Hi Ron, Thanks for the analysis, this is very useful. Reducing the feature to the minimum required for the scenarios helps (though I was hoping that the redact flag would one day help with improving SASL diagnostics, that can be for another day).
In the past when users requested different password storing mechanisms like in KIP-76, the main reason was to avoid storing clear passwords in a file. Now that we can store encrypted passwords in ZK, that is less of a motivation for SSL keystore passwords (at least on the broker-side). But integrating with external password vaults is perhaps still useful for SASL. But an important point is that none of the built-in substitution mechanisms helps with this security requirement. Colin had suggested that it would be better to do this type of substitution outside of Kafka, e.g. using scripts. So if we can store encrypted passwords in ZooKeeper, users can write scripts to extract passwords from their favourite password vault and store them encrypted in ZK, do we still need substitution? I think there are two use cases for SASL: 1. Client configuration (Producer/Consumer/AdminClient) 2. Dynamic password updates with caching (as you mentioned) for both clients and brokers Looking at only SASL, we can do 1) with SASL callback handlers (KIP-86) for both clients and brokers. Callback handlers can do 2) as well. On the broker-side, as you mentioned, dynamic configs in ZK would be better for 2) (we don't currently support changing SASL configs for existing listeners, but eventually we probably would). So if we assume that SSL passwords can be handled by encrypted passwords in ZK, SASL/PLAIN and SCRAM can be handled by callback handlers, can we narrow down the OAuth scenarios that really benefit from substitution? Do we need specific built-in substitution mechanisms for these scenarios given that any built-in substitution mechanism would be inherently insecure? Do we have to support custom substitution mechanisms for these? Perhaps an example would help since most of us are not that familiar with the different OAuth options and you have already thought this through in the context of OAuth? Once we identify what we need for OAuth, we could go back and look at whether this would also help other SASL mechanisms, SSL passwords, other configs etc. Thank you, Rajini On Sun, Apr 15, 2018 at 3:54 AM, Ron Dagostino <rndg...@gmail.com> wrote: > I am unsure if substitution should be supported for just JAAS configs or if > we should allow it for cluster/broker/consumer configs. What I think would > be helpful would be to boil down this proposal to its most essential > requirement, and I think the discussion has helped us arrive at what that > looks like: an ability to inject secrets from external sources. > SASL/OAUTHBEARER (KIP 255) requires this, and there is value for other SASL > mechanisms at the JAAS config level as described in this KIP. If we focus > on just this functionality, and keep in mind the feedback about > configuration getting out of hand, then we likely arrive at the following > conclusions: > > - *If* we allow substitution in producer/consumer/broker configs (and > again, I am not sure if this is a good idea yet) then we would only > allow > it for configs of type Password (which includes sasl.jaas.config); since > these are by definition sensitive values, it is redundant to specify > redact, and therefore redact is no longer needed as an explicit modifier > -- it is always in effect. > - We can and should eliminate dependencies by removing the ability to > refer to another configuration value; this means defaultKey and > fromValueOfKey are no longer needed as modifiers, and the keyValue > substitution type goes away. > - It doesn't seem reasonable to allow an empty or blank secret to be > injected, which means notBlank and notEmpty are redundant and > unnecessary modifiers. > - A default value wouldn't seem to make sense with secret injection, so > we don't need the defaultValue modifier. > > There are still some outstanding issues. > > Are substituted values cached (and if so, for how long?) or are they > recalculated each time they are requested? For example, if a password > comes from some external source (file, password vault, etc.), is that > external source queried every time the password is required, or is queried > once and then always reused, or is it queried once and then reused for some > amount of time before the external source is queried again? Compare this > to dynamic configuration as implemented via KIP 226, which is a > push/event-driven mechanism via kafka-configs.sh, Zookeeper, and the > Reconfigurable interface. Changes to substituted values as proposed in > this KIP are not push/event-driven; as proposed it will be up to Kafka to > somehow check for changes, or to set a cache timeout as described above. > This is clearly inferior to the push/event-driven mechanism provided by > dynamic configuration, and I am not sure what to do with that statement, > but there it is. SASL/OAUTHBEARER requires flexibility due to the flexible > nature of the OAuth 2 framework, and I can't imagine forcing the use of > dynamic configuration for secret injection on SASL/OAUTHBEARER > implementations (or for the SASL/PLAIN password use case taken as > motivation for this KIP). But should we provide a mechanism at the > producer/consumer/broker configuration level that is not push/event-driven > given that dynamic configuration is push/event-driven? Maybe there is > value in retrieving the password.encoder.secret and > password.encoder.old.secret values via substitution. Maybe there is also > value in supporting substitution for producer/consumer/broker configs that > are of type Password despite the fact that they can be managed > dynamically. I don't know. > > Anyway, I think this feature can be boiled down to its essentials as > described above, and the last steps are to decide if the feature should be > used at the producer/consumer/broker config level or not; what supported > mechanisms should exist out-of-the-box (file? environment variable? > system property?); and whether we should allow the addition of > custom-written substitution types. > > Ron > > > On Sat, Apr 14, 2018 at 12:18 AM, Manikumar <manikumar.re...