Simon Willison’s Weblog

4 items tagged “tls”


trustme (via) This looks incredibly useful. Run “python -m trustme” and it will create three files for you: server.pem, server.key and a client.pem client certificate, providing a certificate for “localhost” (or another host you spefict) using a fake certificate authority. Looks like it should be the easiest way to test TLS locally. # 11th February 2021, 8 pm


How CDNs Generate Certificates. Thomas Ptacek (now at Fly) describes in intricate detail the challenges faced by large-scale hosting providers that want to securely issue LetsEncrypt certificates for customer domains. Lots of detail here on the different ACME challenges supported by LetsEncrypt and why the new tls-alpn-01 challenge is the right option for operating at scale. # 26th June 2020, 12:03 am


The death of a TLD. Sony have terminated their .xperia TLD. Ben Cox used Certificate Transparency logs to evaluate the 11 total TLDs that have been abandoned since the gTLD gold rush started—since HTTPS is becoming the default now these logs of issued certificates are a great indicator of which domains (or TLDs) are being actively used. The only deleted TLD with legitimate looking certificates (apparently for a mail server) was .mcdonalds # 28th July 2018, 8:07 pm


the tls report (via) Clever service that analyses a web server’s SSL implementation and grades it based on things like the protocols, certificates, ciphers and key lengths it supports. Includes public reports on the top and bottom 20 sites. # 10th June 2008, 11:49 pm