You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@kafka.apache.org by Rajini Sivaram <ra...@gmail.com> on 2018/05/01 10:08:13 UTC

Re: [VOTE] KIP-235 Add DNS alias support for secured connection

Jonathan,

Not doing the reverse lookup for SASL_SSL limits the usability of this KIP
since it can no longer be used in a secure environment where Kerberos is
used with TLS. Perhaps the best option is to do the lookup if the option is
explicitly enabled regardless of what the security protocol is. If there is
a SSL handshake failure with this option enabled, the error message can be
updated to indicate that it could be because a reverse lookup was used. Can
you state in the KIP that the default value of
bootstrap.reverse.dns.lookup will
be false and hence there is no backwards compatibility issue.

On Mon, Apr 30, 2018 at 1:41 PM, Skrzypek, Jonathan <
Jonathan.Skrzypek@gs.com> wrote:

> Thanks for your comments.
> Have updated the KIP.
>
> I agree SSL and SASL_SSL will face similar issues and should behave the
> same.
> Thinking about this further,  I'm wondering whether setting
> bootstrap.reverse.dns.lookup to true whilst using any of those protocols
> should throw a critical error and stop, or at least log a warning stating
> that the lookup won't be performed.
> This sounds better than silently ignoring and leave users with the
> impression they can use SSL and bootstrap server aliases.
> Abruptly stopping the client sounds a bit extreme so I'm leaning towards a
> warning.
>
> Thoughts ?
>
> I'm not sure about checking whether the list has IP addresses.
> There could be cases where the list has a mix of FQDNs and IPs, so I would
> rather perform the lookup regardless of the case when the parameter is
> enabled.
>
> On the security aspects, I am by no means a security or SASL expert so
> commented the KIP with what I believe to be the case.
>
> Jonathan Skrzypek
>
> -----Original Message-----
> From: Rajini Sivaram [mailto:rajinisivaram@gmail.com]
> Sent: 29 April 2018 15:38
> To: dev
> Subject: Re: [VOTE] KIP-235 Add DNS alias support for secured connection
>
> Hi Jonathan,
>
> Thanks for the KIP.
>
> +1 (binding) with a couple comments below to add more detail to the KIP.
>
>    1. Make it clearer when the new option `bootstrap.reverse.dns.lookup`
>    should or shouldn't be used. Document security considerations as well as
>    other system configurations that may have an impact.
>    2. The PR currently disables the new code path for security protocol
>    SSL. But this doesn't address SASL_SSL which could also do hostname
>    verification. Do we even want to do reverse lookup if bootstrap list
>    contains IP addresses? If we do, we should handle SSL and SASL_SSL in
> the
>    same way (which basically means handling all protocols in the same way).
>
>
> On Thu, Apr 26, 2018 at 2:16 PM, Stephane Maarek <
> stephane@simplemachines.com.au> wrote:
>
> > +1 as a user
> > BUT
> >
> > I am no security expert. I have experienced that issue while setting up a
> > cluster and while I would have liked a feature like that (I opened a JIRA
> > at the time), I always guessed that the reason was because of some
> security
> > protection.
> >
> > Now from a setup point of view this helps a ton, but I really want to
> make
> > sure this doesn't introduce any security risk by relaxing a constraint.
> >
> > Is there a security assessment possible by someone accredited ?
> >
> > Sorry for raising these questions just want to make sure it's addressed
> >
> > On Thu., 26 Apr. 2018, 5:32 pm Gwen Shapira, <gw...@confluent.io> wrote:
> >
> > > +1 (binding)
> > >
> > > This KIP is quite vital to running secured clusters in cloud/container
> > > environment. Would love to see more support from the community to this
> > (or
> > > feedback...)
> > >
> > > Gwen
> > >
> > > On Mon, Apr 16, 2018 at 4:52 PM, Skrzypek, Jonathan <
> > > Jonathan.Skrzypek@gs.com> wrote:
> > >
> > > > Hi,
> > > >
> > > > Could anyone take a look ?
> > > > Does the proposal sound reasonable ?
> > > >
> > > > Jonathan Skrzypek
> > > >
> > > >
> > > > From: Skrzypek, Jonathan [Tech]
> > > > Sent: 23 March 2018 19:05
> > > > To: dev@kafka.apache.org
> > > > Subject: [VOTE] KIP-235 Add DNS alias support for secured connection
> > > >
> > > > Hi,
> > > >
> > > > I would like to start a vote for KIP-235
> > > >
> > > > https://urldefense.proofpoint.com/v2/url?u=https-3A__cwiki.
> apache.org_confluence_display_KAFKA_KIP-2D&d=DwIBaQ&c=
> 7563p3e2zaQw0AB1wrFVgyagb2IE5rTZOYPxLxfZlX4&r=nNmJlu1rR_QFAPdxGlafmDu9_
> r6eaCbPOM0NM1EHo-E&m=2JuW6J_xPCRzueIjC4B6j1v6T9aXMR5k9Nh8oMBVLd0&s=
> SJsuC6ROGH5VTVxQktBbB7xKK4zFDVRkQSUtZbLMfZ4&e=
> > > > 235%3A+Add+DNS+alias+support+for+secured+connection
> > > >
> > > > This is a proposition to add an option for reverse dns lookup of
> > > > bootstrap.servers hosts, allowing the use of dns aliases on clusters
> > > using
> > > > SASL authentication.
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> > > --
> > > *Gwen Shapira*
> > > Product Manager | Confluent
> > > 650.450.2760 | @gwenshap
> > > Follow us: Twitter <https://urldefense.proofpoint.com/v2/url?u=https-
> 3A__twitter.com_ConfluentInc&d=DwIBaQ&c=7563p3e2zaQw0AB1wrFVgyagb2IE5r
> TZOYPxLxfZlX4&r=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E&m=2JuW6J_
> xPCRzueIjC4B6j1v6T9aXMR5k9Nh8oMBVLd0&s=hWdKCJsOe7LyDCcoJqmjOkgepGk776
> 2xXxOZgQwHAm0&e= > | blog
> > > <https://urldefense.proofpoint.com/v2/url?u=http-
> 3A__www.confluent.io_blog&d=DwIBaQ&c=7563p3e2zaQw0AB1wrFVgyagb2IE5r
> TZOYPxLxfZlX4&r=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E&m=2JuW6J_
> xPCRzueIjC4B6j1v6T9aXMR5k9Nh8oMBVLd0&s=Y_WMfuQJKoXlE3I25NKs8d4TefgB8Olv
> O8lDGAhEr7Q&e= >
> > >
> >
>