@gmail.com> > wrote: > > > We can limit substitution mechanism only for password config types and > JAAS > > config. > > We may not want to use to for all config properties. > > > > On Sat, Apr 14, 2018 at 9:21 AM, Colin McCabe <cmcc...@apache.org> > wrote: > > > > > On Fri, Apr 13, 2018, at 10:30, Rajini Sivaram wrote: > > > > Hi Colin, > > > > > > > > JAAS configuration can be provided in a separate file, but that has > > been > > > > the cause of various problems in itself. The configuration option > > > > `sasl.jaas.config` was added to overcome this. This is already a > > dynamic > > > > configuration option stored in ZooKeeper since we allow listeners to > be > > > > added dynamically. Going forward, the property should be the > preferred > > > way > > > > to configure SASL. I don't think we should allow any form of > > > configuration > > > > substitutions for JAAS that don't make sense for regular configs. And > > if > > > we > > > > are going to have a substitution mechanism, e.g. for password > configs, > > > then > > > > it makes sense to allow for SSL as well as SASL. > > > > > > > > So the question really is what forms of substitution, if any, make > > > sense. I > > > > agree that use of system properties and environment variables are > not a > > > > good idea, but should references to files be allowed? Sounds like > that > > > is a > > > > bad idea too from your experience. Does it make sense to have a > > > extensible > > > > substitution mechanism to allow users to integrate with password > vaults > > > or > > > > other sources of config values? > > > > > > Hmm. It seems like in order to authenticate with any kind of password > > > vault, you would need a JAAS configuration, right? So you can't really > > > store your JAAS config in a password vault, although there may be other > > > things you could usefully store there. That's why I think JAAS really > > is a > > > special case here, worth considering separately. Storing your private > > key > > > in a local file seems like a reasonable idea; storing the value of > > > max.poll.records in a file does not seem that useful or reasonable. > > > > > > best, > > > Colin > > > > > > > > > > > > > > > On Fri, Apr 13, 2018 at 5:56 PM, Colin McCabe <cmcc...@apache.org> > > > wrote: > > > > > > > > > I think we need to be a very careful here. Configuration > complexity > > > can > > > > > get out of control very quickly. There are also some conflicting > > goals > > > > > here. > > > > > > > > > > As much as possible, we want the configuration to be a full > > > description of > > > > > what the broker is going to do. If the configuration pulls in > > > environment > > > > > variables, system properties, local files, or other aspects of the > > > local > > > > > system environment, it is no longer a complete description of what > > the > > > > > broker is going to do. Instead, you have to know about the full > UNIX > > > > > environment to understand what is going on. This makes deployments > > > less > > > > > repeatable and will lead to hard-to-track-down problems if one node > > > has a > > > > > different set of environment variables than the others, etc. > > > > > > > > > > We want it to be easy to roll out a new configuration to all > brokers > > > > > without restarting them all. We should expect that in the future, > > > more and > > > > > more configurations will be KIP-226 style dynamic configurations > that > > > are > > > > > stored in ZooKeeper and centrally rolled out to all brokers > without a > > > > > restart. If we have to restart processes with different > environment > > or > > > > > system properties, or change local files, in order to reconfigure, > we > > > can't > > > > > accomplish this goal. As much as possible, the centrally managed > > > > > configurations should not refer to local system properties. > > > > > > > > > > Configurations should be loaded efficiently. But if loading the > > > > > configuration requires opening and reading local files, it could > get > > > > > extremely slow. I saw this problem firsthand in Hadoop, where > > invoking > > > > > "new Configuration()" causes dozens of XML files to be loaded and > > > parsed. > > > > > Also, keep in mind that things other than the broker need to load > > > > > configurations. Every client and every tool needs to perform the > > same > > > > > process. > > > > > > > > > > If configuration keys can reference and include other configuration > > > keys, > > > > > renaming or deprecating something becomes even harder than it is > now. > > > And > > > > > if one configuration key changes because it is a dynamic > > configuration > > > key, > > > > > should all the configuration keys that included that one change as > > > well? > > > > > This feature simply doesn't work well with our other features. > > > > > > > > > > It seems like most of these problems can be solved better and more > > > easily > > > > > outside Kafka. For example, it's straightforward to write a bash > > > script > > > > > that examines some environment variables, constructs a Kafka > > > configuration > > > > > file and then runs the Kafka broker with that file. This also > makes > > it > > > > > straightforward to set configuration keys in tandem, if that's what > > you > > > > > want. > > > > > > > > > > I think we should focus just on what JAAS needs, which seems very > > > > > different than what other configurations need. In the specific > case > > of > > > > > JAAS, it makes sense to consider loading stuff from a separate > file, > > to > > > > > avoid having credentials stored in the properties file. (But I > > > thought we > > > > > already had a way to do that?) > > > > > > > > > > best, > > > > > Colin > > > > > > > > > > > > > > > On Fri, Apr 13, 2018, at 07:16, Rajini Sivaram wrote: > > > > > > Hi Ron, > > > > > > > > > > > > I think we should be able to process substitutions for both > static > > > JAAS > > > > > > configuration file as well as `sasl.jaas.config` property. We > load > > > the > > > > > > configuration using org.apache.kafka.common.security. > > > > > > JaasContext.loadXXXContext() and that would be a good place to do > > any > > > > > > substitution. The method has access to the > producer/consumer/broker > > > > > configs > > > > > > as well in case we want keys to refer to these. > > > > > > > > > > > > On Fri, Apr 13, 2018 at 2:15 PM, Ron Dagostino < > rndg...