900908 Resource forbidden error when invoking an API with an access token obtained with JWT Grant in WSO2

0
votes

I have successfully configured the API Manager, ID and IS according to the documentation: https://docs.wso2.com/display/AM260/JWT+Grant#JWTGrant-UsingtheJWTgrant.

I invoke the WSO2 token endpoint to exchange an external JWT for a WSO2 access token:

curl -i -X POST  -k -d 'grant_type=urn:ietf:params:oauth:grant-type:jwt-bearer&assertion=eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJhZG1pbiIsImF1ZCI6WyJ3c28yIl0sImVudmlyb25tZW50Ijp7InByb2ZpbGVzIjpbImRldiJdfSwiYXV0aCI6eyJyb2xlcyI6WyJVU0VSIiwiQURNSU4iXX0sInVzZXJfbmFtZSI6IjAwMDAwMDk5Iiwic2NvcGUiOlsib3BlcmF0ZSJdLCJpc3MiOiJQQVMiLCJleHAiOjE1NDUzNDgyODcsImdlbmVyYXRlZEJ5IjoiUEFTIiwianRpIjoiOWQ4ZWU3ZTgtNDBlZS00MTZjLTlkYjgtYjU2NDZhYTZhN2JmIiwiY2xpZW50X2lkIjoiZnJvbnQtcG9saXphcyJ9.Ccs1OxjteRsvHTump-ZTawEsqlTrIeO0LJUzt5Ita8udvMOa_tB1rHOtI8GAa2mDCPMD_Z_jtZ2SlXPs10GvsYlF4jS_wcCVAPtHsoigzuNtg5t7CVfeCI2Bzhak721LdYBcjB9s0Jn24G9eb2jqx8NF0RPlKgmhbxwdY0b8XeigLp-kGCsFKY_fDIjFUM0oifzCWOmtaCRMtMx3CKVZOWq9dBIokheCi2foL8YkBCz57yo4vb782AYWXdiHj38TPPe4IguARuoc9FSymyiL1gWHJmyMZFvAeAJkDnHHEnnezqPmcWQweC1ylLwUYGNVLM8YSfuBDtcGBWSO0F-WKw' -H 'Content-Type: application/x-www-form-urlencoded' https://localhost:9443/oauth2/token -d 'client_id=w_paekjnDDY8zcCfCRgj_81g2eYa'

This answers successfully with an access token, a refresh token etc etc.

I have created an application in the WSO2 APIM store. In the production/sandbox tabs, the only checked Grant Type item is JWT.

The point is, I use the previously gotten access token (which is itself an JWT token) to invoke an API subscribed with the above application:

curl -k -X GET "https://192.168.179.129:8243/myapp/api/v1/customers" -H  "accept: application/json;charset=UTF-8" -H  "Authorization: Bearer eyJ4NXQiOiJOVEF4Wm1NeE5ETXlaRGczTVRVMVpHTTBNekV6T0RKaFpXSTRORE5sWkRVMU9HRmtOakZpTVEiLCJraWQiOiJOVEF4Wm1NeE5ETXlaRGczTVRVMVpHTTBNekV6T0RKaFpXSTRORE5sWkRVMU9HRmtOakZpTVEiLCJhbGciOiJSUzI1NiJ9.eyJzdWIiOiJhZG1pbiIsImF1ZCI6IndfcGFla2puRERZOHpjQ2ZDUmdqXzgxZzJlWWEiLCJuYmYiOjE1NDUzNDgxOTgsImF6cCI6IndfcGFla2puRERZOHpjQ2ZDUmdqXzgxZzJlWWEiLCJzY29wZSI6ImRlZmF1bHQiLCJpc3MiOiJodHRwczpcL1wvbG9jYWxob3N0Ojk0NDNcL29hdXRoMlwvdG9rZW4iLCJleHAiOjE1NDUzNDgyODcsImlhdCI6MTU0NTM0ODE5OCwianRpIjoiNjRlM2I5N2UtOTNlNC00YzQ2LThlNmQtMzlmZjQzOWQxM2Y0In0.UBLOsCCD3t4Wf8nXBnDkkGXxefYySelDzEcs1F_IrbshMJXohxcL92Av1nmcpdNdjin7GdC8Y305rrkBt9T1L_cMAHLYYcI5cI1J7wmAgEd1CEv9gI7IUYfAdbga2AeV4kIlNsgiV6PKnU34WnY7rEVqXD908eEHY5UvaNXc0Bz6C8d-p39-SqKUblGHPh9vdkpcCGcK0CgGKjtiU2lai_JkRALdgEgonT37R5eqmuxPxUouWNz9TCJgTuonKPA-9bYOsMvbzGlm--0m0j9gdxnv-3N1Kv_2JqSCR4pToDClhSKgFCE1L025LIICM-sLd_PDU5pwYge_iKseiIDZfA" -d 'client_id=w_paekjnDDY8zcCfCRgj_81g2eYa'

I get the following error (900908) - Resource forbidden:

<ams:fault xmlns:ams="http://wso2.org/apimanager/security"><ams:code>900908</ams:code><ams:message>Resource forbidden </ams:message>
<ams:description>Access failure for API: /myapp/api/v1, version: v1 status: (900908) - Resource forbidden </ams:description></ams:fault>%

I must be missing the final step which is how to allow those access tokens gotten in the JWT grant to be used to access an API subscribed by an application.

2
wso2wso2-am
Unless you have customized the flow, you should receive an OAuth token as a result when you call the Token API. You should be able to use the OAuth token to access the API. It is not clear why you are passing the JWT when accessing the API. – Rans
The access token I get in exchange for the initial (external) JWT is also a JWT. It’s this wso2 accces token that I pass in the api call – codependent
If you can use the JWT token to access the API, what is the requirement to access the Token API? Maybe I'm not clear about the exact use case. – Rans
In exchage for my JWT I got an access token that was also a JWT token. This is because in the service provider configuration, under application settings I had set JWT instead of default in the token issuer option. I changed it back to default. So now I exchange the JWT for a normal (opaque) access token and the error is the same. – codependent
If you already subscribed to the API within the application the flow seems to be correct. Access token should allow accessing API unless you change the handlers inside the API configuration. Try to create a new Application and run the flow again and check. – Rans

2 Answers

5
votes

The error code 900908 means the API is not subscribed by the application. Please double check.

0
votes

Technically Bee was right in his answer, but I would like to point specifically at what I was doing wrong in case it happens to others:

The problem was that the client_id/client_secret I was using when exchanging the JWT to get the access token were the ones from the Service Provider I had created. WRONG!

The ones was that need to be sent are those from the subscribed application. With that the resource forbidden error doesn't show up anymore.