[keycloak-dev] File-based Vault implementation
Marek Posolda
mposolda at redhat.com
Tue Aug 13 09:39:55 EDT 2019
On 13. 08. 19 4:40, Sebastian Laskawiec wrote:
>
>
> On Mon, Aug 12, 2019 at 4:07 PM Marek Posolda <mposolda at redhat.com
> <mailto:mposolda at redhat.com>> wrote:
>
> I have one more question, regarding the fact, that vault is
> supposed to be read-only. In the design [1], it is mentioned that
> the aim of the work is to provide "Read-only access to a secure
> storage (i.e. vault). Vault is managed and written-to by external
> tools specific to vault implementation." .
>
> I am not sure I understand this. How exactly will be new values
> added to the file-based vault considering that SPI doesn't have
> any support for writing ATM? For example what happen if
> administrator wants to register new client in Keycloak with new
> client secret (either generated or provided by admin himself)? IMO
> it will be nice if Keycloak default implementation will be able to
> write new value to the vault OOTB without any further manual
> action required from the administrator to deal specifically with
> the vault.
>
>
> In some environments, like OpenShift/Kubernetes, this won't work (at
> least for a file-based vault implementation). The workflow would have
> to go like this:
> - An administrator (or whoever uses kubectl or oc tool) creates a new
> secret in Kubernetes/OpenShift
> - The secret is being added to your Deployment (or any other
> controller you're using)
> - Kubernetes restarts all Pods and a new secret is available of Keycloak
> - You update Keycloak (using REST, CRD or Admin Console) to use the secret
>
> Writing anything by a running Pod is very tricky. In theory you could
> use a Persistent Volume but this doesn't work with Secrets very well.
> So at least in Kubernetes/OpenShift scenario, having a read-only vault
> and delegating manipulating vault's secrets to the environment is the
> most natural way to tackle this.
I see. Thanks for clarifying Sebastian!
I've talked also with Hynek and now I understand, that items in the DB
won't be encrypted by default and won't use vault by default.
Administrator will need to manually add values to the vault and then in
the DB, you will client secret like "${file-vault:client1-secret}",
which will tell Keycloak to call "file-vault" with "client1-secret". I
missed how this is supposed to work as it wasn't very mentioned in the
design in very detailed way...
Thanks,
Marek
>
> [1]
> https://github.com/keycloak/keycloak-community/blob/master/design/secure-credentials-store.md
>
> Marek
>
> On 09. 08. 19 20:46, Stefan Guilhen wrote:
>> On Fri, Aug 9, 2019 at 10:38 AM Marek Posolda
>> <mposolda at redhat.com <mailto:mposolda at redhat.com>> wrote:
>>
>> On 09. 08. 19 14:46, Hynek Mlnarik wrote:
>> > I agree that certain level of cacheability should be there,
>> however
>> > its being enabled needs to be decided by an administrator.
>> >
>> > If the admin decides to use vault for secrets, we should
>> employ all
>> > measures for obtaining it only when needed. If they decide
>> a secret is
>> > safe to cache it in Keycloak, then we should support it.
>> Both modes
>> > can be implemented for the vault provider (note caching is
>> > implementation dependent, see below), but here I'd start
>> with the
>> > strictest and safest option of accessing the vault whenever
>> needed. As
>> > Sebastian pointed out, the sample implementation might be
>> very fast,
>> > even though certainly slower than putting a secret directly
>> into one
>> > of the models. Once this is done, we can work on caching.
>>
>> Yes, the ideal is if admin can decide if he prefer stronger
>> performance
>> or security, so ideal is, if caching will be provided in the
>> VaultProvider. I agree with that. Maybe we can have
>> CacheVaultProvider,
>> which will just delegate to other providers similarly like we
>> do for
>> models, but invalidation might be tricky, so not sure...
>>
>>
>> +1 to having a cacheable provider in place, so the factory can
>> instantiate the proper provider based on some configuration (e.g.
>> cache-enabled, true-false).
>> Given that memory can't be fully protected and any kind of secret
>> we use that can be overridden with garbage really just shortens
>> the window a secret
>> is exposed in memory, I would simply make the cacheable version
>> default and allow "paranoid" admins to turn it off if they want it
>>
>> @Hynek for us that would mean the Cacheable version of the
>> provider either needs to return a secret whose close() method
>> doesn't do anything or
>> it has to clone the cached secret before returning it as users of
>> the API will prob use the secret in try-with-resources blocks and
>> overriding a cached
>> secret is definitely the wrong thing to do.
>>
>> Irrespective of the choice for a default provider I agree with
>> Sebastian's point that we should run a profiler to get an idea of
>> how much non-cacheable
>> secrets impact the performance.
>>
>> BTV. question is if for the "paranoid" administrators, who
>> would prefer
>> the safe path and more memory protection is the
>> MappedByteBuffer good
>> option? Hopefully it is fine, but just pointing... :)
>>
>>
>> The way I understand it, MappedByteBuffer has the positions of
>> the buffer that holds the file contents in memory, not the buffer
>> itself. So
>> if someone can get a heapdump and tries to analyse it the file
>> contents won't be there. I see it as a protection from a heapdump.
>>
>> Marek
>>
>> >
>> > Caching the secrets is connected with invalidation and that is
>> > dependent on actual vault implementation. The secret value
>> can change
>> > over time, and we'd need to adjust / invalidate the cached
>> value. For
>> > example if Kubernetes secrets change in the file, they are
>> immediately
>> > propagated to a running pod, and we should pick up the new
>> value.
>> > Since this is based on files, we would need to invalidate /
>> reload the
>> > entry if file modification time changes.
>> >
>> > On Fri, Aug 9, 2019 at 10:56 AM Sebastian Laskawiec
>> > <slaskawi at redhat.com <mailto:slaskawi at redhat.com>
>> <mailto:slaskawi at redhat.com <mailto:slaskawi at redhat.com>>> wrote:
>> >
>> > At least for File-based Vault implementation, I would
>> like to
>> > experiment a
>> > bit with MappedByteBuffers [1] (the PR still contains
>> the old
>> > code, I'm
>> > about to update very soon). If that goes well, we
>> should get a sort of
>> > trade-off between performance (reading the same secret
>> over and
>> > over should
>> > be blazing fast) and security (the caller of the vault
>> will obtain
>> > a secret
>> > and the override it with random data when it's done
>> using it).
>> >
>> > But that's actually a good point - we should run a
>> performance
>> > test (or
>> > profile the code using Flight Recorder) once the
>> implementation is
>> > ready.
>> >
>> > [1] https://www.baeldung.com/java-mapped-byte-buffer
>> >
>> > On Thu, Aug 8, 2019 at 7:24 PM Marek Posolda
>> <mposolda at redhat.com <mailto:mposolda at redhat.com>
>> > <mailto:mposolda at redhat.com
>> <mailto:mposolda at redhat.com>>> wrote:
>> >
>> > > I am sorry for joining late.
>> > >
>> > > I guess you already take performance into account,
>> but still I would
>> > > like to point it again here. Because usually there is
>> some trade-off
>> > > between performance and security :)
>> > >
>> > > IMO the important question is at which point exactly
>> the vault
>> > will be
>> > > called? Will it be directly when particular value
>> (eg. client
>> > secret) is
>> > > retrieved from DB, so the secret would be still
>> cached in memory
>> > as it
>> > > is today? Or do you want to prevent caching secrets
>> at all? I would
>> > > personally prefer the first option by default due the
>> better
>> > performance
>> > > and eventually allow the second option in case that
>> people prefer
>> > > stronger security against performance.
>> > >
>> > > For example clientSecret is always needed when
>> refreshing token,
>> > > exchanging code-to-token etc. So if you always need
>> to read the file
>> > > during each refreshToken request, it is not ideal. I
>> see the
>> > main point
>> > > of the vault is to prevent plain-text passwords in
>> DB. The
>> > prevention of
>> > > have secrets in memory is not so big priority if it
>> means the
>> > > significant performance degradation IMO.
