Re: Two open issues on Kafka security
Thanks for getting back Jay! For the interface - Looking at Sentry and other authorization libraries in the Hadoop eco system it seems that “username” is primarily use to perform authorization these days. And then IP for auditing. Hence I feel that username+IP would be sufficient, at least for now. However I would assume that in the future we might need more then just those two, so what about defining the API in a way that we can easily extend in the future, something like? authorize(Context, Entity, Action), where * Action - is the action that user is trying to do (read to topic, read from topic, create topic, …) * Entity - given entity that user is trying to perform that action on (topic, …) * Context - container with user/session information - user name, IP address or perhaps entire certificate as was suggested early on the email thread. The name “context is probably not the right one. The idea is to have an object into which we can easily add additional properties in the future to support additional authorization libraries without breaking backward compatibility with existing ones. The hierarchy is interesting topic - I’m not familiar enough with Kafka internals so I can’t really talk about how much more complex it would be. I can speak about Sentry and the way we designed security model for Hive and Search where introducing the hierarchy wasn’t complex at all and actually lead to a cleaner model. The biggest user visible benefit is that you don’t have to deal with special rules such as “give READ privilege to user jarcec to ALL topics”. If you have a singleton parent entity (service or whatever name seems more accurate), you can easily say that you have the READ access on this root entity and then all topics will simply inherit that. Jarcec On Oct 1, 2014, at 9:33 PM, Jay Kreps jay.kr...@gmail.com wrote: Hey Jarek, I agree with the importance of separating authentication and authorization. The question is what concept of identity is sufficient to pass through to the authorization layer? Just a user name? Or perhaps you also need the ip the request originated from? Whatever these would be it would be nice to enumerate them so the authz portion can be written in a way that ignores the authn part. So if no one else proposes anything different maybe we can just say user name + ip? With respect to hierarchy, it would be nice to have topic hierarchies but we don't have them now so seems overkill to try to think them through wrt security now, right? -Jay On Wed, Oct 1, 2014 at 1:13 PM, Jarek Jarcec Cecho jar...@apache.org wrote: I’m following the security proposal wiki page [1] and this discussion and I would like to jump in with few points if I might :) Let me start by saying that I like the material and the discussion here, good work! I was part of the team who originally designed and worked on Sentry and I wanted to share few to see how it will resonate with people. My first and probably biggest point would be to separate authorization and authentication as two separate systems. I believe that Jao has already stressed that in the email thread, but I wanted to reiterate on that point. In my experience users don’t care that much about how the user has been authenticated if they trust that mechanism, what they care more about is that the authorization model is consistent and behaves the same way. E.g. if I configured that user jarcec can write into topic “logs”, he should be able to do that no matter where the connection came from - whether he has been authorized from Kerberos as he is directly exploring the data from his computer, he is authorized through delegation token because he is running map reduce jobs calculating statistics or he is authorized through SSL certificated because … (well I’m missing good example here, but you’re probably following my point). I’ve also noticed that we are planning to have no hierarchy in the authz object model per the wiki [1] with the reasoning that Kafka do not supports topic hierarchy. I see that point, but at the same time it got me thinking - are we sure that Kafka will never have hierarchic topics? Seems as a nice feature that might be usable for some use cases and something that we might want to add in the future. But regardless of that I would suggest to introduce a hierarchy anyway, even though if it would be just two levels. In sentry (for Hive) we’ve introduced concept of “Service” where all the databases are children of the service. In Kafka I would imagine that we would have “service” and “topics” as the children. Having this is much easier to model general privileges where you need to grant access to all topics - you will just grant access to the entire service and all topics will get “inherited”. I’m wondering what are other people thoughts? Jarcec Links: 1: https://cwiki.apache.org/confluence/display/KAFKA/Security On Oct
Re: Two open issues on Kafka security
This is not nearly as deep as the discussion so far, but I did want to throw this idea out there to make sure we¹ve thought about it. The Kafka project should make sure that when deployed alongside a Hadoop cluster from any major distributions that it can tie seamlessly into the authentication and authorization used within that cluster. For example, Apache Sentry. This may present additional difficulties that means a decision is made to not do that or alternatively the Kerberos authentication and the authorization schemes we are already working on may be sufficient. I¹m not sure that anything I¹ve read so far in this discussion actually poses a problem, but I¹m an Ops guy and being able to more easily integrate more things, makes my life better. :) -Jonathan On 9/30/14, 11:26 PM, Joe Stein joe.st...@stealth.ly wrote: inline On Tue, Sep 30, 2014 at 11:58 PM, Jay Kreps jay.kr...