Hi Jun. I've updated the KIP to add a new section titled "Summary for Production Use" that includes this information along with a consolidated set of references to the applicable specifications. Thanks for the questions.
*We still need another binding vote* (currently there are two binding + 1 votes, from Rajini and Jun, and three non-binding +1 votes, from Mickael, Manikumar, and myself). Please vote before the May 22nd KIP Freeze deadline so this KIP can be included in the 2.0.0 release. A pull request is available and includes additional commits reflecting initial review comments: https://github.com/apache/kafka/pull/4994 Ron On Wed, May 16, 2018 at 8:09 PM, Jun Rao <j...@confluent.io> wrote: > Hi, Ron, > > Thanks. I understand now. It may be useful to add a reference to JWT in the > KIP. > > Jun > > On Tue, May 15, 2018 at 6:51 PM, Ron Dagostino <rndg...@gmail.com> wrote: > > > Hi Jun. I think you are getting at the fact that OAuth 2 is a flexible > > framework that allows different installations to do things differently. > It > > is true that the principal name in Kafka could come from any claim in the > > token. Most of the time it would come from the 'sub' claim, but it could > > certainly come from another claim, or it could be only indirectly based > on > > a claim value (maybe certain text would be trimmed or prefixed/suffixed). > > The point, which I think you are getting at, is that because the > framework > > is flexible we need to accommodate that flexibility. The callback > handler > > class defined by the listener.name.sasl_ssl.oauthbearer.sasl.server. > > callback.handler.class configuration value gives us the required > > flexibility. As an example, I have an implementation that leverages a > > popular open source JOSE library to parse the compact serialization, > > retrieve the public key if it has not yet been retrieved, verify the > > digital signature, and map the 'sub' claim to the OAuthBearerToken's > > principal name (which becomes the SASL authorization ID, which becomes > the > > Kafka principal name). I could just as easily have mapped a different > > claim to the OAuthBearerToken's principal name, manipulated the 'sub' > claim > > value in some way, etc. I write the callback handler code, so I complete > > flexibility to do whatever my OAuth 2 installation requires me to do. > > > > Ron > > > > On Tue, May 15, 2018 at 1:39 PM, Jun Rao <j...@confluent.io> wrote: > > > > > Hi, Ron, > > > > > > Thanks for the reply. I understood your answers to #2 and #3. > > > > > > For #1, will the server map all clients' principal name to the value > > > associated with "sub" claim? How do we support mapping different > clients > > to > > > different principal names? > > > > > > Jun > > > > > > On Mon, May 14, 2018 at 7:02 PM, Ron Dagostino <rndg...@gmail.com> > > wrote: > > > > > > > Hi Jun. Thanks for the +1 vote. > > > > > > > > Regarding the first question about token claims, yes, you have it > > correct > > > > about translating the OAuth token to a principle name via a JAAS > module > > > > option in the default unsecured case. Specifically, the OAuth SASL > > > Server > > > > implementation is responsible for setting the authorization ID, and > it > > > gets > > > > the authorization ID from the OAuthBearerToken's principalName() > > method. > > > > The listener.name.sasl_ssl.oauthbearer.sasl.server. > > > callback.handler.class > > > > is responsible for handling an instance of > OAuthBearerValidatorCallback > > > to > > > > accept a token compact serialization from the client and return an > > > instance > > > > of OAuthBearerToken (assuming the compact serialization validates), > and > > > in > > > > the default unsecured case the builtin unsecured validator callback > > > handler > > > > defines the OAuthBearerToken.principalName() method to return the > > 'sub' > > > > claim value by default (with the actual claim it uses being > > configurable > > > > via the unsecuredValidatorPrincipalClaimName JAAS module option). > So > > > that > > > > is how we translate from a token to a principal name in the default > > > > unsecured (out-of-the-box) case. > > > > > > > > For production use cases, the implementation associated with > > > > listener.name.sasl_ssl.oauthbearer.sasl.server. > callback.handler.class > > > can > > > > do whatever it wants. As an example, I have written a class that > > wraps a > > > > com.nimbusds.jwt.SignedJWT instance (see > > > > https://connect2id.com/products/nimbus-jose-jwt/) and presents it as > > an > > > > OAuthBearerToken: > > > > > > > > public class NimbusSignedJwtOAuthBearerToken implements > > > OAuthBearerToken { > > > > private final SignedJWT signedJwt; > > > > private final String principalName; > > > > private final Set<String> scope; > > > > private final Long startTimeMs; > > > > private final long lifetimeMs; > > > > > > > > /** > > > > * Constructor > > > > * > > > > * @param signedJwt > > > > * the mandatory signed JWT > > > > * @param principalClaimName > > > > * the mandatory claim name identifying the claim from > > > which > > > > the > > > > * principal name will be extracted. The claim must > > exist > > > > and must be > > > > * a String. > > > > * @param optionalScopeClaimName > > > > * the optional claim name identifying the claim from > > > which > > > > any scope > > > > * will be extracted. If specified