@gmail.com> > > > > > wrote: > > > > > > > > > > > > > Hi Rajini. Regarding processing the sasl.jaas.config value > > > up-front, > > > > > there > > > > > > > are a couple of things that occur to me about it. First, the > > older > > > > > way of > > > > > > > storing the JAAS config in a separate file is still supported > > (and > > > is > > > > > at > > > > > > > this time the prevalent mechanism on the broker side since > > > > > sasl.jaas.config > > > > > > > support for brokers was only recently added via KIP 226). We > > could > > > > > state > > > > > > > that substitution is only supported via sasl.jaas.config and > > force > > > > > people > > > > > > > to convert over to get substitution functionality, but that > > > wouldn't be > > > > > > > necessary if we let the login module do the substitution later > > on. > > > > > > > > > > > > > > The second thing that occurs to me is related to namespacing > and > > > > > creates > > > > > > > tension with the first point above. If we refer to the "fubar" > > > key in > > > > > the > > > > > > > config, is that key a JAAS module option or is it a value in > the > > > > > > > cluster/producer/consumer config? It would be very positive if > > we > > > > > could > > > > > > > eliminate namespacing entirely such that when you reference > > another > > > > > key it > > > > > > > is always very clear what is being referred to -- i.e. always a > > > key in > > > > > the > > > > > > > cluster/producer/consumer config. Otherwise the docs have to > > > spell out > > > > > > > when it is one versus the other. > > > > > > > > > > > > > > That is a good point about being able to provide substitution > > > support > > > > > to > > > > > > > SASL/GSSAPI (which relies upon login module code that we do not > > > > > control) if > > > > > > > we choose the simple, consistent way of doing things up front. > > > > > > > > > > > > > > You asked if there are OAuth use cases that require > substitutions > > > to be > > > > > > > performed in a login module that cannot be done if the > > > substitution is > > > > > > > performed when the configuration is parsed. I don't think so, > > no; > > > the > > > > > > > timing should not matter. > > > > > > > > > > > > > > I hadn't thought about the listener prefix issue. I don't know > > > that > > > > > area > > > > > > > of the code very well, but I have looked enough to guess that > the > > > > > > > underlying "originals" map in AbstractConfig is what we would > > want > > > to > > > > > use > > > > > > > when making a reference to something. It would eliminate the > > > listener > > > > > > > prefix namespacing confusion if we always refer to the key as > > > > > originally > > > > > > > provided. > > > > > > > > > > > > > > I'm willing to go with doing substitution once, up-front, at > the > > > > > > > cluster/producer/consumer config level, and supporting > > > substitution for > > > > > > > JAAS configs only when provided via sasl.jaas.config. I'm > > willing > > > to > > > > > try > > > > > > > the coding to introduce it at that level -- tentative given my > > > > > > > unfamiliarity with the code and its subtleties, but willing to > > try. > > > > > Let me > > > > > > > chew on it for a day or two and see what I can make happen. In > > > case > > > > > you > > > > > > > want to try as well, you can pull the current implementation > > > (which I > > > > > think > > > > > > > is in good shape and might only need cosmetic/stylistic code > > review > > > > > changes > > > > > > > as opposed to wholesale API adjustments) from the KAFKA-6664 > > > branch of > > > > > > > https://github.com/rondagostino/kafka.git. > > > > > > > > > > > > > > Ron > > > > > > > > > > > > > > On Fri, Apr 13, 2018 at 7:49 AM, Rajini Sivaram < > > > > > rajinisiva...@gmail.com> > > > > > > > wrote: > > > > > > > > > > > > > > > Hi Ron, > > > > > > > > > > > > > > > > Thanks for the notes and KIP update. > > > > > > > > > > > > > > > > Handling `sasl.jaas.config` as a special case is fine, but it > > > would > > > > > be > > > > > > > > better if we can do any substitutions before we create a > > > > > `Configuration` > > > > > > > > object rather than expect the login module to do the > > > substitution. > > > > > That > > > > > > > > way, we will have a consistent substitution format for all > > login > > > > > modules > > > > > > > > including built-in ones. And since we have users who already > > have > > > > > their > > > > > > > own > > > > > > > > login modules (before KIP-86), they will benefit from > > > substitution > > > > > too > > > > > > > > without adding additional code to the login module, But you > > have > > > > > thought > > > > > > > > about this more in the context of OAuth, so this is more of a > > > > > question. > > > > > > > Are > > > > > > > > there use cases that require substitutions to be performed > in a > > > login > > > > > > > > module that cannot be done if the substitution is performed > > when > > > the > > > > > > > > configuration is parsed? > > > > > > > > > > > > > > > > The ability to refer to other keys is generally quite useful. > > > But as > > > > > you > > > > > > > > said, "*there is a namespacing of sorts going on*". Even with > > > regular > > > > > > > > configs, we have listener prefix, which is also a > "*namespacing > > > of > > > > > > > sorts"*. > > > > > > > > Our current config framework doesn't represent these well. As > > you > > > > > already > > > > > > > > noticed before, there is magic that removes prefixes, > > flattening > > > the > > > > > > > > namespace. Perhaps that is not an issue if we want to allow > > > > > references to > > > > > > > > keys that are in the global namespace (non-listener-prefixed) > > as > > > > > well. > > > > > > > But > > > > > > > > we probably want to make sure namespaces are handled > > consistently > > > > > for ` > > > > > > > > sasl.jaas.config` and other configs. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Tue, Apr 10, 2018 at 3:41 AM, Ron Dagostino < > > > rndg...@gmail.com> > > > > > > > wrote: > > > > > > > > > > > > > > > > > Hi folks. I updated KIP 269 to help clarify some of the > > issues > > > > > > > mentioned > > > > > > > > > previously. In particular, I added a new single-method > > > > > > > UnderlyingValues > > > > > > > > > interface to make it clear how data is to be provided to > > > > > > > > > SubstitutableValues, and I added information about if/how > the > > > > > > > underlying > > > > > > > > > values might be re-read in case they can potentially change > > > > > (basically > > > > > > > an > > > > > > > > > instance of SubstitutableValues never re-reads anything, so > > if > > > the > > > > > > > > > underlying values are expected to change a new instance of > > > > > > > > > SubstitutableValues must be allocated in order to have any > > > chance > > > > > of > > > > > > > > seeing > > > > > > > > > those changes). I kept the KIP focused on the same JAAS > use > > > case > > > > > for > > > > > > > > now, > > > > > > > > > but these additions/clarifications should help if we want > to > > > > > expand the > > > > > > > > > scope to cluster/producer/consumer configs. > > > > > > > > > > > > > > > > > > Ron > > > > > > > > > > > > > > > > > > On Mon, Apr 9, 2018 at 11:22 AM, Ron Dagostino < > > > rndg...@gmail.com> > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > Hi folks. Here is a summary of where I think we stand on > > > this > > > > > KIP > > > > > > > and > > > > > > > > > > what I believe it means for how we move forward. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > - There is some desire to use substitution more > broadly > > > beyond > > > > > > > just > > > > > > > > > > JAAS module options. Specifically, > > > cluster/producer/consumer > > > > > > > config > > > > > > > > > values > > > > > > > > > > such as ssl.keystore.password are places where > > > substitution > > > > > adds > > > > > > > > value > > > > > > > > > > (dormant KIP 76 > > > > > > > > > > <https://cwiki.apache.org/conf > luence/display/KAFKA/KIP- > > > > > > > > > 76+Enable+getting+password+from+executable+rather+than+ > > > > > > > > > passing+as+plaintext+in+config+files> > > > > > > > > > > was an attempt to add value here in the past). > > > > > > > > > > - *More broad review of this KIP is needed given the > > > > > potential for > > > > > > > > its > > > > > > > > > > expanded scope* > > > > > > > > > > - If substitution is applied more broadly, then the > > > > > > > sasl.jaas.config > > > > > > > > > > value should not have substitution performed on it at > > the > > > same > > > > > > > times > > > > > > > > > as > > > > > > > > > > other cluster/producer/consumer configs; that value > > > should be > > > > > > > passed > > > > > > > > > > unchanged to the login module where substitution can > be > > > > > applied > > > > > > > > later. > > > > > > > > > > - There are some adjustments to this KIP that should > be > > > made > > > > > to > > > > > > > > > > reflect the possibility of more broad use: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > 1. The use of delimiters that trigger a substitution > > > attempt > > > > > but > > > > > > > > that > > > > > > > > > > fail to parse should result in the text being > passed > > > > > through > > > > > > > > > unchanged > > > > > > > > > > instead of raising an exception > > > > > > > > > > 2. The application of substitution should generally > > be > > > on > > > > > an > > > > > > > > opt-in > > > > > > > > > > basis > > > > > > > > > > 3. The implicit fact that substitution was > associated > > > with > > > > > a > > > > > > > > > > namespace of sorts (i.e. saying that a default came > > > from a > > > > > > > > > particular key > > > > > > > > > > meant a JAAS module option) needs to be made > > > explicit. The > > > > > > > > > namespace is > > > > > > > > > > defined by the Map that is passed into the > > > > > > > SubstitutableValues() > > > > > > > > > constructor > > > > > > > > > > 4. It is not clear to me if the Map that is passed > > > into the > > > > > > > > > > SubstitutableValues() constructor can be relied > upon > > to > > > > > contain > > > > > > > > > only String > > > > > > > > > > values in the context of cluster/producer/consumer > > > configs. > > > > > > > The > > > > > > > > > > AbstractConfig's so-called "originals" map seems to > > > support > > > > > > > > values > > > > > > > > > of type > > > > > > > > > > String, Boolean, Password, Integer, Short, Long, > > > Number, > > > > > List, > > > > > > > > and > > > > > > > > > Class. > > > > > > > > > > It is not difficult to support non-String values in > > > the Map > > > > > > > that > > > > > > > > > is passed > > > > > > > > > > to the SubstitutableValues() constructor, so I can > > > > > explicitly > > > > > > > add > > > > > > > > > support > > > > > > > > > > for that. > > > > > > > > > > > > > > > > > > > > I don't think these changes impact usage in a JAAS > context, > > > so > > > > > they > > > > > > > do > > > > > > > > no > > > > > > > > > > harm to the original use case while increasing the > > potential > > > for > > > > > more > > > > > > > > > broad > > > > > > > > > > use of the concept. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Ron > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Sun, Apr 8, 2018 at 8:46 PM, Ron Dagostino < > > > rndg...