Re: [HACKERS] MD5 authentication needs help -SCRAM

2015-03-18 Thread Stephen Frost
* Abhijit Menon-Sen (a...@2ndquadrant.com) wrote: > As a followup, I spoke to an IETF friend who's used and implemented both > SRP and SCRAM. He agrees that SRP is cryptographically solid, that it's > significantly more difficult to implement (and therefore has a bit of a > monoculture risk overall

Re: [HACKERS] MD5 authentication needs help -SCRAM

2015-03-18 Thread Alvaro Herrera
Abhijit Menon-Sen wrote: > P.S. I don't know why the SRP code was removed from LibreSSL; nor am I > sure how seriously to take that. It's possible that it's only because > it's (still) rather obscure. As I recall, the working principle of the LibreSSL guys is to remove everything that can't be un

Re: [HACKERS] MD5 authentication needs help -SCRAM

2015-03-18 Thread Abhijit Menon-Sen
As a followup, I spoke to an IETF friend who's used and implemented both SRP and SCRAM. He agrees that SRP is cryptographically solid, that it's significantly more difficult to implement (and therefore has a bit of a monoculture risk overall, though of course that wouldn't apply to us if we were to

Re: [HACKERS] MD5 authentication needs help -SCRAM

2015-03-18 Thread Abhijit Menon-Sen
At 2015-03-14 09:44:02 +0200, hlinn...@iki.fi wrote: > > Perhaps it would be time to restart the discussion on standardizing > SRP as a SASL mechanism in IETF. I haven't seen much evidence that there's any interest in doing this; in fact, I can't remember the author of the draft you pointed to bei

Re: [HACKERS] MD5 authentication needs help -SCRAM

2015-03-14 Thread Heikki Linnakangas
On 03/09/2015 04:43 PM, Abhijit Menon-Sen wrote: At 2015-03-09 13:52:10 +0200, hlinn...@iki.fi wrote: Do you have any insight on why the IETF working group didn't choose a PAKE protocol instead of or in addition to SCRAM, when SCRAM was standardized? Hi Heikki. It was a long time ago, but I

Re: [HACKERS] MD5 authentication needs help -SCRAM

2015-03-09 Thread Abhijit Menon-Sen
At 2015-03-09 13:52:10 +0200, hlinn...@iki.fi wrote: > > Do you have any insight on why the IETF working group didn't choose a > PAKE protocol instead of or in addition to SCRAM, when SCRAM was > standardized? Hi Heikki. It was a long time ago, but I recall that SRP was patent-encumbered: https:

Re: [HACKERS] MD5 authentication needs help -SCRAM

2015-03-09 Thread Heikki Linnakangas
Hi Abhijit, I didn't realize you were involved in the IETF process on SCRAM :-). On 03/09/2015 09:21 AM, Abhijit Menon-Sen wrote: At 2015-03-08 12:48:44 -0700, j...@agliodbs.com wrote: Since SCRAM has been brought up a number of times here, I thought I'd loop in the PostgreSQL contributor who

Re: [HACKERS] MD5 authentication needs help -SCRAM

2015-03-09 Thread Abhijit Menon-Sen
At 2015-03-08 12:48:44 -0700, j...@agliodbs.com wrote: > > Since SCRAM has been brought up a number of times here, I thought > I'd loop in the PostgreSQL contributor who is co-author of the SCRAM > standard to see if he has anything to say about implementing SCRAM as > a built-in auth method for Po

Re: [HACKERS] MD5 authentication needs help -SCRAM

2015-03-08 Thread Josh Berkus
All, Since SCRAM has been brought up a number of times here, I thought I'd loop in the PostgreSQL contributor who is co-author of the SCRAM standard to see if he has anything to say about implementing SCRAM as a built-in auth method for Postgres. Abhijit? -- Josh Berkus PostgreSQL Experts Inc.

