Re: Outgoing DANE not working

2020-05-21 Thread Wietse Venema
Rich Felker: > > The __RES value varies wildly between different platforms. __RES > > never changes for glibc, but it does change on other platforms. > > > > #define __RES 19991006// Fedora 30, glibc 2.29 > > #define __RES 19991006// Alpine 3.11.5, pretends-to-be glibc 2.29 >

Re: Outgoing DANE not working

2020-05-20 Thread Rich Felker
On Wed, May 20, 2020 at 05:41:46PM -0400, Wietse Venema wrote: > Rich Felker: > [dnssec end-to-end probe, log a warning if for any reason results > do not have the authentic data' bit set]'. > > This sounds like a great plan that will also mitigate the problem of > > glibc's AD-stripping by

Re: Outgoing DANE not working

2020-05-20 Thread Wietse Venema
Rich Felker: [dnssec end-to-end probe, log a warning if for any reason results do not have the authentic data' bit set]'. > This sounds like a great plan that will also mitigate the problem of > glibc's AD-stripping by default. FYI I've raised concerns about that > again on libc-alpha: > >

Re: Outgoing DANE not working

2020-05-20 Thread Rich Felker
On Wed, May 20, 2020 at 01:59:47PM -0400, Wietse Venema wrote: > Viktor Dukhovni: > > On Tue, May 19, 2020 at 05:19:26PM -0400, Wietse Venema wrote: > > > > > > https://git.musl-libc.org/cgit/musl/commit/?id=fd7ec068efd590c0393a612599a4fab9bb0a8633 > > > > > > I understand that the AD (authentic

Re: Outgoing DANE not working

2020-05-20 Thread Wietse Venema
Viktor Dukhovni: > On Tue, May 19, 2020 at 05:19:26PM -0400, Wietse Venema wrote: > > > > https://git.musl-libc.org/cgit/musl/commit/?id=fd7ec068efd590c0393a612599a4fab9bb0a8633 > > > > I understand that the AD (authentic data) bit now is 'true' if > > DNSSEC validation was successful. Thanks

Re: Outgoing DANE not working

2020-05-19 Thread Rich Felker
On Tue, May 19, 2020 at 07:00:57PM -0400, Viktor Dukhovni wrote: > On Tue, May 19, 2020 at 05:19:26PM -0400, Wietse Venema wrote: > > > > https://git.musl-libc.org/cgit/musl/commit/?id=fd7ec068efd590c0393a612599a4fab9bb0a8633 > > > > I understand that the AD (authentic data) bit now is 'true' if

Re: Outgoing DANE not working

2020-05-19 Thread Rich Felker
On Tue, May 19, 2020 at 06:51:57PM -0400, Viktor Dukhovni wrote: > On Tue, May 19, 2020 at 04:08:32PM -0400, Rich Felker wrote: > > > I'm not encouraging any to do that; rather I've encouraged them to > > take measures to both: > > > > (1) ensure that DANE is not silently ignored, by either

Re: Outgoing DANE not working

2020-05-19 Thread Viktor Dukhovni
On Tue, May 19, 2020 at 05:19:26PM -0400, Wietse Venema wrote: > > https://git.musl-libc.org/cgit/musl/commit/?id=fd7ec068efd590c0393a612599a4fab9bb0a8633 > > I understand that the AD (authentic data) bit now is 'true' if > DNSSEC validation was successful. Thanks for that. > > Meanwhile I'll

Re: Outgoing DANE not working

2020-05-19 Thread Viktor Dukhovni
On Tue, May 19, 2020 at 04:08:32PM -0400, Rich Felker wrote: > I'm not encouraging any to do that; rather I've encouraged them to > take measures to both: > > (1) ensure that DANE is not silently ignored, by either patching > Postfix to work with old musl (prior to the above commit) or patching