@gmail.com > > > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > >> Hi Rajini. I've also been thinking about how > > > sasl.jaas.config > > > > > will > > > > > > > be > > > > > > > > > >> parsed. Something that is implicit in the current > > proposal > > > > > needs to > > > > > > > > be > > > > > > > > > >> made explicit if this is to be applied more broadly, and > > > that > > > > > is the > > > > > > > > > fact > > > > > > > > > >> that there is a namespacing of sorts going on. For > > > example, in > > > > > the > > > > > > > > > current > > > > > > > > > >> proposal, when you indicate that you want to somehow > refer > > > to > > > > > > > another > > > > > > > > > value > > > > > > > > > >> (via defaultKey=<key> or fromValueOfKey) then the key > > being > > > > > referred > > > > > > > > to > > > > > > > > > is > > > > > > > > > >> taken as a JAAS module option name. If we allow > > > substitution > > > > > at the > > > > > > > > > >> cluster/producer/consumer config level then within the > > > context > > > > > of > > > > > > > > > >> something like ssl.keystore.password any such key being > > > > > referred to > > > > > > > > > >> would be a cluster/producer/consumer config key. But I > > > think > > > > > within > > > > > > > > the > > > > > > > > > >> context of sasl.jaas.config any key reference should > still > > > be > > > > > > > > referring > > > > > > > > > >> to a JAAS module option. I think sasl.jaas.config would > > > need > > > > > to be > > > > > > > > > >> special-cased in the sense that its value would not have > > > > > > > substitution > > > > > > > > > >> applied to it up front but instead would have > substitution > > > > > applied > > > > > > > to > > > > > > > > it > > > > > > > > > >> later on. In other words, the login module would be > where > > > the > > > > > > > > > substitution > > > > > > > > > >> logic is applied. Note that we re-use an existing > > kerberos > > > > > login > > > > > > > > > module, > > > > > > > > > >> so we do not control that code and cannot apply > > substitution > > > > > logic > > > > > > > > > there, > > > > > > > > > >> so I think the statement regarding if/how > sasl.jaas.config > > > (or > > > > > any > > > > > > > > JAAS > > > > > > > > > >> configuration file) is processed with respect to > > > substitution > > > > > is to > > > > > > > > say > > > > > > > > > >> that it is determined by the login module. > > > > > > > > > >> > > > > > > > > > >> I think the chances of an unintended substitution > > > accidentally > > > > > > > parsing > > > > > > > > > >> correctly is pretty close to zero, but making > substitution > > > an > > > > > opt-in > > > > > > > > > means > > > > > > > > > >> the possibility -- regardless of how small it might be > -- > > > will > > > > > be > > > > > > > > > >> explicitly acknowledged. I think that makes it fine. > > > > > > > > > >> > > > > > > > > > >> I suspect you are right that adding substitution into > > > > > > > > > cluster/producer/consumer > > > > > > > > > >> configs will require careful code changes given how > > configs > > > are > > > > > > > > > >> currently implemented. I will take a closer look to see > > > how it > > > > > > > might > > > > > > > > be > > > > > > > > > >> done; if it isn't obvious to me then perhaps it would be > > > best to > > > > > > > split > > > > > > > > > that > > > > > > > > > >> change out into a separate JIRA issue so that someone > with > > > more > > > > > > > > > experience > > > > > > > > > >> with that part of the code can do it. But I'll still > > take a > > > > > look > > > > > > > just > > > > > > > > > in > > > > > > > > > >> case I can see how it should be done. > > > > > > > > > >> > > > > > > > > > >> I agree that the OAuth callback handler that needs to be > > > written > > > > > > > > anyway > > > > > > > > > >> could simply go out and talk directly to a password > vault. > > > With > > > > > > > > > >> substitution as an option, though, the callback handler > > can > > > > > just ask > > > > > > > > for > > > > > > > > > >> the value from a JAAS module option, and then whether > that > > > goes > > > > > out > > > > > > > > to a > > > > > > > > > >> password vault or not would be up to how the app is > > > > > configured. I > > > > > > > > think > > > > > > > > > >> the ability to encapsulate the actual mechanism behind a > > > module > > > > > > > option > > > > > > > > > is > > > > > > > > > >> valuable. > > > > > > > > > >> > > > > > > > > > >> Ron > > > > > > > > > >> > > > > > > > > > >> On Sun, Apr 8, 2018 at 4:47 AM, Rajini Sivaram < > > > > > > > > rajinisiva...@gmail.com > > > > > > > > > > > > > > > > > > > >> wrote: > > > > > > > > > >> > > > > > > > > > >>> Hi Ron, > > > > > > > > > >>> > > > > > > > > > >>> Thanks for the responses. > > > > > > > > > >>> > > > > > > > > > >>> For broader use as configs, opt-in makes sense to avoid > > any > > > > > > > surprises > > > > > > > > > >>> and a > > > > > > > > > >>> global opt-in ought to be fine. > > > > > > > > > >>> > > > > > > > > > >>> If we do want to use this for all configs, a few things > > to > > > > > > > consider: > > > > > > > > > >>> > > > > > > > > > >>> - How will sasl.jaas.config property will get > parsed? > > > This > > > > > is > > > > > > > > > >>> essentially a compound config which may contain some > > > options > > > > > > > that > > > > > > > > > are > > > > > > > > > >>> substitutable. Will it be possible to handle this > and > > > static > > > > > > > JAAS > > > > > > > > > >>> configuration files in the same way? > > > > > > > > > >>> - At the moment I think the whole option is redacted > > if > > > one > > > > > > > > > >>> substitution > > > > > > > > > >>> is marked redact. Would it make sense to define > values > > > that > > > > > > > > consist > > > > > > > > > of > > > > > > > > > >>> some redactable components. I am thinking of > > > > > sasl.jaas.config > > > > > > > as a > > > > > > > > > >>> single property, but perhaps treating this alone > > > separately > > > > > is > > > > > > > > good > > > > > > > > > >>> enough. > > > > > > > > > >>> - If we did treat failed substitutions as pass-thru, > > > would > > > > > it > > > > > > > > cover > > > > > > > > > >>> all > > > > > > > > > >>> cases, or do we also need to be concerned about > valid > > > > > > > > substitutions > > > > > > > > > >>> that > > > > > > > > > >>> weren't intended to be substitutions? I am thinking > > > that we > > > > > > > don't > > > > > > > > > >>> need to > > > > > > > > > >>> worry about the latter if substitutions are only by > > > opt-in. > > > > > > > > > >>> - It will be good to get more feedback on this KIP > > > before > > > > > > > updating > > > > > > > > > the > > > > > > > > > >>> code to use it for all