RE: [VOTE] KIP-235 Add DNS alias support for secured connection

Posted by "Skrzypek, Jonathan" <Jo...@gs.com>.
Up :)
Anyone for a binding vote here ?

Jonathan Skrzypek 

-----Original Message-----
From: Rajini Sivaram [mailto:rajinisivaram@gmail.com] 
Sent: 10 May 2018 13:17
To: dev
Subject: Re: [VOTE] KIP-235 Add DNS alias support for secured connection

Thanks Jonathan. You have binding votes from me and Gwen. One more binding
vote is required for this KIP to be approved.

On Thu, May 10, 2018 at 1:14 PM, Skrzypek, Jonathan <
Jonathan.Skrzypek@gs.com> wrote:

> Hi,
>
> Have implemented the changes discussed.
> bootstrap.reverse.dns.lookup is disabled by default.
> When enabled, the client will perform reverse dns lookup regardless of the
> security protocol used.
>
> https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_apache_kafka_pull_4485&d=DwIBaQ&c=7563p3e2zaQw0AB1wrFVgyagb2IE5rTZOYPxLxfZlX4&r=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E&m=X8udiS6RLS6dhJElpufCtnaJoeGWVp7TAjcW1o7HYRI&s=x8aeZlBx-fTv7gYq8qnfX1I3_rQC8-1b4lBUn36b2nU&e= 
>
>
> Jonathan Skrzypek
>
>
> -----Original Message-----
> From: Skrzypek, Jonathan [Tech]
> Sent: 01 May 2018 17:17
> To: dev
> Subject: RE: [VOTE] KIP-235 Add DNS alias support for secured connection
>
> Oops, yes indeed that makes sense, got confused between SASL_SSL and SSL.
>
> Updated the KIP.
>
>
>
> Jonathan Skrzypek
>
>
> -----Original Message-----
> From: Rajini Sivaram [mailto:rajinisivaram@gmail.com]
> Sent: 01 May 2018 11:08
> To: dev
> Subject: Re: [VOTE] KIP-235 Add DNS alias support for secured connection
>
> Jonathan,
>
> Not doing the reverse lookup for SASL_SSL limits the usability of this KIP
> since it can no longer be used in a secure environment where Kerberos is
> used with TLS. Perhaps the best option is to do the lookup if the option is
> explicitly enabled regardless of what the security protocol is. If there is
> a SSL handshake failure with this option enabled, the error message can be
> updated to indicate that it could be because a reverse lookup was used. Can
> you state in the KIP that the default value of
> bootstrap.reverse.dns.lookup will
> be false and hence there is no backwards compatibility issue.
>
> On Mon, Apr 30, 2018 at 1:41 PM, Skrzypek, Jonathan <
> Jonathan.Skrzypek@gs.com> wrote:
>
> > Thanks for your comments.
> > Have updated the KIP.
> >
> > I agree SSL and SASL_SSL will face similar issues and should behave the
> > same.
> > Thinking about this further,  I'm wondering whether setting
> > bootstrap.reverse.dns.lookup to true whilst using any of those protocols
> > should throw a critical error and stop, or at least log a warning stating
> > that the lookup won't be performed.
> > This sounds better than silently ignoring and leave users with the
> > impression they can use SSL and bootstrap server aliases.
> > Abruptly stopping the client sounds a bit extreme so I'm leaning towards
> a
> > warning.
> >
> > Thoughts ?
> >
> > I'm not sure about checking whether the list has IP addresses.
> > There could be cases where the list has a mix of FQDNs and IPs, so I
> would
> > rather perform the lookup regardless of the case when the parameter is
> > enabled.
> >
> > On the security aspects, I am by no means a security or SASL expert so
> > commented the KIP with what I believe to be the case.
> >
> > Jonathan Skrzypek
> >
> > -----Original Message-----
> > From: Rajini Sivaram [mailto:rajinisivaram@gmail.com]
> > Sent: 29 April 2018 15:38
> > To: dev
> > Subject: Re: [VOTE] KIP-235 Add DNS alias support for secured connection
> >
> > Hi Jonathan,
> >
> > Thanks for the KIP.
> >
> > +1 (binding) with a couple comments below to add more detail to the KIP.
> >
> >    1. Make it clearer when the new option `bootstrap.reverse.dns.lookup`
> >    should or shouldn't be used. Document security considerations as well