Re: Outgoing DANE not working

2020-05-19 Thread Wietse Venema
Rich Felker: > > > > Do let us know when libc-musl provides an indication whether a DNS > > > > lookup result is authentic (DNSSEC pass). > > > > > > It is now in master. I've also recommended the patch to Alpine. > > > > A pointer to how one would use the updated code would be welcome, > >

Re: Outgoing DANE not working

2020-05-19 Thread Rich Felker
On Tue, May 19, 2020 at 01:25:52PM -0400, Wietse Venema wrote: > Rich Felker: > > On Tue, May 19, 2020 at 11:11:56AM -0400, Wietse Venema wrote: > > > Rich Felker: > > > > On Tue, May 19, 2020 at 10:23:18AM -0400, Wietse Venema wrote: > > > > > Rich Felker: > > > > > > The is fundamentally no

Re: Outgoing DANE not working

2020-05-19 Thread Viktor Dukhovni
On Tue, May 19, 2020 at 10:28:57AM -0400, Rich Felker wrote: > On Tue, May 19, 2020 at 10:23:18AM -0400, Wietse Venema wrote: > > Rich Felker: > > > The is fundamentally no build-time test possible for this. Even if we > > > were willing to make flags for each bug (or missing feature) that was >

Re: Outgoing DANE not working

2020-05-19 Thread Wietse Venema
Rich Felker: > On Tue, May 19, 2020 at 11:11:56AM -0400, Wietse Venema wrote: > > Rich Felker: > > > On Tue, May 19, 2020 at 10:23:18AM -0400, Wietse Venema wrote: > > > > Rich Felker: > > > > > The is fundamentally no build-time test possible for this. Even if we > > > > > were willing to make

Re: Outgoing DANE not working

2020-05-19 Thread Rich Felker
On Tue, May 19, 2020 at 11:11:56AM -0400, Wietse Venema wrote: > Rich Felker: > > On Tue, May 19, 2020 at 10:23:18AM -0400, Wietse Venema wrote: > > > Rich Felker: > > > > The is fundamentally no build-time test possible for this. Even if we > > > > were willing to make flags for each bug (or

Re: Outgoing DANE not working

2020-05-19 Thread Wietse Venema
Rich Felker: > On Tue, May 19, 2020 at 10:23:18AM -0400, Wietse Venema wrote: > > Rich Felker: > > > The is fundamentally no build-time test possible for this. Even if we > > > were willing to make flags for each bug (or missing feature) that was > > > ever fixed indicating the change, that would

Re: Outgoing DANE not working

2020-05-19 Thread Rich Felker
On Tue, May 19, 2020 at 10:23:18AM -0400, Wietse Venema wrote: > Rich Felker: > > The is fundamentally no build-time test possible for this. Even if we > > were willing to make flags for each bug (or missing feature) that was > > ever fixed indicating the change, that would only tell you whether

Re: Outgoing DANE not working

2020-05-19 Thread Wietse Venema
Rich Felker: > The is fundamentally no build-time test possible for this. Even if we > were willing to make flags for each bug (or missing feature) that was > ever fixed indicating the change, that would only tell you whether the > version present at build time had the property, not whether the >

Re: Outgoing DANE not working

2020-05-19 Thread Rich Felker
On Tue, May 19, 2020 at 09:22:59AM -0400, Wietse Venema wrote: > Viktor Dukhovni: > > Robust detection of MUSL features at build time would be much > > appreciated. Precludes any tests that depend on live DNS queries. > > The tests need to *statically* test the features of the platform's > > C

Re: Outgoing DANE not working

2020-05-19 Thread Rich Felker
On Tue, May 19, 2020 at 05:06:10AM -0400, Viktor Dukhovni wrote: > On Tue, May 19, 2020 at 01:44:30AM -0400, Rich Felker wrote: > > > > This sounds reasonable. Will there be a way for Postfix to detect the > > > new library version, so that we don't disable DANE for musl-libc > > > versions that

