If you have trouble creating a Letsencrypt certificate, one of the following tools may be helpful.
- Tools from active forum members:
1.1. Letsdebug - @_az
Checks a lot of things if the certificate creation doesn’t work. Option http/dns - checks. The main page is
with a Certificate Transparency search that removes duplicated pre/leaf-versions and some other features.
1.2 Unboundtest - Unbound DNS checker - @jsha
Use this server to make DNS queries against an Unbound instance and get logs. The Unbound instance is configured very similarly to Let’s Encrypt’s production servers, and is started fresh for each query so there are no caching effects.
1.3 Check your website - @JuergenAuer
Checks http / https / non-www / www to find wrong redirects and loops. Shows nameserver, dnssec, certificates, connection-settings and other dns-records (txt, CAA).
- Certificate Transparency Logs:
CRT / Comodo: https://crt.sh/
Use one of these search engines to find your certificates. Both are logging precertificates and leaf certificates. So creating one certificate -> two entries. Helpful if you don’t understand an Expiration mail (see https://letsencrypt.org/docs/expiration-emails/ ).
- Checking your DNS CAA configuration:
Use “Load Current Policy” to check if your CAA entry is correct. If your domain name is
- Checking your DNSSEC - configuration.
- Tools to check your DNS - propagation
https://tools.keycdn.com/ - with ipv6-, curl- and other online-checks, Certificate-request-check
https://dnschecker.org/ - allows A, AAAA, TXT and CAA - check
https://mxtoolbox.com/NetworkTools.aspx - mailserver, dns and other checks
- The Public Suffix List:
If you want to get a Letsencrypt certificate, your domain must end with a public suffix.
- If you want a certificate to secure your internal server, but you don’t have a domain name: There are some free domain provider.
Some of them have limitations. So if you have an important project, don’t use them.
You’ve got a new certificate. Now check your installation:
- Global SSL-configuration:
The main reference to check your SSL-configuration.
- The Mozilla website check - SSL and other parts
- Mozilla SSL Configuration Generator (Linux)
- IISCrypto (Windows 8 / 12 / 16)
Check your mixed content warnings: FireFox or Chrome (Desktop), Then Ctrl + Shift + I, open the console. There the wrong links are listed.
Has one limit: Doesn’t understand my own Letsencrypt EC-384 bit certificate. EC-256 works.
If you use cPanel, Plesk, Synology DiskStation Manager (DSM) or Pfsense: These tools have integrated solutions to create and install Letsencrypt certificates. So it’s the best idea to use these tools. Don’t mix them with command line tools.
- The Google HSTS Preload list
Requires Strict Transport Security header, domains are added to the Chrome Source code. Then browsers load the domain only via https.
- Static pages with configurations (no interactive online check):
- Certificate Transparency Search Engine with API: https://censys.io/
Ideas, questions, other tools? Send a message or use the contact form of my profile link. Or use this topic: