[2/3] Unbound: Use caps for IDs

Message ID c9d3419f-5ca9-bcfa-9e01-7047025af279@link38.eu
State Superseded
Headers
Series [1/3] Unbound: Enable DNS cache poisoning mitigation |

Commit Message

Peter Müller Aug. 20, 2018, 4:11 a.m. UTC
  Attempt to detect DNS spoofing attacks by inserting 0x20-encoded
random bits into upstream queries. Upstream documentation claims
it to be an experimental implementation, it did not cause any trouble
on productive systems here.

See https://nlnetlabs.nl/documentation/unbound/unbound.conf/ for
further details.

Signed-off-by: Peter Müller <peter.mueller@link38.eu>
---
 config/unbound/unbound.conf | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
  

Comments

Michael Tremer Aug. 23, 2018, 11:40 p.m. UTC | #1
This was deliberately not enabled because the documentation contains a
warning about various incompatibilities with various other DNS servers.

Is there some sort of study saying that this can be safely enabled?

-Michael

On Sun, 2018-08-19 at 20:11 +0200, Peter Müller wrote:
> Attempt to detect DNS spoofing attacks by inserting 0x20-encoded
> random bits into upstream queries. Upstream documentation claims
> it to be an experimental implementation, it did not cause any trouble
> on productive systems here.
> 
> See https://nlnetlabs.nl/documentation/unbound/unbound.conf/ for
> further details.
> 
> Signed-off-by: Peter Müller <peter.mueller@link38.eu>
> ---
>  config/unbound/unbound.conf | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/config/unbound/unbound.conf b/config/unbound/unbound.conf
> index fa2ca3fd4..8b5d34ee3 100644
> --- a/config/unbound/unbound.conf
> +++ b/config/unbound/unbound.conf
> @@ -59,7 +59,7 @@ server:
>  	harden-below-nxdomain: yes
>  	harden-referral-path: yes
>  	harden-algo-downgrade: no
> -	use-caps-for-id: no
> +	use-caps-for-id: yes
>  
>  	# Harden against DNS cache poisoning
>  	unwanted-reply-threshold: 5000000
  
Peter Müller Aug. 24, 2018, 5:15 a.m. UTC | #2
Hello,

> This was deliberately not enabled because the documentation contains a
> warning about various incompatibilities with various other DNS servers.
Yes, there are a lot of broken DNS servers out there...
> 
> Is there some sort of study saying that this can be safely enabled?
I know people operating DNS resolvers for > 30k customers with this setting
enabled. They never experienced any issue with this so far. This is enabled
on my systems too.

Currently, I am not aware of a public study.

Best regards,
Peter Müller
> 
> -Michael
> 
> On Sun, 2018-08-19 at 20:11 +0200, Peter Müller wrote:
>> Attempt to detect DNS spoofing attacks by inserting 0x20-encoded
>> random bits into upstream queries. Upstream documentation claims
>> it to be an experimental implementation, it did not cause any trouble
>> on productive systems here.
>>
>> See https://nlnetlabs.nl/documentation/unbound/unbound.conf/ for
>> further details.
>>
>> Signed-off-by: Peter Müller <peter.mueller@link38.eu>
>> ---
>>  config/unbound/unbound.conf | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/config/unbound/unbound.conf b/config/unbound/unbound.conf
>> index fa2ca3fd4..8b5d34ee3 100644
>> --- a/config/unbound/unbound.conf
>> +++ b/config/unbound/unbound.conf
>> @@ -59,7 +59,7 @@ server:
>>  	harden-below-nxdomain: yes
>>  	harden-referral-path: yes
>>  	harden-algo-downgrade: no
>> -	use-caps-for-id: no
>> +	use-caps-for-id: yes
>>  
>>  	# Harden against DNS cache poisoning
>>  	unwanted-reply-threshold: 5000000
>
  
Michael Tremer Aug. 24, 2018, 9:51 p.m. UTC | #3
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

Okay, let's give it a try then.

On Thu, 2018-08-23 at 21:15 +0200, Peter Müller wrote:
> Hello,
> 
> > This was deliberately not enabled because the documentation contains a
> > warning about various incompatibilities with various other DNS servers.
> 
> Yes, there are a lot of broken DNS servers out there...
> > 
> > Is there some sort of study saying that this can be safely enabled?
> 
> I know people operating DNS resolvers for > 30k customers with this setting
> enabled. They never experienced any issue with this so far. This is enabled
> on my systems too.
> 
> Currently, I am not aware of a public study.
> 
> Best regards,
> Peter Müller
> > 
> > -Michael
> > 
> > On Sun, 2018-08-19 at 20:11 +0200, Peter Müller wrote:
> > > Attempt to detect DNS spoofing attacks by inserting 0x20-encoded
> > > random bits into upstream queries. Upstream documentation claims
> > > it to be an experimental implementation, it did not cause any trouble
> > > on productive systems here.
> > > 
> > > See https://nlnetlabs.nl/documentation/unbound/unbound.conf/ for
> > > further details.
> > > 
> > > Signed-off-by: Peter Müller <peter.mueller@link38.eu>
> > > ---
> > >  config/unbound/unbound.conf | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/config/unbound/unbound.conf b/config/unbound/unbound.conf
> > > index fa2ca3fd4..8b5d34ee3 100644
> > > --- a/config/unbound/unbound.conf
> > > +++ b/config/unbound/unbound.conf
> > > @@ -59,7 +59,7 @@ server:
> > >  	harden-below-nxdomain: yes
> > >  	harden-referral-path: yes
> > >  	harden-algo-downgrade: no
> > > -	use-caps-for-id: no
> > > +	use-caps-for-id: yes
> > >  
> > >  	# Harden against DNS cache poisoning
> > >  	unwanted-reply-threshold: 5000000
> 
> 
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Patch

diff --git a/config/unbound/unbound.conf b/config/unbound/unbound.conf
index fa2ca3fd4..8b5d34ee3 100644
--- a/config/unbound/unbound.conf
+++ b/config/unbound/unbound.conf
@@ -59,7 +59,7 @@  server:
 	harden-below-nxdomain: yes
 	harden-referral-path: yes
 	harden-algo-downgrade: no
-	use-caps-for-id: no
+	use-caps-for-id: yes
 
 	# Harden against DNS cache poisoning
 	unwanted-reply-threshold: 5000000