Re: Outgoing DANE not working

2020-05-19 Thread Wietse Venema
Viktor Dukhovni: > Robust detection of MUSL features at build time would be much > appreciated. Precludes any tests that depend on live DNS queries. > The tests need to *statically* test the features of the platform's > C library. Agreed. You're welcome to provide a reliable static test (no live

Re: Outgoing DANE not working

2020-05-19 Thread Christian
Am Dienstag, den 19.05.2020, 05:06 -0400 schrieb Viktor Dukhovni: > We have no choice, we can't ship code that silently fails to honour > its > configuration. I'm not worried about DANE "working", I'm worried > about > DANE *not* working, and the user being none-the-wiser. > Just my 50cents to

Re: Outgoing DANE not working

2020-05-19 Thread Viktor Dukhovni
On Tue, May 19, 2020 at 01:44:30AM -0400, Rich Felker wrote: > > This sounds reasonable. Will there be a way for Postfix to detect the > > new library version, so that we don't disable DANE for musl-libc > > versions that do set the AD bit? > > I'm really disappointed with the detection, which

Re: Outgoing DANE not working

2020-05-18 Thread Rich Felker
On Mon, May 18, 2020 at 10:38:14PM -0400, Viktor Dukhovni wrote: > On Mon, May 18, 2020 at 09:37:36PM -0400, Rich Felker wrote: > > > > Mostly dig, unbound-host, ... Most of the platform C libraries support > > > DO=1, which obviates the need for AD=1, so they don't do that, but it is > > >

Re: Outgoing DANE not working

2020-05-18 Thread Viktor Dukhovni
On Mon, May 18, 2020 at 09:37:36PM -0400, Rich Felker wrote: > > Mostly dig, unbound-host, ... Most of the platform C libraries support > > DO=1, which obviates the need for AD=1, so they don't do that, but it is > > nevertheless safe. AD=1 is much cheaper than DO=1, because you get back > >

Re: Outgoing DANE not working

2020-05-18 Thread Rich Felker
On Tue, Apr 14, 2020 at 05:59:51PM -0400, Viktor Dukhovni wrote: > > > That RFC was published in 2013. That's long enough ago. > > > > We support environments that haven't been touched since 2009 or so, > > and to a lesser/minimal-support extent ones that haven't been touched > > since around

Re: Outgoing DANE not working

2020-04-17 Thread Florian Weimer
* Rich Felker: > On Wed, Apr 15, 2020 at 08:27:08PM +0200, Florian Weimer wrote: >> >> I don't understand your PTR example. It seems such a fringe case that >> >> people produce larger PTR responses because they add all virtual hosts >> >> to the reverse DNS zone. Sure, it happens, but not

Re: Outgoing DANE not working

2020-04-16 Thread Viktor Dukhovni
On Thu, Apr 16, 2020 at 11:40:59PM -0400, Rich Felker wrote: > TC bit is for truncation, and means that the complete response would > have been larger than 512 bytes and was truncated to whatever number > of whole RRs fit in 512 bytes. Actually whole RRsets. Nameservers must not truncate in the

Re: Outgoing DANE not working

2020-04-16 Thread Rich Felker
On Wed, Apr 15, 2020 at 08:27:08PM +0200, Florian Weimer wrote: > >> I don't understand your PTR example. It seems such a fringe case that > >> people produce larger PTR responses because they add all virtual hosts > >> to the reverse DNS zone. Sure, it happens, but not often. > > > > I think

Re: Outgoing DANE not working

2020-04-15 Thread Viktor Dukhovni
On Wed, Apr 15, 2020 at 02:01:49PM -0400, Rich Felker wrote: > I'd be interested in reading more on this if you know any references. > Over 512 bytes of MX records seems like a lot, and seems like a really > bad idea for a domain configuration since there have always been (as > you noted, with