>> > >
>> > > Marek
>> > >
>> > >
>> > > On 08. 08. 19 14:35, Pedro Igor Silva wrote:
>> > > > On Thu, Aug 8, 2019 at 4:34 AM Sebastian Laskawiec
>> > <slaskawi at redhat.com <mailto:slaskawi at redhat.com>
>> <mailto:slaskawi at redhat.com <mailto:slaskawi at redhat.com>>>
>> > > > wrote:
>> > > >
>> > > >> I briefly looked at the SPI and it seems a bit
>> over the top
>> > comparing to
>> > > >> what we need. Plus we would create a strong connection
>> > between Keycloak
>> > > and
>> > > >> Elytron Security SPIs and I'm not sure if this is
>> desirable.
>> > > >>
>> > > >> Maybe a translation layer (a simple Vault SPI
>> implementation that
>> > > >> delegates to Elytron SPIs) would be better?
>> > > >>
>> > > > Yeah, it is. Like I said, for this particular case
>> your SPI is
>> > more
>> > > simple
>> > > > and you won't get much from Elytron.
>> > > >
>> > > >
>> > > >>> For read-write, you have the key store
>> implementation from
>> > Elytron that
>> > > >>> can save you some time. So your credentials are
>> stored more
>> > securely
>> > > and
>> > > >>> you can easily look up them.
>> > > >>>
>> > > >> I agree with you here. The write path of the Vault
>> SPI is a
>> > bit tricky.
>> > > >> But I'm not sure if that will happen (we will
>> probably see in the
>> > > future).
>> > > >>
>> > > >> My personal vote here is to leave the door open
>> and implement a
>> > > delegation
>> > > >> layer to Elytron SPIs. We can leave that as an
>> Experimental
>> > Feature if
>> > > we
>> > > >> want to avoid extensive testing on the product side.
>> > > >>
>> > > > I see. If you are not planning to deliver the write
>> path
>> > anytime soon,
>> > > > let's talk more about it later.
>> > > >
>> > > > Thanks.
>> > > >
>> > > >
>> > > >>
>> > > >>> I just wanted to let you know about Elytron
>> Credential
>> > Store. I haven't
>> > > >>> joined the discussions about the credential store
>> proposal
>> > so I may be
>> > > just
>> > > >>> messing your thread :)
>> > > >>>
>> > > >>> On Tue, Aug 6, 2019 at 10:35 AM Sebastian Laskawiec <
>> > > slaskawi at redhat.com <mailto:slaskawi at redhat.com>
>> <mailto:slaskawi at redhat.com <mailto:slaskawi at redhat.com>>>
>> > > >>> wrote:
>> > > >>>
>> > > >>>> The idea sounds interesting to me. Although,
>> having in mind
>> > our plans
>> > > >>>> related to Keycloak.next, I'm not sure if we
>> should provide
>> > it out of
>> > > the
>> > > >>>> box.
>> > > >>>>
>> > > >>>> Perhaps we should provide a community-driven
>> extension (as
>> > a separate
>> > > >>>> jar) to use this?
>> > > >>>>
>> > > >>>> On Tue, Aug 6, 2019 at 2:59 PM Pedro Igor Silva
>> > <psilva at redhat.com <mailto:psilva at redhat.com>
>> <mailto:psilva at redhat.com <mailto:psilva at redhat.com>>>
>> > > >>>> wrote:
>> > > >>>>
>> > > >>>>> Hey Hynek,
>> > > >>>>>
>> > > >>>>> Elytron came into my mind because it provides
>> an SPI for
>> > plugging
>> > > >>>>> different implementations based on a SPI [1].
>> There are
>> > some OOTB
>> > > >>>>> implementations such as a keystore-based and
>> map-based.
>> > > >>>>>
>> > > >>>>> You should be able to delegate to other vault
>> types or
>> > even build
>> > > your
>> > > >>>>> own on top of some default implementation.
>> Considering
>> > that Elytron
>> > > >>>>> Subsystem is available as a subsystem you also
>> have the
>> > necessary
>> > > means to
>> > > >>>>> manage your credential stores (via CLI, etc).
