On Thu, Aug 17, 2017 at 12:10 AM, Aleksander Alekseev <a.aleks...@postgrespro.ru> wrote: >> The SCRAM salt length is currently set as >> >> /* length of salt when generating new verifiers */ >> #define SCRAM_DEFAULT_SALT_LEN 12 >> >> without further comment. >> >> I suspect that this length was chosen based on the example in RFC 5802 >> (SCRAM-SHA-1) section 5. But the analogous example in RFC 7677 >> (SCRAM-SHA-256) section 3 uses a length of 16. Should we use that instead?
In the initial discussions there was as well a mention about using 16 bytes. https://www.postgresql.org/message-id/507550bd.2030...@vmware.com As we are using SCRAM-SHA-256, let's bump it up and be consistent. That's now or never. > Maybe this length was chosen just because it becomes a 16-characters > string after base64encode. If I understand correctly RFC 5802 and RFC > 7677 don't say much about the required or recommended length of the > salt. Yep, it doesn't provide any recommendation. > I personally believe that 2^96 of possible salts is consistent with both > RFCs and should be enough in practice. (12 bytes * 8) = 96, so you would favor 12 as length. -- Michael -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