Re: [HACKERS] MD5 authentication needs help

2015-03-07 Thread Stephen Frost
* Bruce Momjian (br...@momjian.us) wrote: > On Sat, Mar 7, 2015 at 03:15:46PM -0500, Bruce Momjian wrote: > > > Gave me 9.15s, or ~0.00915s per connection on a single thread. That > > > times 16k is 146s or about two and a half minutes. Of course, I'm > > > comparing this against what we current

Re: [HACKERS] MD5 authentication needs help

2015-03-07 Thread Bruce Momjian
On Sat, Mar 7, 2015 at 03:15:46PM -0500, Bruce Momjian wrote: > > Gave me 9.15s, or ~0.00915s per connection on a single thread. That > > times 16k is 146s or about two and a half minutes. Of course, I'm > > comparing this against what we currently do since, well, that's what we > > currently do

Re: [HACKERS] MD5 authentication needs help

2015-03-07 Thread Stephen Frost
* Bruce Momjian (br...@momjian.us) wrote: > On Sat, Mar 7, 2015 at 01:56:51PM -0500, Stephen Frost wrote: > > * Bruce Momjian (br...@momjian.us) wrote: > > > Yes, I used the term cluster-wide salt in two cases: first, > > > cluster-wide counter for the MD5 session salt improvement, and second, >

Re: [HACKERS] MD5 authentication needs help

2015-03-07 Thread Bruce Momjian
On Sat, Mar 7, 2015 at 01:56:51PM -0500, Stephen Frost wrote: > * Bruce Momjian (br...@momjian.us) wrote: > > On Sat, Mar 7, 2015 at 12:49:15PM -0500, Stephen Frost wrote: > > > Ok, this is the incremented counter approach you brought up previously. > > > Using the term 'cluster-wide salt' confus

Re: [HACKERS] MD5 authentication needs help

2015-03-07 Thread Stephen Frost
* Bruce Momjian (br...@momjian.us) wrote: > On Sat, Mar 7, 2015 at 12:49:15PM -0500, Stephen Frost wrote: > > Ok, this is the incremented counter approach you brought up previously. > > Using the term 'cluster-wide salt' confused me as I thought you were > > referring to changing the on-disk forma

Re: [HACKERS] MD5 authentication needs help

2015-03-07 Thread Bruce Momjian
On Sat, Mar 7, 2015 at 12:49:15PM -0500, Stephen Frost wrote: > * Bruce Momjian (br...@momjian.us) wrote: > > On Fri, Mar 6, 2015 at 07:02:36PM -0500, Stephen Frost wrote: > > > * Bruce Momjian (br...@momjian.us) wrote: > > > > I think the best solution to this would be to introduce a per-cluster

Re: [HACKERS] MD5 authentication needs help

2015-03-07 Thread Bruce Momjian
On Sat, Mar 7, 2015 at 12:52:15PM -0500, Stephen Frost wrote: > * Bruce Momjian (br...@momjian.us) wrote: > > On Fri, Mar 6, 2015 at 07:00:10PM -0500, Stephen Frost wrote: > > > suggested to me as one change we could make that would reduce the risk > > > of disk-based attacks while trading that o

Re: [HACKERS] MD5 authentication needs help

2015-03-07 Thread Stephen Frost
* Bruce Momjian (br...@momjian.us) wrote: > On Fri, Mar 6, 2015 at 07:00:10PM -0500, Stephen Frost wrote: > > suggested to me as one change we could make that would reduce the risk > > of disk-based attacks while trading that off for a higher risk on the > > side of network-based attacks while not

Re: [HACKERS] MD5 authentication needs help

2015-03-07 Thread Stephen Frost
* Bruce Momjian (br...@momjian.us) wrote: > On Fri, Mar 6, 2015 at 07:02:36PM -0500, Stephen Frost wrote: > > * Bruce Momjian (br...@momjian.us) wrote: > > > I think the best solution to this would be to introduce a per-cluster > > > salt that is used for every password hash. That way, you could

