How to see certificate for intermediate CA in Keychain?

Question

When I check details of a certificate I only see information about the certificate itself. Is there any way to see the issuer’s certificate? In my case it’s an intermediate CA. The certificate that I care is for S/MIME (hence the tag), but I think this should apply to all kinds of certificates in general.

I think there should be a way because it’s very intuitive in Windows. Also Chrome on macOS displays the full chain for websites. I think Keychain.app has this information because it labels the certificate as a verified one.

Answer 1

Evaluate Certificate

1. Launch the Keychain Access.app
2. Select the certificate of interest
3. Select the menu item: Keychain Access (menu) > Certificate Assistant (sub-menu) > Evaluate "certificate name"…
4. Select Continue to choose Generic evaulation (certificate chain validation only)
5. Select Show Certificate… button

You can now navigate through the certificate chain and view the leaf, intermediate, and root certificate details.

Answer 2

For any Stored certificate, using Keychain Utility:

Open Keychain Utility, choose any certificate, double click it, select Detais:

The certificate will popup up, click on Details triangle.

Look for the issuer on the info below:

Here is the same certificate showed above, with the window extended to show full information: (NOTE: this osu.edu certificate is EXPIRED, so it is shown as "not trusted", but its issuer chain is present on it, and it is valid [the issuer InCommon CA chain].

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Here is an Intermediate CA Certificate stored on my Keychain:

Here is another Intermediate CA Certificate

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For any website certificate, using Safari:

After clicking "Show Certificate", folow the same procedure and click on the Details Triangle.