Re: [HACKERS] Re: [BUGS] BUG #6189: libpq: sslmode=require verifies server certificate if root.crt is present
On Fri, Sep 23, 2011 at 16:44, Alvaro Herrera alvhe...@commandprompt.com wrote: Excerpts from Magnus Hagander's message of vie sep 23 11:31:37 -0300 2011: On Fri, Sep 23, 2011 at 15:55, Alvaro Herrera alvhe...@commandprompt.com wrote: This seems strange to me. Why not have a second option to let the user indicate the desired SSL verification? sslmode=disable/allow/prefer/require sslverify=none/ca-if-present/ca/full (ca-if-present being the current require sslmode behavior). We could then deprecate sslmode=verify and verify-full and have them be synonyms of sslmode=require and corresponding sslverify. Hmm. I agree that the other suggestion was a bit weird, but I'm not sure I like the multiple-options approach either. That's going to require redesign of all software that deals with it at all today :S Why? They could continue to use the existing options; or switch to the new options if they wanted different behavior, as is the case of the OP. I guess. I was mostly thinking in the terms of anything that has connection things that look anything like the one in pgadmin for example - which will now suddenly need more than one dropdown box, for what really should be a simple setting. But I guess that can be considered an UI thing, and jus thave said application map a single dropdown to multiple options in the connection string. Maybe we should just update the docs and be done with it :-) That's another option, sure ... :-) I've applied a docs fix for this now. We can keep discussing how to make a more extensive fix in head :) -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
[HACKERS] Re: [BUGS] BUG #6189: libpq: sslmode=require verifies server certificate if root.crt is present
On Wed, Aug 31, 2011 at 11:59, Srinivas Aji srinivas@emc.com wrote: The following bug has been logged online: Bug reference: 6189 Logged by: Srinivas Aji Email address: srinivas@emc.com PostgreSQL version: 9.0.4 Operating system: Linux Description: libpq: sslmode=require verifies server certificate if root.crt is present Details: From the documentation of sslmode values in http://www.postgresql.org/docs/9.0/static/libpq-ssl.html , it looks like libpq will not verify the server certificate when the option sslmode=require is used, and will perform different levels of certificate verification in the cases sslmode=verify-ca and sslmode=verify-full. The observed behaviour is a bit different. If the ~/.postgresql/root.crt file (or any other filename set through sslrootcert option) is found, sslmode=require also performs the same level of certificate verification as verify-ca. The difference between require and verify-ca is that it is an error for the file to not exist when sslmode is verify-ca. I looked at this again, and I'm pretty sure we did this intentionally. The idea being that before we had the verify-ca/verify-full options, adding the root cert would enable the verification. And we didn't want to turn installations that previously did verify the certificate to stop doing so in the new version. So basically, the behaviour that is by design is: * require: if certificate exists, verify. if certificate doesn't exist, don't verify. * verify-ca: if certificate exists, verify. if certificate doesn't exist, disconnect. The question is, have we had the new options long enough now that we should change it so that we don't verify the cert in the case of cert-exists-but-verification-wasn't-explicitly-asked-for? Or should we just update the documentation to mention how this works? -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #6189: libpq: sslmode=require verifies server certificate if root.crt is present
From: Magnus Hagander mag...@hagander.net To: Srinivas Aji srinivas@emc.com Cc: PostgreSQL-development pgsql-hackers@postgresql.org Sent: Friday, September 23, 2011 7:28:09 AM Subject: [HACKERS] Re: [BUGS] BUG #6189: libpq: sslmode=require verifies server certificate if root.crt is present On Wed, Aug 31, 2011 at 11:59, Srinivas Aji srinivas@emc.com wrote: The following bug has been logged online: Bug reference: 6189 Logged by: Srinivas Aji Email address: srinivas@emc.com PostgreSQL version: 9.0.4 Operating system: Linux Description: libpq: sslmode=require verifies server certificate if root.crt is present Details: ... The observed behaviour is a bit different. If the ~/.postgresql/root.crt file (or any other filename set through sslrootcert option) is found, sslmode=require also performs the same level of certificate verification as verify-ca. The difference between require and verify-ca is that it is an error for the file to not exist when sslmode is verify-ca. I looked at this again, and I'm pretty sure we did this intentionally. The idea being that before we had the verify-ca/verify-full options, adding the