Keycloak-gatekeeper: 'aud' claim and 'client_id' do not match - keycloak

Question

What is the correct way to set the aud claim to avoid the error below?
unable to verify the id token {"error": "oidc: JWT claims invalid: invalid claims, 'aud' claim and 'client_id' do not match, aud=account, client_id=webapp"}
I kinda worked around this error message by hardcoding aud claim to be the same as my client_id. Is there any better way?
Here is my docker-compose.yml:
version: '3'
services:
keycloak-proxy:
image: "keycloak/keycloak-gatekeeper"
environment:
- PROXY_LISTEN=0.0.0.0:3000
- PROXY_DISCOVERY_URL=http://keycloak.example.com:8181/auth/realms/realmcom
- PROXY_CLIENT_ID=webapp
- PROXY_CLIENT_SECRET=0b57186c-e939-48ff-aa17-cfd3e361f65e
- PROXY_UPSTREAM_URL=http://test-server:8000
ports:
- "8282:3000"
command:
- "--verbose"
- "--enable-refresh-tokens=true"
- "--enable-default-deny=true"
- "--resources=uri=/*"
- "--enable-session-cookies=true"
- "--encryption-key=AgXa7xRcoClDEU0ZDSH4X0XhL5Qy2Z2j"
test-server:
image: "test-server"

Answer 1

With recent keycloak version 4.6.0 the client id is apparently no longer automatically added to the audience field 'aud' of the access token.
Therefore even though the login succeeds the client rejects the user.
To fix this you need to configure the audience for your clients (compare doc [2]).
Configure audience in Keycloak
Add realm or configure existing
Add client my-app or use existing
Goto to the newly added "Client Scopes" menu [1]
Add Client scope 'good-service'
Within the settings of the 'good-service' goto Mappers tab
Create Protocol Mapper 'my-app-audience'
Name: my-app-audience
Choose Mapper type: Audience
Included Client Audience: my-app
Add to access token: on
Configure client my-app in the "Clients" menu
Client Scopes tab in my-app settings
Add available client scopes "good-service" to assigned default client scopes
If you have more than one client repeat the steps for the other clients as well and add the good-service scope.
The intention behind this is to isolate client access. The issued access token will only be valid for the intended audience.
This is thoroughly described in Keycloak's documentation [1,2].
Links to recent master version of keycloak documentation:
[1] https://github.com/keycloak/keycloak-documentation/blob/master/server_admin/topics/clients/client-scopes.adoc
[2] https://github.com/keycloak/keycloak-documentation/blob/master/server_admin/topics/clients/oidc/audience.adoc
Links with git tag:
[1] https://github.com/keycloak/keycloak-documentation/blob/f490e1fba7445542c2db0b4202647330ddcdae53/server_admin/topics/clients/oidc/audience.adoc
[2] https://github.com/keycloak/keycloak-documentation/blob/5e340356e76a8ef917ef3bfc2e548915f527d093/server_admin/topics/clients/client-scopes.adoc

Answer 2

This is due to a bug: https://issues.jboss.org/browse/KEYCLOAK-8954
There are two workarounds described in the bug report, both of which appear to do basically the same thing as the accepted answer here but can be applied to the Client Scope role, so you don't have to apply them to every client individually.

Answer 3

If, like me, you want to automate the keycloak config, you can use kcadm
/opt/jboss/keycloak/bin/kcadm.sh \
create clients/d3170ee6-7778-413b-8f41-31479bdb2166/protocol-mappers/models -r your-realm \
-s name=audience-mapping \
-s protocol=openid-connect \
-s protocolMapper=oidc-audience-mapper \
-s config.\"included.client.audience\"="your-audience" \
-s config.\"access.token.claim\"="true" \
-s config.\"id.token.claim\"="false"

Answer 4

Its works to me:
In my SecurityConfiguration class:
#Bean
public CorsConfigurationSource corsConfigurationSource() {
UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
CorsConfiguration config = new CorsConfiguration();
config.setAllowCredentials(true);
config.setAllowedOrigins(Arrays.asList("http://localhost:3000"));
config.setAllowedMethods(Arrays.asList(CorsConfiguration.ALL));
config.setAllowedHeaders(Arrays.asList(CorsConfiguration.ALL));
config.setAllowCredentials(true);
source.registerCorsConfiguration("/**", config);
return source;
}