Add the DEI Certification Authority

Google Chrome Mozilla Firefox Safari Internet Explorer

“A certificate authority or certification authority (CA) is an entity that issues digital certificates. The digital certificate certifies the ownership of a public key by the named subject of the certificate. This allows others (relying parties) to rely upon signatures or assertions made by the private key that corresponds to the public key that is certified.

In this model of trust relationships, a CA is a trusted third party that is trusted by both the subject (owner) of the certificate and the party relying upon the certificate. CAs are characteristic of many public key infrastructure (PKI) schemes." — from Wikipedia

Given that the DEI Certification Authority is not in the list of authorities automatically recognised by your browser, you are advised to import it to ensure proper security and avoid further warnings.


CA

Download the CA (Certificate Authority) from https://helpdesk.dei.uc.pt/ca/dei-ca-chain.crt


Google Chrome

1. First open Settings available at right corner

Google Chrome Menu → Settings

2. Click in "Show advanced settings..."

3. Scroll down until you find "HTTPS/SSL" and then click in the button "Manage certificates".

4. In case you never imported the DEI certificate, skip this step. Otherwise you must remove it by doing the following:
  • Select "Trusted Root Certification Authorities"
  • Find and select the certificate with the following parameters:
    • Issued To: DEI
    • Issued By: DEI
    • Expiration Date: 05-04-2020
  • Click the "Remove" button.

5. Select "Trusted Root Certification Authorities" header menu and click "Import..." button

It will show an Import Wizard and then:

  • Click in the button Next

  • Browse and select the .crt file downloaded before (DEI-CA.crt)
  • Click in the button Next
  • Click in the button Finish

Firefox

1. First go to Options located in Firefox Menu → Options → Options

2. Then go to the "Advanced" in Header Menu, select Certificates tab and click in "View Certificates" button.

3. When "Certificate Manager" appear, select tab "Servers",

click in the "Import..." button and then import the previous downloaded file DEI-CA.crt.

Internet Explorer

1. First go to the "Internet Options"

2. Choose the "Content" from Header Menu and click in the button "Certificates".

3. Now continue from the step 4 of the Google Chrome (similar procedure).

Safari

1. Open the previous downloaded file DEI-CA.crt

2. If KeyChain Access prompts for location to store the certificate, select the System keychain.

3. Click in the button “Always Trust”.

4. Insert your administrator credentials