root cert would enable the verification. And we didn't want to turn installations that previously did verify the certificate to stop doing so in the new version. So basically, the behaviour that is by design is: * require: if certificate exists, verify. if certificate doesn't exist, don't verify. * verify-ca: if certificate exists, verify. if certificate doesn't exist, disconnect. The question is, have we had the new options long enough now that we should change it so that we don't verify the cert in the case of cert-exists-but-verification-wasn't-explicitly-asked-for? Or should we just update the documentation to mention how this works? -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ Magnus, If you're accepting votes on this: I would say 'yes' - change the behavior to the most logically consistent ones; ie, isolate the verification bits a bit more explicitly. And, in documentation, indicate the deprecation of the old behavior. Our mileage, in practical terms, is that the perceived inconsistencies create a minor support hassle - we don't want to present any - even trivial - hurdle to adoption of SSL to our clients. Lou Picciano
Re: [HACKERS] Re: [BUGS] BUG #6189: libpq: sslmode=require verifies server certificate if root.crt is present
On Fri, Sep 23, 2011 at 14:35, Lou Picciano loupicci...@comcast.net wrote: On Wed, Aug 31, 2011 at 11:59, Srinivas Aji srinivas@emc.com wrote: The following bug has been logged online: Bug reference: 6189 Logged by: Srinivas Aji Email address: srinivas@emc.com PostgreSQL version: 9.0.4 Operating system: Linux Description: libpq: sslmode=require verifies server certificate if root.crt is present Details: ... The observed behaviour is a bit different. If the ~/.postgresql/root.crt file (or any other filename set through sslrootcert option) is found, sslmode=require also performs the same level of certificate verification as verify-ca. The difference between require and verify-ca is that it is an error for the file to not exist when sslmode is verify-ca. I looked at this again, and I'm pretty sure we did this intentionally. The idea being that before we had the verify-ca/verify-full options, adding the root cert would enable the verification. And we didn't want to turn installations that previously did verify the certificate to stop doing so in the new version. So basically, the behaviour that is by design is: * require: if certificate exists, verify. if certificate doesn't exist, don't verify. * verify-ca: if certificate exists, verify. if certificate doesn't exist, disconnect. The question is, have we had the new options long enough now that we should change it so that we don't verify the cert in the case of cert-exists-but-verification-wasn't-explicitly-asked-for? Or should we just update the documentation to mention how this works? Magnus, If you're accepting votes on this: I would say 'yes' - change the behavior to the most logically consistent ones; ie, isolate the verification bits a bit more explicitly. And, in documentation, indicate the deprecation of the old behavior. Our mileage, in practical terms, is that the perceived inconsistencies create a minor support hassle - we don't want to present any - even trivial - hurdle to adoption of SSL to our clients. There are really two options to this as well - we can backpatch such a change, or we can change it only in 9.2. I'm leaning towards a no on the backport, because that will change things for existing users. So probably a doc change in backbranches and a behaviour change in 9.2 would be the reasonable choice in this case. -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #6189: libpq: sslmode=require verifies server certificate if root.crt is present
On Fri, Sep 23, 2011 at 8:38 AM, Magnus Hagander mag...@hagander.net wrote: On Fri, Sep 23, 2011 at 14:35, Lou Picciano loupicci...@comcast.net wrote: On Wed, Aug 31, 2011 at 11:59, Srinivas Aji srinivas@emc.com wrote: The following bug has been logged online: Bug reference: 6189 Logged by: Srinivas Aji Email address: srinivas@emc.com PostgreSQL version: 9.0.4 Operating system: Linux Description: libpq: sslmode=require verifies server certificate if root.crt is present Details: ... The observed behaviour is a bit different. If the ~/.postgresql/root.crt file (or any other filename set through sslrootcert option) is found, sslmode=require also performs the same level of certificate verification as verify-ca. The difference between require and verify-ca is that it is an error for the file to not exist when sslmode is verify-ca. I looked at this again, and I'm pretty sure we did this intentionally. The idea being that before we had the verify-ca/verify-full options, adding the root cert would enable the verification. And we didn't want to turn installations that previously did verify the certificate to stop doing so in the new version. So basically, the