> as
> >    other system configurations that may have an impact.
> >    2. The PR currently disables the new code path for security protocol
> >    SSL. But this doesn't address SASL_SSL which could also do hostname
> >    verification. Do we even want to do reverse lookup if bootstrap list
> >    contains IP addresses? If we do, we should handle SSL and SASL_SSL in
> > the
> >    same way (which basically means handling all protocols in the same
> way).
> >
> >
> > On Thu, Apr 26, 2018 at 2:16 PM, Stephane Maarek <
> > stephane@simplemachines.com.au> wrote:
> >
> > > +1 as a user
> > > BUT
> > >
> > > I am no security expert. I have experienced that issue while setting
> up a
> > > cluster and while I would have liked a feature like that (I opened a
> JIRA
> > > at the time), I always guessed that the reason was because of some
> > security
> > > protection.
> > >
> > > Now from a setup point of view this helps a ton, but I really want to
> > make
> > > sure this doesn't introduce any security risk by relaxing a constraint.
> > >
> > > Is there a security assessment possible by someone accredited ?
> > >
> > > Sorry for raising these questions just want to make sure it's addressed
> > >
> > > On Thu., 26 Apr. 2018, 5:32 pm Gwen Shapira, <gw...@confluent.io>
> wrote:
> > >
> > > > +1 (binding)
> > > >
> > > > This KIP is quite vital to running secured clusters in
> cloud/container
> > > > environment. Would love to see more support from the community to
> this
> > > (or
> > > > feedback...)
> > > >
> > > > Gwen
> > > >
> > > > On Mon, Apr 16, 2018 at 4:52 PM, Skrzypek, Jonathan <
> > > > Jonathan.Skrzypek@gs.com> wrote:
> > > >
> > > > > Hi,
> > > > >
> > > > > Could anyone take a look ?
> > > > > Does the proposal sound reasonable ?
> > > > >
> > > > > Jonathan Skrzypek
> > > > >
> > > > >
> > > > > From: Skrzypek, Jonathan [Tech]
> > > > > Sent: 23 March 2018 19:05
> > > > > To: dev@kafka.apache.org
> > > > > Subject: [VOTE] KIP-235 Add DNS alias support for secured
> connection
> > > > >
> > > > > Hi,
> > > > >
> > > > > I would like to start a vote for KIP-235
> > > > >
> > > > > https://urldefense.proofpoint.com/v2/url?u=https-3A__cwiki.
> > apache.org_confluence_display_KAFKA_KIP-2D&d=DwIBaQ&c=
> > 7563p3e2zaQw0AB1wrFVgyagb2IE5rTZOYPxLxfZlX4&r=nNmJlu1rR_QFAPdxGlafmDu9_
> > r6eaCbPOM0NM1EHo-E&m=2JuW6J_xPCRzueIjC4B6j1v6T9aXMR5k9Nh8oMBVLd0&s=
> > SJsuC6ROGH5VTVxQktBbB7xKK4zFDVRkQSUtZbLMfZ4&e=
> > > > > 235%3A+Add+DNS+alias+support+for+secured+connection
> > > > >
> > > > > This is a proposition to add an option for reverse dns lookup of
> > > > > bootstrap.servers hosts, allowing the use of dns aliases on
> clusters
> > > > using
> > > > > SASL authentication.
> > > > >
> > > > >
> > > > >
> > > > >
> > > >
> > > >
> > > > --
> > > > *Gwen Shapira*
> > > > Product Manager | Confluent
> > > > 650.450.2760 | @gwenshap
> > > > Follow us: Twitter <https://urldefense.proofpoint.com/v2/url?u=https-3A__urldefense&d=DwIBaQ&c=7563p3e2zaQw0AB1wrFVgyagb2IE5rTZOYPxLxfZlX4&r=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E&m=X8udiS6RLS6dhJElpufCtnaJoeGWVp7TAjcW1o7HYRI&s=hDAB0m_XF2YeA649vcL62Z25Qp7oAVjXv3VgcKP1v7o&e= .> proofpoint.com/v2/url?u=https-
> > 3A__twitter.com_ConfluentInc&d=DwIBaQ&c=7563p3e2zaQw0AB1wrFVgyagb2IE5r
> > TZOYPxLxfZlX4&r=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E&m=2JuW6J_
> > xPCRzueIjC4B6j1v6T9aXMR5k9Nh8oMBVLd0&s=hWdKCJsOe7LyDCcoJqmjOkgepGk776
> > 2xXxOZgQwHAm0&e= > | blog
> > > > <https://urldefense.proofpoint.com/v2/url?u=http-> > 3A__www.confluent.io_blog&d=DwIBaQ&c=7563p3e2zaQw0AB1wrFVgyagb2IE5r
> > TZOYPxLxfZlX4&r=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E&m=2JuW6J_
> > xPCRzueIjC4B6j1v6T9aXMR5k9Nh8oMBVLd0&s=Y_WMfuQJKoXlE3I25NKs8d4TefgB8Olv
> > O8lDGAhEr7Q&e= >
> > > >
> > >
> >
>

