GrpcTlsClientCredentials

TLS/SSL credentials for secure transport.

TLS credentials establish an encrypted connection to the gRPC server using TLS/SSL. This credential type supports both server authentication (standard TLS) and mutual TLS (mTLS) where the client also authenticates to the server.

Server Authentication (TLS)

Verify the server's identity using a trust manager with root certificates:

val tlsCredentials = GrpcTlsClientCredentials {
    trustManager(serverCertPem)
}

val client = GrpcClient("example.com", 443) {
    credentials = tlsCredentials
}

Mutual TLS (mTLS)

For mutual authentication, provide both trust manager and key manager:

val credentials = GrpcTlsClientCredentials {
    trustManager(caCertPem)              // Server's CA certificate
    keyManager(clientCertPem, clientKeyPem)  // Client's certificate and private key
}

Default System Trust Store

If no trust manager is configured, the system's default trust store is used:

val credentials = TlsClientCredentials { }  // Uses system CA certificates

Note: The server certificate's Common Name (CN) or Subject Alternative Name (SAN) must match the authority specified in the client configuration, or the connection will fail.

See also