Articles & Guides
Useful resources for web developers and system administrators
Found 43 · SSL/TLS · Reset
SSL/TLS
Nginx TLS configuration: an annotated path toward A+
Annotated nginx TLS configuration covering protocols, certificate chains, HSTS and validation. An A+ grade depends on a real test of the entire delivery path.
SSL/TLS
Let’s Encrypt ended OCSP: what to check on your server
Let’s Encrypt shut down OCSP on August 6, 2025. Check stapling, certificate metadata and nginx settings without mistaking missing OCSP for revocation.
SSL/TLS
curl TLS errors 35 and 60: diagnosis and the legacy code 51
Reproduced curl errors 35 and 60 for TLS negotiation, expired certificates and hostname mismatches. Learn why legacy code 51 is absent from current curl docs.
SSL/TLS
ACME HTTP-01 vs DNS-01 vs TLS-ALPN-01: choose a challenge
Compare ACME HTTP-01 on port 80, DNS-01 with TXT, and TLS-ALPN-01 on port 443. Choose a challenge for wildcard certificates, proxies and renewal.
SSL/TLS
openssl s_client: 30 tested commands for TLS debugging
30 tested openssl s_client commands with observed output: certificates, SNI, TLS versions, ALPN, STARTTLS and verification failures.
SSL/TLS
Your Connection Is Not Private: What It Means and How to Fix It
“Your connection is not private” explained: what each NET::ERR_CERT code means, how to fix it on your device or server, and when it is safe to proceed.
SSL/TLS
Russian Trusted Root CA: why browsers reject it and how to install
Russian bank sites fail in Chrome, Safari and Firefox: the Ministry root is in no trust store. How to install it per platform, and what trusting a root means.
SSL/TLS
Your Connection Is Not Private: Which of Six Errors It Is
The warning is identical for six unrelated faults. The code beneath it says whether the cause is your clock, your network, or the site's certificate.
SSL/TLS
ERR_CERT_COMMON_NAME_INVALID: Certificate Name Mismatch
Browsers stopped reading the Common Name in 2017 and match the SAN list instead. Print the names your certificate covers and fix the real mismatch in minutes.
SSL/TLS
TLS Works in the Browser but Fails in curl, Java and Python
A green padlock is not proof. Browsers repair a missing intermediate certificate silently while strict clients reject it. How to find and fix the real cause.