behaviour that is by design is: * require: if certificate exists, verify. if certificate doesn't exist, don't verify. * verify-ca: if certificate exists, verify. if certificate doesn't exist, disconnect. The question is, have we had the new options long enough now that we should change it so that we don't verify the cert in the case of cert-exists-but-verification-wasn't-explicitly-asked-for? Or should we just update the documentation to mention how this works? Magnus, If you're accepting votes on this: I would say 'yes' - change the behavior to the most logically consistent ones; ie, isolate the verification bits a bit more explicitly. And, in documentation, indicate the deprecation of the old behavior. Our mileage, in practical terms, is that the perceived inconsistencies create a minor support hassle - we don't want to present any - even trivial - hurdle to adoption of SSL to our clients. There are really two options to this as well - we can backpatch such a change, or we can change it only in 9.2. I'm leaning towards a no on the backport, because that will change things for existing users. So probably a doc change in backbranches and a behaviour change in 9.2 would be the reasonable choice in this case. I definitely don't think we should back-patch a behavior change that silently weakens security. That's not good. But what about not doing it in master, either? It seems to me that we could avoid ever breaking backward compatibility by adding a new option require-no-verify. -- 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
Re: [HACKERS] Re: [BUGS] BUG #6189: libpq: sslmode=require verifies server certificate if root.crt is present
Magnus Hagander mag...@hagander.net writes: I looked at this again, and I'm pretty sure we did this intentionally. Yeah, we did. Or should we just update the documentation to mention how this works? +1 for doc change only. I think the behavior was thought through carefully, and the wording of the docs maybe not so much. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #6189: libpq: sslmode=require verifies server certificate if root.crt is present
From: Magnus Hagander mag...@hagander.net To: Lou Picciano loupicci...@comcast.net Cc: PostgreSQL-development pgsql-hackers@postgresql.org, Srinivas Aji srinivas@emc.com Sent: Friday, September 23, 2011 8:38:00 AM Subject: Re: [HACKERS] Re: [BUGS] BUG #6189: libpq: sslmode=require verifies server certificate if root.crt is present On Fri, Sep 23, 2011 at 14:35, Lou Picciano loupicci...@comcast.net wrote: On Wed, Aug 31, 2011 at 11:59, Srinivas Aji srinivas@emc.com wrote: The following bug has been logged online: Bug reference: 6189 Logged by: Srinivas Aji Email address: srinivas@emc.com PostgreSQL version: 9.0.4 Operating system: Linux Description: libpq: sslmode=require verifies server certificate if root.crt is present Details: ... The observed behaviour is a bit different. If the ~/.postgresql/root.crt file (or any other filename set through sslrootcert option) is found, sslmode=require also performs the same level of certificate verification as verify-ca. The difference between require and verify-ca is that it is an error for the file to not exist when sslmode is verify-ca. I looked at this again, and I'm pretty sure we did this intentionally. The idea being that before we had the verify-ca/verify-full options, adding the root cert would enable the verification. And we didn't want to turn installations that previously did verify the certificate to stop doing so in the new version. So basically, the behaviour that is by design is: * require: if certificate exists, verify. if certificate doesn't exist, don't verify. * verify-ca: if certificate exists, verify. if certificate doesn't exist, disconnect. The question is, have we had the new options long enough now that we should change it so that we don't verify the cert in the case of cert-exists-but-verification-wasn't-explicitly-asked-for? Or should we just update the documentation to mention how this works? Magnus, If you're accepting votes on this: I would say 'yes' - change the behavior to the most logically consistent ones; ie, isolate the verification bits a bit more explicitly. And, in documentation, indicate the deprecation of the old behavior. Our mileage, in practical terms, is that the perceived inconsistencies create a minor support hassle - we don't want to present any - even trivial - hurdle to adoption of SSL to our clients. There are really two options to this as well - we can backpatch such a change, or we can change it only in 9.2. I'm leaning towards a no on the backport, because that will change things for existing users. So probably a doc change in backbranches and a behaviour change in 9.2 would be the reasonable choice in this case. Again, if you were soliciting votes, I'd take the aggressive stance: +1 for the backport to 9.1. Of the population using SSL, you'd be pulling out the subset getting all the way down into PKI implementation, then, those actually doing apps teasing out these differences in verification behavior... Among _that_ group, you're only concerned with recent adopters of 9.1, and only those who wouldn't be in a position to adapt pretty quickly. Probably a pretty small cohort for something this esoteric. In our case, we do run into it - for our new clients. We find ourselves in something of a support role regarding pqlib's SSL capabilities! Lou Picciano