Re: [VOTE] KIP-235 Add DNS alias support for secured connection

Posted by Rajini Sivaram <ra...@gmail.com>.
Thanks Jonathan. You have binding votes from me and Gwen. One more binding
vote is required for this KIP to be approved.

On Thu, May 10, 2018 at 1:14 PM, Skrzypek, Jonathan <
Jonathan.Skrzypek@gs.com> wrote:

> Hi,
>
> Have implemented the changes discussed.
> bootstrap.reverse.dns.lookup is disabled by default.
> When enabled, the client will perform reverse dns lookup regardless of the
> security protocol used.
>
> https://github.com/apache/kafka/pull/4485
>
>
> Jonathan Skrzypek
>
>
> -----Original Message-----
> From: Skrzypek, Jonathan [Tech]
> Sent: 01 May 2018 17:17
> To: dev
> Subject: RE: [VOTE] KIP-235 Add DNS alias support for secured connection
>
> Oops, yes indeed that makes sense, got confused between SASL_SSL and SSL.
>
> Updated the KIP.
>
>
>
> Jonathan Skrzypek
>
>
> -----Original Message-----
> From: Rajini Sivaram [mailto:rajinisivaram@gmail.com]
> Sent: 01 May 2018 11:08
> To: dev
> Subject: Re: [VOTE] KIP-235 Add DNS alias support for secured connection
>
> Jonathan,
>
> Not doing the reverse lookup for SASL_SSL limits the usability of this KIP
> since it can no longer be used in a secure environment where Kerberos is
> used with TLS. Perhaps the best option is to do the lookup if the option is
> explicitly enabled regardless of what the security protocol is. If there is
> a SSL handshake failure with this option enabled, the error message can be
> updated to indicate that it could be because a reverse lookup was used. Can
> you state in the KIP that the default value of
> bootstrap.reverse.dns.lookup will
> be false and hence there is no backwards compatibility issue.
>
> On Mon, Apr 30, 2018 at 1:41 PM, Skrzypek, Jonathan <
> Jonathan.Skrzypek@gs.com> wrote:
>
> > Thanks for your comments.
> > Have updated the KIP.
> >
> > I agree SSL and SASL_SSL will face similar issues and should behave the
> > same.
> > Thinking about this further,  I'm wondering whether setting
> > bootstrap.reverse.dns.lookup to true whilst using any of those protocols
> > should throw a critical error and stop, or at least log a warning stating
> > that the lookup won't be performed.
> > This sounds better than silently ignoring and leave users with the
> > impression they can use SSL and bootstrap server aliases.
> > Abruptly stopping the client sounds a bit extreme so I'm leaning towards
> a
> > warning.
> >
> > Thoughts ?
> >
> > I'm not sure about checking whether the list has IP addresses.
> > There could be cases where the list has a mix of FQDNs and IPs, so I
> would
> > rather perform the lookup regardless of the case when the parameter is
> > enabled.
> >
> > On the security aspects, I am by no means a security or SASL expert so
> > commented the KIP with what I believe to be the case.
> >
> > Jonathan Skrzypek
> >
> > -----Original Message-----
> > From: Rajini Sivaram [mailto:rajinisivaram@gmail.com]
> > Sent: 29 April 2018 15:38
> > To: dev
> > Subject: Re: [VOTE] KIP-235 Add DNS alias support for secured connection
> >
> > Hi Jonathan,
> >
> > Thanks for the KIP.
> >
> > +1 (binding) with a couple comments below to add more detail to the KIP.
> >
> >    1. Make it clearer when the new option `bootstrap.reverse.dns.lookup`
> >    should or shouldn't be used. Document security considerations as well
> as
> >    other system configurations that may have an impact.
