Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1YTc5w-0004Qs-QP for pgsql-hackers@arkaria.postgresql.org; Thu, 05 Mar 2015 20:10:08 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.80) (envelope-from ) id 1YTc5v-0001bl-MS for pgsql-hackers@arkaria.postgresql.org; Thu, 05 Mar 2015 20:10:07 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1YTc5u-0001ag-Pq for pgsql-hackers@postgreSQL.org; Thu, 05 Mar 2015 20:10:06 +0000 Received: from mail-bn1bon0613.outbound.protection.outlook.com ([2a01:111:f400:fc10::1:613] helo=na01-bn1-obe.outbound.protection.outlook.com) by magus.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1YTc5p-0006Wy-66 for pgsql-hackers@postgreSQL.org; Thu, 05 Mar 2015 20:10:05 +0000 Received: from decina.attlocal.net (2602:306:ce8b:3460:75e0:5448:6acd:4893) by BY1PR11MB0341.namprd11.prod.outlook.com (25.160.206.154) with Microsoft SMTP Server (TLS) id 15.1.99.14; Thu, 5 Mar 2015 20:09:46 +0000 Message-ID: <54F8B7FD.8070706@BlueTreble.com> Date: Thu, 5 Mar 2015 14:09:33 -0600 From: Jim Nasby User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Stephen Frost , Bruce Momjian CC: PostgreSQL-development Subject: Re: MD5 authentication needs help References: <20150304155230.GW29780@tamriel.snowman.net> <20150304173059.GF23933@momjian.us> <20150304174354.GC29780@tamriel.snowman.net> <20150304175857.GA31979@momjian.us> <20150304182731.GG29780@tamriel.snowman.net> <20150304191625.GB31979@momjian.us> <20150304192151.GJ29780@tamriel.snowman.net> <20150304193715.GC31979@momjian.us> <20150304194654.GL29780@tamriel.snowman.net> <20150304204327.GD31979@momjian.us> <20150304205603.GM29780@tamriel.snowman.net> In-Reply-To: <20150304205603.GM29780@tamriel.snowman.net> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [2602:306:ce8b:3460:75e0:5448:6acd:4893] X-ClientProxiedBy: BL2PR01CA0049.prod.exchangelabs.com (10.141.66.49) To BY1PR11MB0341.namprd11.prod.outlook.com (25.160.206.154) Authentication-Results: postgreSQL.org; dkim=none (message not signed) header.d=none; X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:;SRVR:BY1PR11MB0341; X-Microsoft-Antispam-PRVS: X-Forefront-Antispam-Report: BMV:0; SFV:NSPM; SFS:(10009020)(6009001)(479174004)(24454002)(377454003)(51704005)(80316001)(19580395003)(53416004)(33656002)(59896002)(50466002)(23746002)(40100003)(54356999)(76176999)(87976001)(86362001)(46102003)(42186005)(93886004)(83506001)(36756003)(47776003)(50986999)(87266999)(77156002)(62966003)(15975445007)(92566002)(65956001)(122386002)(2950100001)(3826002)(336755003)(18886065003); DIR:OUT; SFP:1101; SCL:1; SRVR:BY1PR11MB0341; H:decina.attlocal.net; FPR:; SPF:None; MLV:sfv; LANG:en; X-Exchange-Antispam-Report-Test: UriScan:; X-Exchange-Antispam-Report-CFA-Test: BCL:0; PCL:0; RULEID:(601004)(5005006)(5001007); SRVR:BY1PR11MB0341; BCL:0; PCL:0; RULEID:; SRVR:BY1PR11MB0341; X-Forefront-PRVS: 05066DEDBB X-OriginatorOrg: bluetreble.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 05 Mar 2015 20:09:46.1567 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-Transport-CrossTenantHeadersStamped: BY1PR11MB0341 X-Pg-Spam-Score: -1.9 (-) List-Archive: List-Help: List-ID: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: X-Mailing-List: pgsql-hackers Precedence: bulk Sender: pgsql-hackers-owner@postgresql.org 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 situation to be in. Is there some reason we don't just fix that? I'm thinking that this is a special case where we could just modify the pg_auth tuple in-place without bloating the catalog (we already do that somewhere else). Is there something else that makes this difficult? Are we afraid of an extra GUC to control it? -- Jim Nasby, Data Architect, Blue Treble Consulting Data in Trouble? Get it in Treble! http://BlueTreble.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers