NoClassDefFoundError in the APIMgtGatewayJWTGeneratorImpl - wso2

Question

I updated wso2 from version 2.6.0 to 4.1.0 and in the old version was only this JWTGenerator generator class.
In the class that extended JWTGenerator, there was a method that retrieves the custom config from api-maneger.xml via java using:
APIManagerConfiguration config = ServiceReferenceHolder.getInstance().getAPIManagerConfigurationService().getAPIManagerConfiguration();
String jwtExpirySetting = config.getFirstProperty(JWT_EXPIRY_CONFIG);
The first question. Is it possible to somehow add your own custom config in version 4.1.0?
**The second question. How do I get the desired config (which refers to the gateway token cache and JWT Expiry) from deployment.toml through java code in the generator that extends APIMgtGatewayJWTGeneratorImpl?
When I add the method ServiceReferenceHolder.getInstance().getAPIManagerConfigurationService().getAPIManagerConfiguration(); to my generator (com.carus.api.gateway.JwtTokenGenerator) and when I make a request on the API manager, I get the following error in the log file (wso2carbon.log), cannot find ServiceReferenceHolder class:
TID: [-1234] [] [2022-10-03 13:09:19,097] ERROR {org.wso2.carbon.apimgt.impl.jwt.JWTValidatorImpl} - Error while parsing JWT org.apache.http.client.ClientProtocolException: URI does not specify a valid host name: https:9443/oauth2/jwks
at org.apache.http.impl.client.CloseableHttpClient.determineTarget(CloseableHttpClient.java:95)
at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:83)
at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:108)
at org.wso2.carbon.apimgt.impl.utils.JWTUtil.retrieveJWKSConfiguration_aroundBody0(JWTUtil.java:58)
at org.wso2.carbon.apimgt.impl.utils.JWTUtil.retrieveJWKSConfiguration(JWTUtil.java:52)
at org.wso2.carbon.apimgt.impl.jwt.JWTValidatorImpl.retrieveJWKSet_aroundBody22(JWTValidatorImpl.java:227)
at org.wso2.carbon.apimgt.impl.jwt.JWTValidatorImpl.retrieveJWKSet(JWTValidatorImpl.java:224)
at org.wso2.carbon.apimgt.impl.jwt.JWTValidatorImpl.validateSignature_aroundBody8(JWTValidatorImpl.java:145)
at org.wso2.carbon.apimgt.impl.jwt.JWTValidatorImpl.validateSignature(JWTValidatorImpl.java:135)
at org.wso2.carbon.apimgt.impl.jwt.JWTValidatorImpl.validateToken_aroundBody0(JWTValidatorImpl.java:62)
at org.wso2.carbon.apimgt.impl.jwt.JWTValidatorImpl.validateToken(JWTValidatorImpl.java:57)
at org.wso2.carbon.apimgt.impl.jwt.JWTValidationServiceImpl.validateJWTToken_aroundBody0(JWTValidationServiceImpl.java:44)
at org.wso2.carbon.apimgt.impl.jwt.JWTValidationServiceImpl.validateJWTToken(JWTValidationServiceImpl.java:36)
at org.wso2.carbon.apimgt.gateway.handlers.security.jwt.JWTValidator.getJwtValidationInfo_aroundBody32(JWTValidator.java:691)
at org.wso2.carbon.apimgt.gateway.handlers.security.jwt.JWTValidator.getJwtValidationInfo(JWTValidator.java:659)
at org.wso2.carbon.apimgt.gateway.handlers.security.jwt.JWTValidator.authenticate_aroundBody0(JWTValidator.java:174)
at org.wso2.carbon.apimgt.gateway.handlers.security.jwt.JWTValidator.authenticate(JWTValidator.java:142)
at org.wso2.carbon.apimgt.gateway.handlers.security.oauth.OAuthAuthenticator.authenticate_aroundBody4(OAuthAuthenticator.java:301)
at org.wso2.carbon.apimgt.gateway.handlers.security.oauth.OAuthAuthenticator.authenticate(OAuthAuthenticator.java:111)
at org.wso2.carbon.apimgt.gateway.handlers.security.APIAuthenticationHandler.isAuthenticate_aroundBody56(APIAuthenticationHandler.java:522)
at org.wso2.carbon.apimgt.gateway.handlers.security.APIAuthenticationHandler.isAuthenticate(APIAuthenticationHandler.java:516)
at org.wso2.carbon.apimgt.gateway.handlers.security.APIAuthenticationHandler.handleRequest_aroundBody46(APIAuthenticationHandler.java:402)
at org.wso2.carbon.apimgt.gateway.handlers.security.APIAuthenticationHandler.handleRequest(APIAuthenticationHandler.java:353)
at org.apache.synapse.api.API.process(API.java:403)
at org.apache.synapse.api.AbstractApiHandler.apiProcessNonDefaultStrategy(AbstractApiHandler.java:107)
at org.apache.synapse.api.AbstractApiHandler.identifyAPI(AbstractApiHandler.java:127)
at org.apache.synapse.api.AbstractApiHandler.dispatchToAPI(AbstractApiHandler.java:59)
at org.apache.synapse.api.rest.RestRequestHandler.dispatchToAPI(RestRequestHandler.java:90)
at org.apache.synapse.api.rest.RestRequestHandler.process(RestRequestHandler.java:76)
at org.apache.synapse.rest.RESTRequestHandler.process(RESTRequestHandler.java:54)
at org.apache.synapse.core.axis2.Axis2SynapseEnvironment.injectMessage(Axis2SynapseEnvironment.java:344)
at org.apache.synapse.core.axis2.SynapseMessageReceiver.receive(SynapseMessageReceiver.java:101)
at org.apache.axis2.engine.AxisEngine.receive(AxisEngine.java:180)
at org.apache.synapse.transport.passthru.ServerWorker.processNonEntityEnclosingRESTHandler(ServerWorker.java:376)
at org.apache.synapse.transport.passthru.ServerWorker.run(ServerWorker.java:190)
at org.apache.axis2.transport.base.threads.NativeWorkerPool$1.run(NativeWorkerPool.java:172)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:829)
TID: [-1234] [] [2022-10-03 13:09:19,307] INFO {org.wso2.carbon.apimgt.keymgt.handlers.DefaultKeyValidationHandler} - org.wso2.carbon.apimgt.keymgt.handlers.DefaultKeyValidationHandler Initialised
TID: [-1234] [] [2022-10-03 13:09:19,367] ERROR {org.apache.axis2.transport.base.threads.NativeWorkerPool} - Uncaught exception java.lang.NoClassDefFoundError: org/wso2/carbon/apimgt/impl/internal/ServiceReferenceHolder
at com.carus.api.gateway.JwtTokenGenerator.getJwtEpiryMillis(JwtTokenGenerator.java:45)
at com.carus.api.gateway.JwtTokenGenerator.populateStandardClaims(JwtTokenGenerator.java:87)
at org.wso2.carbon.apimgt.common.gateway.jwtgenerator.AbstractAPIMgtGatewayJWTGenerator.buildBody(AbstractAPIMgtGatewayJWTGenerator.java:153)
at org.wso2.carbon.apimgt.common.gateway.jwtgenerator.AbstractAPIMgtGatewayJWTGenerator.generateToken(AbstractAPIMgtGatewayJWTGenerator.java:77)
at org.wso2.carbon.apimgt.gateway.handlers.security.jwt.JWTValidator.generateAndRetrieveJWTToken_aroundBody4(JWTValidator.java:290)
at org.wso2.carbon.apimgt.gateway.handlers.security.jwt.JWTValidator.generateAndRetrieveJWTToken(JWTValidator.java:270)
at org.wso2.carbon.apimgt.gateway.handlers.security.jwt.JWTValidator.authenticate_aroundBody0(JWTValidator.java:221)
at org.wso2.carbon.apimgt.gateway.handlers.security.jwt.JWTValidator.authenticate(JWTValidator.java:142)
at org.wso2.carbon.apimgt.gateway.handlers.security.oauth.OAuthAuthenticator.authenticate_aroundBody4(OAuthAuthenticator.java:301)