and the claim > exists > > > then > > > > the > > > > * value must be either a String or a String List. > > > > * @throws ParseException > > > > * if the principal claim does not exist or is not a > > > > String; the > > > > * scope claim is neither a String nor a String List; > > the > > > > 'exp' > > > > * claim does not exist or is not a number; the 'iat' > > > claim > > > > exists > > > > * but is not a number; or the 'nbf' claim exists and > > is > > > > not a > > > > * number. > > > > */ > > > > public NimbusSignedJwtOAuthBearerToken(SignedJWT signedJwt, > String > > > > principalClaimName, > > > > String optionalScopeClaimName) throws ParseException { > > > > // etc... > > > > } > > > > > > > > The callback handler runs the following code if the digital signature > > > > validates: > > > > > > > > callback.token(new NimbusSignedJwtOAuthBearerToken(signedJwt, > > "sub", > > > > null)); > > > > > > > > I hope that answers the first question. If not let me know what I > > > > missed/misunderstood and I'll be glad to try to address it. > > > > > > > > Regarding the second question, the classes OAuthBearerTokenCallback > and > > > > OAuthBearerValidatorCallback implement the Callback interface -- they > > are > > > > the callbacks that the AuthenticateCallbackHandler implementations > need > > > to > > > > handle. Specifically, unless the unsecured functionality is what is > > > > desired, the two configuration values [listener.name.sasl_ssl. > > > oauthbearer. > > > > ]sasl.login.callback.handler.class and > > > > listener.name.sasl_ssl.oauthbearer.sasl.server. > callback.handler.class > > > > define the callback handlers that need to handle > > OAuthBearerTokenCallback > > > > and OAuthBearerValidatorCallback, respectively. > > > > > > > > Regarding the third question, yes, I see your point that the way the > > spec > > > > is worded could be taken to imply that the error code is a single > > > > character: "A single ASCII..." ( > > > > https://tools.ietf.org/html/rfc6749#section-5.2). However, it is > not > > a > > > > single character. See the end of that section 5.2 for an example > that > > > > shows "error":"invalid_request" as the response. > > > > > > > > Thanks again for the +1 vote, Jun, and please do let me know if I can > > > cover > > > > anything else. > > > > > > > > Ron > > > > > > > > > > > > On Mon, May 14, 2018 at 7:10 PM, Jun Rao <j...@confluent.io> wrote: > > > > > > > > > Hi, Ron, > > > > > > > > > > Thanks for the KIP. +1 from me. Just a few minor comments below. > > > > > > > > > > 1. It seems that we can translate an OAuth token to a principle > name > > > > > through the claim name configured in JASS. However, it's not clear > to > > > me > > > > > how an OAuth token is mapped to a claim. Could you clarify that? > > > > > > > > > > 2. The wiki has the following code. It seems that > > > > OAuthBearerTokenCallback > > > > > should implement AuthenticateCallbackHandler? Ditto > > > > > for OAuthBearerValidatorCallback. > > > > > > > > > > public class OAuthBearerTokenCallback implements Callback > > > > > > > > > > 3. In OAuthBearerTokenCallback, we have the following method. The > > OAuth > > > > > spec says the error code is a single ASCII. So, should we return a > > Char > > > > or > > > > > a String? > > > > > > > > > > public String errorCode() > > > > > > > > > > Jun > > > > > > > > > > > > > > > On Thu, May 3, 2018 at 8:55 PM, Ron Dagostino <rndg...@gmail.com> > > > wrote: > > > > > > > > > > > Hi everyone. I would like to start the vote for KIP-255: > > > > > > https://cwiki.apache.org/confluence/pages/viewpage. > > > > > action?pageId=75968876 > > > > > > > > > > > > This KIP proposes to add the following functionality related to > > > > > > SASL/OAUTHBEARER: > > > > > > > > > > > > 1) Allow clients (both brokers when SASL/OAUTHBEARER is the > > > > inter-broker > > > > > > protocol as well as non-broker clients) to flexibly retrieve an > > > access > > > > > > token from an OAuth 2 authorization server based on the > declaration > > > of > > > > a > > > > > > custom login CallbackHandler implementation and have that access > > > token > > > > > > transparently and automatically transmitted to a broker for > > > > > authentication. > > > > > > > > > > > > 2) Allow brokers to flexibly validate provided access tokens > when a > > > > > client > > > > > > establishes a connection based on the declaration of a custom > SASL > > > > Server > > > > > > CallbackHandler implementation. > > > > > > > > > > > > 3) Provide implementations of the above retrieval and validation > > > > features > > > > > > based on an unsecured JSON Web Token that function out-of-the-box > > > with > > > > > > minimal configuration required (i.e. implementations of the two > > types > > > > of > > > > > > callback handlers mentioned above will be used by default with no > > > need > > > > to > > > > > > explicitly declare them). > > > > > > > > > > > > 4) Allow clients (both brokers when SASL/OAUTHBEARER is the > > > > inter-broker > > > > > > protocol as well as non-broker clients) to transparently > retrieve a > > > new > > > > > > access token in the background before the existing access token > > > expires > > > > > in > > > > > > case the client has to open new connections. > > > > > > > > > > > > Thanks, > > > > > > > > > > > > Ron > > > > > > > > > > > > > > > > > > > > >
