Hi Brad, your link about not enforcing regular password expiration for users is spot on. For these reasons I decided to not expand that CEP in that direction. Sure, technically possible, but practically questionable. I think that all these guides and recommendations should be looked at from the perspective of the system they are meant to be implemented in. Enforcing password to be changed in a database system is rather interesting take. After I briefly took a look, I do not think there is a database on the market which is enforcing this. On the other hand, for example, Neo4j forces you to change the password on the first login as the default one is "neo4j" for user "neo4j". This does make sense to implement for Cassandra as well. I do consider password "cassandra" for role "cassandra" very insecure and it is not forced by anybody to change it. However, it is quite interesting problem how to achieve that.
Also, the reason I want to leave out historical verification of passwords in (at least the initial) implementation is that if we do that, we should also restrict the frequency how often a user can change the password. Lets think this through. If the depth of historical verification is 5 passwords, a user just has to regenerate a password 5 times in a row an he can use the same one. So implmenting this without restricting how often he can change his password does not make sense. We can indeed explore this further but I feel like the initial implementation should not deal with this for now. When it comes to section 5.1.1.2 of NIST document, as already mention at the bottom of the CEP, we used Appendix A of this (1) to model what the good password should be. Your link is way more descriptive though. Particularly interesting points are these: - Passwords obtained from previous breach corpuses. - Dictionary words. - Repetitive or sequential characters (e.g. ‘aaaaaa’, ‘1234abcd’). - Context-specific words, such as the name of the service, the username, and derivatives thereof. I believe that points 1), 2) and 4) can be implemented easily as checking the password against a dictionary. The library we want to use is able to check the password against a dictionary. Dictionary check can be also implemented as a separate ticket which would just expand the functionality of DefaultPasswordValidator. I do not have a problem to include dictionary check into the first iteration as well. Repetitive or sequential characters are already covered in the POC implementation. The document you linked also contains this: Verifiers SHOULD offer guidance to the subscriber, such as a password-strength meter [Meters], to assist the user in choosing a strong memorized secret. This is particularly important following the rejection of a memorized secret on the above list as it discourages trivial modification of listed (and likely very weak) memorized secrets We are already doing this, quite intelligently, by telling a user what is wrong with his password that it can not be used (e.g. that it does not contain so and so number of specific characters). The "meter" is also there - we have three levels - OK password, password with a warning and failed password. We inform a user about the strength of his password retroactively - we do not tell him what the password should be before he tries to set one however I think that is acceptable when using Cassandra and cqlsh in console environment. (1) https://pages.nist.gov/800-63-3/sp800-63b.html#appA ________________________________________ From: Brad <bscho...@gmail.com> Sent: Monday, October 10, 2022 17:43 To: dev@cassandra.apache.org Subject: Re: [Discuss] CEP-24 Password validation and generation NetApp Security WARNING: This is an external email. Do not click links or open attachments unless you recognize the sender and know the content is safe. I would suggest reviewing the guidelines in sec in 5.1.1.2 of NIST Special Publication 800-63B<https://pages.nist.gov/800-63-3/sp800-63b.html#memsecretver> and the NCSC Password policy: updating your approach - NCSC.GOV.UK<https://www.ncsc.gov.uk/collection/passwords/updating-your-approach#PasswordGuidance:UpdatingYourApproach-Don'tenforceregularpasswordexpiry> Regards, Brad On Mon, Sep 19, 2022 at 7:27 AM Miklosovic, Stefan <stefan.mikloso...@netapp.com<mailto:stefan.mikloso...@netapp.com>> wrote: Hi list, together with my colleague Jackson Fleming we put together CEP-24 about password validation and password generation in Cassandra. https://cwiki.apache.org/confluence/x/QoueDQ We are looking forward to discuss this CEP with you in depth. The outcome of this thread would be to sort out any issues / concerns you have so we might eventually vote and implement that in upstream if our contribution is found to be useful. There is a reference implementation provided we would like to build our solution on top. Regards Stefan Miklosovic
