On Tue, Feb 22, 2011 at 8:01 AM, Heikki Linnakangas <heikki.linnakan...@enterprisedb.com> wrote: > This is hashing, not encryption, there is no key. The point is that even if > the attacker has the hash value and knows the algorithm, he can not > construct *another* snapshot that has the same hash.
What good does that do us? > Yes. It would be good to perform those sanity checks anyway. I don't think it's good; I think it's absolutely necessary. Otherwise someone can generate arbitrary garbage, hash it, and feed it to us. No? > But even if we don't allow it, there's no harm in sending the whole snapshot > to the client, anyway. Ie. instead of "1" as the identifier, use the > snapshot itself. That leaves the door open for allowing it in the future, > should we choose to do so. The door is open either way, AFAICS: we could eventually allow: BEGIN TRANSACTION (SNAPSHOT '1'); and also BEGIN TRANSACTION (SNAPSHOT '{xmin 123 xmax 456 xids 128 149 201}'); -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers