Dockerfile

FROM centos:7 AS BUILD

ARG COMPILEFOLDER=/tmp/build
ARG INSTALLBASESSHD=/opt/.ssh
ARG INSTALLBASESSSL=/opt/.ssl

RUN yum -y -q install gcc make perl glibc-static wget

RUN mkdir -p "$COMPILEFOLDER/root"


# Build zlib:
RUN wget -qO- https://netcologne.dl.sourceforge.net/project/libpng/zlib/1.2.11/zlib-1.2.11.tar.gz | tar zxf - -C ${COMPILEFOLDER} && \
    cd ${COMPILEFOLDER}/zlib-* && \
    ./configure --prefix="$COMPILEFOLDER/root" --static && \
    make -j8 && \
    make install

# Build openssl:
RUN wget -qO- https://ftp.openssl.org/source/openssl-1.1.1d.tar.gz | tar zxf - -C ${COMPILEFOLDER} && \
    cd ${COMPILEFOLDER}/openssl-* && \
    ./config --prefix="$INSTALLBASESSSL" no-shared -static zlib --with-zlib-include=$COMPILEFOLDER/root/include --with-zlib-lib=$COMPILEFOLDER/root/lib && \
    make -j8 && \
    make install_sw

# Build openssh:
RUN wget -qO- https://cloudflare.cdn.openbsd.org/pub/OpenBSD/OpenSSH/portable/openssh-8.1p1.tar.gz | tar zxf - -C ${COMPILEFOLDER} && \
    cd ${COMPILEFOLDER}/openssh-* && \
    cp -p "$COMPILEFOLDER/root"/lib/*.a . && \
    [ -f sshd_config.orig ] || cp -p sshd_config sshd_config.orig  && \
    sed \
        -e 's/^#\(PubkeyAuthentication\) .*/\1 yes/' \
        -e '/^# *Kerberos/d' \
        -e '/^# *GSSAPI/d' \
        -e 's/^#\([A-Za-z]*Authentication\) .*/\1 no/' \
        sshd_config.orig \
    >sshd_config && \
    ./configure --prefix="$INSTALLBASESSHD" --with-privsep-user=nobody --with-privsep-path="$INSTALLBASESSHD/var/empty" --with-ssl-dir="$INSTALLBASESSSL" --with-zlib="$COMPILEFOLDER/root" LIBS="-lpthread" --with-ldflags=-static && \
    make -j8 && \
    make install

## Remove manual pages:
RUN rm -rf "$INSTALLBASESSSL/share"

# No need to clean-up...
#    rm -rf "$COMPILEFOLDER" && \
#    yum -y -q remove gcc make perl glibc-static wget && \
#    yum clean all && rm -rf /var/cache/yum

############### MAIN CONTAINER #######

FROM centos:7

COPY --from=BUILD /opt /opt

## Replace with your own key:
ENV PUBKEY="ssh-rsa mypubkey [email protected]"

RUN mkdir -p /root/.ssh/ && \
    echo "$PUBKEY" >>/root/.ssh/authorized_keys && \
    chmod -R 700 /root/.ssh

CMD /opt/.ssh/sbin/sshd -D -d -e

This Dockerfile creates a static version of openssl and openssh.

It uses Centos:7 has the base.
Good to add temporary functionality and remove it later without dependencies of Distro.