Re: [HACKERS] Re: [BUGS] BUG #6189: libpq: sslmode=require verifies server certificate if root.crt is present
On Fri, Sep 23, 2011 at 14:49, Robert Haas robertmh...@gmail.com wrote: On Fri, Sep 23, 2011 at 8:38 AM, Magnus Hagander mag...@hagander.net wrote: On Fri, Sep 23, 2011 at 14:35, Lou Picciano loupicci...@comcast.net wrote: On Wed, Aug 31, 2011 at 11:59, Srinivas Aji srinivas@emc.com wrote: The following bug has been logged online: Bug reference: 6189 Logged by: Srinivas Aji Email address: srinivas@emc.com PostgreSQL version: 9.0.4 Operating system: Linux Description: libpq: sslmode=require verifies server certificate if root.crt is present Details: ... The observed behaviour is a bit different. If the ~/.postgresql/root.crt file (or any other filename set through sslrootcert option) is found, sslmode=require also performs the same level of certificate verification as verify-ca. The difference between require and verify-ca is that it is an error for the file to not exist when sslmode is verify-ca. I looked at this again, and I'm pretty sure we did this intentionally. The idea being that before we had the verify-ca/verify-full options, adding the root cert would enable the verification. And we didn't want to turn installations that previously did verify the certificate to stop doing so in the new version. So basically, the behaviour that is by design is: * require: if certificate exists, verify. if certificate doesn't exist, don't verify. * verify-ca: if certificate exists, verify. if certificate doesn't exist, disconnect. The question is, have we had the new options long enough now that we should change it so that we don't verify the cert in the case of cert-exists-but-verification-wasn't-explicitly-asked-for? Or should we just update the documentation to mention how this works? Magnus, If you're accepting votes on this: I would say 'yes' - change the behavior to the most logically consistent ones; ie, isolate the verification bits a bit more explicitly. And, in documentation, indicate the deprecation of the old behavior. Our mileage, in practical terms, is that the perceived inconsistencies create a minor support hassle - we don't want to present any - even trivial - hurdle to adoption of SSL to our clients. There are really two options to this as well - we can backpatch such a change, or we can change it only in 9.2. I'm leaning towards a no on the backport, because that will change things for existing users. So probably a doc change in backbranches and a behaviour change in 9.2 would be the reasonable choice in this case. I definitely don't think we should back-patch a behavior change that silently weakens security. That's not good. But what about not doing it in master, either? It seems to me that we could avoid ever breaking backward compatibility by adding a new option require-no-verify. Hmm. Intersting. and we could then deprecate the require option and kill it off 4 releases later or so, I guess... -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #6189: libpq: sslmode=require verifies server certificate if root.crt is present
Excerpts from Magnus Hagander's message of vie sep 23 10:39:46 -0300 2011: On Fri, Sep 23, 2011 at 14:49, Robert Haas robertmh...@gmail.com wrote: On Fri, Sep 23, 2011 at 8:38 AM, Magnus Hagander mag...@hagander.net wrote: On Fri, Sep 23, 2011 at 14:35, Lou Picciano loupicci...@comcast.net wrote: On Wed, Aug 31, 2011 at 11:59, Srinivas Aji srinivas@emc.com wrote: The following bug has been logged online: Bug reference: 6189 Logged by: Srinivas Aji Email address: srinivas@emc.com PostgreSQL version: 9.0.4 Operating system: Linux Description: libpq: sslmode=require verifies server certificate if root.crt is present So basically, the behaviour that is by design is: * require: if certificate exists, verify. if certificate doesn't exist, don't verify. * verify-ca: if certificate exists, verify. if certificate doesn't exist, disconnect. I definitely don't think we should back-patch a behavior change that silently weakens security. That's not good. But what about not doing it in master, either? It seems to me that we could avoid ever breaking backward compatibility by adding a new option require-no-verify. Hmm. Intersting. and we could then deprecate the require option and kill it off 4 releases later or so, I guess... So we would have sslmode=verify-ca / require-no-verify / verify-full / disable / allow / prefer ? This seems strange to me. Why not have a second option to let the user indicate the desired SSL verification? sslmode=disable/allow/prefer/require sslverify=none/ca-if-present/ca/full (ca-if-present being the current require sslmode behavior). We could then deprecate sslmode=verify and verify-full and have them be synonyms of sslmode=require and corresponding sslverify. -- Álvaro Herrera alvhe...