A port of OpenBSD's doas which runs on FreeBSD, Linux, NetBSD, illumos, macOS and MidnightBSD.

The doas utility is a program originally written for OpenBSD which allows a user to run a command as though they were another user. Typically doas is used to allow non-privileged users to run commands as though they were the root user. The doas program acts as an alternative to sudo, which is a popular method in the Linux community for granting admin access to specific users.

The doas program offers two benefits over sudo: its configuration file has a simple syntax and it is smaller, requiring less effort to audit the code. This makes it harder for both admins and coders to make mistakes that potentially open security holes in the system.

This port of doas has been made to work on FreeBSD 11.x and newer, most distributions of Linux, NetBSD 8.x and newer, and most illumos distributions (tested on OmniOS and SmartOS). It also works on macOS Sonoma.

Installing doas is accomplished in three steps:

0. Optionally install the package/port for your operating system, OR
1. Installing build tools.
2. Compiling and installing the doas utility.
3. Creating a configuration file for doas.

For Arch Linux users (and Arch-based distributions) there is a package available in the AUR:

git clone https://aur.archlinux.org/doas.git
cd doas
makepkg -si

The doas command is in FreeBSD's ports collection and may be installed by simply running the following command as the root user:

pkg install doas

Also from MidnightBSD's mports collection with:

mport install doas

Or from Pacstall (Debian/Ubuntu):

pacstall -I doas-git

The doas program has virtually no dependencies. So long as you have a compiler (such as the GNU Compiler or Clang) installed and GNU make (gmake on NetBSD, FreeBSD, and illumos). On illumos, the build-essential package will install all the necessary build tools.

sudo apt install build-essential make bison flex libpam0g-dev

sudo dnf install gcc gcc-c++ make flex bison pam-devel byacc

sudo dnf install gcc gcc-c++ make flex bison pam-devel byacc git

sudo yum install gcc gcc-c++ make flex bison pam-devel byacc git

sudo zypper install gcc gcc-c++ make flex bison pam-devel byacc git

pfexec pkg install build-essentials

xcode-select --install

To install doas, download the source code and, in the source code's directory, run one of the below commands:

make

gmake

PREFIX=/opt/local gmake

Alternatively, bison can be used if yacc is not installed.

YACC="bison -y" PREFIX=/opt/local gmake

YACC="bison -y" CFLAGS+="-DOMNIOS_PAM" PREFIX=/usr pfexec gmake

This builds the source code. Then, as the root user, run

make install

cp /etc/pam.d/sudo /etc/pam.d/doas

In situations where you do not have a /etc/pam.d/sudo file (perhaps due to sudo not being installed) then create a new file with your preferred text editor called /etc/pam.d/doas and insert the following lines:

#%PAM-1.0
@include common-auth
@include common-account
@include common-session-noninteractive

After you save this file you may need to reboot for the change to take effect.

gmake install

To build doas, you'll need to have Xcode Command Line Tools, and use bison instead of byacc:

YACC='bison -y' PREFIX=/opt/local make

Alternatively, if you have Xcode.app installed, you can just:

xcode-select --switch /Applications/Xcode.app/Contents/Developer
make

Lastly, run the following:

make install
cp /etc/pam.d/sudo /etc/pam.d/doas

PREFIX=/opt/local gmake install

The doas configuration file is located at /usr/local/etc/doas.conf or /opt/local/etc/doas.conf for illumos. To create a rule allowing a user to perform admin actions, add a line to the configuration file. Details on how to do this are covered on the doas.conf manual page. However, most of the time a rule is as simple as

permit <user> as root

Where "user" is the username of the person who is being granted root access. For instance:

permit jesse as root

Additional users can be added to the file, one per line.

vidoas

Please be aware that, by default, doas scrubs most environment variables. In effect this means certain information about your environment will not be passed to the target user and graphical desktop applications (GUI applications) will not be able to run. To enable graphical applications to run from doas, please use the keepenv keyword in the configuration file. See the doas.conf manual page for details.

To make use of doas, run it in front of any command. Here are some examples:

Confirm doas is working by printing our effective user ID:

doas id

Create a new file in the root user's home:

doas touch /root/new-file

Edit a text file that requires admin access without running the text editor as the root user:

doasedit /path/to/text/file

On Linux versions of doas prior to 6.3p1 required commands with arguments to be prefixed by a double-dash (--). From 6.3p1 and onward the double-dash is no longer required. Here we remove a directory owned by root:

doas -- rm -rf old-directory

To remove doas and its helper programs, you can pass the "uninstall" parameter to the Makefile. On most Linux distributions, you can run the following from the doas source directory:

make uninstall

While on most other platforms, such as FreeBSD, you can run:

gmake uninstall

Contributions, in various forms, are always welcome. If you run into a problem or have an improvement you'd like to see included, please use GitHub's tools to submit an issue ticket or a pull request. Should you encounter a bug you feel is a security concern, please contact the developer privately at jessefrgsmith AT yahoo DOT ca.

Financial donations are always welcome and can be submitted via PayPal to jessefrgsmith AT yahoo DOT ca or through Patreon at https://www.patreon.com/sysvinit. Thank you for your support.