sftp: Fix Host keys

images/sftp/Dockerfile

 # Install dependencies
 RUN apt-get update \
     && apt-get install -y --no-install-recommends \
-       openssh-server \
+       openssh-server openssl \
     && rm -rf /var/lib/apt/lists/*
 
 COPY docker-entrypoint.sh /usr/local/bin/docker-entrypoint.sh

images/sftp/Dockerfile.template

 # Install dependencies
 RUN apt-get update \
     && apt-get install -y --no-install-recommends \
-       openssh-server \
+       openssh-server openssl \
     && rm -rf /var/lib/apt/lists/*
 
 COPY docker-entrypoint.sh /usr/local/bin/docker-entrypoint.sh

images/sftp/docker-entrypoint.sh

 chown ${PAPERLESS_FTP_USER} ${PAPERLESS_CONSUMPTION_DIR}
 chmod 777 ${PAPERLESS_CONSUMPTION_DIR}
 
-# Copy Server Public key if any (this is needed at least for Brother ADS-2400n)
+# Copy Server Host key if any (this is needed at least for Brother ADS-2400n)
 if [[ -s ${PAPERLESS_CONSUMPTION_DIR}/ssh_host_rsa_key.pub ]]; then
     cp ${PAPERLESS_CONSUMPTION_DIR}/ssh_host_rsa_key.pub /etc/ssh/;
 fi
+if [[ -s ${PAPERLESS_CONSUMPTION_DIR}/ssh_host_rsa_key ]]; then
+    cp ${PAPERLESS_CONSUMPTION_DIR}/ssh_host_rsa_key /etc/ssh/;
+fi
+sed -i 's/#HostKey \/etc\/ssh\/ssh_host_rsa_key/HostKey \/etc\/ssh\/ssh_host_rsa_key/g' /etc/ssh/sshd_config
+echo "HostKeyAlgorithms ssh-rsa" >> /etc/ssh/sshd_config
 
 # https://bugs.launchpad.net/ubuntu/+source/openssh/+bug/45234
 mkdir -p /var/run/sshd