configs since the code may > need > > > to > > > > > change > > > > > > > > > >>> quite a > > > > > > > > > >>> bit to fit in with the config classes. > > > > > > > > > >>> > > > > > > > > > >>> > > > > > > > > > >>> For the callbacks, I agree that we want a LoginModule > for > > > OAuth > > > > > > > that > > > > > > > > > can > > > > > > > > > >>> be > > > > > > > > > >>> reused. But to use OAuth, you will probably have your > own > > > > > callback > > > > > > > > > >>> handler > > > > > > > > > >>> implementation to process OAuthBearerLoginCallback . > From > > > the > > > > > > > > example, > > > > > > > > > it > > > > > > > > > >>> is not clear to me why the callback handler that > > processes > > > > > > > > > >>> OAuthBearerLoginCallback cannot do whatever a custom > > > > > substitution > > > > > > > > class > > > > > > > > > >>> would do, e,g. read some options like passwordVaultUrl > > > from the > > > > > > > JAAS > > > > > > > > > >>> config > > > > > > > > > >>> (which it has access to) and retrieve passwords from a > > > password > > > > > > > > vault? > > > > > > > > > If > > > > > > > > > >>> we are going to have extensible substitution anyway, > then > > > > > > > obviously, > > > > > > > > we > > > > > > > > > >>> could use that as an option here too. > > > > > > > > > >>> > > > > > > > > > >>> > > > > > > > > > >>> > > > > > > > > > >>> On Fri, Apr 6, 2018 at 2:47 PM, Ron Dagostino < > > > > > rndg...@gmail.com> > > > > > > > > > wrote: > > > > > > > > > >>> > > > > > > > > > >>> > Hi folks. I think there are a couple of issues that > > were > > > > > just > > > > > > > > raised > > > > > > > > > >>> in > > > > > > > > > >>> > this thread. One is whether the ability to use > > > > > PasswordCallback > > > > > > > > > >>> exists, > > > > > > > > > >>> > and if so whether that impacts the applicability of > > this > > > KIP > > > > > to > > > > > > > the > > > > > > > > > >>> > SASL/OAUTHBEARER KIP-255. The second issue is > related > > to > > > > > how we > > > > > > > > > might > > > > > > > > > >>> > leverage this KIP more broadly (including as an > > > alternative > > > > > to > > > > > > > > > KIP-76) > > > > > > > > > >>> > while maintaining forward compatibility and not > causing > > > > > > > unexpected > > > > > > > > > >>> > substitutions/parsing exceptions. > > > > > > > > > >>> > > > > > > > > > > >>> > Let me address the second issue (more broad use) > first, > > > > > since I > > > > > > > > think > > > > > > > > > >>> > Rajini hit on a good possibility. Currently this KIP > > > > > addresses > > > > > > > the > > > > > > > > > >>> > possibility of an unexpected substitution by saying > > "This > > > > > would > > > > > > > > > cause a > > > > > > > > > >>> > substitution to be attempted, which of course would > > fail > > > and > > > > > > > raise > > > > > > > > an > > > > > > > > > >>> > exception." I think Rajini's idea is to explicitly > > state > > > > > that > > > > > > > any > > > > > > > > > >>> > substitution that cannot be parsed is to be treated > as > > a > > > > > > > pass-thru > > > > > > > > > or a > > > > > > > > > >>> > no-op. So, for example, if a configured password > > > happened to > > > > > > > look > > > > > > > > > like > > > > > > > > > >>> > "Asd$[,mhsd_4]Q" and a substitution was attempted on > > that > > > > > value > > > > > > > > then > > > > > > > > > >>> the > > > > > > > > > >>> > result should not be an exception simply because > > > "$[,mhsd_4]" > > > > > > > > > couldn't > > > > > > > > > >>> be > > > > > > > > > >>> > parsed according to the required delimited syntax but > > > should > > > > > > > > instead > > > > > > > > > >>> just > > > > > > > > > >>> > end up doing nothing and the password would > > > > > > > remain"Asd$[,mhsd_4]Q". > > > > > > > > > >>> > Rajini, do I have that right? If so, then I think it > > is > > > > > worth > > > > > > > > > >>> considering > > > > > > > > > >>> > the possibility that substitution could be turned on > > more > > > > > broadly > > > > > > > > > with > > > > > > > > > >>> an > > > > > > > > > >>> > acceptably low risk. In the interest of caution > > > substitution > > > > > > > could > > > > > > > > > >>> still > > > > > > > > > >>> > be turned on only as an opt-in, but it could be a > > global > > > > > opt-in > > > > > > > if > > > > > > > > we > > > > > > > > > >>> > explicitly take a "do no harm" approach to things > that > > > have > > > > > > > > > delimiters > > > > > > > > > >>> but > > > > > > > > > >>> > do not parse as valid substitutions. > > > > > > > > > >>> > > > > > > > > > > >>> > Regarding whether the ability to use PasswordCallback > > > exists > > > > > in > > > > > > > > > >>> > SASL/OAUTHBEARER KIP-255, I don't think it does. The > > > reason > > > > > is > > > > > > > > > because > > > > > > > > > >>> > customers do not generally write the login module > > > > > implementation; > > > > > > > > > they > > > > > > > > > >>> use > > > > > > > > > >>> > the implementation provided, which is short and > > > delegates the > > > > > > > token > > > > > > > > > >>> > retrieval to the callback handler (which users are > > > expected > > > > > to > > > > > > > > > >>> provide). > > > > > > > > > >>> > Here is the login module code: > > > > > > > > > >>> > > > > > > > > > > >>> > @Override > > > > > > > > > >>> > public boolean login() throws LoginException { > > > > > > > > > >>> > OAuthBearerLoginCallback callback = new > > > > > > > > > >>> OAuthBearerLoginCallback(); > > > > > > > > > >>> > try { > > > > > > > > > >>> > this.callbackHandler.handle(new > Callback[] > > > > > > > > {callback}); > > > > > > > > > >>> > } catch (IOException | > > > UnsupportedCallbackException > > > > > e) { > > > > > > > > > >>> > log.error(e.getMessage(), e); > > > > > > > > > >>> > throw new LoginException("An internal > error > > > > > > > occurred"); > > > > > > > > > >>> > } > > > > > > > > > >>> > token = callback.token(); > > > > > > > > > >>> > if (token == null) { > > > > > > > > > >>> > log.info(String.format("Login failed: > %s : > > > %s > > > > > > > > (URI=%s)", > > > > > > > > > >>> > callback.errorCode(), callback.errorDescription(), > > > > > > > > > >>> > callback.errorUri())); > > > > > > > > > >>> > throw