Note: You can generally avoid worrying about these details by using the scripts described in DomTool/AdminProcedures. The instructions here are mostly of interest to people implementing those scripts.

These instructions assume you are running as a user in group wheel on deleuze.hcoop.net.

1. Creating a certificate authority

I followed the instructions on this page:

• http://sial.org/howto/openssl/ca/

This blog post revealed the source of a puzzling error:

• http://ilovett.com/blog/projects/debian-apache-ssl

It turns out leaving some fields (like the city name for your new certificate) blank leads to baffling messages!

Extracting the relevant commands from the Makefile available at the former page, we run these commands to create our CA:

mkdir -p /etc/domtool/ca
cd /etc/domtool/ca
mkdir crl newcerts private
chmod go-rwx private
echo '01' > serial
touch index

cd ..
# NOTE remove ":2048" below if running OpenSSL lower than 0.9.8a
openssl req -nodes -config openssl.conf -days 1825 -x509 -newkey rsa:2048 -out ca/ca-cert.pem -outform PEM

(NOTE: remove the "o" from all openssl.conf when running all commands (above and below); I used .conf just because wiki anti-spam methods do not allow .c-n-f (no comment)).

Now the directory structure of our CA exists, and we have the certificate we will use to sign certificates.

After creating the CA, dump its certificate to DomTool's trust store (see trustStore configuration value for the location). If you are creating a new CA (e.g. the domtool CA was compromised, or the private key otherwise leaked or destroyed) make sure to remove the invalid CA certificate from this file.

cat /etc/domtool/ca/ca-cert.pem >> ${LOCATION OF TRUST STORE}

2. Creating a certificate for a node or user

I followed the instructions on these pages:

• http://marc.theaimsgroup.com/?l=openssl-users&m=97049654211960&w=2

  http://www.postgresql.org/docs/8.1/interactive/ssl-tcp.html

The commands to run are:

openssl genrsa -out serverkey.pem
openssl req -new -key serverkey.pem -out newreq.pem -days 365
cat newreq.pem serverkey.pem > new.pem
openssl ca -config /etc/domtool/openssl.conf -policy policy_anything -out servercert.pem -infiles new.pem

replacing serverkey.pem and servercert.pem with appropriate names for your new key and certificate, respectively. The change I made from the cited source is to include the -config flag to reference the modified config file obtained from the page about creating a CA.

Once I figure out the final directory layout, there will be instructions here on where to put these files once they're created.

3. Baffling things that can happen

If openssl ca tells you this:

failed to update database
TXT_DB error number 2

it means that you have it configured not to sign a certificate for the same user multiple times, but you've gone ahead and asked it to do so anyway. Add this line to the section for your default CA in openssl.conf:

unique_subject = no

If you've already been signing some keys and you want to keep what you've done so far, you may also need to make similar changes in index.attr and possibly index.attr.old.