Safari: Can't establish a secure connection

If you delete the certificate, the next time you go to the sire, it should download a new one.

See if anything here helps.

How I solved the Safari 13 and High Sierra problem with idmsa.apple.com unsecure connection (all Apple logins)

https://discussions.apple.com/thread/251211674

Kenjutsu...

"Safari: Can't establish a secure connection: Hi, When I try to connect to https://developer.apple.com/download/more/ Safari responds with the error "Can\t establish a secure connection". I can, however, connect to the site without problems with Chrome. My specs: macOS: 10.13.6 Safari: 13.1.2 (13609.3.5.1.5)"

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Clear your Temporary Internet Files in Safe Mode:

Boot into Safe Mode and then Clear your Temporary Internet Files of Safari:

• Booting into Safe Mode:

[hold down shift upon boot until the login screen appears]. See if this is still an issue. Safe Mode lets items run as default, without changes whatsoever. That is possible because caches of your macOS are temporarily disabled while in Safe Mode. If other apps have settings, then Safe Mode would place those app' preferences aside, while the blow is cleared.

• Clearing your Temporary Internet Files (Cookies & Cache) of Safari:

Cookies perform remembrance of certain site-entered data. Whereas Cache keeps a snapshot of the last time you visited a site.  Use this Link: Clearing History and Cache - Apple Communities

I resolved this issue by updating to macOS Mojave. I'm sorry to say this, because this isn't an option for everybody—but I am typing this response on ASC on my MacBook, having successfully logged in! I can log into iCloud.com as well, so everything seems to be working now.

Further digging has revealed an expired certificate in Keychain Access. Could this be the problem?

The expired cert is called “com.apple.idms.appleid.prd.<string of seemingly random characters>.”

It expired August 16, 2019.

Is there a way to renew this cert to see if it’s the issue?

I have this problem too—when I try to log into ASC on my MacBook! Obviously I’m writing this from another device since I can’t sign in to ASC on my Mac.* The error message ends with “…because Safari can’t establish a secure connection to the server “idmsa.apple.com”.”

This has been an issue for a while, but I’m currently rocking macOS 10.13.6 (gotta run 3rd party apps that don’t play nice with newer OSes) and Safari 13.1.2.

I tried all applicable troubleshooting steps in the second recommended link (above) but still no dice. Help please!

*(ASC works just fine on the same Wi-Fi network on my iPhone though.)

Thanks for your reply, Eric! I tried deleting the cert and navigating to an Apple login page, but it still doesn’t work.

I’ll have to think about whether I trust that mystery Python script enough to run it.

Do you know if updating macOS to Mojave, for instance, would resolve this issue? I run a lot of software that works fine on High Sierra and may break on Mojave, so I’m not excited about updating. But there are some other good reasons to do it, so if it may fix this issue as well, that will bump up the priority of upgrading. :)

Thanks, I did see that, but got psyched out by lots of people calling that a “workaround.” I know little about certs, and I’d prefer to understand what I’m doing with a workaround before I do it.

I’ll try it, but it will have to wait until I have time to look into what makes this a workaround and just understand what’s going on.

Hello Kenjutsu,

Thanks for asking the Apple Support Communities for help with the alert about a connection not secure.

This article talks about the security: If Safari says it can’t establish a secure connection, or the website is using weak encryption - Apple Support

Since it works properly in another browser, go through the troubleshooting in this help article: If Safari doesn't load a page or webpage items are missing - Apple Support

Cheers.

You are welcome. Did you read the discussion in the last line of my post. Manually download that certificate and install it. It worked for me when I was getting the same error message (idmsa.apple.com unsecure connection (all Apple logins)