> >    2. The PR currently disables the new code path for security protocol
> >    SSL. But this doesn't address SASL_SSL which could also do hostname
> >    verification. Do we even want to do reverse lookup if bootstrap list
> >    contains IP addresses? If we do, we should handle SSL and SASL_SSL in
> > the
> >    same way (which basically means handling all protocols in the same
> way).
> >
> >
> > On Thu, Apr 26, 2018 at 2:16 PM, Stephane Maarek <
> > stephane@simplemachines.com.au> wrote:
> >
> > > +1 as a user
> > > BUT
> > >
> > > I am no security expert. I have experienced that issue while setting
> up a
> > > cluster and while I would have liked a feature like that (I opened a
> JIRA
> > > at the time), I always guessed that the reason was because of some
> > security
> > > protection.
> > >
> > > Now from a setup point of view this helps a ton, but I really want to
> > make
> > > sure this doesn't introduce any security risk by relaxing a constraint.
> > >
> > > Is there a security assessment possible by someone accredited ?
> > >
> > > Sorry for raising these questions just want to make sure it's addressed
> > >
> > > On Thu., 26 Apr. 2018, 5:32 pm Gwen Shapira, <gw...@confluent.io>
> wrote:
> > >
> > > > +1 (binding)
> > > >
> > > > This KIP is quite vital to running secured clusters in
> cloud/container
> > > > environment. Would love to see more support from the community to
> this
> > > (or
> > > > feedback...)
> > > >
> > > > Gwen
> > > >
> > > > On Mon, Apr 16, 2018 at 4:52 PM, Skrzypek, Jonathan <
> > > > Jonathan.Skrzypek@gs.com> wrote:
> > > >
> > > > > Hi,
> > > > >
> > > > > Could anyone take a look ?
> > > > > Does the proposal sound reasonable ?
> > > > >
> > > > > Jonathan Skrzypek
> > > > >
> > > > >
> > > > > From: Skrzypek, Jonathan [Tech]
> > > > > Sent: 23 March 2018 19:05
> > > > > To: dev@kafka.apache.org
> > > > > Subject: [VOTE] KIP-235 Add DNS alias support for secured
> connection
> > > > >
> > > > > Hi,
> > > > >
> > > > > I would like to start a vote for KIP-235
> > > > >
> > > > > https://urldefense.proofpoint.com/v2/url?u=https-3A__cwiki.
> > apache.org_confluence_display_KAFKA_KIP-2D&d=DwIBaQ&c=
> > 7563p3e2zaQw0AB1wrFVgyagb2IE5rTZOYPxLxfZlX4&r=nNmJlu1rR_QFAPdxGlafmDu9_
> > r6eaCbPOM0NM1EHo-E&m=2JuW6J_xPCRzueIjC4B6j1v6T9aXMR5k9Nh8oMBVLd0&s=
> > SJsuC6ROGH5VTVxQktBbB7xKK4zFDVRkQSUtZbLMfZ4&e=
> > > > > 235%3A+Add+DNS+alias+support+for+secured+connection
> > > > >
> > > > > This is a proposition to add an option for reverse dns lookup of
> > > > > bootstrap.servers hosts, allowing the use of dns aliases on
> clusters
> > > > using
> > > > > SASL authentication.
> > > > >
> > > > >
> > > > >
> > > > >
> > > >
> > > >
> > > > --
> > > > *Gwen Shapira*
> > > > Product Manager | Confluent
> > > > 650.450.2760 | @gwenshap
> > > > Follow us: Twitter <https://urldefense.
> proofpoint.com/v2/url?u=https-
> > 3A__twitter.com_ConfluentInc&d=DwIBaQ&c=7563p3e2zaQw0AB1wrFVgyagb2IE5r
> > TZOYPxLxfZlX4&r=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E&m=2JuW6J_
> > xPCRzueIjC4B6j1v6T9aXMR5k9Nh8oMBVLd0&s=hWdKCJsOe7LyDCcoJqmjOkgepGk776
> > 2xXxOZgQwHAm0&e= > | blog
> > > > <https://urldefense.proofpoint.com/v2/url?u=http-
> > 3A__www.confluent.io_blog&d=DwIBaQ&c=7563p3e2zaQw0AB1wrFVgyagb2IE5r
> > TZOYPxLxfZlX4&r=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E&m=2JuW6J_
> > xPCRzueIjC4B6j1v6T9aXMR5k9Nh8oMBVLd0&s=Y_WMfuQJKoXlE3I25NKs8d4TefgB8Olv
> > O8lDGAhEr7Q&e= >
> > > >
> > >
> >
>

