# Certificate Transparency Logs

`Certificate Transparency` (`CT`) logs are public, append-only ledgers that record the issuance of SSL/TLS certificates. Whenever a Certificate Authority (CA) issues a new certificate, it must submit it to multiple CT logs. Independent organizations maintain these logs and are open for anyone to inspect.

### <mark style="color:red;">**crt.sh lookup**</mark>

```bash
z3tssu@htb[/htb]$ curl -s "https://crt.sh/?q=facebook.com&output=json" | jq -r '.[]
 | select(.name_value | contains("dev")) | .name_value' | sort -u
 
*.dev.facebook.com
*.newdev.facebook.com
*.secure.dev.facebook.com
dev.facebook.com
devvm1958.ftw3.facebook.com
facebook-amex-dev.facebook.com
facebook-amex-sign-enc-dev.facebook.com
newdev.facebook.com
secure.dev.facebook.com
```