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PKCS#11 Compliance Criteria

Graham Steel
November 5, 2014

Updated March 2018

We originally published our compliance criteria for PKCS#11v2.20 back in 2014. We recently completed an update for v2.40, which contains new criteria for the extra attributes added in the new version, as well as revised references that take you directly to the right section of the HTML document of PKCS#11v2.40. Since we started applying these criteria to commercially available PKCS#11 devices using our Analyzer, we have found multiple vulnerabilities and non-compliances in several major manufacturer's products, all of which had FIPS/CC certifications. As a result, some of our customers have changed suppliers, and some have changed the strategy on major projects. To try Analyzer on your HSM installation just get in touch.  We've mentioned before that the PKCS#11 crypto token API standard doesn't come with a set of compliance criteria. However, the 407 page standard is full of vital implementation notes that affect not just interoperability and compatibility, but robustness and security, which is why we built a compliance testing tool.

Estimating Criticality

We have 118 compliance criteria in our initial list for PKCS#11v2.20, all of which come with a direct reference to the section and page in the standard where the compliance requirement comes from.Of these 118 conditions, 16 are rated "High" criticality, 53 "Medium" and 49 "Low". What do these ratings mean? Broadly speaking, if we were testing your P11 implementation, this is the order that we would recommend you prioritize fixes. In more detail, High means that there is a "direct" attack if the device is not compliant, Medium means that an attack is plausible if the application is using the interface in a particular way, while "Low" means the issue seems to be one of compatibility or interoperability.Most cases are clearly in one category or another, but some are not so clear. We may well update the list over time. But it's important to have a starting point. Using the compliance tester, we have already unearthed a serious issue in a major manufacturer's HSM. They're working on a patch - more about that in a future post.In the meantime, find out more about PKCS#11 security in our whitepaper.