RE: [VOTE] KIP-235 Add DNS alias support for secured connection

Posted by "Skrzypek, Jonathan" <Jo...@gs.com>.
Hi,

Have implemented the changes discussed.
bootstrap.reverse.dns.lookup is disabled by default.
When enabled, the client will perform reverse dns lookup regardless of the security protocol used.

https://github.com/apache/kafka/pull/4485


Jonathan Skrzypek 


-----Original Message-----
From: Skrzypek, Jonathan [Tech] 
Sent: 01 May 2018 17:17
To: dev
Subject: RE: [VOTE] KIP-235 Add DNS alias support for secured connection

Oops, yes indeed that makes sense, got confused between SASL_SSL and SSL.

Updated the KIP.



Jonathan Skrzypek 


-----Original Message-----
From: Rajini Sivaram [mailto:rajinisivaram@gmail.com] 
Sent: 01 May 2018 11:08
To: dev
Subject: Re: [VOTE] KIP-235 Add DNS alias support for secured connection

Jonathan,

Not doing the reverse lookup for SASL_SSL limits the usability of this KIP
since it can no longer be used in a secure environment where Kerberos is
used with TLS. Perhaps the best option is to do the lookup if the option is
explicitly enabled regardless of what the security protocol is. If there is
a SSL handshake failure with this option enabled, the error message can be
updated to indicate that it could be because a reverse lookup was used. Can
you state in the KIP that the default value of
bootstrap.reverse.dns.lookup will
be false and hence there is no backwards compatibility issue.

On Mon, Apr 30, 2018 at 1:41 PM, Skrzypek, Jonathan <
Jonathan.Skrzypek@gs.com> wrote:

> Thanks for your comments.
> Have updated the KIP.
>
> I agree SSL and SASL_SSL will face similar issues and should behave the
> same.
> Thinking about this further,  I'm wondering whether setting
> bootstrap.reverse.dns.lookup to true whilst using any of those protocols
> should throw a critical error and stop, or at least log a warning stating
> that the lookup won't be performed.
> This sounds better than silently ignoring and leave users with the
> impression they can use SSL and bootstrap server aliases.
> Abruptly stopping the client sounds a bit extreme so I'm leaning towards a
> warning.
>
> Thoughts ?
>
> I'm not sure about checking whether the list has IP addresses.
> There could be cases where the list has a mix of FQDNs and IPs, so I would
> rather perform the lookup regardless of the case when the parameter is
> enabled.
>
> On the security aspects, I am by no means a security or SASL expert so
> commented the KIP with what I believe to be the case.
>
> Jonathan Skrzypek
>
> -----Original Message-----
> From: Rajini Sivaram [mailto:rajinisivaram@gmail.com]
> Sent: 29 April 2018 15:38
> To: dev
> Subject: Re: [VOTE] KIP-235 Add DNS alias support for secured connection
>
> Hi Jonathan,
>
> Thanks for the KIP.
>
> +1 (binding) with a couple comments below to add more detail to the KIP.
>
>    1. Make it clearer when the new option `bootstrap.reverse.dns.lookup`
>    should or shouldn't be used. Document security considerations as well as
>    other system configurations that may have an impact.
>    2. The PR currently disables the new code path for security protocol
