomains, detected naming patterns, issuer counts, and wildcard certificate findings.