Tom Lane wrote: > "Jim C. Nasby" <decibel@xxxxxxxxxxx> writes: > > Simply put, MD5 is no longer strong enough for protecting secrets. It's > > just too easy to brute-force. SHA1 is ok for now, but it's days are > > numbered as well. I think it would be good to alter SHA1 (or something > > stronger) as an alternative to MD5, and I see no reason not to use a > > random salt instead of username. > > Well, I have no particular problem with offering SHA1 as an alternative > hash method for those who find MD5 too weak ... but I still question the > value of putting any random salt in the table. AFAICS you would have to > send that salt as part of the initial password challenge, which means > any potential attacker could find it out even before trying to > compromise pg_shadow; so Stephen's argument that there is a useful > improvement in protection against precomputation of password hashes > still falls down. > > BTW, one could also ask exactly what threat model Stephen is concerned > about. ISTM anyone who can obtain the contents of pg_shadow has > *already* broken your database security. That's what I told him. I think his concern about pre-computed hashes is the only real issue, and give 'postgres' is usually the super-user, I can see someone pre-computing md5 postgres hashes and doing quick comparisons, perhaps as a root kit so you don't have to do the hashing yourself. I personally don't find that very compelling either. -- Bruce Momjian | http://candle.pha.pa.us pgman@xxxxxxxxxxxxxxxx | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073
