Inter-VM Pass password manager for Qubes OS

This is a very simple password management system that lets you securely store passwords in a compartment fully isolated from your other compartments.

It accomplishes this feat by by leveraging both the excellent pass program, and Qubes OS IPC to isolate the actual password store — and the master password for the store — from the environments where you may use the passwords in the store.

With this program, you can store and retrieve passwords between VMs without having to grant any of the VMs any special policy privileges other than access to the Qubes services implemented here.

Details and features

1. The actual password store is stored in a separate VM, decrypted solely on demand from it, and sent to the VM you manage / request the from.
2. You do not need to set up your own GPG key, as qvm-pass init does it for you.
3. There are two different services one for read-only access and one for read-write.
4. There is a get-or-generate feature, not available in normal pass, which is useful for stuff like programs that need a password generated and then remembered (such as the excellent qubes-pass Ansible lookup plugin.
5. The program mlockall()s during execution, which prevents passwords from being swapped to the disk of the VM running qvm-pass. Dishonorable exceptions from this security feature are the -c and -q command-line options, since these run bash scripts to do their work, and bash cannot lock memory.

Tip: combine this program with the excellent qubes-pass lookup plugin for Ansible Qubes or the pass lookup plugin for Ansible so that you can securely manage VMs and machines that require secrets.

Compatibility

This program is supported only in Qubes 4.1, although it may work in earlier versions.

Using the software

These instructions assume you have installed the software. See the Installing the software heading below for more information.

Step 1: decide which VM you'll use to manage passwords, and which VM you'll use to store passwords in.

In the password store VM, make sure that the GPG key you'll use to encrypt the pass store is available there. Make a note of the GPG ID of that key.

In the password manager VM, create the file /rw/config/pass-split-domain and add the name of the password store VM as the first and only line of the file.

Now, from the password manager VM, run the command:

qvm-pass init <GPG key ID available in the password store VM>

This step will initialize the password store database in the password store VM. You'll receive a Qubes policy prompt asking you whether to allow your password manager VM to access ruddo.PassManage — it is safe to say yes. You will then receive a confirmation that the pass store has been created and is encrypting keys with the specified GPG key ID.

Note: don't forget to back your password store VM up regularly! Both your GPG ID and your encrypted passwords are there.

At this point, you are ready to list, insert and run other operations in your password store VM. list and get operations will use the service ruddo.PassRead, while management operations will use the service ruddo.PassManage, which allows you to set different policies for different VMs based on what you want these VMs to be able to do with the password store VM.

Run qvm-pass -? on a terminal to get usage information.

Tip: fool programs that use pass into using qvm-pass instead. After installation, you can export PATH=/usr/libexec/qubes-pass:$PATH prior to invoking said programs, to induce programs (which invoke the pass store command line program) to invoke qvm-pass instead.

Installing the software

There are three components for this software:

• The client qubes-pass you install in the VMs (or their templates) where you want to manage your passwords.
• The service qubes-pass-service you install in the VMs (or their templates) where you want to store your passwords.
• The policy qubes-pass-dom0 is the dom0 side of things, necessary to enable the services and control access from the clients to the service.

Here's how you install qubes-pass on Fedora VMs (see below for other OSes):

After cloning this repository on a suitable VM, and installing the rpm-build package onto that VM, run the command:

make rpm

This will generate three installable packages on the local directory:

• qubes-pass-<version>.noarch.rpm
• qubes-pass-service-<version>.noarch.rpm
• qubes-pass-dom0-<version>.noarch.rpm

Copy the qubes-pass-<version>.noarch.rpm file to the template VM or standalone VM where you plan to manage passwords. Install the RPM with dnf install <name of the RPM>. At this point, this VM, as well as any VMs using this as a template, have gained the ability to list and store passwords stored in other VMs.

Now copy the qubes-pass-service-<version>.noarch.rpm file to the template VM or standalone VM where you plan to store passwords. Install the RPM with dnf install <name of the RPM>. At this point, this VM, as well as any VMs using this as a template, have gained the ability to securely store passwords in /home/user/.password-store.

Now power off any template VMs you've installed software into, as well as any VMs based on that template VM you plan to use the software from.

Now copy the qubes-pass-dom0-<version>.noarch.rpm file to your dom0. At this point, the default policy (which is ask) is active on your Qubes OS system, and you can begin using the client.

Those clever among you will have discovered that there is a Makefile included, and that you can use the Makefile to install the software on other non-RPM, non-Fedora templates. I welcome pull requests to add support for other distro packages and Qubes OS templates. Thanks in advance for your help.

Troubleshooting and debugging

As always, you can file new issues on the repo of this project for help with fixing bugs that the programs may have. Pull requests also welcome.