@gmail.com wrote: Hey Joe, For (1) what are you thinking for the PermissionManager api? The way I see it, the first question we have to answer is whether it is possible to make authentication and authorization independent. What I mean by that is whether I can write an authorization library that will work the same whether you authenticate with ssl or kerberos. To me that is a requirement. We can't tie them together. We have to provide the ability for authorization to work regardless of the authentication. One *VERY* important use case is level of trust in authentication from the authorization perpsective. e.g. I authorize identity based on the how you authenticated Alice is able to view topic X if Alice authenticated over kerberos. Bob isn't allowed to view topic X no matter what. Alice can authenticate over not kerberos (uses cases for that) and in that case Alice wouldn't see topic X. A concrete use case for this with Kafka would be a third party bank consuming data to a broker. The service provider would have some kerberos local auth for that bank to-do back up that would also have access to other topics related to that banks data the bank itself over SSL wants a stream of events (some specific topic) and that banks identity only sees that topic. It is important to not confuse identity, authentication and authorization. If so then we need to pick some subset of identity information that we can extract from both and have this constitute the identity we pass into the authorization interface. The original proposal had just the username/subject. But maybe we should add the ip address as well as that is useful. What I would prefer not to do is add everything in the certificate. I think the assumption is that you are generating these certificates for Kafka so you can put whatever identity info you want in the Subject Alternative Name. If that is true then just using that should be okay, right? I think we should just push the byte[] and let the plugin deal with it. So, if we have a certificate object then pass that along with whatever other meta data (e.g. IP address of client) we can. I don't think we should do any parsing whatsover and let the plugin deal with that. Any parsing we do on the identity information for the security object forces us into specific implementations and I don't see any reason to-do that... If plug-ins want an easier time to deal with certs and parsing and blah blah blah then we can implement some way they can do this without much fuss we also need to make sure that crypto library is plugable too (so we can expose an API for them to call) so that HSM can be easily dropped in without Kafka caring... so in the plugin we could provide a indentity.getAlternativeAttribute() and then that use case is solved (and we can use bouncy castle or whatever to parse it for them to make it easier) and always give them raw bytes so they could do it themselves. -Jay On Tue, Sep 30, 2014 at 4:09 PM, Joe Stein joe.st...@stealth.ly wrote: 1) We need to support the most flexibility we can and make this transparent to kafka (to use Gwen's term). Any specific implementation is going to make it not work with some solution stopping people from using Kafka. That is a reality because everyone just does it slightly differently enough. If we have an identity byte structure (lets not use string because some security objects are bytes) this should just fall through to the implementor. For certs this is the entire x509 object (not just the certificate part as it could contain an ASN.1 timestamp) and inside you parse and do what you want with it. 2) While I think there are many benefits to just the handshake approach I don't think it outweighs the cons Jay expressed. a) We can't lead the client libraries down a new path of interacting with Kafka. By incrementally adding to the wire protocol we are directing a very clear and expect ted approach. We already have issues with implementation even with the wire protocol in place and are trying to
Re: Two open issues on Kafka security
Hi Jonathan, Hadoop delegation tokens to enable MapReduce, Samza, or other frameworks running in the Hadoop environment to access Kafka https://cwiki.apache.org/confluence/display/KAFKA/Security is on the list, yup! /*** Joe Stein Founder, Principal Consultant Big Data Open Source Security LLC http://www.stealth.ly Twitter: @allthingshadoop http://www.twitter.com/allthingshadoop / On Wed, Oct 1, 2014 at 12:35 PM, Jonathan Creasy jonathan.cre...@turn.com wrote: This is not nearly as deep as the discussion so far, but I did want to throw this idea out there to make sure we¹ve thought about it. The Kafka project should make sure that when deployed alongside a Hadoop cluster from any major distributions that it can tie seamlessly into the authentication and authorization used within that cluster. For example, Apache Sentry. This may present additional difficulties that means a decision is made to not do that or alternatively the Kerberos authentication and the authorization schemes we are already working on may be sufficient. I¹m not sure that anything I¹ve read so far in this discussion actually poses a problem, but I¹m an Ops guy and being able to more easily integrate more things, makes my life better. :) -Jonathan On 9/30/14, 11:26 PM, Joe Stein joe.st...@stealth.ly wrote: inline On Tue, Sep 30, 2014 at 11:58 PM, Jay Kreps jay.kr...@gmail.com wrote: Hey Joe, For (1) what are you thinking for the PermissionManager api? The way I see it, the first question we have to answer is whether it is possible to make authentication and authorization independent. What I mean by that is whether I can write an authorization library that will work the same whether you authenticate with ssl or kerberos. To me that is a requirement. We can't tie them together. We have to provide the ability for authorization to work regardless of the authentication. One *VERY* important use case is level of trust in authentication from the authorization perpsective. e.g. I authorize identity based on the how you authenticated Alice is able to view topic X if Alice authenticated over kerberos. Bob isn't allowed to view topic X no matter what. Alice can authenticate over not kerberos (uses cases for that) and in that case Alice wouldn't see topic X. A concrete use case for this with Kafka would be a third party bank consuming data to a broker. The service provider would have some kerberos local auth for that bank to-do back up that would also have access to other topics related to that banks data the bank itself over SSL wants a stream of events (some specific topic) and that banks identity only sees that topic. It is important to not confuse identity, authentication and authorization. If so then we need to pick some subset of identity information that we can extract from both and have this constitute the identity we pass into the authorization interface. The original proposal had just the username/subject. But maybe we should add the ip address as well as that is useful. What I would prefer not to do is add everything in the certificate. I think the assumption is that you are generating these certificates for Kafka so you can put whatever identity info you want in the Subject Alternative Name. If that is true then just using that should be okay, right? I think we should just push the byte[] and let the plugin deal with it. So, if we have a certificate object then pass that along with whatever other meta data (e.g. IP address of client) we can. I don't think we should do any parsing whatsover and let the plugin deal with that. Any parsing we do on the identity information for the security object forces us into specific implementations and I don't see any reason to-do that... If plug-ins want an easier time to deal with certs and parsing and blah blah blah then we can implement some way they can do this without much fuss we also need to make sure that crypto library is plugable too (so we can expose an API for them to call) so that HSM can be easily dropped in without Kafka caring... so in the plugin we could provide a indentity.getAlternativeAttribute() and then that use case is solved (and we can use bouncy castle or whatever to parse it for them to make it easier) and always give them raw bytes so they could do it themselves. -Jay On Tue, Sep 30, 2014 at 4:09 PM, Joe Stein joe.st...