new LoginException(callback. > > > > > > > errorDescription()); > > > > > > > > > >>> > } > > > > > > > > > >>> > log.info("Login succeeded"); > > > > > > > > > >>> > return true; > > > > > > > > > >>> > } > > > > > > > > > >>> > > > > > > > > > > >>> > I don't see the callbackHandler using a > > PasswordCallback > > > > > instance > > > > > > > > to > > > > > > > > > >>> ask > > > > > > > > > >>> > (itself?) to retrieve a password. If the > > callbackHandler > > > > > needs a > > > > > > > > > >>> password, > > > > > > > > > >>> > then I imagine it will get that password from a login > > > module > > > > > > > > option, > > > > > > > > > >>> and > > > > > > > > > >>> > that could in turn come from a file, environment > > > variable, > > > > > > > password > > > > > > > > > >>> vault, > > > > > > > > > >>> > etc. if substitution is applicable. > > > > > > > > > >>> > > > > > > > > > > >>> > Ron > > > > > > > > > >>> > > > > > > > > > > >>> > > > > > > > > > > >>> > > > > > > > > > > >>> > On Fri, Apr 6, 2018 at 4:41 AM, Rajini Sivaram < > > > > > > > > > >>> rajinisiva...@gmail.com> > > > > > > > > > >>> > wrote: > > > > > > > > > >>> > > > > > > > > > > >>> > > Yes, I was going to suggest that we should do this > > for > > > all > > > > > > > > configs > > > > > > > > > >>> > earlier, > > > > > > > > > >>> > > but was reluctant to do that since in its current > > form, > > > > > there > > > > > > > is > > > > > > > > a > > > > > > > > > >>> > > property enableSubstitution > > > > > > > > > >>> > > (in JAAS config at the moment) that indicates if > > > > > substitution > > > > > > > is > > > > > > > > to > > > > > > > > > >>> be > > > > > > > > > >>> > > performed. If enabled, all values in that config > are > > > > > considered > > > > > > > > for > > > > > > > > > >>> > > substitution. That works for JAAS configs with a > > small > > > > > number > > > > > > > of > > > > > > > > > >>> > > properties, but I wasn't sure it was reasonable to > do > > > this > > > > > for > > > > > > > > all > > > > > > > > > >>> Kafka > > > > > > > > > >>> > > configs where there are several configs that may > > > contain > > > > > > > > arbitrary > > > > > > > > > >>> > > characters including substitution delimiters. It > will > > > be > > > > > good > > > > > > > if > > > > > > > > > some > > > > > > > > > >>> > > configs that contain arbitrary characters can be > > > specified > > > > > > > > directly > > > > > > > > > >>> in > > > > > > > > > >>> > the > > > > > > > > > >>> > > config while others are substituted from elsewhere. > > > > > Perhaps a > > > > > > > > > >>> > substitution > > > > > > > > > >>> > > type that simply uses the value within delimiters > > would > > > > > work? > > > > > > > > Ron, > > > > > > > > > >>> what > > > > > > > > > >>> > do > > > > > > > > > >>> > > you think? > > > > > > > > > >>> > > > > > > > > > > > >>> > > > > > > > > > > > >>> > > > > > > > > > > > >>> > > On Fri, Apr 6, 2018 at 7:49 AM, Manikumar < > > > > > > > > > manikumar.re...@gmail.com > > > > > > > > > >>> > > > > > > > > > > >>> > > wrote: > > > > > > > > > >>> > > > > > > > > > > > >>> > > > Hi, > > > > > > > > > >>> > > > > > > > > > > > > >>> > > > Substitution mechanism can be useful to configure > > > regular > > > > > > > > > password > > > > > > > > > >>> > > configs > > > > > > > > > >>> > > > liken ssl.keystore.password, > > ssl.truststore.password, > > > > > etc. > > > > > > > > > >>> > > > This is can be good alternative to previously > > > proposed > > > > > KIP-76 > > > > > > > > and > > > > > > > > > >>> will > > > > > > > > > >>> > > give > > > > > > > > > >>> > > > more options to the user. > > > > > > > > > >>> > > > > > > > > > > > > >>> > > > https://cwiki.apache.org/confl > > > uence/display/KAFKA/KIP- > > > > > > > > > >>> > > > 76+Enable+getting+password+fro > > > m+executable+rather+than+ > > > > > > > > > >>> > > > passing+as+plaintext+in+config+files > > > > > > > > > >>> > > > > > > > > > > > > >>> > > > > > > > > > > > > >>> > > > Thanks, > > > > > > > > > >>> > > > > > > > > > > > > >>> > > > On Fri, Apr 6, 2018 at 4:29 AM, Rajini Sivaram < > > > > > > > > > >>> > rajinisiva...@gmail.com> > > > > > > > > > >>> > > > wrote: > > > > > > > > > >>> > > > > > > > > > > > > >>> > > > > Hi Ron, > > > > > > > > > >>> > > > > > > > > > > > > > >>> > > > > For the password example, you could define a > > login > > > > > > > > > >>> CallbackHandler > > > > > > > > > >>> > that > > > > > > > > > >>> > > > > processes PasswordCallback to provide > passwords. > > We > > > > > don't > > > > > > > > > >>> currently > > > > > > > > > >>> > do > > > > > > > > > >>> > > > this > > > > > > > > > >>> > > > > with PLAIN/SCRAM because login callback > handlers > > > were > > > > > not > > > > > > > > > >>> > configurable > > > > > > > > > >>> > > > > earlier and we haven't updated the login > modules > > > to do > > > > > > > this. > > > > > > > > > But > > > > > > > > > >>> that > > > > > > > > > >>> > > > could > > > > > > > > > >>> > > > > be one way of providing passwords and > integrating > > > with > > > > > > > other > > > > > > > > > >>> password > > > > > > > > > >>> > > > > sources, now that we have configurable login > > > callback > > > > > > > > handlers. > > > > > > > > > >>> I was > > > > > > > > > >>> > > > > wondering whether similar approach could be > used > > > for > > > > > the > > > > > > > > > >>> parameters > > > > > > > > > >>> > > that > > > > > > > > > >>> > > > > OAuth needed to obtain at runtime. We could > still > > > have > > > > > this > > > > > > > > KIP > > > > > > > > > >>> with > > > > > > > > > >>> > > > > built-in substitutable types to handle common > > cases > > > > > like > > > > > > > > > getting > > > > > > > > > >>> > > options > > > > > > > > > >>> > > > > from a file without writing any code. But I > > wasn't > > > > > sure if > > > > > > > > > there > > > > > > > > > >>> were > > > > > > > > > >>> > > > OAuth > > > > > > > > > >>> > > > > options that couldn't be handled as callbacks > > > using the > > > > > > > login > > > > > > > > > >>> > callback > > > > > > > > > >>> > > > > handler. > > > > > > > > > >>> > > > > > > > > > > > > > >>> > > > > On Thu, Apr 5, 2018 at 10:25 PM, Ron Dagostino > < > > > > > > > > > >>> rndg...