Add letsencrypt certificate to dd-wrt web interface

binds_on_mount.sh

#!/bin/sh


if [ `nvram get https_enable` -gt 0 ] ; then

        # get the absolute directory of the executable
        SELF_PATH=$(cd -P "$(dirname "$0")" && pwd -P)
	echo SELF_PATH: ${SELF_PATH}

        # extract the mount path
        MOUNT_PATH=`echo ${SELF_PATH} | cut -d / -f1-2`
	echo MOUNT_PATH: ${MOUNT_PATH}

        # do binds
        for BIND_PATH in '/jffs' ; do
           echo Binding ${BIND_PATH}
           if [ "${MOUNT_PATH}" != "${BIND_PATH}" ]; then
                grep -q -e "${BIND_PATH}" /proc/mounts || mount -o bind ${MOUNT_PATH}${BIND_PATH} ${BIND_PATH}
           fi
        done

        HTTPS_RESET=0

        if [ `pidof httpd` -gt 0 ]; then
		echo Stopping httpd
                stopservice httpd
                HTTPS_RESET=1
        fi

        echo Binding HTTPS certifcate
        grep -q -e "/etc/cert.pem" /proc/mounts || mount -o bind ${MOUNT_PATH}/etc/cert.pem /etc/cert.pem
        grep -q -e "/etc/key.pem" /proc/mounts || mount -o bind ${MOUNT_PATH}/etc/key.pem /etc/key.pem
        grep -q -e "/etc/privkey.pem" /proc/mounts || mount -o bind ${MOUNT_PATH}/etc/privkey.pem /etc/privkey.pem

        if [ "$HTTPS_RESET" = "1" ]; then
		echo Starting httpd
                startservice httpd
                unset HTTPS_RESET
        fi
fi

letsencrypt-ddwrt.md

Inspired from this blog post.

1. Prepare the router

   1. Use portfw to forward port 80 and 445 to the ip of the computer where you have certbot installed

   2. Enable Secure Shell from Services tab

   3. Enable JFFS2 Support form Administration tab

2. Create the certificate files

   1. Install certbot

      brew install certbot

   2. Go to a folder where you will configure certbot

   3. Execute certbot to create the certificate

      certbot certonly --config-dir . --logs-dir . --work-dir .
      

      When promted select Spin up a temporary webserver (standalone)

   4. Go to ./live/[your.domain]

   5. Create rsa key from private key

      openssl rsa -in privkey.pem -out key.pem

3. Put the certificate files into the router

   1. cd to jffs

      cd /jffs

   2. create startup folder

      mkdir startup

   3. create the script (binds_on_mount.sh) that binds certificate files and make it executable

      chmod +x binds_on_mount.sh

   4. create etc folder in jffs and cd in it

      mkdir /jffs/etc && cd /jffs/etc

   5. create the certificate files from local certbot files

      1. paste contents of key.pem, cert.pem and privkey.pem into their respective file in /jffs/etc

4. Remove portfw and enable Web GUI Management remote access from Administration tab

   1. Web Access

      1. Protocol: Check https and Uncheck http

   2. Remote Access

      1. Web GUI Management: Enable

      2. Web GUI Port: 443

5. Test by executing the script and then try to access the web gui. If the browser has a green lock next to the address than everything is correct.

6. Add command to execute the script on startup

   1. save this command as Startup in Administration > Commands

      cd /jffs/startup && ./binds_on_mount.sh > ./log