PKI Tutorials - Herong's Tutorial Examples - v2.20, by Dr. Herong Yang
Mozilla Firefox Displaying Certificate Error Page
This section provides a tutorial example showing that Mozilla Firefox fails to validate an HTTPS server certificate and displays a certificate error page.
Now I want to see how Mozilla Firefox behaves after I deleted the root certificate "VeriSign Class 3 Public Primary Certification Authority - G5".
1. Open Mozilla Firefox to visit "https://login.yahoo.com".
2. Mozilla Firefox returns with an untrusted connection error page:
3. Read the error message:
This Connection is not secure The owner of login.yahoo.com has configured their website improperly. To protect your information from being stolen, Firefox has not connected to this website. This site uses HTTP Strict Transport Security (HSTS) to specify that Firefox may only connect to it securely. As a result, it is not possible to add an exception for this certificate.
Mozilla Firefox fails to validate "login.yahoo.com" certificate as expected, because the root CA "VeriSign Class 3 Public Primary Certification Authority - G5" certificate has been deleted from Firefox.
See next tutorials on how install the root CA back, or add an security exception to continue using the Website.
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