User-managed smart cards are an oxymoron

In an earlier post, I talked about what it is like to get an EV Code Signing Certificate in 2022 but what I didn’t talk about in that post was token management.

The first thing is that most smart cards implement a proprietary card edge, for example, the SafeNet 5110 is probably the most popular PKI-based smart card token. Since this token is totally proprietary you need to install what is called the SafeNet Authentication Client (SAC) before you can do much of anything with this token.

Most CAs will mail you an unprovisioned token, and tell you to install this client which contains amongst other things a PKCS#11 library that can work with it. The most important part of this package is actually the administration client though.

Without this, you can not initialize the token (roughly the equivalent of formatting it), set or change the passwords for using it, unblock it, or delete certificates from it (necessary as they have limited space).

What is important to understand is that these smart cards have their own administration model, in essence, there is a root user (the Security Officer or SO) and a regular user (that’s the person doing the code signing).

To make things easier for the recipient of a token these tokens are shipped with default secrets, at a minimum that involves the SO and user password (often all zeros or some other well-known sequence of numbers). For example, the default SO password for the SafeNet 5100 is a sequence of 48 zeros. 

While the SAC client will generate a random value for the SO password if you want it to, if you do not know what you are doing, it’s actually pretty natural to let it keep re-using the all zeros secret. On the other hand, if you let it assign a random value and do not secure it in some way so it is not lost if you type your password wrong 5 times the token is bricked.

This leaves us with a spectrum of choices that starts with a charade of protection and ends with something that would fail to meet the most basic business continuity expectations.

One might argue that anyone who wants to use a smart card would be savvy enough to know the above and make sure to use the appropriate practices. I personally find that hard to believe. If you do a search on the web right now I bet the only thing you will find is a few screenshots of how to get the token to the point it can have a key generated on it.

There are some providers who have built out remote signing capabilities using proprietary REST APIs and tooling, these are arguably a better choice than using a smart card but they also tend not to work very well or be very reliable. Not exactly what you want in a process that can gate your releases.

In summary, today, even when you manage to get a smart card enrollment to work remotely, there is a very good chance that you are not managing the smart card lifecycle and associate secretes effectively.

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