@stealth.ly wrote: 1) We need to support the most flexibility we can and make this transparent to kafka (to use Gwen's term). Any specific implementation is going to make it not work with some solution stopping people from using Kafka. That is a reality because everyone just does it slightly differently enough. If we have an identity byte structure (lets not use string because some security
Re: Two open issues on Kafka security
I’m following the security proposal wiki page [1] and this discussion and I would like to jump in with few points if I might :) Let me start by saying that I like the material and the discussion here, good work! I was part of the team who originally designed and worked on Sentry and I wanted to share few to see how it will resonate with people. My first and probably biggest point would be to separate authorization and authentication as two separate systems. I believe that Jao has already stressed that in the email thread, but I wanted to reiterate on that point. In my experience users don’t care that much about how the user has been authenticated if they trust that mechanism, what they care more about is that the authorization model is consistent and behaves the same way. E.g. if I configured that user jarcec can write into topic “logs”, he should be able to do that no matter where the connection came from - whether he has been authorized from Kerberos as he is directly exploring the data from his computer, he is authorized through delegation token because he is running map reduce jobs calculating statistics or he is authorized through SSL certificated because … (well I’m missing good example here, but you’re probably following my point). I’ve also noticed that we are planning to have no hierarchy in the authz object model per the wiki [1] with the reasoning that Kafka do not supports topic hierarchy. I see that point, but at the same time it got me thinking - are we sure that Kafka will never have hierarchic topics? Seems as a nice feature that might be usable for some use cases and something that we might want to add in the future. But regardless of that I would suggest to introduce a hierarchy anyway, even though if it would be just two levels. In sentry (for Hive) we’ve introduced concept of “Service” where all the databases are children of the service. In Kafka I would imagine that we would have “service” and “topics” as the children. Having this is much easier to model general privileges where you need to grant access to all topics - you will just grant access to the entire service and all topics will get “inherited”. I’m wondering what are other people thoughts? Jarcec Links: 1: https://cwiki.apache.org/confluence/display/KAFKA/Security On Oct 1, 2014, at 9:44 AM, Joe Stein joe.st...@stealth.ly wrote: Hi Jonathan, Hadoop delegation tokens to enable MapReduce, Samza, or other frameworks running in the Hadoop environment to access Kafka https://cwiki.apache.org/confluence/display/KAFKA/Security is on the list, yup! /*** Joe Stein Founder, Principal Consultant Big Data Open Source Security LLC http://www.stealth.ly Twitter: @allthingshadoop http://www.twitter.com/allthingshadoop / On Wed, Oct 1, 2014 at 12:35 PM, Jonathan Creasy jonathan.cre...@turn.com wrote: This is not nearly as deep as the discussion so far, but I did want to throw this idea out there to make sure we¹ve thought about it. The Kafka project should make sure that when deployed alongside a Hadoop cluster from any major distributions that it can tie seamlessly into the authentication and authorization used within that cluster. For example, Apache Sentry. This may present additional difficulties that means a decision is made to not do that or alternatively the Kerberos authentication and the authorization schemes we are already working on may be sufficient. I¹m not sure that anything I¹ve read so far in this discussion actually poses a problem, but I¹m an Ops guy and being able to more easily integrate more things, makes my life better. :) -Jonathan On 9/30/14, 11:26 PM, Joe Stein joe.st...@stealth.ly wrote: inline On Tue, Sep 30, 2014 at 11:58 PM, Jay Kreps jay.kr...@gmail.com wrote: Hey Joe, For (1) what are you thinking for the PermissionManager api? The way I see it, the first question we have to answer is whether it is possible to make authentication and authorization independent. What I mean by that is whether I can write an authorization library that will work the same whether you authenticate with ssl or kerberos. To me that is a requirement. We can't tie them together. We have to provide the ability for authorization to work regardless of the authentication. One *VERY* important use case is level of trust in authentication from the authorization perpsective. e.g. I authorize identity based on the how you authenticated Alice is able to view topic X if Alice authenticated over kerberos. Bob isn't allowed to view topic X no matter what. Alice can authenticate over not kerberos (uses cases for that) and in that case Alice wouldn't see topic X. A concrete use case for this with Kafka would be a third party bank consuming data to a broker. The service provider would have some kerberos local auth for that bank to-do back up that
Re: Two open issues on Kafka security