Re: [HACKERS] MD5 authentication needs help

2015-03-07 Thread Bruce Momjian
On Fri, Mar 6, 2015 at 07:00:10PM -0500, Stephen Frost wrote: > > > I'm also worried about both, but if the admin is worried about sniffing > > > in their environment, they're much more likely to use TLS than to set up > > > client side certificates, kerberos, or some other strong auth mechanism,

Re: [HACKERS] MD5 authentication needs help

2015-03-07 Thread Bruce Momjian
On Fri, Mar 6, 2015 at 07:02:36PM -0500, Stephen Frost wrote: > * Bruce Momjian (br...@momjian.us) wrote: > > On Fri, Mar 6, 2015 at 12:50:14PM -0800, Josh Berkus wrote: > > > On 03/06/2015 08:19 AM, Stephen Frost wrote: > > > > Well, server-side, we already have that- have pgbouncer run on the >

Re: [HACKERS] MD5 authentication needs help

2015-03-06 Thread Stephen Frost
* Bruce Momjian (br...@momjian.us) wrote: > On Fri, Mar 6, 2015 at 12:50:14PM -0800, Josh Berkus wrote: > > On 03/06/2015 08:19 AM, Stephen Frost wrote: > > > Well, server-side, we already have that- have pgbouncer run on the > > > database server (something which I'm typically in favor of anyway)

Re: [HACKERS] MD5 authentication needs help

2015-03-06 Thread Stephen Frost
* Bruce Momjian (br...@momjian.us) wrote: > On Thu, Mar 5, 2015 at 11:15:55AM -0500, Stephen Frost wrote: > > * Bruce Momjian (br...@momjian.us) wrote: > > > On Wed, Mar 4, 2015 at 05:56:25PM -0800, Josh Berkus wrote: > > > > So, are we more worried about attackers getting a copy of pg_authid, or

Re: [HACKERS] MD5 authentication needs help

2015-03-06 Thread Bruce Momjian
On Fri, Mar 6, 2015 at 12:50:14PM -0800, Josh Berkus wrote: > On 03/06/2015 08:19 AM, Stephen Frost wrote: > > * Alvaro Herrera (alvhe...@2ndquadrant.com) wrote: > >> Stephen Frost wrote: > >> Sure. I was thinking we would have some mechanism to authenticate the > >> connection as coming from a p

Re: [HACKERS] MD5 authentication needs help

2015-03-06 Thread Bruce Momjian
On Thu, Mar 5, 2015 at 11:15:55AM -0500, Stephen Frost wrote: > * Bruce Momjian (br...@momjian.us) wrote: > > On Wed, Mar 4, 2015 at 05:56:25PM -0800, Josh Berkus wrote: > > > So, are we more worried about attackers getting a copy of pg_authid, or > > > sniffing the hash on the wire? > > > > Bot

Re: [HACKERS] MD5 authentication needs help

2015-03-06 Thread Josh Berkus
On 03/06/2015 08:19 AM, Stephen Frost wrote: > * Alvaro Herrera (alvhe...@2ndquadrant.com) wrote: >> Stephen Frost wrote: >> Sure. I was thinking we would have some mechanism to authenticate the >> connection as coming from a pooler that has been previously authorized; >> something simple as a new

Re: [HACKERS] MD5 authentication needs help

2015-03-06 Thread Stephen Frost
* Alvaro Herrera (alvhe...@2ndquadrant.com) wrote: > Stephen Frost wrote: > > * Alvaro Herrera (alvhe...@2ndquadrant.com) wrote: > > > Perhaps one of the requirements of a new auth method should be to allow > > > middlemen such as connection poolers. It's been over two years since I > > > had a lo

Re: [HACKERS] MD5 authentication needs help

2015-03-06 Thread Alvaro Herrera
Stephen Frost wrote: > Alvaro, > > * Alvaro Herrera (alvhe...@2ndquadrant.com) wrote: > > Perhaps one of the requirements of a new auth method should be to allow > > middlemen such as connection poolers. It's been over two years since I > > had a look, but IIRC pgbouncer had the very ugly requir