>> > > >>>>>
>> > > >>>>> [1]
>> > > >>>>>
>> > >
>> >
>> https://github.com/wildfly-security/wildfly-elytron/blob/1c42623a343e138ac4a31bd5dcfd8d2ccc47633e/credential/store/src/main/java/org/wildfly/security/credential/store/CredentialStoreSpi.java#L35
>> > > >>>>>
>> > > >>>>> On Tue, Aug 6, 2019 at 3:37 AM Hynek Mlnarik
>> > <hmlnarik at redhat.com <mailto:hmlnarik at redhat.com>
>> <mailto:hmlnarik at redhat.com <mailto:hmlnarik at redhat.com>>>
>> > > >>>>> wrote:
>> > > >>>>>
>> > > >>>>>> Hi Pedro,
>> > > >>>>>>
>> > > >>>>>> Elytron Cred Store has been considered, any
>> details would be
>> > > >>>>>> appreciated. Specifically, does it support
>> delegation to
>> > other
>> > > vault types?
>> > > >>>>>> Is it able to delegate access to other vault
>> types, e.g.
>> > Kubernetes
>> > > >>>>>> credentials? See [1] for further context.
>> > > >>>>>>
>> > > >>>>>> Pros and cons of other vault implementations
>> are highly
>> > appreciated
>> > > as
>> > > >>>>>> well. The number of built-in implementations
>> mus be kept
>> > low (one
>> > > or two)
>> > > >>>>>> for maintenance reasons, so we need convincing
>> arguments for
>> > > including any
>> > > >>>>>> in Keycloak. On the other hand, support for
>> other vault
>> > types can be
>> > > >>>>>> contributed as a Community Extension [2].
>> > > >>>>>>
>> > > >>>>>> --Hynek
>> > > >>>>>>
>> > > >>>>>> [1]
>> > > >>>>>>
>> > >
>> >
>> https://github.com/keycloak/keycloak-community/pull/18#discussion_r304860227
>> > > >>>>>> [2] https://www.keycloak.org/extensions.html
>> > > >>>>>>
>> > > >>>>>> On Mon, Aug 5, 2019 at 2:55 PM Pedro Igor Silva
>> > <psilva at redhat.com <mailto:psilva at redhat.com>
>> <mailto:psilva at redhat.com <mailto:psilva at redhat.com>>>
>> > > >>>>>> wrote:
>> > > >>>>>>
>> > > >>>>>>> Hi Sebastian,
>> > > >>>>>>>
>> > > >>>>>>> Elytron has a very powerful and flexible
>> Credential
>> > Store SPI
>> > > (Peter
>> > > >>>>>>> can
>> > > >>>>>>> give more details) that can help managing
>> credentials
>> > based on
>> > > keys.
>> > > >>>>>>> You
>> > > >>>>>>> could even use an implementation backed by a
>> java key
>> > store (with
>> > > >>>>>>> in-memory
>> > > >>>>>>> support).
>> > > >>>>>>>
>> > > >>>>>>> Wouldn't make sense to use it or at least
>> check how the
>> > design
>> > > could
>> > > >>>>>>> be
>> > > >>>>>>> improved to fit our requirements?
>> > > >>>>>>>
>> > > >>>>>>> Regards.
>> > > >>>>>>> Pedro Igor
>> > > >>>>>>>
>> > > >>>>>>> On Fri, Aug 2, 2019 at 6:39 AM Sebastian
>> Laskawiec <
>> > > >>>>>>> slaskawi at redhat.com
>> <mailto:slaskawi at redhat.com> <mailto:slaskawi at redhat.com
>> <mailto:slaskawi at redhat.com>>>
>> > > >>>>>>> wrote:
>> > > >>>>>>>
>> > > >>>>>>>> Hey,
>> > > >>>>>>>>
>> > > >>>>>>>> We are considering an initial, file-based
>> Vault [1]
>> > implementation
>> > > >>>>>>> that
>> > > >>>>>>>> we'll ship out of the box. I imagine a
>> minimum set of
>> > requirements
>> > > >>>>>>> as the
>> > > >>>>>>>> following:
>> > > >>>>>>>> - Easy to write by hand (for testing)
>> > > >>>>>>>> - Works out of the box in Kubernetes
>> (Kubernetes can
>> > mount Secrets
>> > > >>>>>>> as
>> > > >>>>>>>> files)
>> > > >>>>>>>> - Make sure we do not cache file content
>> anywhere, so
>> > we don't
>> > > >>>>>>> compromise a
>> > > >>>>>>>> secret value in Keycloak
>> > > >>>>>>>>
>> > > >>>>>>>> Essentially, there are two approaches for
>> such an
>> > implementation.