Regarding question #1, I’m not sure I follow you, Joe: you’re proposing (I think) that the API take a byte[], but what will be in that array? A serialized certificate if the client authenticated via SSL and the principal name (perhaps normalized) if the client authenticated via Kerberos? Regarding question #2, I think I was unclear in the meeting yesterday: I was proposing a separate port for each authentication method (including none). That is, if a client wants no authentication, then they would connect to port N on the broker. If they wanted to talk over SSL, then they connect to port N+1 (say). Kerberos: N+2. This would remove the need for a new request, since the authentication type would be implicit in the port on which the client connected (and it was my understanding that it was desirable to not introduce any new messages). Perhaps the confusion comes from the fact, correctly pointed out by Jay, that when you want to use SASL on a single port, there does of course need to be a way for the incoming client to signal which mechanism it wants to use, and that’s out of scope of the SASL spec. I didn’t see there being a desire to add new SASL mechanisms going forward, but perhaps I was incorrect? In any event, I’d like to suggest we keep the “open” or “no auth” port separate, both to make it easy for admins to force the use of security (by shutting down that port) and to avoid downgrade attacks (where an attacker intercepts the opening packet from a client requesting security alters it to request none). I’ll update the Wiki with my notes from yesterday’s meeting this afternoon. Thanks, On 10/1/14, 9:35 AM, Jonathan Creasy jonathan.cre...@turn.com wrote: This is not nearly as deep as the discussion so far, but I did want to throw this idea out there to make sure we¹ve thought about it. The Kafka project should make sure that when deployed alongside a Hadoop cluster from any major distributions that it can tie seamlessly into the authentication and authorization used within that cluster. For example, Apache Sentry. This may present additional difficulties that means a decision is made to not do that or alternatively the Kerberos authentication and the authorization schemes we are already working on may be sufficient. I¹m not sure that anything I¹ve read so far in this discussion actually poses a problem, but I¹m an Ops guy and being able to more easily integrate more things, makes my life better. :) -Jonathan On 9/30/14, 11:26 PM, Joe Stein joe.st...@stealth.ly wrote: inline On Tue, Sep 30, 2014 at 11:58 PM, Jay Kreps jay.kr...@gmail.com wrote: Hey Joe, For (1) what are you thinking for the PermissionManager api? The way I see it, the first question we have to answer is whether it is possible to make authentication and authorization independent. What I mean by that is whether I can write an authorization library that will work the same whether you authenticate with ssl or kerberos. To me that is a requirement. We can't tie them together. We have to provide the ability for authorization to work regardless of the authentication. One *VERY* important use case is level of trust in authentication from the authorization perpsective. e.g. I authorize identity based on the how you authenticated Alice is able to view topic X if Alice authenticated over kerberos. Bob isn't allowed to view topic X no matter what. Alice can authenticate over not kerberos (uses cases for that) and in that case Alice wouldn't see topic X. A concrete use case for this with Kafka would be a third party bank consuming data to a broker. The service provider would have some kerberos local auth for that bank to-do back up that would also have access to other topics related to that banks data the bank itself over SSL wants a stream of events (some specific topic) and that banks identity only sees that topic. It is important to not confuse identity, authentication and authorization. If so then we need to pick some subset of identity information that we can extract from both and have this constitute the identity we pass into the authorization interface. The original proposal had just the username/subject. But maybe we should add the ip address as well as that is useful. What I would prefer not to do is add everything in the certificate. I think the assumption is that you are generating these certificates for Kafka so you can put whatever identity info you want in the Subject Alternative Name. If that is true then just using that should be okay, right? I think we should just push the byte[] and let the plugin deal with it. So, if we have a certificate object then pass that along with whatever other meta data (e.g. IP address of client) we can. I don't think we should do any parsing whatsover and let the plugin deal with that. Any parsing we do on the identity information for the security object forces us into specific implementations and I don't see any reason to-do that... If plug-ins
Re: Two open issues on Kafka security
Here is the client side in ZK: https://svn.apache.org/repos/asf/zookeeper/trunk/src/java/main/org/apache/zookeeper/client/ZooKeeperSaslClient.java Note how they have a special Zookeeper request API that is used to send the SASL bytes (e.g. see ZooKeeperSaslClient.sendSaslPacket). This API follows the same protocol and rpc mechanism all their other request/response types follow but it just has a simple byte[] entry for the SASL token in both the request and response. -Jay On Wed, Oct 1, 2014 at 9:46 PM, Jay Kreps jay.kr...@gmail.com wrote: Hey Michael, WRT question 2, I think for SASL you do need the mechanism information but what I was talking about was the challenge/response byte[] that is sent back and forth from the client to the server. My understanding is that SASL gives you an api for the client and server to use to produce these byte[]'s but doesn't actually specify any way of exchanging them (that is protocol specific). I could be wrong here since my knowledge of this stuff is pretty weak. But according to my understanding you must be imagining some protocol for exchanging challenge/response information. This protocol would have to be clearly documented for client implementors. What is that protocol? -Jay On Wed, Oct 1, 2014 at 2:36 PM, Michael Herstine mherst...@linkedin.com.invalid wrote: Regarding question #1, I’m not sure I follow you, Joe: you’re proposing (I think) that the API take a byte[], but what will be in that array? A serialized certificate if the client authenticated via SSL and the principal name (perhaps normalized) if the client authenticated via Kerberos? Regarding question #2, I think I was unclear in the meeting yesterday: I was proposing a separate port for each authentication method (including none). That is, if a client wants no authentication, then they would connect to port N on the broker. If they wanted to talk over SSL, then they connect to port N+1 (say). Kerberos: N+2. This would remove the need for a new request, since the authentication type would be implicit in the port on which the client connected (and it was my understanding that it was desirable to not introduce any new messages). Perhaps the confusion comes from the fact, correctly pointed out by Jay, that when you want to use SASL on a single port, there does of course need to be a way for the incoming client to signal which mechanism it wants to use, and that’s out of scope of the SASL spec. I didn’t see there being a desire to add new SASL mechanisms going forward, but perhaps I was incorrect? In any event, I’d like to suggest we keep the “open” or “no auth” port separate, both to make it easy for admins to force the use of security (by shutting down that port) and to avoid downgrade attacks (where an attacker intercepts the opening packet from a client requesting security alters it to request none). I’ll update the Wiki with my notes from yesterday’s meeting this afternoon. Thanks, On 10/1/14, 9:35 AM, Jonathan Creasy jonathan.cre...