Certificate signing with an ePass2003

I have a fairly creative ssl setup on my webserver:

  • I run my own ‘certificate authority’ which signs the server certificate;
  • I have a bunch of alternative names specified;
  • The CA certificate sits on an ePass 2003 PKI token.

I’m writing down how I sign certificates in this context so I can use this to look up the procedure instead of spending hours in DuckDuckGo. This is more of a tutorial than elegant prose.

Creating the certificate request:

I use this openssl config, saved as req.cnf. I found an example version file somewhere but I can’t remember where, this is the one with my own modifications.

[ req ]
default_bits = 4096
default_keyfile = server.rded.nl.key
encrypt_key = no
default_md = sha256
prompt = no
utf8 = yes
req_extensions = my_extensions
distinguished_name = my_req_name

[ my_req_name ]
C = NL
ST = Gelderland
L = Nijmegen
O = Thom Wiggers servers
CN = *.rded.nl

[ my_extensions ]
basicConstraints=CA:FALSE
subjectAltName=@my_subject_alts
subjectKeyIdentifier = hash

[my_subject_alts]
DNS.1 = *.thomwiggers.nl
DNS.2 = thomwiggers.nl
DNS.3 = *.rded.nl
DNS.4 = rded.nl
DNS.5 = *.clearlyreta.rded.nl

I use this command to then create a new certificate request:

openssl req -new -key /etc/ssl/private/wildcard_private.key \
   -out server.csr -config req.cnf -days 365

File wildcard_private.key is my private key. You might still need to generate one.

Sign the certificate request:

Step 1: figure out the key id:

$ pkcs15-tool --list-keys

(Thom, it’s the one with a16)

Then start the openssl console and execute the following (be sure to replace <id>):

$ openssl
OpenSSL> engine dynamic \
  -pre SO_PATH:/usr/lib/engines/engine_pkcs11.so \
  -pre ID:pkcs11 \
  -pre LIST_ADD:1 \
  -pre LOAD \
  -pre MODULE_PATH:opensc-pkcs11.so

OpenSSL> ca -engine pkcs11 \
   -keyform engine \
   -cert ca.pem \
   -keyfile slot_1-id_<id> \
   -in wildcard_2_request.csr \
   -out cert.pem \
   -outdir . \
   -days 365

And then you can upload cert.pem back to your server.

Weird stuff:

  • I had to run the signing step as root and had to add some weird files in /etc/ssl/.

  • You get a non-obvious error if you issue a new cert for other domains with the same subject.

Sources:

Edits:

2015-1-22: Updated req.cnf to have better defaults, added same-subject note.

Avatar
Thom Wiggers
PhD candidate at Radboud University

My research interests include (post-quantum) cryptography and protocols

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