>> > > >>>>>>>>
>> > > >>>>>>>> The first option is to put all secrets into
>> a shared file
>> > > >>>>>>> representing
>> > > >>>>>>>> key-value pairs (a properties file is a natural
>> > candidate for such
>> > > >>>>>>> an
>> > > >>>>>>>> implementation). This approach very easy to
>> use but
>> > it's pretty
>> > > >>>>>>> hard to
>> > > >>>>>>>> search for a particular key in a file. We
>> would need to
>> > make sure
>> > > >>>>>>> that we
>> > > >>>>>>>> don't cache anything wile parsing the file (in
>> > BufferedInputStream
>> > > >>>>>>> for
>> > > >>>>>>>> example). Such an implementation would also
>> be pretty
>> > slow, since
>> > > >>>>>>> whenever
>> > > >>>>>>>> we'd access the vault for a particular key,
>> we would
>> > potentially
>> > > >>>>>>> need to
>> > > >>>>>>>> search the whole file.
>> > > >>>>>>>>
>> > > >>>>>>>> The second option is more complicated.
>> Imagine the
>> > following file
>> > > >>>>>>> structure
>> > > >>>>>>>> (inside a vault directory):
>> > > >>>>>>>> my-secret-1 (secret value in its content)
>> > > >>>>>>>> my-secret-2 (secret value in its content)
>> > > >>>>>>>> my-secret-3 (secret value in its content)
>> > > >>>>>>>> In other words, each key is a file in a
>> vault directory
>> > and its
>> > > >>>>>>> content
>> > > >>>>>>>> corresponds the secret value. Such an
>> implementation is
>> > not very
>> > > >>>>>>> easy to
>> > > >>>>>>>> use as we'd need to create many small files.
>> However,
>> > it's super
>> > > >>>>>>> fast for
>> > > >>>>>>>> searching and we can securely read the value
>> without a
>> > risk of
>> > > >>>>>>> compromising
>> > > >>>>>>>> other secret values provided by the vault.
>> > > >>>>>>>>
>> > > >>>>>>>> I wonder what do you think about this? My
>> personal take
>> > on this is
>> > > >>>>>>> that we
>> > > >>>>>>>> should provide both implementations. The
>> former (single
>> > file)
>> > > would
>> > > >>>>>>> be used
>> > > >>>>>>>> in our testsuite (because of simplicity) and
>> the latter
>> > (multiple
>> > > >>>>>>> files) in
>> > > >>>>>>>> production and in Kubernetes.
>> > > >>>>>>>>
>> > > >>>>>>>> Thanks,
>> > > >>>>>>>> Sebastian
>> > > >>>>>>>>
>> > > >>>>>>>> [1]
>> > > >>>>>>>>
>> > > >>>>>>>>
>> > > >>>>>>>
>> > >
>> >
>> https://github.com/keycloak/keycloak-community/blob/master/design/secure-credentials-store.md
>> > > >>>>>>>> _______________________________________________
>> > > >>>>>>>> keycloak-dev mailing list
>> > > >>>>>>>> keycloak-dev at lists.jboss.org
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>> <mailto:keycloak-dev at lists.jboss.org>>
>> > > >>>>>>>>
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>> > > >>>>>>>>
>> > > >>>>>>> _______________________________________________
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>> > > >>>>>>>
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>> > > >>>>>>>
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>>
>> --
>>
>> Stefan Guilhen
>>
>> Principal Software Engineer
>>
>> Red Hat<https://www.redhat.com/>
>>
>> sguilhen at redhat.com <mailto:sguilhen at redhat.com> IM: sguilhen
>>
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