@turn.com wrote: This is not nearly as deep as the discussion so far, but I did want to throw this idea out there to make sure we¹ve thought about it. The Kafka project should make sure that when deployed alongside a Hadoop cluster from any major distributions that it can tie seamlessly into the authentication and authorization used within that cluster. For example, Apache Sentry. This may present additional difficulties that means a decision is made to not do that or alternatively the Kerberos authentication and the authorization schemes we are already working on may be sufficient. I¹m not sure that anything I¹ve read so far in this discussion actually poses a problem, but I¹m an Ops guy and being able to more easily integrate more things, makes my life better. :) -Jonathan On 9/30/14, 11:26 PM, Joe Stein joe.st...@stealth.ly wrote: inline On Tue, Sep 30, 2014 at 11:58 PM, Jay Kreps jay.kr...@gmail.com wrote: Hey Joe, For (1) what are you thinking for the PermissionManager api? The way I see it, the first question we have to answer is whether it is possible to make authentication and authorization independent. What I mean by that is whether I can write an authorization library that will work the same whether you authenticate with ssl or kerberos. To me that is a requirement. We can't tie them together. We have to provide the ability for authorization to work regardless of the authentication. One *VERY* important use case is level of trust in authentication from the authorization perpsective. e.g. I authorize identity based on the how you authenticated Alice is able to view topic X if Alice authenticated over kerberos. Bob isn't allowed to view topic X no matter what. Alice can authenticate over not kerberos (uses cases for that) and in that case Alice wouldn't see topic X. A concrete use case for this with Kafka would be a third party bank consuming data to a broker. The service provider would
Re: Two open issues on Kafka security
Re #1: Since the auth_to_local is a kerberos config, its up to the admin to decide how he likes the user names and set it up properly (or leave empty) and make sure the ACLs match. Simplified names may be needed if the authorization system integrates with LDAP to get groups or something fancy like that. Note that its completely transparent to Kafka - if the admin sets up auth_to_local rules, we simply see a different principal name. No need to do anything different. Gwen On Tue, Sep 30, 2014 at 3:31 PM, Jay Kreps jay.kr...@gmail.com wrote: Current proposal is here: https://cwiki.apache.org/confluence/display/KAFKA/Security Here are the two open questions I am aware of: 1. We want to separate authentication and authorization. This means permissions will be assigned to some user-like subject/entity/person string that is independent of the authorization mechanism. It sounds like we agreed this could be done and we had in mind some krb-specific mangling that Gwen knew about and I think the plan was to use whatever the user chose to put in the Subject Alternative Name of the cert for ssl. So in both cases these would translate to a string denoting the entity whom we are granting permissions to in the authorization layer. We should document these in the wiki to get feedback on them. The Hadoop approach to extraction was something like this: http://docs.hortonworks.com/HDPDocuments/HDP1/HDP-1.3.1/bk_installing_manually_book/content/rpm-chap14-2-3-1.html But actually I'm not sure if just using the full kerberos principal is so bad? I.e. having the user be jenni...@athena.mit.edu versus just jennifer. Where this would make a difference would be in a case where you wanted the same user/entity to be able to authenticate via different mechanisms (Hadoop auth, kerberos, ssl) and have a single set of permissions. 2. For SASL/Kerberos we need to figure out how the communication between client and server will be handled to pass the challenge/response byte[]. I.e. http://docs.oracle.com/javase/7/docs/api/javax/security/sasl/SaslClient.html#evaluateChallenge(byte[]) http://docs.oracle.com/javase/7/docs/api/javax/security/sasl/SaslServer.html#evaluateResponse(byte[]) I am not super expert in this area but I will try to give my understanding and I'm sure someone can correct me if I am confused. Unlike SSL the transmission of this is actually outside the scope of SASL so we have to specify this. Two proposals Original Proposal: Add a new authenticate request/response The proposal in the original wiki was to add a new authenticate request/response to pass this information. This matches what was done in the kerberos implementation for zookeeper. The intention is that the client would send this request immediately after establishing a connection, in which case it acts much like a handshake, however there is no requirement that they do so. Whether the authentication happens via SSL or via Kerberos, the effect will just be to set the username in their session. This will default to the anybody user. So in the default non-secure case we will just be defaulting anybody to have full permission. So to answer the question about whether changing user is required or not, I don't think it is but I think we kind of get it for free in this approach. In this approach there is no particular need or advantage to having a separate port for kerberos I don't think. Alternate Proposal: Create a Handshake The alternative I think Michael was proposing was to create a handshake that would happen at connection time on connections coming in on the SASL port. This would require a separate port for SASL since otherwise you wouldn't be able to tell if the bytes you were getting were for SASL or were the first request of an unauthenticated connection. Michael it would be good to work out the details of how this works. Are we just sending size-delimited byte arrays back and forth until the challenge response terminates? My Take The pro I see for Michael's proposal is that it keeps the authentication logic more localized in the socket server. I see two cons: 1. Since the handshake won't go through the normal api layer it won't go through the normal logging (e.g. request log), jmx monitoring, client trace token, correlation id, etc that we get for other requests. This could make operations a little confusing and make debugging a little harder since the client will be blocking on network requests without the normal logging. 2. This part of the protocol will be inconsistent with the rest of the Kafka protocol so it will be a little odd for client implementors as this will effectively be a request/response that they will have to implement that will be different from all the other request/responses they implement. In practice these two alternatives are not very different except that in the original proposal the bytes you send are prefixed by the normal request header