>    SSL. But this doesn't address SASL_SSL which could also do hostname
>    verification. Do we even want to do reverse lookup if bootstrap list
>    contains IP addresses? If we do, we should handle SSL and SASL_SSL in
> the
>    same way (which basically means handling all protocols in the same way).
>
>
> On Thu, Apr 26, 2018 at 2:16 PM, Stephane Maarek <
> stephane@simplemachines.com.au> wrote:
>
> > +1 as a user
> > BUT
> >
> > I am no security expert. I have experienced that issue while setting up a
> > cluster and while I would have liked a feature like that (I opened a JIRA
> > at the time), I always guessed that the reason was because of some
> security
> > protection.
> >
> > Now from a setup point of view this helps a ton, but I really want to
> make
> > sure this doesn't introduce any security risk by relaxing a constraint.
> >
> > Is there a security assessment possible by someone accredited ?
> >
> > Sorry for raising these questions just want to make sure it's addressed
> >
> > On Thu., 26 Apr. 2018, 5:32 pm Gwen Shapira, <gw...@confluent.io> wrote:
> >
> > > +1 (binding)
> > >
> > > This KIP is quite vital to running secured clusters in cloud/container
> > > environment. Would love to see more support from the community to this
> > (or
> > > feedback...)
> > >
> > > Gwen
> > >
> > > On Mon, Apr 16, 2018 at 4:52 PM, Skrzypek, Jonathan <
> > > Jonathan.Skrzypek@gs.com> wrote:
> > >
> > > > Hi,
> > > >
> > > > Could anyone take a look ?
> > > > Does the proposal sound reasonable ?
> > > >
> > > > Jonathan Skrzypek
> > > >
> > > >
> > > > From: Skrzypek, Jonathan [Tech]
> > > > Sent: 23 March 2018 19:05
> > > > To: dev@kafka.apache.org
> > > > Subject: [VOTE] KIP-235 Add DNS alias support for secured connection
> > > >
> > > > Hi,
> > > >
> > > > I would like to start a vote for KIP-235
> > > >
> > > > https://urldefense.proofpoint.com/v2/url?u=https-3A__cwiki.
> apache.org_confluence_display_KAFKA_KIP-2D&d=DwIBaQ&c=
> 7563p3e2zaQw0AB1wrFVgyagb2IE5rTZOYPxLxfZlX4&r=nNmJlu1rR_QFAPdxGlafmDu9_
> r6eaCbPOM0NM1EHo-E&m=2JuW6J_xPCRzueIjC4B6j1v6T9aXMR5k9Nh8oMBVLd0&s=
> SJsuC6ROGH5VTVxQktBbB7xKK4zFDVRkQSUtZbLMfZ4&e=
> > > > 235%3A+Add+DNS+alias+support+for+secured+connection
> > > >
> > > > This is a proposition to add an option for reverse dns lookup of
> > > > bootstrap.servers hosts, allowing the use of dns aliases on clusters
> > > using
> > > > SASL authentication.
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> > > --
> > > *Gwen Shapira*
> > > Product Manager | Confluent
> > > 650.450.2760 | @gwenshap
> > > Follow us: Twitter <https://urldefense.proofpoint.com/v2/url?u=https-
> 3A__twitter.com_ConfluentInc&d=DwIBaQ&c=7563p3e2zaQw0AB1wrFVgyagb2IE5r
> TZOYPxLxfZlX4&r=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E&m=2JuW6J_
> xPCRzueIjC4B6j1v6T9aXMR5k9Nh8oMBVLd0&s=hWdKCJsOe7LyDCcoJqmjOkgepGk776
> 2xXxOZgQwHAm0&e= > | blog
> > > <https://urldefense.proofpoint.com/v2/url?u=http-
> 3A__www.confluent.io_blog&d=DwIBaQ&c=7563p3e2zaQw0AB1wrFVgyagb2IE5r
> TZOYPxLxfZlX4&r=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E&m=2JuW6J_
> xPCRzueIjC4B6j1v6T9aXMR5k9Nh8oMBVLd0&s=Y_WMfuQJKoXlE3I25NKs8d4TefgB8Olv
> O8lDGAhEr7Q&e= >
> > >
> >
>

