bypassing the “ssl_error_no_cypher_overlap” error in Firefox 34

Generally speaking, it’s a bad idea to override security protocols browsers have instituted as they are designed to keep you safe on the internet (in the “less likely to be hacked” sense).  However, with a recent update to Firefox 34, a website I use all the time for my research that is run by my university was no longer allowing me to login.  Instead, I was receiving this message:

ssl1

Since I know the website is safe (I’ve used it thousands of times over the last seven years), I needed to bypass this security protocol in Firefox.  After some googling for solutions, I found one, but it wasn’t very clear.  So, here’s what I did with screen captures for assistance…

1) Open a new tab in Firefox and type “about:config” in the URL bar (without the quotes, of course):

ssl3

2) You’re likely to get another warning message saying “This might void your warranty!” (see screen capture below)  Firefox is trying to keep you from making changes to the underlying settings of the browser.  Promise to be careful and move on:

ssl2

3) Once you click on the “I promise to be careful” button, you’ll see a search box and a huge list of settings:

ssl4

4) In the search bar, enter the following (without the quotes): “security.tls.version.”:

ssl6

5) You’re going to change two of those settings.  First, right-click on the setting “security.tls.version.fallback-limit” and select modify.  You’re going to change the “1” to “0”.  Then do the same thing with “security.tls.version.min”, changing the “1” to “0”.  You should now see the following:

ssl5

6) Now trying loading the page that was giving you the security warning.  It should load.

NOTE: Keep in mind, you have now made your browser less secure.  Really what you should do is contact the administrator of the website that isn’t loading and tell them that they need to update their security on the website so you don’t have to expose yourself to greater security risks.  But, if this is an essential website for you to use in the meantime, this should get you around the issue.

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Linux – Fixing PDFs opening in GIMP in Firefox/Zotero (instead of Evince or Okular)

I’m not exactly sure why, but with the latest Firefox updates, every time I download a PDF using Firefox or try to open one using Zotero integrated with Firefox, the PDF opens in GIMP.  This didn’t used to happen, but it’s really annoying.  It’s doubly annoying since you can’t solve it inside Firefox.

It would make sense to be able to change this in one of two ways.  First, by simply setting your system-wide preference for what program opens PDFs, that should do it, but mine was already set to Okular (you can change the default for most programs by right-clicking a PDF file, selecting Properties, then File Type Options and setting the program you want to be the default).

The second logical solution would be to change the default applications in Firefox, but that doesn’t do anything.  It turns out, the solution is to edit a different file, changing the order of default applications for opening PDFs. Here’s what you need to do:

Open a terminal and gain root privilege to edit the following file: /usr/share/applications/mimeinfo.cache.  Here’s the command I use in Kubuntu:

sudo kate /usr/share/applications/mimeinfo.cache

NOTE: As of Kubuntu 18.04, you now have to use the following command to edit protected files with Kate:

SUDO_EDITOR=kate sudoedit /usr/share/applications/mimeinfo.cache

Once you have edit permissions for that file, search for this line:

application/pdf=gimp.desktop;okularApplication_pdf.desktop;

The order of the applications after the “=” indicates the order in which they will be used to load PDFs. Right now, GIMP will be used first. All you need to do to fix this is to change the order so Okular is first, like this:

application/pdf=kde4-okularApplication_pdf.desktop;gimp.desktop;

Once you change it, save your changes and then restart Firefox.  Your PDFs should now load in Okular.

