There's a Chromium bug that goes into more details, but the basic idea was that they didn't want the cert details button to be in the Page Info pop up, but didn't have a new place to put it. In Chrome 56, the SSL icon now shows "Secure" or "Not Secure", so more users will be clicking on Page Info, and they didn't like technical details in that pane. There's a new bug to find a better place for certificate details in Chrome 57.

https://bugs.chromium.org/p/chromium/issues/detail?id=646465

https://bugs.chromium.org/p/chromium/issues/detail?id=663971

>I noticed that Chrome had moved the SSL details dialog away from the lock dropdown too.

I have no idea about the rationale but here's where SSL details reside now... it's insane what they have done:

>First, get into Developer tools. You can do this via Chrome’s upper-right three vertical dots, then click “More tools” — then “Developer tools” — or on many systems you can just press the F12 button.

>But wait, there’s still more (yeah, Google took a simple click in an intuitive place and replaced it with a bunch of clicks scattered around).

>Once the panel opens, look up at its top. If you don’t see the word “Security” already, click on the “>>” to the right of “Console” — then look down the list that appears and click on “Security” — which will open the Security panel with all of the certificate-related goodies. When you’re done there, click the big “X” in the upper right of the panel to return to normal browser operations.

https://lauren.vortex.com/2017/01/28/heres-where-google-hid-...

Or

>Click on the Secure/Not Secure/(i) page info button.

>Click "Details" to go straight to the Security panel of the Developer Tools