Unable to Install Viber due to missing libssl1.0.0 package

for all the people out there who do not like to install the flatpak version and want to stick to the deb version, there is another way: since new versions of Ubuntu are shipped with libssl1.1 or have this package in their repositories, viber.deb can be tinkered to state libssl1.1 as a dependency.

I cannot guarantee 100% that all dependencies are met, but retro-compatibility should function. I have also applied this method and so far I do not have any problem on Xubuntu 19.10.

Here is a short walkthrough:

1. Ensure that libssl1.1 is installed:

   sudo apt install libssl1.1
   

   Note: if a newer version of libssl is available, this should be used further on on step 4.

2. Download viber.deb from the Viber webpage and copy it to a temp folder. I have used /home/<user>/temp for this.

3. Now we need to make some changes to the package, following this guide.

   mkdir viber
   cd viber 
   ar x ../viber.deb
   tar xzf control.tar.gz
   

   Line by line this does the following:

   • Creates a new folder named viber.
   • Moves to the new folder.
   • Unpacks viber.deb.
   • Unpacks control.tar.gz.

4. Now we need to change dependencies:

   • Open the control file with a text editor.

   • Change on line 6: libssl1.0.0 to libssl1.1.

     Note: in case of newer version of libssl use the new version (see step 1!).

   • Save the file and exit.

5. Repackage the .deb file.

   tar --ignore-failed-read -cvzf control.tar.gz {post,pre}{inst,rm} md5sums control
   ar rcs viber-new.deb debian-binary control.tar.gz data.tar.gz
   

6. Install the new deb:

   sudo dpkg -i viber-new.deb
   

Voila!

Viber installation on Ubuntu 19.04, 19.10, 20.04

Download libssl1.0.0 deb package from here and install it before installing viber (18.04 repository still contains it).

You could install this package by executing the next commands:

wget http://security.ubuntu.com/ubuntu/pool/main/o/openssl1.0/libssl1.0.0_1.0.2n-1ubuntu5.3_amd64.deb
sudo dpkg -i libssl1.0.0_1.0.2n-1ubuntu5.3_amd64.deb

Go to folder with viber (cd ~/Downloads, for example) and install viber:

sudo dpkg -i viber.deb

Run the next command if viber depends on some other packages that have not been installed on your system yet:

sudo apt install -f

If you've encountered some viber launching issues (viber starts and crashes), then try to change display manager (to gdm3, for example):

sudo dpkg-reconfigure gdm3

Viber's Flatpak solves the issue:

To Install:

flatpak install flathub com.viber.Viber

To Run:

flatpak run com.viber.Viber