Receiving "Client authentication with client secret signed JWT failed: Token reuse detected" when trying to get access token with client_Assertion

Getting advice
,
1

Hi,
I am using “signed jwt with Client secret” client authentication. After generating the JWT token, while passing the JWT token against client_assertion for token endpoint, it returns the error “Client authentication with client secret signed JWT failed: Token reuse detected” , though it is the first attempt to retrieve access token.

Stack trace snippet :
        KC-SERVICES0025: Error when validating client assertion: java.lang.RuntimeException: Token reuse detected
at org.keycloak.keycloak-services@14.0.0//org.keycloak.authentication.authenticators.client.JWTClientSecretAuthenticator.authenticateClient(JWTClientSecretAuthenticator.java:181)

Using quay.io/keycloak/keycloak :15.0.2 docker image. 

Please  suggest what is missing.

Thanks,
Cathy

2

Same here, also with 15.0.2.
Sample token payload used as ‘client_assertion’:
{
“sub”: “rest_api”,
“iss”: “rest_api”,
“aud”: “https://<…>”,
“exp”: 1640100249,
“jti”: “1640098496163”
}
The jti is newly generated on each request and has never been used before.
Any hint would be welcome

3

In Keycloak 16.1.0 and 18.0.0 had the same problem using the next jwt:

{
“alg”: “HS512”
…
}
{
“sub”: “{realm}”,
“aud”: “https://{server:port}/auth/realms/{realm}”,
“nbf”: 1651814483,
“iss”: “{realm}”,
“exp”: 1651922482,
“iat”: 1651814482,
“jti”: “{uuid}”
}

The problem was that the certificate field in the keys tab had value, you only need to enable Use JWKS URL or Use JWKS and works for me. For example:
image