Re: Two open issues on Kafka security
Re #2: I don't object to the late authentication approach, but we need to make it easy for secured clusters to pass audits (SOX, PCI and friends). So, we need to be able to configure a cluster as secured and with this config switch nobody user to zero privileges. I liked the multi-port approach because blocking a non-secured port is very definite and easy to audit, but a single security=on switch will work as well. On Tue, Sep 30, 2014 at 4:09 PM, Joe Stein joe.st...@stealth.ly wrote: 1) We need to support the most flexibility we can and make this transparent to kafka (to use Gwen's term). Any specific implementation is going to make it not work with some solution stopping people from using Kafka. That is a reality because everyone just does it slightly differently enough. If we have an identity byte structure (lets not use string because some security objects are bytes) this should just fall through to the implementor. For certs this is the entire x509 object (not just the certificate part as it could contain an ASN.1 timestamp) and inside you parse and do what you want with it. 2) While I think there are many benefits to just the handshake approach I don't think it outweighs the cons Jay expressed. a) We can't lead the client libraries down a new path of interacting with Kafka. By incrementally adding to the wire protocol we are directing a very clear and expect ted approach. We already have issues with implementation even with the wire protocol in place and are trying to improve that aspect of the community as a whole. Lets not take a step backwards with this there... also we need to not add more/different hoops to debugging/administering/monitoring kafka so taking advantage (as Jay says) of built in logging (etc) is important... also for the client librariy developers too :) On Tue, Sep 30, 2014 at 6:44 PM, Gwen Shapira gshap...@cloudera.com wrote: Re #1: Since the auth_to_local is a kerberos config, its up to the admin to decide how he likes the user names and set it up properly (or leave empty) and make sure the ACLs match. Simplified names may be needed if the authorization system integrates with LDAP to get groups or something fancy like that. Note that its completely transparent to Kafka - if the admin sets up auth_to_local rules, we simply see a different principal name. No need to do anything different. Gwen On Tue, Sep 30, 2014 at 3:31 PM, Jay Kreps jay.kr...@gmail.com wrote: Current proposal is here: https://cwiki.apache.org/confluence/display/KAFKA/Security Here are the two open questions I am aware of: 1. We want to separate authentication and authorization. This means permissions will be assigned to some user-like subject/entity/person string that is independent of the authorization mechanism. It sounds like we agreed this could be done and we had in mind some krb-specific mangling that Gwen knew about and I think the plan was to use whatever the user chose to put in the Subject Alternative Name of the cert for ssl. So in both cases these would translate to a string denoting the entity whom we are granting permissions to in the authorization layer. We should document these in the wiki to get feedback on them. The Hadoop approach to extraction was something like this: http://docs.hortonworks.com/HDPDocuments/HDP1/HDP-1.3.1/bk_installing_manually_book/content/rpm-chap14-2-3-1.html But actually I'm not sure if just using the full kerberos principal is so bad? I.e. having the user be jenni...@athena.mit.edu versus just jennifer. Where this would make a difference would be in a case where you wanted the same user/entity to be able to authenticate via different mechanisms (Hadoop auth, kerberos, ssl) and have a single set of permissions. 2. For SASL/Kerberos we need to figure out how the communication between client and server will be handled to pass the challenge/response byte[]. I.e. http://docs.oracle.com/javase/7/docs/api/javax/security/sasl/SaslClient.html#evaluateChallenge(byte[]) http://docs.oracle.com/javase/7/docs/api/javax/security/sasl/SaslServer.html#evaluateResponse(byte[]) I am not super expert in this area but I will try to give my understanding and I'm sure someone can correct me if I am confused. Unlike SSL the transmission of this is actually outside the scope of SASL so we have to specify this. Two proposals Original Proposal: Add a new authenticate request/response The proposal in the original wiki was to add a new authenticate request/response to pass this information. This matches what was done in the kerberos implementation for zookeeper. The intention is that the client would send this request immediately after establishing a connection, in which case it acts much like a handshake, however there is no requirement that they do so. Whether the authentication happens via SSL or via Kerberos, the effect will just be to set the
Re: Two open issues on Kafka security
we need to make it easy for secured clusters to pass audits (SOX, PCI and friends) I think this is the MVP for the security features for 0.9 as a guideline for how we should be proceeding. On Tue, Sep 30, 2014 at 7:25 PM, Gwen Shapira gshap...@cloudera.com wrote: Re #2: I don't object to the late authentication approach, but we need to make it easy for secured clusters to pass audits (SOX, PCI and friends). So, we need to be able to configure a cluster as secured and with this config switch nobody user to zero privileges. I liked the multi-port approach because blocking a non-secured port is very definite and easy to audit, but a single security=on switch will work as well. On Tue, Sep 30, 2014 at 4:09 PM, Joe Stein joe.st...