ERR_SSL_PROTOCOL and SSL_ERROR_RX_RECORD_TOO_LONG with a specific ISP only-CodePudding

The

How is the connection done to the ISP vs. how is the connection done to a different ISP or mobile network

Mac user connects to the wireless modem: SSL errors come up

Mac user connects to the wireless mobile hotspot: No error comes up

Update 12 Oct 2022

We re-installed a new certificate from scratch and this one is not showing 'self signed' anywhere. Will see if it helps.

CodePudding user response：

HTTPS is end to end encryption and integrity protection. It should not depend on the ISP used by the client. If it is specific only to the ISP or specific clients then something is messed up at their end, like some middleboxes or antivirus interfering with the connection, a captive portal asking the client to acknowledge some rules first, DNS resolution pointing to a different IP then yours etc. There is nothing you can do from the server end against this, since maybe the server is not even reached by the client.

CodePudding user response：

Problem turned out to be with safebrowse.io which was somehow caching the incorrect certificate (clearing SSL cert in chrome didn't help).

It in turn affected other browsers also like Firefox. So once the incorrect cert was cached it flagged it globally as an unsafe site..

It looks like it was cached inside the logged in users chrome profile (Google Workspace account).

Solution was to login as Guest > Go to web-site > Click 'Proceed anyway' > Restart Chrome

This looks like a serious design flaw with safebrowse.io, why/how it caches SSL certificates in Chrome profile is unclear. This should have worked while accessing the web-site in Chrome incognito but it didn't..