Certificate chain about cipherfox

[gavinhungry]

Hi @alevesely,

I'm pretty dense, but I don't see the GTE Corp cert you're referring to on GitHub's cert chain (viewing directly in the Firefox cert viewer).

As to the CN issue, there is actually an undocumented $CERTCN formatting variable (for the life of me, I can't remember why I didn't document it). Give that a try.

[alevesely]

Hi Gavin,

On Mon 09/Dec/2013 21:40:15 +0100 Gavin Lloyd wrote:

I'm pretty dense, but I don't see the GTE Corp cert you're referring
to on GitHub's cert chain (viewing directly in the Firefox cert viewer).

I attach a picture of that window.

Put it another way, if you export the three certificates shown,
concatenate them, and verify the chain by certtool --verify-chain,
then you get the warning:

certtool: the last certificate is not self signed

If you add DigiCert_Global_Root_CA to the chain, the tool is happy.

As to the CN issue, there is actually an undocumented |$CERTCN|
formatting variable (for the life of me, I can't remember why I didn't
document it). Give that a try.

Yup, that works. Great! (I just miss $ISSUERDN, but both the latter
and $ISSUER will be useless after fixing the chain, methinks.)

[gavinhungry]

Not sure what to tell you. That cert does not show up in my cert chain viewer in Firefox, tested in Windows and Linux.

It does show up in the Firefox cert list (Prefs => Advanced => Certificates => View Certificates => Authorities), but if it's not in the chain as reported when viewing the site, there's no way I can add it into CipherFox.

[gavinhungry]

Hmm. I can see it if I select the CA-1 cert, but not with the GitHub cert (as in your screenshot).

[alevesely]

I also have Cert Viewer Plus 1.9 (https://addons.mozilla.org/en-US/firefox/addon/cert-viewer-plus/) but I think it only affects the "pem" view window.

For the certificate chain, certtool displays it like so:

Certificate[0]: C=US,ST=California,L=San Francisco,O=GitHub, Inc.,CN=github.com
Issued by: C=US,O=DigiCert Inc,OU=www.digicert.com,CN=DigiCert High Assurance EV CA-1
Verifying against certificate[1].
Verification output: Verified.

Certificate[1]: C=US,O=DigiCert Inc,OU=www.digicert.com,CN=DigiCert High Assurance EV CA-1
Issued by: C=US,O=DigiCert Inc,OU=www.digicert.com,CN=DigiCert High Assurance EV Root CA
Verifying against certificate[2].
Verification output: Verified.

Certificate[2]: C=US,O=DigiCert Inc,OU=www.digicert.com,CN=DigiCert High Assurance EV Root CA
Issued by: C=US,O=GTE Corporation,OU=GTE CyberTrust Solutions, Inc.,CN=GTE CyberTrust Global Root
Verifying against certificate[3].
Verification output: Verified.

Certificate[3]: C=US,O=GTE Corporation,OU=GTE CyberTrust Solutions, Inc.,CN=GTE CyberTrust Global Root
Issued by: C=US,O=GTE Corporation,OU=GTE CyberTrust Solutions, Inc.,CN=GTE CyberTrust Global Root
Verification output: Verified.

Chain verification output: Verified.

I think displaying a chain means up to and including the root, self-signed certificate. However, I tried ssllabs (https://www.ssllabs.com/ssltest/) and their output seems to imply that github.com sends both its own certificate [0] and the CA-1 [1]; then ssllabs find EVRoot [2] in their trusted store and thus verify no further. From a practical point of view, verifying the root certificate self signature adds no trust. A similar behavior results from using "openssl s_client -showcerts", which truncates displaying the chain as soon as it sees a trusted certificate.

Perhaps certificate chains are displayed according to different philosophies in your version of FireFox than mine?

Now, you have to figure out which philosophy is better for your tool. Consider what would happen if someone removes just EVRoot [2] from their trusted certificates store: A connection to github.com would only be verified if the server sent three certificates, rather than the two it currently sends, because the root certificate [3] is still in the trusted store.

[gavinhungry]

@alevesely,

I just noticed in Firefox 30b1 that I can see the GTE Corporation cert. Not sure what changed, does it work for you? I realize that 29 is the stable release, don't know if it applies there as well.

[gavinhungry]

@alevesely,

I'm now on Firefox 42, and I can't see the GTE cert anymore. I'm not sure this is something I can fix.

[gavinhungry]

Closing, as I haven't heard an update and this is likely out of my hands.