at org.wso2.carbon.apimgt.gateway.handlers.security.oauth.OAuthAuthenticator.authenticate(OAuthAuthenticator.java:111)
at org.wso2.carbon.apimgt.gateway.handlers.security.APIAuthenticationHandler.isAuthenticate_aroundBody56(APIAuthenticationHandler.java:522)
at org.wso2.carbon.apimgt.gateway.handlers.security.APIAuthenticationHandler.isAuthenticate(APIAuthenticationHandler.java:516)
at org.wso2.carbon.apimgt.gateway.handlers.security.APIAuthenticationHandler.handleRequest_aroundBody46(APIAuthenticationHandler.java:402)
at org.wso2.carbon.apimgt.gateway.handlers.security.APIAuthenticationHandler.handleRequest(APIAuthenticationHandler.java:353)
at org.apache.synapse.api.API.process(API.java:403)
at org.apache.synapse.api.AbstractApiHandler.apiProcessNonDefaultStrategy(AbstractApiHandler.java:107)
at org.apache.synapse.api.AbstractApiHandler.identifyAPI(AbstractApiHandler.java:127)
at org.apache.synapse.api.AbstractApiHandler.dispatchToAPI(AbstractApiHandler.java:59)
at org.apache.synapse.api.rest.RestRequestHandler.dispatchToAPI(RestRequestHandler.java:90)
at org.apache.synapse.api.rest.RestRequestHandler.process(RestRequestHandler.java:76)
at org.apache.synapse.rest.RESTRequestHandler.process(RESTRequestHandler.java:54)
at org.apache.synapse.core.axis2.Axis2SynapseEnvironment.injectMessage(Axis2SynapseEnvironment.java:344)
at org.apache.synapse.core.axis2.SynapseMessageReceiver.receive(SynapseMessageReceiver.java:101)
at org.apache.axis2.engine.AxisEngine.receive(AxisEngine.java:180)
at org.apache.synapse.transport.passthru.ServerWorker.processNonEntityEnclosingRESTHandler(ServerWorker.java:376)
at org.apache.synapse.transport.passthru.ServerWorker.run(ServerWorker.java:190)
at org.apache.axis2.transport.base.threads.NativeWorkerPool$1.run(NativeWorkerPool.java:172)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:829)
Caused by: java.lang.ClassNotFoundException: org.wso2.carbon.apimgt.impl.internal.ServiceReferenceHolder cannot be found by JwtTokenGenerator_2.0.0
at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:512)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:423)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:415)
at org.eclipse.osgi.internal.loader.ModuleClassLoader.loadClass(ModuleClassLoader.java:155)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
... 30 more
The main question is how to get the config I need through APIMgtGatewayJWTGeneratorImpl?

Answer 1

You can find a sample that uses a configuration service - https://github.com/wso2/samples-apim/tree/master/CustomJWTTransformer/src/main/java/org/wso2/caron/test/internal
The config file deployment.toml is based on the j2 template files. You can find the j2 templates inside the pack(repository/resources/conf/templates/repository/conf). You can edit these templates in this case and add some config in the deployment.toml.
For an example let's say you want to add the following config in the api-manager.xml.
<IdentityProviderImpl>
<ServerURL>some_value</ServerURL>
</IdentityProviderImpl>
Update the j2 template -
{% if apim.idpidp is defined %}
<IdentityProviderImpl>
<ServerURL>{{apim.idpidp.server_url}}</ServerURL>
</IdentityProviderImpl>
{% endif %}
Add the following to the deployment.toml
[apim.idpidp]
server_url = "some_value"