Articles & Guides
Useful resources for web developers and system administrators
Found 38 · SSL/TLS · Reset
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.
SSL/TLS
HTTPS Not Working: Causes, Checks and How to Fix It
HTTPS not working: tell a local fault from a server one, decode NET::ERR_CERT_* errors, and check the certificate, chain, port 443 and redirect loops step by step.
SSL/TLS
What Is HTTPS: How It Works and How It Differs from HTTP
What HTTPS is in plain terms: how it differs from HTTP, how the TLS handshake works, what the browser padlock really proves and how to check HTTPS on your own site.
SSL/TLS
Certbot Not Renewing: Let's Encrypt Auto-Renewal Fixes
Why Let's Encrypt auto-renewal stops working: certbot renew --dry-run, renewal configs, HTTP-01 and DNS-01 failures, deploy hooks, rate limits, Docker.
SSL/TLS
Cannot Verify Server Certificate: What It Means and Fixes
What the "cannot verify the server certificate/identity" error means and how to fix it: name mismatch, expiry, self-signed, incomplete chain, revocation.
SSL/TLS
NET::ERR_CERT_AUTHORITY_INVALID: Causes and Exact Fixes
NET::ERR_CERT_AUTHORITY_INVALID means the issuer is untrusted. Find your case in one minute: missing chain, self-signed cert, antivirus, clock, proxy.