credentials via the STS API. It can authenticate via a client certificate and obtain a access/secret key pair as well as a session token. These credentials are associated to an S3 policy at the MinIO server.

In case of certificate-based authentication, MinIO has to map the client-provided certificate to an S3 policy. MinIO does this via the subject common name field of the X.509 certificate. So, MinIO will associate a certificate with a subject `CN = foobar` to a S3 policy named `foobar`....

1. [Install MinIO Server](#install-minio-server)
2. [Use an Existing Key and Certificate with MinIO](#use-an-existing-key-and-certificate-with-minio)
3. [Generate and use Self-signed Keys and Certificates with MinIO](#generate-use-self-signed-keys-certificates)
4. [Install Certificates from Third-party CAs](#install-certificates-from-third-party-cas)

The domains are securely verified and the certificates are generated automatically. This also allows automating the renewal of these certificates.

	// configured expiry and the duration until the certificate itself
	// expires.
	// We must not issue credentials that out-live the certificate.
	if validUntil := time.Until(certificate.NotAfter); validUntil < expiry {
		expiry = validUntil
	}

	// Associate any service accounts to the certificate CN
	parentUser := "tls" + getKeySeparator() + certificate.Subject.CommonName

	}

	cert, ok := clientKey.(*ssh.Certificate)
	if !ok {
		return errSftpPublicKeyWithoutCert
	}

	// ssh.CheckCert called by ssh.Authenticate accepts certificates
	// with empty principles list so we block those in here.
	if len(cert.ValidPrincipals) == 0 {
		return errSftpCertWithoutPrincipals
	}

	// Verify that certificate provided by user is issued by trusted CA,

signatures on certificates that use SHA-1 based signature algorithms.

Go 1.24 changes the default value of the [`x509usepolicies`
setting.](/pkg/crypto/x509/#CreateCertificate) from `0` to `1`. When marshalling
certificates, policies are now taken from the
[`Certificate.Policies`](/pkg/crypto/x509/#Certificate.Policies) field rather
than the

tls              (on|off)    set to 'on' to enable TLS
tls_skip_verify  (on|off)    trust server TLS without verification, defaults to "on" (verify)
client_tls_cert  (path)      path to client certificate for mTLS auth
client_tls_key   (path)      path to client key for mTLS auth
version          (string)    specify the version of the Kafka cluster
comment          (sentence)  optionally add a comment to this setting
```

For testing purposes, here is [how to create self-signed certificates](https://github.com/minio/minio/tree/master/docs/tls#3-generate-self-signed-certificates).

## 2. Create Kubernetes secret

provide the password via:

```
export MINIO_KMS_KES_KEY_PASSWORD=<your-password>
```

Note that MinIO only supports encrypted private keys - not encrypted certificates.
Certificates are no secrets and sent in plaintext as part of the TLS handshake.

## Explore Further

- [Use `mc` with MinIO Server](https://docs.min.io/community/minio-object-store/reference/minio-mc.html)

	}

	if _, ok := claims[subClaim]; ok {
		providerPrefix, _, found := strings.Cut(credentials.ParentUser, getKeySeparator())
		if found {
			return providerPrefix // this is true for certificate and custom providers
		}
		return madmin.OpenIDProvider // openid users are already hashed, so no separator
	}

	return madmin.BuiltinProvider // default to internal
}