@commandprompt.com The PostgreSQL Company - Command Prompt, Inc. PostgreSQL Replication, Consulting, Custom Development, 24x7 support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #6189: libpq: sslmode=require verifies server certificate if root.crt is present
On Fri, Sep 23, 2011 at 15:55, Alvaro Herrera alvhe...@commandprompt.com wrote: Excerpts from Magnus Hagander's message of vie sep 23 10:39:46 -0300 2011: On Fri, Sep 23, 2011 at 14:49, Robert Haas robertmh...@gmail.com wrote: On Fri, Sep 23, 2011 at 8:38 AM, Magnus Hagander mag...@hagander.net wrote: On Fri, Sep 23, 2011 at 14:35, Lou Picciano loupicci...@comcast.net wrote: On Wed, Aug 31, 2011 at 11:59, Srinivas Aji srinivas@emc.com wrote: The following bug has been logged online: Bug reference: 6189 Logged by: Srinivas Aji Email address: srinivas@emc.com PostgreSQL version: 9.0.4 Operating system: Linux Description: libpq: sslmode=require verifies server certificate if root.crt is present So basically, the behaviour that is by design is: * require: if certificate exists, verify. if certificate doesn't exist, don't verify. * verify-ca: if certificate exists, verify. if certificate doesn't exist, disconnect. I definitely don't think we should back-patch a behavior change that silently weakens security. That's not good. But what about not doing it in master, either? It seems to me that we could avoid ever breaking backward compatibility by adding a new option require-no-verify. Hmm. Intersting. and we could then deprecate the require option and kill it off 4 releases later or so, I guess... So we would have sslmode=verify-ca / require-no-verify / verify-full / disable / allow / prefer ? This seems strange to me. Why not have a second option to let the user indicate the desired SSL verification? sslmode=disable/allow/prefer/require sslverify=none/ca-if-present/ca/full (ca-if-present being the current require sslmode behavior). We could then deprecate sslmode=verify and verify-full and have them be synonyms of sslmode=require and corresponding sslverify. Hmm. I agree that the other suggestion was a bit weird, but I'm not sure I like the multiple-options approach either. That's going to require redesign of all software that deals with it at all today :S Maybe we should just update the docs and be done with it :-) -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #6189: libpq: sslmode=require verifies server certificate if root.crt is present
Excerpts from Magnus Hagander's message of vie sep 23 11:31:37 -0300 2011: On Fri, Sep 23, 2011 at 15:55, Alvaro Herrera alvhe...@commandprompt.com wrote: This seems strange to me. Why not have a second option to let the user indicate the desired SSL verification? sslmode=disable/allow/prefer/require sslverify=none/ca-if-present/ca/full (ca-if-present being the current require sslmode behavior). We could then deprecate sslmode=verify and verify-full and have them be synonyms of sslmode=require and corresponding sslverify. Hmm. I agree that the other suggestion was a bit weird, but I'm not sure I like the multiple-options approach either. That's going to require redesign of all software that deals with it at all today :S Why? They could continue to use the existing options; or switch to the new options if they wanted different behavior, as is the case of the OP. Maybe we should just update the docs and be done with it :-) That's another option, sure ... :-) -- Álvaro Herrera alvhe...@commandprompt.com The PostgreSQL Company - Command Prompt, Inc. PostgreSQL Replication, Consulting, Custom Development, 24x7 support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
[HACKERS] Re: [BUGS] BUG #6189: libpq: sslmode=require verifies server certificate if root.crt is present