UPDATE:

For those who have used this workaround in the past, they may have realized that this fix is temporary. The next time you update your software or change something, gimp, again, gets set as the default for PDF files. In order to make this a permanent fix, there is another option. You can override the mimeinfo.cache list by creating a file in the /usr/share/applications directory called “mimeapps.list” that overrides mimeinfo.cache. Here’s what you would add to the file if you want Okular to be your default PDF reader:

[Default Applications]
application/pdf=okularApplication_pdf.desktop

Now, whenever there is an update to your system, the mimeapps.list file will override the mimeinfo.cache file and you shouldn’t have to keep changing this. (Source)

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LinuxMint: Run Two Instances of Firefox Simultaneously (for Zotero)

Advanced users of Zotero, the amazing, free bibliography management software, may have run into the problem that you have two separate Zotero databases and want to access them at the same time.  I used to manage multiple databases simultaneously by using a really cool Firefox extension: Foxtester.  Alas, that extension is no longer working with the latest versions of Firefox, so I had to find another way of running two instances of Firefox simultaneously (this makes it much easier to transfer references between databases).  Luckily, built into Firefox is the ability to run multiple instances simultaneously, but it’s a bit trickier to set up (thus this tutorial).

First, you need to have Firefox installed, which is generally the case with most versions of Linux.  If not, use your software manager or Synaptic to install it.

Next, you’ll need to access the Profile Manager that comes with Firefox.  To do this, close any Firefox windows you have running then open a terminal and type:

/usr/bin/firefox -profilemanager

That will launch the Profile Manager:

firefoxX2-01

 

As you can see, I’ve already set up one extra profile (default is the one you normally use), but I’ll set up another to show that it works.

To add another profile, simple select the “Create Profile” button.  It will ask you for some information in a new window:

firefoxX2-02

You’ll need a name for the new profile.  Since I’m using these exclusively to run alternative instances of Zotero, I’m calling them “Zotero1”, “Zotero2”, and “Zotero3”.  By default, Firefox will create the new profiles in the default folder where it stores the default profile (on Linux machines, this is in: /home/USER/.mozilla  (Replace “USER” with your user directory.  Also, the “.” before the “mozilla” in the name of that folder makes it a hidden directory; you can view hidden directories in Linux if you tell your file manager to show you those folders.)  You can use that location, or choose a different folder.  Then select “Finish”.

Once you’ve created your profiles, you’ll now need a way to launch them.  This is a little tricky as it requires adding some code to the launch command in order to launch a SEPARATE instance of Firefox.  If you don’t use the code, then all that will launch is a new Firefox window, and what you want is a completely separate instance of Firefox.  You can launch the separate profile as an independent instance of Firefox from the command line using this command:

/usr/bin/firefox -P “Zotero1” -no-remote

Of course, replace “Zotero1” with whatever you named your profile.  The key is the “-no-remote” code which tells Firefox to run a separate instance rather than launch a new window.  Go ahead and try it to see that it works.  Of course, you’ll need to install Zotero in the new profile if that’s why you want a separate instance running.

And if you want to make this even easier to launch in the future, you can add a new application launcher for your alternate profile.  Doing this is window manager specific (e.g., Unity, Gnome, KDE, XFCE, etc.).  Since I’m running KDE, I’ll show you how to do this in KDE.

First, right-click the Kick-Off Application Launcher (bottom left corner in most installs) and select “Edit Applications.”

firefoxX2-05

You’ll get this window:

firefoxX2-03

 

Select “New Item”.  In the fields under the “General” tab, add a name in the “Name” field, e.g., “Zotero1”.  In the “Command” field add the same command that we used earlier to launch the separate profile: /usr/bin/firefox -P “Zotero1” -no-remote.  Once you “Save” this, it will add the New Item to the Application Launcher menu.  If you want to get fancy, you can add an icon for the launcher.  I created three Zotero icons that have little numbers so I know which profile I’m launching.  You’re welcome to use them: icon 1, icon 2, icon 3.  And if you want to make it even easier to launch the profiles, you can drag your new application launcher to your quick launch bar, so a single-click will launch your separate instance of Firefox, like this:

firefoxX2-04

 

 

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Update 2014-12-21:

I’ve recently started using a slightly different approach.  I follow the directions above to create multiple profiles.  But rather than set specific icons to launch those profiles, I use the following code to choose which profile I want to launch when I start Firefox:

/usr/bin/firefox -P -no-remote

Once you’ve created multiple profiles, this code will simply ask you which profile you want to launch and will launch it as a remote session, so you can have multiple Firefox profiles open at once.

 

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