Re: Outgoing DANE not working

2020-04-15 Thread Florian Weimer
* Rich Felker: > On Wed, Apr 15, 2020 at 07:19:43PM +0200, Florian Weimer wrote: >> * Rich Felker: >> >> > This is true for users running local nameservers, which ideally will >> > eventually be everyone, but at present that's far from the case. >> > Differences like concurrent attempts from

Re: Outgoing DANE not working

2020-04-15 Thread Rich Felker
On Wed, Apr 15, 2020 at 07:19:43PM +0200, Florian Weimer wrote: > * Rich Felker: > > > This is true for users running local nameservers, which ideally will > > eventually be everyone, but at present that's far from the case. > > Differences like concurrent attempts from multiple nameservers

Re: Outgoing DANE not working

2020-04-15 Thread Florian Weimer
* Rich Felker: > This is true for users running local nameservers, which ideally will > eventually be everyone, but at present that's far from the case. > Differences like concurrent attempts from multiple nameservers and/or > lack of TCP fallback on TC are what makes netstat fast on musl vs >

Re: Outgoing DANE not working (tentative patch for glibc >= 2.31, released Feb 2020)

2020-04-15 Thread Christian
Am Mittwoch, den 15.04.2020, 05:05 -0400 schrieb Viktor Dukhovni: > On Wed, Apr 15, 2020 at 10:36:26AM +0200, Christian wrote: > > > I don't yet have access to systems with this recent a glibc to > confirm > the above, but this is likely relevant to Postfix administrators who > enable DANE. You

Re: Outgoing DANE not working (tentative patch for glibc >= 2.31, released Feb 2020)

2020-04-15 Thread Viktor Dukhovni
On Wed, Apr 15, 2020 at 10:36:26AM +0200, Christian wrote: > > I don't yet have access to systems with this recent a glibc to confirm > > the above, but this is likely relevant to Postfix administrators who > > enable DANE. You may need to explicitly add the "trust-ad" option to > > your

Re: Outgoing DANE not working

2020-04-15 Thread Christian
Am Mittwoch, den 15.04.2020, 02:28 -0400 schrieb Viktor Dukhovni: > On Tue, Apr 14, 2020 at 05:59:51PM -0400, Viktor Dukhovni wrote: > > > but if that is incompatible with other stub resolver libraries on the > same machine, you may need a private musl-specific configuration file. > > My money is

Re: Outgoing DANE not working

2020-04-15 Thread Viktor Dukhovni
On Tue, Apr 14, 2020 at 05:59:51PM -0400, Viktor Dukhovni wrote: > but if that is incompatible with other stub resolver libraries on the > same machine, you may need a private musl-specific configuration file. > > My money is on this being unnecessary. I'll let [you] know what I find > from

Re: Outgoing DANE not working

2020-04-14 Thread Viktor Dukhovni
On Tue, Apr 14, 2020 at 12:06:41PM -0400, Rich Felker wrote: > > Well, ISP resolvers and anycast resolvers from Google, Cloudflare, > > Verisign and Quad are generally not too far away. > > If you're on dialup or saturated DSL or cellular link, they're easily > 300-1000 ms away. Each round trip

Re: Outgoing DANE not working

2020-04-14 Thread Rich Felker
On Tue, Apr 14, 2020 at 02:16:20AM -0400, Viktor Dukhovni wrote: > On Mon, Apr 13, 2020 at 11:53:03PM -0400, Rich Felker wrote: > > > > Your local nameserver has already done the TCP failover and paid the > > > cost of obtaining the full RRset, your stub resolver is just failing to > > > give it

Re: Outgoing DANE not working

2020-04-14 Thread Viktor Dukhovni
On Mon, Apr 13, 2020 at 11:53:03PM -0400, Rich Felker wrote: > > Your local nameserver has already done the TCP failover and paid the > > cost of obtaining the full RRset, your stub resolver is just failing to > > give it the opportunity to return the full data to you. The performance > > cost