On Wed, Aug 31, 2011 at 09:59:18AM +, Srinivas Aji wrote: The following bug has been logged online: Bug reference: 6189 Logged by: Srinivas Aji Email address: srinivas@emc.com PostgreSQL version: 9.0.4 Operating system: Linux Description:libpq: sslmode=require verifies server certificate if root.crt is present Details: From the documentation of sslmode values in http://www.postgresql.org/docs/9.0/static/libpq-ssl.html , it looks like libpq will not verify the server certificate when the option sslmode=require is used, and will perform different levels of certificate verification in the cases sslmode=verify-ca and sslmode=verify-full. The observed behaviour is a bit different. If the ~/.postgresql/root.crt file (or any other filename set through sslrootcert option) is found, sslmode=require also performs the same level of certificate verification as verify-ca. The difference between require and verify-ca is that it is an error for the file to not exist when sslmode is verify-ca. Thanks, Srinivas It looks to me like there could at least in theory be an attack vector or two that we're not covering with this bug. Anybody want to tackle same? Cheers, David. -- David Fetter da...@fetter.org http://fetter.org/ Phone: +1 415 235 3778 AIM: dfetter666 Yahoo!: dfetter Skype: davidfetter XMPP: david.fet...@gmail.com iCal: webcal://www.tripit.com/feed/ical/people/david74/tripit.ics Remember to vote! Consider donating to Postgres: http://www.postgresql.org/about/donate -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #6189: libpq: sslmode=require verifies server certificate if root.crt is present
On Mon, Sep 12, 2011 at 19:21, David Fetter da...@fetter.org wrote: On Wed, Aug 31, 2011 at 09:59:18AM +, Srinivas Aji wrote: The following bug has been logged online: Bug reference: 6189 Logged by: Srinivas Aji Email address: srinivas@emc.com PostgreSQL version: 9.0.4 Operating system: Linux Description: libpq: sslmode=require verifies server certificate if root.crt is present Details: From the documentation of sslmode values in http://www.postgresql.org/docs/9.0/static/libpq-ssl.html , it looks like libpq will not verify the server certificate when the option sslmode=require is used, and will perform different levels of certificate verification in the cases sslmode=verify-ca and sslmode=verify-full. The observed behaviour is a bit different. If the ~/.postgresql/root.crt file (or any other filename set through sslrootcert option) is found, sslmode=require also performs the same level of certificate verification as verify-ca. The difference between require and verify-ca is that it is an error for the file to not exist when sslmode is verify-ca. Thanks, Srinivas It looks to me like there could at least in theory be an attack vector or two that we're not covering with this bug. Anybody want to tackle same? I haven't checked the code yet, but from the report it sounds like we're checking *too much* - how could that be an attack vector? -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #6189: libpq: sslmode=require verifies server certificate if root.crt is present
On Mon, Sep 12, 2011 at 07:37:23PM +0200, Magnus Hagander wrote: On Mon, Sep 12, 2011 at 19:21, David Fetter da...@fetter.org wrote: On Wed, Aug 31, 2011 at 09:59:18AM +, Srinivas Aji wrote: The following bug has been logged online: Bug reference: 6189 Logged by: Srinivas Aji Email address: srinivas@emc.com PostgreSQL version: 9.0.4 Operating system: Linux Description: libpq: sslmode=require verifies server certificate if root.crt is present Details: From the documentation of sslmode values in http://www.postgresql.org/docs/9.0/static/libpq-ssl.html , it looks like libpq will not verify the server certificate when the option sslmode=require is used, and will perform different levels of certificate verification in the cases sslmode=verify-ca and sslmode=verify-full. The observed behaviour is a bit different. If the ~/.postgresql/root.crt file (or any other filename set through sslrootcert option) is found, sslmode=require also performs the same level of certificate verification as verify-ca. The difference between require and verify-ca is that it is an error for the file to not exist when sslmode is verify-ca. Thanks, Srinivas It looks to me like there could at least in theory be an attack vector or two that we're not covering with this bug. Anybody want to tackle same? I haven't checked the code yet, but from the report it sounds like we're checking *too much* - how could that be an attack vector? Well, too much checking, classically, is a source of denial of service attacks. It's not a super likely source, but it's a source, and it'd be better to fix it than leave it lie. :) Cheers, David. -- David Fetter da...@fetter.org http://fetter.org/ Phone: +1 415 235 3778 AIM: dfetter666 Yahoo!: dfetter Skype: davidfetter XMPP: david.fet...@gmail.com iCal: webcal://www.tripit.com/feed/ical/people/david74/tripit.ics Remember to vote! Consider donating to Postgres: http://www.postgresql.org/about/donate -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Re: [BUGS] BUG #6189: libpq: sslmode=require verifies server certificate if root.crt is present
On Mon, Sep 12, 2011 at 2:20 PM, David Fetter da...@fetter.org wrote: Well, too much checking, classically, is a source of denial of service attacks. It's not a super likely source, but it's a source, and it'd be better to fix it than leave it lie. :) You forgot to attach the patch. -- 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
