Backport OpenSSH for Debian / Ubuntu distros.

A simple script to build backport openssh deb, using Debian sid sources.

Similar Project:　Backport OpenSSH RPM for CentOS

Current Version:

Package version are defined in version.env file.

• OpenSSH 9.8p1
• OpenSSL 3.0.15

Supported (tested) Distro:

• Ubuntu 24.04
• Ubuntu 22.04
• Ubuntu 20.04
• Debian 13/trixie
• Debian 12/bookworm
• Debian 11/bullseye
• UnionTech OS Desktop 20 Home (Debian GLIBC 2.28.21-1+deepin-1)
• Kylin V10 SP1 (Ubuntu GLIBC 2.31-0kylin9.2k0.1)

Direct Build

# Install Dependencies
sudo apt install pkgconf build-essential fakeroot \
    dpkg-dev debhelper debhelper-compat dh-exec dh-runit \
    libkrb5-dev libpam0g-dev libwrap0-dev \
    libaudit-dev libedit-dev libfido2-dev \
    libgtk-3-dev libselinux1-dev libsystemd-dev \
    libcbor-dev

# pull source
./pullsrc.sh

# direct build
./compile.sh

Docker Build

Build without installing a bunch of dev packages, also for a different distro by changing build-arg.

# pull source from debian sid
./pullsrc.sh

# build a docker image that fits your target system.
docker build \
    -t opensshbuild \
    --build-arg DISTRO=ubuntu \
    --build-arg DISTVER=22.04 \
    --build-arg APT_MIRROR=ftp.us.debian.org \
    -f ./docker/Dockerfile \
    .

# run the build process
docker run --rm -v $PWD/output:/data/output opensshbuild

# clean up docker image
docker image rm opensshbuild
docker builder prune

Install DEBs

Generated DEBs are right under the output directory. (either direct build or docker build).

ls -l output/*.deb

# Ignore dbgsym and tests
find output -maxdepth 1 ! -name '*dbgsym*' ! -name '*tests*' -name '*.deb' | xargs sudo apt install -y

NOTES

Known issues

sshd-session issue

If installing backported openssh 9.8+ on older distros, some other programs may face problems while interacting with the openssh service. Since openssh-9.8, the subprocess name have changed from sshd to sshd-session.

Known programs with issue:

• fail2ban
• sshguard

Make sure to upgrade or reconfigure them to meet the latest changes.

fail2ban

change in filter.d/sshd.conf:

_daemon = sshd

into

_daemon = sshd(?:-session)?

Compile Issues

some extra steps are needed to install on these special distros.

UnionTech OS Desktop 20 Home (Debian GLIBC 2.28.21-1+deepin-1)

1. Exclude libfido2-dev from the build Dependencies intall command, it's not available.
2. Install following packages from debian/bullseye.
   • bullseye/dwz
   • bullseye/dh-runit

Kylin V10 SP1 (Ubuntu GLIBC 2.31-0kylin9.2k0.1)

Run ./compile.sh from the desktop Terminal(mate-terminal). During install the builddep/*.deb, a kysec_auth dialog would pop up asking for installing permissions. Manual click on the permit button is needed.

If running in a ssh session, the compile script would fail without permissions.