Am Montag, 15. Dezember 2014, 17:01:02 schrieb George Spelvin: Hi George, >> With that then, I'm really fine with the changes given that they pass >> the NIST tests. > >So here's the current list of issues. First, minor ones: >1) Add const to DRBG interface, as per Stephan's request. >2) Revised version of that final patch that, you know, actually works. >3) Re-run tests at the very end just to make sure. > >And the major ones: >4) Is non-deterministic DT desired? >5) If yes, how to request it? > >On point 4, here are the primary arguments against: > >* It makes the generator non-deterministic, which is a significant > interface change and may break some applications. >* This is a crufty old generator, used primarily for compatibility, > and it's best not to upset its quiet retirement. > >And the primary arguments for: >* It's an honest good-faith implementation of the spec requirements. > Using a counter is, IMHO, a strained interpretation. >* The implementation isn't particularly difficult. > >After considering various options, my current (not very firm) thought >is that the best way to provide a non-deterministic option would be via >a separate algorithm name. > >But externally-visible names are a high-level design issue and I could >definitely use some guidance there. Opinions? The standard X9.31 is called ansi_cprng. Logically your non-deterministic approach is a constant reseeding of the DRNG. In SP800-90A speak this is called "prediction-resistance". Hence, my DRBGs use "pr" for that approach -- e.g. drbg_pr_sha256. The name follows the structure of "RNG type"_"[pr|nopr]"_"algo". For the X9.31 RNG we do not have an algorithmic reference as we only have AES128. We only have the RNG type and the "pr" reference. Thus, I would propose "ansi_cprng_pr" as a name that is analogous to the DRBG implementations. Ciao Stephan -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
