Adding Security Exception in Firefox 35

This section provides a tutorial example on how to add a security exception in Firefox 35 to continue visiting an HTTPS Web site with an un-trusted certificate.

What should you do when Firefox 35 tells you that "This Connection is Untrusted"? My suggestions is:

Here is what I did to add a security exception to pass the error page:

1. Open Firefox 35 to visit to https://login.yahoo.com again and wait for the error page.

2. Click the link "I Understand the Risks". Firefox 35 displays more warning messages:

If you understand what's going on, you can tell Firefox to start
trusting this site's identification. Even if you trust the site,
this error could mean that someone is tampering with your connection.

Don't add an exception unless you know there's good reason why this
site doesn't use trusted identification.

[ Add Exception... ]

3. Click the "Add Exception" button. The "Add Security Exception" dialog box shows up:

Add Security Exception - Firefox 35
Adding Security Exception in Firefox 35

4. Read messages on the dialog box carefully:

You are about to override how Firefox identifies this site.
Legitimate banks, stores, and other public sites will not ask
to do this.

Server Location: https://login.yahoo.com/...

Certificate Status - This site attempts to identify itself with
invalid information.

Unknown Identity - Certificate is not trusted, because it hasn't
been verified by a recognized authority.

[ ] Permanently store this exception

5. Click the "Confirm Security Exception" button. The Yahoo login page shows up.

I could continue to login to my Yahoo account and access my email box if I want to, because I can trust the Yahoo site.

Note that I left the "Permanently store this exception" checkbox unchecked, because I don't want Firefox to remember this exception. When I close Firefox and open it to visit https://login.yahoo.com, I want to see the error page again.

Last update: 2015.

Table of Contents

 About This Book

 Introduction of PKI (Public Key Infrastructure)

 Introduction of HTTPS (Hypertext Transfer Protocol Secure)

 Using HTTPS with IE (Internet Explorer) 10

 Using HTTPS with Chrome 40

Using HTTPS with Firefox 35

 Visiting "https" Web Site with Firefox 35

 Viewing Server Certificate in Firefox 35

 Server Certificate General Information

 Viewing Server Certificate Path in Firefox 35

 Exporting Server Certificate to File in Firefox 35

 Viewing Pre-Installed Certificates in Firefox 35

 Listing of Trusted Root CA in Firefox 35

 Exporting Certificate to File from Firefox 35

 Deleting Root CA Certificates from Firefox 35

 Firefox 35 Displaying Certificate Error Page

Adding Security Exception in Firefox 35

 Failing to Import Root CA Certificates to Firefox 35

 Certificate Trust Settings in Firefox 35

 Perl Scripts Communicating with HTTPS Servers

 PHP Scripts Communicating with HTTPS Servers

 Java Programs Communicating with HTTPS Servers

 Certificate Stores and Certificate Console

 .NET Programs Communicating with HTTPS Servers

 CAcert.org - Root CA Offering Free Certificates

 PKI CA Administration - Issuing Certificates

 Digital Signature - Microsoft Word 2007

 Digital Signature - OpenOffice.org 3

 S/MIME and Email Security

 PKI (Public Key Infrastructure) Terminology

 Outdated Tutorials

 References

 PDF Printing Version