RE: [VOTE] KIP-235 Add DNS alias support for secured connection

Posted by "Skrzypek, Jonathan" <Jo...@gs.com>.
Oops, yes indeed that makes sense, got confused between SASL_SSL and SSL.

Updated the KIP.



Jonathan Skrzypek 


-----Original Message-----
From: Rajini Sivaram [mailto:rajinisivaram@gmail.com] 
Sent: 01 May 2018 11:08
To: dev
Subject: Re: [VOTE] KIP-235 Add DNS alias support for secured connection

Jonathan,

Not doing the reverse lookup for SASL_SSL limits the usability of this KIP
since it can no longer be used in a secure environment where Kerberos is
used with TLS. Perhaps the best option is to do the lookup if the option is
explicitly enabled regardless of what the security protocol is. If there is
a SSL handshake failure with this option enabled, the error message can be
updated to indicate that it could be because a reverse lookup was used. Can
you state in the KIP that the default value of
bootstrap.reverse.dns.lookup will
be false and hence there is no backwards compatibility issue.

On Mon, Apr 30, 2018 at 1:41 PM, Skrzypek, Jonathan <
Jonathan.Skrzypek@gs.com> wrote:

> Thanks for your comments.
> Have updated the KIP.
>
> I agree SSL and SASL_SSL will face similar issues and should behave the
> same.
> Thinking about this further,  I'm wondering whether setting
> bootstrap.reverse.dns.lookup to true whilst using any of those protocols
> should throw a critical error and stop, or at least log a warning stating
> that the lookup won't be performed.
> This sounds better than silently ignoring and leave users with the
> impression they can use SSL and bootstrap server aliases.
> Abruptly stopping the client sounds a bit extreme so I'm leaning towards a
> warning.
>
> Thoughts ?
>
> I'm not sure about checking whether the list has IP addresses.
> There could be cases where the list has a mix of FQDNs and IPs, so I would
> rather perform the lookup regardless of the case when the parameter is
> enabled.
>
> On the security aspects, I am by no means a security or SASL expert so
> commented the KIP with what I believe to be the case.
>
> Jonathan Skrzypek
>
> -----Original Message-----
> From: Rajini Sivaram [mailto:rajinisivaram@gmail.com]
> Sent: 29 April 2018 15:38
> To: dev
> Subject: Re: [VOTE] KIP-235 Add DNS alias support for secured connection
>
> Hi Jonathan,
>
> Thanks for the KIP.
>
> +1 (binding) with a couple comments below to add more detail to the KIP.
>
>    1. Make it clearer when the new option `bootstrap.reverse.dns.lookup`
>    should or shouldn't be used. Document security considerations as well as
>    other system configurations that may have an impact.
>    2. The PR currently disables the new code path for security protocol
>    SSL. But this doesn't address SASL_SSL which could also do hostname
>    verification. Do we even want to do reverse lookup if bootstrap list
>    contains IP addresses? If we do, we should handle SSL and SASL_SSL in
> the
>    same way (which basically means handling all protocols in the same way).
>
>
> On Thu, Apr 26, 2018 at 2:16 PM, Stephane Maarek <
> stephane@simplemachines.com.au> wrote:
>
> > +1 as a user
> > BUT
> >
> > I am no security expert. I have experienced that issue while setting up a
> > cluster and while I would have liked a feature like that (I opened a JIRA
> > at the time), I always guessed that the reason was because of some
> security
> > protection.
> >
> > Now from a setup point of view this helps a ton, but I really want to
> make
> > sure this doesn't introduce any security risk by relaxing a constraint.
> >
> > Is there a security assessment possible by someone accredited ?
> >
> > Sorry for raising these questions just want to make sure it's addressed
> >
> > On Thu., 26 Apr. 2018, 5:32 pm Gwen Shapira, <gw...@confluent.io> wrote:
> >
> > > +1 (binding)
> > >
> > > This KIP is quite vital to running secured clusters in cloud/container
> > > environment. Would love to see more support from the community to this
> > (or
> > > feedback...)
> > >
> > > Gwen
> > >
> > > On Mon, Apr 16, 2018 at 4:52 PM, Skrzypek, Jonathan <
> > > Jonathan.Skrzypek@gs.com> wrote:
> > >
> > > > Hi,
> > > >
> > > > Could anyone take a look ?
> > > > Does the proposal sound reasonable ?
> > > >
> > > > Jonathan Skrzypek
> > > >
> > > >
> > > > From: Skrzypek, Jonathan [Tech]
> > > > Sent: 23 March 2018 19:05
> > > > To: dev@kafka.apache.org
> > > > Subject: [VOTE] KIP-235 Add DNS alias support for secured connection
> > > >
> > > > Hi,
> > > >
> > > > I would like to start a vote for KIP-235
> > > >
> > > > https://urldefense.proofpoint.com/v2/url?u=https-3A__cwiki.
> apache.org_confluence_display_KAFKA_KIP-2D&d=DwIBaQ&c=
> 7563p3e2zaQw0AB1wrFVgyagb2IE5rTZOYPxLxfZlX4&r=nNmJlu1rR_QFAPdxGlafmDu9_
> r6eaCbPOM0NM1EHo-E&m=2JuW6J_xPCRzueIjC4B6j1v6T9aXMR5k9Nh8oMBVLd0&s=
> SJsuC6ROGH5VTVxQktBbB7xKK4zFDVRkQSUtZbLMfZ4&e=
> > > > 235%3A+Add+DNS+alias+support+for+secured+connection
> > > >
> > > > This is a proposition to add an option for reverse dns lookup of
> > > > bootstrap.servers hosts, allowing the use of dns aliases on clusters
> > > using
> > > > SASL authentication.
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> > > --
> > > *Gwen Shapira*
> > > Product Manager | Confluent
> > > 650.450.2760 | @gwenshap
> > > Follow us: Twitter <https://urldefense.proofpoint.com/v2/url?u=https-
> 3A__twitter.com_ConfluentInc&d=DwIBaQ&c=7563p3e2zaQw0AB1wrFVgyagb2IE5r
> TZOYPxLxfZlX4&r=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E&m=2JuW6J_
> xPCRzueIjC4B6j1v6T9aXMR5k9Nh8oMBVLd0&s=hWdKCJsOe7LyDCcoJqmjOkgepGk776
> 2xXxOZgQwHAm0&e= > | blog
> > > <https://urldefense.proofpoint.com/v2/url?u=http-
> 3A__www.confluent.io_blog&d=DwIBaQ&c=7563p3e2zaQw0AB1wrFVgyagb2IE5r
> TZOYPxLxfZlX4&r=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E&m=2JuW6J_
> xPCRzueIjC4B6j1v6T9aXMR5k9Nh8oMBVLd0&s=Y_WMfuQJKoXlE3I25NKs8d4TefgB8Olv
> O8lDGAhEr7Q&e= >
> > >
> >
>