Re: [HACKERS] MD5 authentication needs help

2015-03-06 Thread Stephen Frost
Alvaro, * Alvaro Herrera (alvhe...@2ndquadrant.com) wrote: > Stephen Frost wrote: > > * Josh Berkus (j...@agliodbs.com) wrote: > > > > > 3) Using the user name for the MD5 storage salt allows the MD5 stored > > > > hash to be used on a different cluster if the user used the same > > > > password

Re: [HACKERS] MD5 authentication needs help

2015-03-06 Thread Alvaro Herrera
Stephen Frost wrote: > * Josh Berkus (j...@agliodbs.com) wrote: > > > 3) Using the user name for the MD5 storage salt allows the MD5 stored > > > hash to be used on a different cluster if the user used the same > > > password. > > > > This is a feature as well as a bug. For example, pgBouncer r

Re: [HACKERS] MD5 authentication needs help

2015-03-06 Thread Stephen Frost
Greg, * Greg Stark (st...@mit.edu) wrote: > Locked accounts are a terrible terrible idea. All they do is hand attackers > an easy DOS vulnerability. They're pure security theatre if your > authentication isn't vulnerable to brute force attacks and an unreliable > band-aid if they are. For starter

Re: [HACKERS] MD5 authentication needs help

2015-03-06 Thread Stephen Frost
* Albe Laurenz (laurenz.a...@wien.gv.at) wrote: > Stephen Frost wrote: > > Yes, it certainly was. I think Bruce was thinking that we could simply > > hash what goes on to disk with an additional salt that's stored, but > > that wouldn't actually work without requiring a change to the wireline > >

Re: [HACKERS] MD5 authentication needs help

2015-03-06 Thread Greg Stark
Locked accounts are a terrible terrible idea. All they do is hand attackers an easy DOS vulnerability. They're pure security theatre if your authentication isn't vulnerable to brute force attacks and an unreliable band-aid if they are. Having dealt with mechanisms for locking accounts in other dat

Re: [HACKERS] MD5 authentication needs help

2015-03-06 Thread Albe Laurenz
Stephen Frost wrote: > * Tom Lane (t...@sss.pgh.pa.us) wrote: >> Bruce Momjian writes: >>> Let me update my list of possible improvements: >> >>> 1) MD5 makes users feel uneasy (though our usage is mostly safe) >> >>> 2) The per-session salt sent to the client is only 32-bits, meaning >>> that i

Re: [HACKERS] MD5 authentication needs help

2015-03-05 Thread Stephen Frost
* Jim Nasby (jim.na...@bluetreble.com) wrote: > On 3/5/15 2:17 PM, Stephen Frost wrote: > >* Jim Nasby (jim.na...@bluetreble.com) wrote: > >I'm all for it, though I would ask that we provide a way for superusers > >to delegate the ability to reset locked accounts to non-superusers. > > > >I'd want

Re: [HACKERS] MD5 authentication needs help

2015-03-05 Thread Jim Nasby
On 3/5/15 2:17 PM, Stephen Frost wrote: * Jim Nasby (jim.na...@bluetreble.com) wrote: On 3/4/15 2:56 PM, Stephen Frost wrote: 2) The per-session salt sent to the client is only 32-bits, meaning that it is possible to reply an observed MD5 hash in ~16k connection attempts. Yes, and we have no

Re: [HACKERS] MD5 authentication needs help

2015-03-05 Thread Stephen Frost
* Jim Nasby (jim.na...@bluetreble.com) wrote: > On 3/4/15 2:56 PM, Stephen Frost wrote: > >>2) The per-session salt sent to the client is only 32-bits, meaning > >>>that it is possible to reply an observed MD5 hash in ~16k connection > >>>attempts. > >Yes, and we have no (PG-based) mechanism to pr

