Micronaut mTLS with Self-Signed Certificate Without CA - Getting Unauthorized (401), but Works in Postman & Terminal

[Vibhanshu3]

Expected Behavior

1. The Micronaut HTTP client should send the client certificate correctly.
2. The request should not be rejected with 401 Unauthorized.
3. Since Postman & curl work fine, Micronaut should behave the same way.

Actual Behaviour

I am trying to configure Micronaut HTTP Client to communicate with a self-signed HTTPS server using mutual TLS (mTLS).

The server does not use a CA certificate, and I have set up client keystore and truststore as per the Micronaut documentation in which skipped the root CA cert.

However, I am still receiving a 401 Unauthorized error when making requests.

mTLS communication works fine in Postman & Terminal (curl). Fails with 401 Unauthorized in Micronaut HTTP Client.

application.yml (For Client):

micronaut:
  http:
    client:
      ssl:
        enabled: true
        key-store:
          path: classpath:certs/client.p12
          password: changeit
          type: PKCS12
        trust-store:
          path: classpath:certs/truststore.jks
          password: changeit
          type: JKS

Environment Information

• JDK Version: 17

Version

3.9.6