@stealth.ly wrote: 1) We need to support the most flexibility we can and make this transparent to kafka (to use Gwen's term). Any specific implementation is going to make it not work with some solution stopping people from using Kafka. That is a reality because everyone just does it slightly differently enough. If we have an identity byte structure (lets not use string because some security objects are bytes) this should just fall through to the implementor. For certs this is the entire x509 object (not just the certificate part as it could contain an ASN.1 timestamp) and inside you parse and do what you want with it. 2) While I think there are many benefits to just the handshake approach I don't think it outweighs the cons Jay expressed. a) We can't lead the client libraries down a new path of interacting with Kafka. By incrementally adding to the wire protocol we are directing a very clear and expect ted approach. We already have issues with implementation even with the wire protocol in place and are trying to improve that aspect of the community as a whole. Lets not take a step backwards with this there... also we need to not add more/different hoops to debugging/administering/monitoring kafka so taking advantage (as Jay says) of built in logging (etc) is important... also for the client librariy developers too :) On Tue, Sep 30, 2014 at 6:44 PM, Gwen Shapira gshap...@cloudera.com wrote: Re #1: Since the auth_to_local is a kerberos config, its up to the admin to decide how he likes the user names and set it up properly (or leave empty) and make sure the ACLs match. Simplified names may be needed if the authorization system integrates with LDAP to get groups or something fancy like that. Note that its completely transparent to Kafka - if the admin sets up auth_to_local rules, we simply see a different principal name. No need to do anything different. Gwen On Tue, Sep 30, 2014 at 3:31 PM, Jay Kreps jay.kr...@gmail.com wrote: Current proposal is here: https://cwiki.apache.org/confluence/display/KAFKA/Security Here are the two open questions I am aware of: 1. We want to separate authentication and authorization. This means permissions will be assigned to some user-like subject/entity/person string that is independent of the authorization mechanism. It sounds like we agreed this could be done and we had in mind some krb-specific mangling that Gwen knew about and I think the plan was to use whatever the user chose to put in the Subject Alternative Name of the cert for ssl. So in both cases these would translate to a string denoting the entity whom we are granting permissions to in the authorization layer. We should document these in the wiki to get feedback on them. The Hadoop approach to extraction was something like this: http://docs.hortonworks.com/HDPDocuments/HDP1/HDP-1.3.1/bk_installing_manually_book/content/rpm-chap14-2-3-1.html But actually I'm not sure if just using the full kerberos principal is so bad? I.e. having the user be jenni...@athena.mit.edu versus just jennifer. Where this would make a difference would be in a case where you wanted the same user/entity to be able to authenticate via different mechanisms (Hadoop auth, kerberos, ssl) and have a single set of permissions. 2. For SASL/Kerberos we need to figure out how the communication between client and server will be handled to pass the challenge/response byte[]. I.e. http://docs.oracle.com/javase/7/docs/api/javax/security/sasl/SaslClient.html#evaluateChallenge(byte[]) http://docs.oracle.com/javase/7/docs/api/javax/security/sasl/SaslServer.html#evaluateResponse(byte[]) I am not super expert in this area but I will try to give my understanding and I'm sure someone can correct me if I am confused. Unlike SSL the transmission of this is actually outside the scope of SASL so we have to specify this. Two proposals Original Proposal: Add a new authenticate request/response The proposal in the original wiki was to add a new authenticate request/response to pass this information. This
Re: Two open issues on Kafka security
Hey Joe, For (1) what are you thinking for the PermissionManager api? The way I see it, the first question we have to answer is whether it is possible to make authentication and authorization independent. What I mean by that is whether I can write an authorization library that will work the same whether you authenticate with ssl or kerberos. If so then we need to pick some subset of identity information that we can extract from both and have this constitute the identity we pass into the authorization interface. The original proposal had just the username/subject. But maybe we should add the ip address as well as that is useful. What I would prefer not to do is add everything in the certificate. I think the assumption is that you are generating these certificates for Kafka so you can put whatever identity info you want in the Subject Alternative Name. If that is true then just using that should be okay, right? -Jay On Tue, Sep 30, 2014 at 4:09 PM, Joe Stein joe.st...@stealth.ly wrote: 1) We need to support the most flexibility we can and make this transparent to kafka (to use Gwen's term). Any specific implementation is going to make it not work with some solution stopping people from using Kafka. That is a reality because everyone just does it slightly differently enough. If we have an identity byte structure (lets not use string because some security objects are bytes) this should just fall through to the implementor. For certs this is the entire x509 object (not just the certificate part as it could contain an ASN.1 timestamp) and inside you parse and do what you want with it. 2) While I think there are many benefits to just the handshake approach I don't think it outweighs the cons Jay expressed. a) We can't lead the client libraries down a new path of interacting with Kafka. By incrementally adding to the wire protocol we are directing a very clear and expect ted approach. We already have issues with implementation even with the wire protocol in place and are trying to improve that aspect of the community as a whole. Lets not take a step backwards with this there... also we need to not add more/different hoops to debugging/administering/monitoring kafka so taking advantage (as Jay says) of built in logging (etc) is important... also for the client librariy developers too :) On Tue, Sep 30, 2014 at 6:44 PM, Gwen Shapira gshap...@cloudera.com wrote: Re #1: Since the auth_to_local is a kerberos config, its up to the admin to decide how he likes the user names and set it up properly (or leave empty) and make sure the ACLs match. Simplified names may be needed if the authorization system integrates with LDAP to get groups or something fancy like that. Note that its completely transparent to Kafka - if the admin sets up auth_to_local rules, we simply see a different principal name. No need to do anything different. Gwen On Tue, Sep 30, 2014 at 3:31 PM, Jay Kreps jay.kr...