Re: [HACKERS] MD5 authentication needs help

2015-03-05 Thread Jim Nasby
On 3/4/15 2:56 PM, Stephen Frost wrote: 2) The per-session salt sent to the client is only 32-bits, meaning >that it is possible to reply an observed MD5 hash in ~16k connection >attempts. Yes, and we have no (PG-based) mechanism to prevent those connection attempts, which is a pretty horrible

Re: [HACKERS] MD5 authentication needs help

2015-03-05 Thread Stephen Frost
* Bruce Momjian (br...@momjian.us) wrote: > On Wed, Mar 4, 2015 at 04:19:00PM -0500, Stephen Frost wrote: > > > Hm, well, "don't change the wireline protocol" could be another wanna-have > > > ... but if we want to stop using MD5, that's not really a realistic goal > > > is it? > > > > I'm trying

Re: [HACKERS] MD5 authentication needs help

2015-03-05 Thread Stephen Frost
* Bruce Momjian (br...@momjian.us) wrote: > One way to fix #2 would be to use a per-user or per-cluster counter for > the session salt, rather than a random number --- that would change > replays from ~16k to 4 billion, with no wire protocol change needed. I'm not against doing that if we decide t

Re: [HACKERS] MD5 authentication needs help

2015-03-05 Thread Stephen Frost
* Bruce Momjian (br...@momjian.us) wrote: > On Wed, Mar 4, 2015 at 05:56:25PM -0800, Josh Berkus wrote: > > So, are we more worried about attackers getting a copy of pg_authid, or > > sniffing the hash on the wire? > > Both. Stephen is more worried about pg_authid, but I am more worried > about

Re: [HACKERS] MD5 authentication needs help

2015-03-05 Thread Stephen Frost
* Josh Berkus (j...@agliodbs.com) wrote: > Catching up here ... > > On 03/03/2015 06:01 PM, Bruce Momjian wrote: > > It feels like MD5 has accumulated enough problems that we need to start > > looking for another way to store and pass passwords. The MD5 problems > > are: > > > > 1) MD5 makes us

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Bruce Momjian
On Wed, Mar 4, 2015 at 05:56:25PM -0800, Josh Berkus wrote: > Catching up here ... > > On 03/03/2015 06:01 PM, Bruce Momjian wrote: > > It feels like MD5 has accumulated enough problems that we need to start > > looking for another way to store and pass passwords. The MD5 problems > > are: > >

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Josh Berkus
Catching up here ... On 03/03/2015 06:01 PM, Bruce Momjian wrote: > It feels like MD5 has accumulated enough problems that we need to start > looking for another way to store and pass passwords. The MD5 problems > are: > > 1) MD5 makes users feel uneasy (though our usage is mostly safe) > > 2

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Bruce Momjian
On Wed, Mar 4, 2015 at 04:19:00PM -0500, Stephen Frost wrote: > > Hm, well, "don't change the wireline protocol" could be another wanna-have > > ... but if we want to stop using MD5, that's not really a realistic goal > > is it? > > I'm trying to address both sides of the issue- improve the curre

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Bruce Momjian
On Wed, Mar 4, 2015 at 03:59:02PM -0500, Stephen Frost wrote: > * Tom Lane (t...@sss.pgh.pa.us) wrote: > > Bruce Momjian writes: > > > Let me update my list of possible improvements: > > > > > 1) MD5 makes users feel uneasy (though our usage is mostly safe) > > > > > 2) The per-session salt s

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Bruce Momjian
On Wed, Mar 4, 2015 at 03:54:09PM -0500, Tom Lane wrote: > Bruce Momjian writes: > > Let me update my list of possible improvements: > > > 1) MD5 makes users feel uneasy (though our usage is mostly safe) > > > 2) The per-session salt sent to the client is only 32-bits, meaning > > that it is

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Stephen Frost
* Robert Haas (robertmh...@gmail.com) wrote: > So, the server can only authenticate the user with the salts it has > stored, because those are the only salts for which it knows what the > response should be? That's correct- except that it doesn't directly know what the response is, it only knows

