Let's Encrypt on QNAP
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Latest commit 307511b Jan 12, 2019


Let's Encrypt on QNAP

Install Instructions

NAS Setup

  1. Login to your NAS and make sure that the Python 2.7 app is installed.
  2. Make sure your NAS is reachable from the public internet under the domain you want to get a certificate for on port 80.
  3. Create a folder to store qnap-letsencrypt in under /share/YOUR_DRIVE/. Do not create it directly in /share/, as it will be lost after a reboot!

Installing git

If there is a git package available for your NAS model in the QNAP App-Center, use that. Otherwise, install entware. Apart from git, it provides many more useful packages. You may need to install git-http in addition to git.

After logging out and in again, you can use opkg install git to install git.

Setting up a valid ca-bundle and cloning this repo

By default, there is no ca-bundle (bundle of root certificates which we should trust) installed. Therefore we will have to download one manually.

  1. On your local pc with an intact certificate store, run

    curl --silent https://curl.haxx.se/ca/cacert.pem | sha1sum
  2. On your nas, in the directory you want to install qnap-letsencrypt in, run

    curl --silent --location --remote-name --insecure https://curl.haxx.se/ca/cacert.pem
    sha1sum cacert.pem
  3. Compare the hashes obtained in step 1 and 2, they must match.

  4. On your nas, in the directory you were in before

    git config --system http.sslVerify true
    git config --system http.sslCAinfo `pwd`/cacert.pem
    git clone https://github.com/Yannik/qnap-letsencrypt.git
    mv cacert.pem qnap-letsencrypt
    cd qnap-letsencrypt
    git config --system http.sslCAinfo `pwd`/cacert.pem

Setting up qnap-letsencrypt

  1. Run init.sh

  2. Create a Certificate Signing Request(csr):

    single domain cert: (replace nas.xxx.de with your domain name)

    cd letsencrypt
    openssl req -new -sha256 -key keys/domain.key -subj "/CN=nas.xxx.de" > domain.csr

    multiple domain cert: (replace nas.xxx.de and nas.xxx.com with your domain names)

    cd letsencrypt
    cp ../openssl.cnf openssl-csr-config.cnf
    printf "subjectAltName=DNS:nas.xxx.de,DNS:nas.xxx.com" >> openssl-csr-config.cnf
    openssl req -new -sha256 -key keys/domain.key -subj "/" -reqexts SAN -config openssl-csr-config.cnf > domain.csr
  3. mv /etc/stunnel/stunnel.pem /etc/stunnel/stunnel.pem.orig (backup)

  4. Run renew_certificate.sh

  5. account.key, domain.key and even the csr (according to acme-tiny readme) can be reused, so just create a cronjob to run renew_certificate.sh every night, which will renew your certificate if it has less than 30 days left

    Add this to /etc/config/crontab:

    30 3 * * * cd /share/CE_CACHEDEV1_DATA/qnap-letsencrypt/ && ./renew_certificate.sh >> ./renew_certificate.log 2>&1

    Then run:

    crontab /etc/config/crontab
    /etc/init.d/crond.sh restart


Why is xxx not working after a reboot?

Anything that's added to one of the following directories is gone after a reboot:

  • /root/ (.gitconfig, .bash_history)
  • /share/ (with the exception of anything added to drives mounted there)
  • /etc/ssl/, /etc/ssl/certs

Additionally, the following is not surviving a reboot:

  • Cronjobs added using crontab -e

Note that qpkgs get installed to /share/CE_CACHEDEV1_DATA/.qpkg. Due to this they are only available after unlocking your disks encryption.

What is actually surving a reboot?

  • Anything that is on a drive, e.g. /share/CE_CACHEDEV1_DATA/
  • /etc/stunnel/stunnel.pem (the ssl certificate used for the webinterface) seems to survive a reboot

What about surviving an firmware update?

In my tests, all the above applied. I couldn't see anything additional being lost.

How to generate content of /etc/ssl/certs?

This is only documented as it was part of my research and is not needed for the letsencrypt certificate generation.

First, install Perl from the qnap app manager.

Then, in your qnap-letsencrypt directory:

mkdir certs
cat cacert.pem | awk 'split_after==1{n++;split_after=0} /-----END CERTIFICATE-----/ {split_after=1} {print > "certs/cert" n ".pem"}'
wget --ca-certificate cacert.pem https://raw.githubusercontent.com/ChatSecure/OpenSSL/master/tools/c_rehash
/opt/bin/perl c_rehash certs
export SSL_CERT_FILE=`pwd`/cacert.pem

You can now copy this to /etc/ssl/certs. Alternatively, you can do this directly in /etc/ssl/certs if you want to, but remember, that it is lost after a reboot.

How to test whether a python script fails due to missing ca certificates

#from urllib.request import urlopen # Python 3
#from urllib2 import urlopen # Python 2

If you get this:

urllib2.URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:581)>

there is something wrong.

Remember to run export SSL_CERT_FILE=cacert.pem though, as it is done in renew_certificates.sh

How can I contribute anything to this project?

Please open a pull request!

You want to buy me a coffee?

Feel free to send a donation this way: https://www.paypal.me/qnapletsencrypt

What license is this code licensed under?