Re: Outgoing DANE not working

2020-04-13 Thread Rich Felker
On Mon, Apr 13, 2020 at 05:41:38PM -0400, Viktor Dukhovni wrote: > > Fallback to tcp on TC would also yield very bad performance for users > > who are not running a local nameserver whenever looking up names with > > ridiculous numbers of A/ records, where the truncated response > > certainly

Re: Outgoing DANE not working

2020-04-13 Thread Viktor Dukhovni
On Mon, Apr 13, 2020 at 03:35:05PM -0400, Rich Felker wrote: > > It is also not uncommon for applications that use SRV records to > > encounter large RRsets (e.g. Windows Domain controller lists for > > large Active-Directory domains in MIT Kerberos or Heimdal). > > The justification here has

Re: Outgoing DANE not working

2020-04-13 Thread Rich Felker
On Mon, Apr 13, 2020 at 03:04:12PM -0400, Viktor Dukhovni wrote: > On Mon, Apr 13, 2020 at 02:35:22PM -0400, Rich Felker wrote: > > > > The problem can be partly resolved by setting the "AD" bit in the > > > outgoing DNS query header sent by the musl-libc stub resolver. Then > > > the local

Re: Outgoing DANE not working

2020-04-13 Thread Viktor Dukhovni
On Mon, Apr 13, 2020 at 02:35:22PM -0400, Rich Felker wrote: > > The problem can be partly resolved by setting the "AD" bit in the > > outgoing DNS query header sent by the musl-libc stub resolver. Then > > the local iterative resolver will return the AD bit in its response. > > > > However,

Re: Outgoing DANE not working

2020-04-13 Thread Rich Felker
On Mon, Apr 13, 2020 at 02:15:14PM -0400, Viktor Dukhovni wrote: > > On Apr 13, 2020, at 7:18 AM, Christian wrote: > > > > FYI: I put your findings forward to the musl-libc mailing list and > > asked what they now think what should be done. > > The problem can be partly resolved by setting the

Re: Outgoing DANE not working

2020-04-13 Thread Viktor Dukhovni
> On Apr 13, 2020, at 7:18 AM, Christian wrote: > > FYI: I put your findings forward to the musl-libc mailing list and > asked what they now think what should be done. The problem can be partly resolved by setting the "AD" bit in the outgoing DNS query header sent by the musl-libc stub

Re: Outgoing DANE not working

2020-04-13 Thread Christian
To finalise this as solved Just moved Postfix to a Debian based container and now DANE is working as expected. Hence if anyone comes by this thread, follow Viktors advice: > DO NOT run Postfix over musl-libc. Hence not on regular Alpine.

Re: Outgoing DANE not working

2020-04-13 Thread Christian
Am Montag, den 13.04.2020, 06:57 -0400 schrieb Viktor Dukhovni: > > On Apr 13, 2020, at 6:38 AM, Christian wrote: > > Nevertheless, it should probably be included in the Postfix DANE > documentation to avoid muslc setups with postfix for now. > > Postfix expects a C-library implementation of the

Re: Outgoing DANE not working

2020-04-13 Thread Viktor Dukhovni
> On Apr 13, 2020, at 6:38 AM, Christian wrote: > > Nevertheless, it should probably be included in the Postfix DANE > documentation to avoid muslc setups with postfix for now. Postfix expects a C-library implementation of the DNS stub resolver routines that is compatible with the original BSD

Re: Outgoing DANE not working

2020-04-13 Thread Christian
Am Montag, den 13.04.2020, 05:52 -0400 schrieb Viktor Dukhovni: > > On Apr 13, 2020, at 4:56 AM, Christian wrote: > > The container is running on alpine, hence with muslc libc. After > seeing > the tcpdump yesterday, I thought as well, if that could be an issue. > > I am no programmer, however 2