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Robert Haas
On Wed, Mar 4, 2015 at 10:52 AM, Stephen Frost wrote: > I've been discussing this with a few folks outside of the PG community > (Debian and Openwall people specifically) and a few interesting ideas > have come out of that which might be useful to discuss. > > The first is a "don't break anything"

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Stephen Frost
* Tom Lane (t...@sss.pgh.pa.us) wrote: > Stephen Frost writes: > > * Tom Lane (t...@sss.pgh.pa.us) wrote: > >> What happened to "possession of the contents of pg_authid is sufficient > >> to log in"? I thought fixing that was one of the objectives here. > > > Yes, it certainly was. I think Bruc

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Tom Lane
Stephen Frost writes: > * Tom Lane (t...@sss.pgh.pa.us) wrote: >> What happened to "possession of the contents of pg_authid is sufficient >> to log in"? I thought fixing that was one of the objectives here. > Yes, it certainly was. I think Bruce was thinking that we could simply > hash what goe

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Stephen Frost
* Tom Lane (t...@sss.pgh.pa.us) wrote: > Bruce Momjian writes: > > Let me update my list of possible improvements: > > > 1) MD5 makes users feel uneasy (though our usage is mostly safe) > > > 2) The per-session salt sent to the client is only 32-bits, meaning > > that it is possible to reply a

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Stephen Frost
* Bruce Momjian (br...@momjian.us) wrote: > On Wed, Mar 4, 2015 at 02:46:54PM -0500, Stephen Frost wrote: > > > Well, passwords are already addressed by certificate authentication, so > > > what's your point? I think we decided we wanted a way to do passwords > > > without requiring network encry

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Tom Lane
Bruce Momjian writes: > Let me update my list of possible improvements: > 1) MD5 makes users feel uneasy (though our usage is mostly safe) > 2) The per-session salt sent to the client is only 32-bits, meaning > that it is possible to reply an observed MD5 hash in ~16k connection > attempts. >

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Bruce Momjian
On Wed, Mar 4, 2015 at 02:46:54PM -0500, Stephen Frost wrote: > > Well, passwords are already addressed by certificate authentication, so > > what's your point? I think we decided we wanted a way to do passwords > > without requiring network encryption. > > It's completely unclear to me what you

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Stephen Frost
* Magnus Hagander (mag...@hagander.net) wrote: > On Wed, Mar 4, 2015 at 5:03 PM, Stephen Frost wrote: > > No, I'm not suggesting that OpenSSL or TLS become mandatory but was > > thinking it might be good alternative as a middle-ground between full > > client-and-server side certificates and straig

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Bruce Momjian
On Wed, Mar 4, 2015 at 02:21:51PM -0500, Stephen Frost wrote: > * Bruce Momjian (br...@momjian.us) wrote: > > On Wed, Mar 4, 2015 at 01:27:32PM -0500, Stephen Frost wrote: > > > This further makes what is sent over the network not directly > > > susceptible to a replay attack because the server h

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Stephen Frost
* Bruce Momjian (br...@momjian.us) wrote: > On Wed, Mar 4, 2015 at 02:21:51PM -0500, Stephen Frost wrote: > > * Bruce Momjian (br...@momjian.us) wrote: > > > On Wed, Mar 4, 2015 at 01:27:32PM -0500, Stephen Frost wrote: > > > > This further makes what is sent over the network not directly > > > >

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Stephen Frost
* Bruce Momjian (br...@momjian.us) wrote: > On Wed, Mar 4, 2015 at 01:27:32PM -0500, Stephen Frost wrote: > > This further makes what is sent over the network not directly > > susceptible to a replay attack because the server has multiple values > > available to pick for the salt to use and sends

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Stephen Frost
* Heikki Linnakangas (hlinn...@iki.fi) wrote: > I'm not sure how expensive a brute force attack on SRP would be, > using a stolen backup tape. There doesn't seem to be an iterations > count similar to SCRAM. But note that SRP's resistance to > brute-forcing the authentication handshake is of a diff

