Authentication and Security

public interface Authenticator {
    Request authenticate(Proxy proxy, Response response) throws IOException;
    Request authenticateProxy(Proxy proxy, Response response) throws IOException;
}

public final class CertificatePinner {
    public static final CertificatePinner DEFAULT;
    public static String pin(Certificate certificate);
    public void check(String hostname, List<Certificate> peerCertificates) throws SSLPeerUnverifiedException;
    public void check(String hostname, Certificate... peerCertificates) throws SSLPeerUnverifiedException;
}

public final class Credentials {
    public static String basic(String userName, String password);
}

public final class Challenge {
    public Challenge(String scheme, String realm);
    public String getScheme();
    public String getRealm();
}

public final class Handshake {
    public static Handshake get(SSLSession session);
    public static Handshake get(String cipherSuite, List<Certificate> peerCertificates, List<Certificate> localCertificates);
    public String cipherSuite();
    public List<Certificate> peerCertificates();
    public Principal peerPrincipal();
    public List<Certificate> localCertificates();
    public Principal localPrincipal();
}

// Basic authentication
client.setAuthenticator(new Authenticator() {
    @Override
    public Request authenticate(Proxy proxy, Response response) {
        String credential = Credentials.basic("username", "password");
        return response.request().newBuilder()
            .header("Authorization", credential)
            .build();
    }
    
    @Override
    public Request authenticateProxy(Proxy proxy, Response response) {
        return null; // No proxy auth
    }
});

// Certificate pinning
CertificatePinner pinner = new CertificatePinner.Builder()
    .add("api.example.com", "sha1/ABC123...")
    .build();
client.setCertificatePinner(pinner);