@gmail.com wrote: Current proposal is here: https://cwiki.apache.org/confluence/display/KAFKA/Security Here are the two open questions I am aware of: 1. We want to separate authentication and authorization. This means permissions will be assigned to some user-like subject/entity/person string that is independent of the authorization mechanism. It sounds like we agreed this could be done and we had in mind some krb-specific mangling that Gwen knew about and I think the plan was to use whatever the user chose to put in the Subject Alternative Name of the cert for ssl. So in both cases these would translate to a string denoting the entity whom we are granting permissions to in the authorization layer. We should document these in the wiki to get feedback on them. The Hadoop approach to extraction was something like this: http://docs.hortonworks.com/HDPDocuments/HDP1/HDP-1.3.1/bk_installing_manually_book/content/rpm-chap14-2-3-1.html But actually I'm not sure if just using the full kerberos principal is so bad? I.e. having the user be jenni...@athena.mit.edu versus just jennifer. Where this would make a difference would be in a case where you wanted the same user/entity to be able to authenticate via different mechanisms (Hadoop auth, kerberos, ssl) and have a single set of permissions. 2. For SASL/Kerberos we need to figure out how the communication between client and server will be handled to pass the challenge/response byte[]. I.e. http://docs.oracle.com/javase/7/docs/api/javax/security/sasl/SaslClient.html#evaluateChallenge(byte[]) http://docs.oracle.com/javase/7/docs/api/javax/security/sasl/SaslServer.html#evaluateResponse(byte[]) I am not super expert in this area but I will try to give my understanding and I'm sure someone can correct me if I am confused. Unlike SSL the transmission of this is actually outside the scope of SASL so we have to specify this. Two proposals Original Proposal: Add a new
Re: Two open issues on Kafka security
inline On Tue, Sep 30, 2014 at 11:58 PM, Jay Kreps jay.kr...@gmail.com wrote: Hey Joe, For (1) what are you thinking for the PermissionManager api? The way I see it, the first question we have to answer is whether it is possible to make authentication and authorization independent. What I mean by that is whether I can write an authorization library that will work the same whether you authenticate with ssl or kerberos. To me that is a requirement. We can't tie them together. We have to provide the ability for authorization to work regardless of the authentication. One *VERY* important use case is level of trust in authentication from the authorization perpsective. e.g. I authorize identity based on the how you authenticated Alice is able to view topic X if Alice authenticated over kerberos. Bob isn't allowed to view topic X no matter what. Alice can authenticate over not kerberos (uses cases for that) and in that case Alice wouldn't see topic X. A concrete use case for this with Kafka would be a third party bank consuming data to a broker. The service provider would have some kerberos local auth for that bank to-do back up that would also have access to other topics related to that banks data the bank itself over SSL wants a stream of events (some specific topic) and that banks identity only sees that topic. It is important to not confuse identity, authentication and authorization. If so then we need to pick some subset of identity information that we can extract from both and have this constitute the identity we pass into the authorization interface. The original proposal had just the username/subject. But maybe we should add the ip address as well as that is useful. What I would prefer not to do is add everything in the certificate. I think the assumption is that you are generating these certificates for Kafka so you can put whatever identity info you want in the Subject Alternative Name. If that is true then just using that should be okay, right? I think we should just push the byte[] and let the plugin deal with it. So, if we have a certificate object then pass that along with whatever other meta data (e.g. IP address of client) we can. I don't think we should do any parsing whatsover and let the plugin deal with that. Any parsing we do on the identity information for the security object forces us into specific implementations and I don't see any reason to-do that... If plug-ins want an easier time to deal with certs and parsing and blah blah blah then we can implement some way they can do this without much fuss we also need to make sure that crypto library is plugable too (so we can expose an API for them to call) so that HSM can be easily dropped in without Kafka caring... so in the plugin we could provide a indentity.getAlternativeAttribute() and then that use case is solved (and we can use bouncy castle or whatever to parse it for them to make it easier) and always give them raw bytes so they could do it themselves. -Jay On Tue, Sep 30, 2014 at 4:09 PM, Joe Stein joe.st...@stealth.ly wrote: 1) We need to support the most flexibility we can and make this transparent to kafka (to use Gwen's term). Any specific implementation is going to make it not work with some solution stopping people from using Kafka. That is a reality because everyone just does it slightly differently enough. If we have an identity byte structure (lets not use string because some security objects are bytes) this should just fall through to the implementor. For certs this is the entire x509 object (not just the certificate part as it could contain an ASN.1 timestamp) and inside you parse and do what you want with it. 2) While I think there are many benefits to just the handshake approach I don't think it outweighs the cons Jay expressed. a) We can't lead the client libraries down a new path of interacting with Kafka. By incrementally adding to the wire protocol we are directing a very clear and expect ted approach. We already have issues with implementation even with the wire protocol in place and are trying to improve that aspect of the community as a whole. Lets not take a step backwards with this there... also we need to not add more/different hoops to debugging/administering/monitoring kafka so taking advantage (as Jay says) of built in logging (etc) is important... also for the client librariy developers too :) On Tue, Sep 30, 2014 at 6:44 PM, Gwen Shapira gshap...@cloudera.com wrote: Re #1: Since the auth_to_local is a kerberos config, its up to the admin to decide how he likes the user names and set it up properly (or leave empty) and make sure the ACLs match. Simplified names may be needed if the authorization system integrates with LDAP to get groups or something fancy like that. Note that its completely transparent to Kafka - if the admin sets up auth_to_local rules, we simply see