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Heikki Linnakangas
On 03/04/2015 08:59 PM, Stephen Frost wrote: * Heikki Linnakangas (hlinn...@iki.fi) wrote: The big difference between SRP and SCRAM is that if you eavesdrop the SCRAM handshake, you can use that information to launch a brute-force or dictionary attack. With SRP, you cannot do that. That makes it

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Bruce Momjian
On Wed, Mar 4, 2015 at 01:27:32PM -0500, Stephen Frost wrote: > This further makes what is sent over the network not directly > susceptible to a replay attack because the server has multiple values > available to pick for the salt to use and sends one at random to the > client, exactly how our cur

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Stephen Frost
* Heikki Linnakangas (hlinn...@iki.fi) wrote: > The big difference between SRP and SCRAM is that if you eavesdrop > the SCRAM handshake, you can use that information to launch a > brute-force or dictionary attack. With SRP, you cannot do that. That > makes it relatively safe to use weak passwords w

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Heikki Linnakangas
On 03/04/2015 06:11 PM, Stephen Frost wrote: * Magnus Hagander (mag...@hagander.net) wrote: On Wed, Mar 4, 2015 at 5:03 PM, Stephen Frost wrote: No, I'm not suggesting that OpenSSL or TLS become mandatory but was thinking it might be good alternative as a middle-ground between full client-and-

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Stefan Kaltenbrunner
On 03/04/2015 04:52 PM, Stephen Frost wrote: > Bruce, all, > > I've been discussing this with a few folks outside of the PG community > (Debian and Openwall people specifically) and a few interesting ideas > have come out of that which might be useful to discuss. > > The first is a "don't break a

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Stephen Frost
* Bruce Momjian (br...@momjian.us) wrote: > On Wed, Mar 4, 2015 at 12:43:54PM -0500, Stephen Frost wrote: > > > What does storing multiple hash(password || stoarage_salt) values do for > > > us that session_salt doesn't already do? > > > > By storing a hash of the result of the challenge/response

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Bruce Momjian
On Wed, Mar 4, 2015 at 12:43:54PM -0500, Stephen Frost wrote: > > What does storing multiple hash(password || stoarage_salt) values do for > > us that session_salt doesn't already do? > > By storing a hash of the result of the challenge/response, we wouldn't > be susceptible to attacks where the

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Stephen Frost
* Stephen Frost (sfr...@snowman.net) wrote: > * Bruce Momjian (br...@momjian.us) wrote: > > On Wed, Mar 4, 2015 at 11:36:23AM -0500, Stephen Frost wrote: > > > * Andres Freund (and...@2ndquadrant.com) wrote: > > > > On 2015-03-04 11:06:33 -0500, Stephen Frost wrote: > > > > > * Andres Freund (and.

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Stephen Frost
* Bruce Momjian (br...@momjian.us) wrote: > On Wed, Mar 4, 2015 at 11:36:23AM -0500, Stephen Frost wrote: > > * Andres Freund (and...@2ndquadrant.com) wrote: > > > On 2015-03-04 11:06:33 -0500, Stephen Frost wrote: > > > > * Andres Freund (and...@2ndquadrant.com) wrote: > > > > > On 2015-03-04 10:

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Stephen Frost
* Bruce Momjian (br...@momjian.us) wrote: > On Wed, Mar 4, 2015 at 10:52:30AM -0500, Stephen Frost wrote: > > The first is a "don't break anything" approach which would move the > > needle between "network data sensitivity" and "on-disk data sensitivity" > > a bit back in the direction of making t

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Bruce Momjian
On Wed, Mar 4, 2015 at 11:36:23AM -0500, Stephen Frost wrote: > * Andres Freund (and...@2ndquadrant.com) wrote: > > On 2015-03-04 11:06:33 -0500, Stephen Frost wrote: > > > * Andres Freund (and...@2ndquadrant.com) wrote: > > > > On 2015-03-04 10:52:30 -0500, Stephen Frost wrote: > > > > > The firs