Re: Outgoing DANE not working

2020-04-13 Thread Viktor Dukhovni
> On Apr 13, 2020, at 5:52 AM, Viktor Dukhovni > wrote: > > Indeed searching the github repo for RES_USE_DNSSEC and RES_USE_EDNS0 finds > hits only the header file, and similarly: > > > https://raw.githubusercontent.com/runtimejs/musl-libc/master/src/network/res_state.c > > pretty much

Re: Outgoing DANE not working

2020-04-13 Thread Damian
>> The validator [1] says TLSA is ok, so is this even be a DNS issue? If I >> have to guess, Postfix encounters the following situation: >> >> >> When TLSA records are found, but are all unusable the effective security >> level is "encrypt" >> >> The documentation does not state that self-signed

Re: Outgoing DANE not working

2020-04-13 Thread Viktor Dukhovni
> On Apr 13, 2020, at 4:56 AM, Christian wrote: > > The container is running on alpine, hence with muslc libc. After seeing > the tcpdump yesterday, I thought as well, if that could be an issue. > > I am no programmer, however 2 things strike me: > Dig is able to construct a proper request and

Re: Outgoing DANE not working

2020-04-13 Thread Christian
Hi Damian, Am Montag, den 13.04.2020, 11:22 +0200 schrieb Damian: > The validator [1] says TLSA is ok, so is this even be a DNS issue? If I > have to guess, Postfix encounters the following situation: > > > When TLSA records are found, but are all unusable the effective security > level is

Re: Outgoing DANE not working

2020-04-13 Thread Viktor Dukhovni
[ To the OP: feel free to ignore the below response, it is irrelevant. ] > On Apr 13, 2020, at 5:22 AM, Damian wrote: > > The validator [1] says TLSA is ok, so is this even be a DNS issue? If I > have to guess, Postfix encounters the following situation: > >> When TLSA records are found, but

Re: Outgoing DANE not working

2020-04-13 Thread Damian
The validator [1] says TLSA is ok, so is this even be a DNS issue? If I have to guess, Postfix encounters the following situation: > When TLSA records are found, but are all unusable the effective security > level is "encrypt" The documentation does not state that self-signed certificates are

Re: Outgoing DANE not working

2020-04-13 Thread Christian
Hello Viktor, thanks again, please see my answers inline. Am Sonntag, den 12.04.2020, 22:47 -0400 schrieb Viktor Dukhovni: > On Mon, Apr 13, 2020 at 02:12:49AM +0200, Christian wrote: > > > thanks for the response! Apparently the mail was too long (>4000) and > got rejected, hence I put it to

Re: Outgoing DANE not working

2020-04-12 Thread Viktor Dukhovni
On Mon, Apr 13, 2020 at 02:12:49AM +0200, Christian wrote: > thanks for the response! Apparently the mail was too long (>4000) and > got rejected, hence I put it to pastebin: https://pastebin.com/1e3sR0Hq The query in your PCAP file was not sent to 127.0.0.11, and had no EDNS OPT record (so no

Re: Outgoing DANE not working

2020-04-12 Thread Christian
Hi Viktor, thanks for the response! Apparently the mail was too long (>4000) and got rejected, hence I put it to pastebin: https://pastebin.com/1e3sR0Hq I think the tcpdumps are interesting, as they show that postfix is not requesting with the right flags (If I am not reading everything wrong).

Re: Outgoing DANE not working

2020-04-12 Thread Viktor Dukhovni
On Sun, Apr 12, 2020 at 04:20:48PM +0200, Christian wrote: > I am running in a docker setup (alpine based on debian host) with my own > unbound DNS resolver. What is the content of /etc/resolv.conf? > I started to check if I have problems in my DNSSEC checks. running a > "dig com. SOA +dnssec"

Outgoing DANE not working

2020-04-12 Thread Christian
Hi there, I tried the DANE Test on "havedane.net" and figured, that outgoing DANE is not working. I get the following: Email to non-DANE domain delivered. Email to DANE domain delivered. Email to domain with invalid DANE delivered. So apparently the check for the last one is failing