@gmail.com> > > > > > > > > > >>> > > > wrote: > > > > > > > > > >>> > > > > > > > > > > > > > >>> > > > > > Hi Rajini. Thanks for the questions. I > could > > > see > > > > > > > someone > > > > > > > > > >>> wanting > > > > > > > > > >>> > to > > > > > > > > > >>> > > > > > retrieve a password from a vended password > > vault > > > > > solution > > > > > > > > > (for > > > > > > > > > >>> > > > example); > > > > > > > > > >>> > > > > > that is the kind of scenario that the ability > > to > > > add > > > > > new > > > > > > > > > >>> > > substitutable > > > > > > > > > >>> > > > > > types would be meant for. I do still > consider > > > this > > > > > KIP > > > > > > > 269 > > > > > > > > > to > > > > > > > > > >>> be a > > > > > > > > > >>> > > > > > prerequisite for the SASL/OAUTHBEARER KIP > 255. > > > I am > > > > > open > > > > > > > > to > > > > > > > > > a > > > > > > > > > >>> > > > different > > > > > > > > > >>> > > > > > perspective in case I missed or misunderstood > > > your > > > > > point. > > > > > > > > > >>> > > > > > > > > > > > > > > >>> > > > > > Ron > > > > > > > > > >>> > > > > > > > > > > > > > > >>> > > > > > On Thu, Apr 5, 2018 at 8:13 AM, Rajini > Sivaram > > < > > > > > > > > > >>> > > > rajinisiva...@gmail.com> > > > > > > > > > >>> > > > > > wrote: > > > > > > > > > >>> > > > > > > > > > > > > > > >>> > > > > > > Hi Ron, > > > > > > > > > >>> > > > > > > > > > > > > > > > >>> > > > > > > Now that login callback handlers are > > > configurable, > > > > > is > > > > > > > > this > > > > > > > > > >>> KIP > > > > > > > > > >>> > > still > > > > > > > > > >>> > > > a > > > > > > > > > >>> > > > > > > pre-req for OAuth? I was wondering whether > we > > > still > > > > > > > need > > > > > > > > > the > > > > > > > > > >>> > > ability > > > > > > > > > >>> > > > to > > > > > > > > > >>> > > > > > add > > > > > > > > > >>> > > > > > > new substitutable types or whether it would > > be > > > > > > > sufficient > > > > > > > > > to > > > > > > > > > >>> add > > > > > > > > > >>> > > the > > > > > > > > > >>> > > > > > > built-in ones to read from file etc. > > > > > > > > > >>> > > > > > > > > > > > > > > > >>> > > > > > > > > > > > > > > > >>> > > > > > > On Thu, Mar 29, 2018 at 6:48 AM, Ron > > Dagostino > > > < > > > > > > > > > >>> > rndg...@gmail.com> > > > > > > > > > >>> > > > > > wrote: > > > > > > > > > >>> > > > > > > > > > > > > > > > >>> > > > > > > > Hi everyone. There have been no comments > > on > > > this > > > > > > > KIP, > > > > > > > > > so I > > > > > > > > > >>> > > intend > > > > > > > > > >>> > > > to > > > > > > > > > >>> > > > > > put > > > > > > > > > >>> > > > > > > > it to a vote next week if there are no > > > comments > > > > > that > > > > > > > > > might > > > > > > > > > >>> > entail > > > > > > > > > >>> > > > > > changes > > > > > > > > > >>> > > > > > > > between now and then. Please take a look > > in > > > the > > > > > > > > meantime > > > > > > > > > >>> if > > > > > > > > > >>> > you > > > > > > > > > >>> > > > > wish. > > > > > > > > > >>> > > > > > > > > > > > > > > > > >>> > > > > > > > Ron > > > > > > > > > >>> > > > > > > > > > > > > > > > > >>> > > > > > > > On Thu, Mar 15, 2018 at 2:36 PM, Ron > > > Dagostino < > > > > > > > > > >>> > > rndg...@gmail.com> > > > > > > > > > >>> > > > > > > wrote: > > > > > > > > > >>> > > > > > > > > > > > > > > > > >>> > > > > > > > > Hi everyone. > > > > > > > > > >>> > > > > > > > > > > > > > > > > > >>> > > > > > > > > I created KIP-269: Substitution Within > > > > > > > Configuration > > > > > > > > > >>> Values > > > > > > > > > >>> > > > > > > > > <https://cwiki.apache.org/ > > > > > > > > > confluence/display/KAFKA/KIP+ > > > > > > > > > >>> > > > > > > > 269+Substitution+Within+Config > > > uration+Values> > > > > > > > > > >>> > > > > > > > > (https://cwiki.apache.org/conf > > > > > > > > > >>> luence/display/KAFKA/KIP+269+ > > > > > > > > > >>> > > > > > > > > Substitution+Within+Configurat > ion+Values > > > > > > > > > >>> > > > > > > > > <https://cwiki.apache.org/ > > > > > > > confluence/pages/viewpage. > > > > > > > > > >>> > > > > > > > action?pageId=75968876> > > > > > > > > > >>> > > > > > > > > ). > > > > > > > > > >>> > > > > > > > > > > > > > > > > > >>> > > > > > > > > This KIP proposes adding support for > > > > > substitution > > > > > > > > > within > > > > > > > > > >>> > client > > > > > > > > > >>> > > > > JAAS > > > > > > > > > >>> > > > > > > > > configuration values for PLAIN and > > > > > SCRAM-related > > > > > > > SASL > > > > > > > > > >>> > > mechanisms > > > > > > > > > >>> > > > > in a > > > > > > > > > >>> > > > > > > > > backwards-compatible manner and making > > the > > > > > > > > > functionality > > > > > > > > > >>> > > > available > > > > > > > > > >>> > > > > to > > > > > > > > > >>> > > > > > > > other > > > > > > > > > >>> > > > > > > > > existing (or future) configuration > > contexts > > > > > where > > > > > > > it > > > > > > > > is > > > > > > > > > >>> > deemed > > > > > > > > > >>> > > > > > > > appropriate. > > > > > > > > > >>> > > > > > > > > > > > > > > > > > >>> > > > > > > > > This KIP was extracted from (and is > now a > > > > > > > > prerequisite > > > > > > > > > >>> for) > > > > > > > > > >>> > > > > KIP-255: > > > > > > > > > >>> > > > > > > > > OAuth Authentication via > SASL/OAUTHBEARER > > > > > > > > > >>> > > > > > > > > <https://cwiki.apache.org/ > > > > > > > confluence/pages/viewpage. > > > > > > > > > >>> > > > > > > > action?pageId=75968876> > > > > > > > > > >>> > > > > > > > > based on discussion of that KIP. > > > > > > > > > >>> > > > > > > > > > > > > > > > > > >>> > > > > > > > > Ron > > > > > > > > > >>> > > > > > > > > > > > > > > > > > >>> > > > > > > > > > > > > > > > > >>> > > > > > > > > > > > > > > > >>> > > > > > > > > > > > > > > >>> > > > > > > > > > > > > > >>> > > > > > > > > > > > > >>> > > > > > > > > > > > >>> > > > > > > > > > > >>> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