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Bruce Momjian
On Wed, Mar 4, 2015 at 10:52:30AM -0500, Stephen Frost wrote: > The first is a "don't break anything" approach which would move the > needle between "network data sensitivity" and "on-disk data sensitivity" > a bit back in the direction of making the network data more sensitive. > > this approach

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Stephen Frost
* Andres Freund (and...@2ndquadrant.com) wrote: > On 2015-03-04 11:06:33 -0500, Stephen Frost wrote: > > * Andres Freund (and...@2ndquadrant.com) wrote: > > > On 2015-03-04 10:52:30 -0500, Stephen Frost wrote: > > > > The first is a "don't break anything" approach which would move the > > > > needl

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Andres Freund
On 2015-03-04 11:06:33 -0500, Stephen Frost wrote: > * Andres Freund (and...@2ndquadrant.com) wrote: > > On 2015-03-04 10:52:30 -0500, Stephen Frost wrote: > > > The first is a "don't break anything" approach which would move the > > > needle between "network data sensitivity" and "on-disk data sen

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Stephen Frost
* Andres Freund (and...@2ndquadrant.com) wrote: > Hi, > > On 2015-03-04 10:52:30 -0500, Stephen Frost wrote: > > I've been discussing this with a few folks outside of the PG community > > (Debian and Openwall people specifically) and a few interesting ideas > > have come out of that which might be

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Magnus Hagander
On Wed, Mar 4, 2015 at 5:03 PM, Stephen Frost wrote: > Magnus, > > * Magnus Hagander (mag...@hagander.net) wrote: > > On Wed, Mar 4, 2015 at 4:52 PM, Stephen Frost > wrote: > > > A lot of discussion has been going on with SCRAM and SASL, which is all > > > great, but that means we end up with a

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Stephen Frost
Magnus, * Magnus Hagander (mag...@hagander.net) wrote: > On Wed, Mar 4, 2015 at 4:52 PM, Stephen Frost wrote: > > A lot of discussion has been going on with SCRAM and SASL, which is all > > great, but that means we end up with a dependency on SASL or we have to > > reimplement SCRAM (which I've b

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Andres Freund
Hi, On 2015-03-04 10:52:30 -0500, Stephen Frost wrote: > I've been discussing this with a few folks outside of the PG community > (Debian and Openwall people specifically) and a few interesting ideas > have come out of that which might be useful to discuss. > > The first is a "don't break anythin

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Stephen Frost
Bruce, all, I've been discussing this with a few folks outside of the PG community (Debian and Openwall people specifically) and a few interesting ideas have come out of that which might be useful to discuss. The first is a "don't break anything" approach which would move the needle between "netw

Re: [HACKERS] MD5 authentication needs help

2015-03-04 Thread Magnus Hagander
On Wed, Mar 4, 2015 at 4:52 PM, Stephen Frost wrote: > > A lot of discussion has been going on with SCRAM and SASL, which is all > great, but that means we end up with a dependency on SASL or we have to > reimplement SCRAM (which I've been thinking might not be a bad idea- > it's actually not tha

Re: [HACKERS] MD5 authentication needs help

2015-03-03 Thread Stephen Frost
Bruce, all, * Bruce Momjian (br...@momjian.us) wrote: > It feels like MD5 has accumulated enough problems that we need to start > looking for another way to store and pass passwords. The MD5 problems > are: > > 1) MD5 makes users feel uneasy (though our usage is mostly safe) > > 2) The per-s

[HACKERS] MD5 authentication needs help

2015-03-03 Thread Bruce Momjian
It feels like MD5 has accumulated enough problems that we need to start looking for another way to store and pass passwords. The MD5 problems are: 1) MD5 makes users feel uneasy (though our usage is mostly safe) 2) The per-session salt sent to the client is only 32-bits, meaning that it is po