[mitreid-connect] JWT Signatures - which public key?

[Justin Richer]

Yannick, thanks for that pointer. Could you please add an issue to the MITREid Connect project to use those classes? The references will be helpful as well.

 — Justin

> On Oct 11, 2016, at 4:59 PM, Yannick Béot <yannick.beot at gmail.com> wrote:
> 
> If you use JWSVerificationKeySelector from Nimbus to check the JWT (as stated http://connect2id.com/products/nimbus-jose-jwt/examples/validating-jwt-access-tokens <http://connect2id.com/products/nimbus-jose-jwt/examples/validating-jwt-access-tokens>), you should be fine.. 
> JWSKeySelector is filtering keys with a JWKMatcher which checks the kid (https://bitbucket.org/connect2id/nimbus-jose-jwt/src/3810eb0a96565e7768cd54bf734dfea373ecc561/src/main/java/com/nimbusds/jose/jwk/JWKMatcher.java?at=4.15&fileviewer=file-view-default#JWKMatcher.java-562 <https://bitbucket.org/connect2id/nimbus-jose-jwt/src/3810eb0a96565e7768cd54bf734dfea373ecc561/src/main/java/com/nimbusds/jose/jwk/JWKMatcher.java?at=4.15&fileviewer=file-view-default#JWKMatcher.java-562>) 
> 
> JWSVerificationKeySelector is responsible for creating the JWKMatcher based on information from the signature, and especially the kid (https://bitbucket.org/connect2id/nimbus-jose-jwt/src/3810eb0a96565e7768cd54bf734dfea373ecc561/src/main/java/com/nimbusds/jose/proc/JWSVerificationKeySelector.java?at=4.15&fileviewer=file-view-default#JWSVerificationKeySelector.java-70 <https://bitbucket.org/connect2id/nimbus-jose-jwt/src/3810eb0a96565e7768cd54bf734dfea373ecc561/src/main/java/com/nimbusds/jose/proc/JWSVerificationKeySelector.java?at=4.15&fileviewer=file-view-default#JWSVerificationKeySelector.java-70>)
> 
> @Luiz: what are you using to validate the token? 
> 
> 
> 
> On Tue, Oct 11, 2016 at 9:13 PM, Justin Richer <jricher at mit.edu <mailto:jricher at mit.edu>> wrote:
> The “kid” will be in the header of the JWT you’re validating. I think we’ve got a long-standing issue to enforce that check in the client library, but it should still work as-is.
> 
>  — Justin
> 
>> On Oct 11, 2016, at 12:27 PM, Luiz Omori <luiz.omori at duke.edu <mailto:luiz.omori at duke.edu>> wrote:
>> 
>> Well, which “kid” value should we look for? I checked the <root>/.well-known/openid-configuration and although it lists the jwk endpoint we couldn’t find the “kid” anywhere. Does it mean this info has to be transmitted offline?
>>  
>> {
>>   "keys":[
>>     {
>>       "alg":"RS256",
>>       "e":"xxx",
>>       "n":"xxx”,
>>       "kty":"RSA",
>>       "use":"enc",
>>       "kid":"mc.duke.edu <http://mc.duke.edu/>"
>>     },
>>     {
>>       "e":"xxx",
>>       "n":"xxx”,
>>       "kty":"RSA",
>>       "kid":"Test1"
>>     },
>>     {
>>       "e":"xxx",
>>       "n":"xxx”,
>>       "kty":"RSA",
>>       "kid":"Test2"
>>     },
>>     {
>>       "e":"xxx",
>>       "n":"xxx",
>>       "kty":"RSA",
>>       "kid":"rsa1"
>>     }
>>   ]
>> } 
>>  
>> From: "yannick.beot at gmail.com <mailto:yannick.beot at gmail.com>" <yannick.beot at gmail.com <mailto:yannick.beot at gmail.com>>
>> Date: Tuesday, October 11, 2016 at 12:16 PM
>> To: Luiz Omori <luiz.omori at duke.edu <mailto:luiz.omori at duke.edu>>, "mitreid-connect at mit.edu <mailto:mitreid-connect at mit.edu>" <mitreid-connect at mit.edu <mailto:mitreid-connect at mit.edu>>
>> Subject: RE: [mitreid-connect] JWT Signatures - which public key?
>>  
>> There is a key id present in the header that is interpreted by Nimbus: https://tools.ietf.org/html/rfc7515#section-4.1.4 <https://urldefense.proofpoint.com/v2/url?u=https-3A__tools.ietf.org_html_rfc7515-23section-2D4.1.4&d=CwMFaQ&c=imBPVzF25OnBgGmVOlcsiEgHoG1i6YHLR0Sj_gZ4adc&r=R6m41WT3w_KtulQAsSIxc_C2mwuKoWSycEMpss0QQJA&m=946nVG8V76cufZ4NS83yWjsqNfm4xIW2uP9rsciX32I&s=HLXHrA80eziVyXZG3UyPxIKg-x7A1JpFPBB-62UILWw&e=>
>>  
>> You should use it to differentiate the keys.
>>  
>>  
>> Envoyé de mon téléphone Windows 10
>>  
>> De : Luiz Omori <mailto:luiz.omori at duke.edu>
>> Envoyé le :mardi 11 octobre 2016 18:04
>> À : mitreid-connect at mit.edu <mailto:mitreid-connect at mit.edu>
>> Objet :[mitreid-connect] JWT Signatures - which public key?
>>  
>> Hi,
>>  
>> In our implementation, the RS upon receiving a request it first validates the access token signature locally before introspecting it. To perform the signature validation we use a previously retrieved public key. The issue we are facing is that in our case the <root>/jwk endpoint is returning multiple keys. How do we figure out which one should be used? Should we check the “use” field? If yes, is there a standard value to check for?  
>>  
>> Regards,
>> Luiz
>>  
>> _______________________________________________
>> mitreid-connect mailing list
>> mitreid-connect at mit.edu <mailto:mitreid-connect at mit.edu>
>> http://mailman.mit.edu/mailman/listinfo/mitreid-connect <http://mailman.mit.edu/mailman/listinfo/mitreid-connect>
> 
> 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.mit.edu/pipermail/mitreid-connect/attachments/20161011/52dd36dc/attachment.html