Authentication result = null;
        if (auth != null) {
            AuthenticationBuilder authBuilder = new AuthenticationBuilder();
            authBuilder.addUsername(auth.getUsername()).addPassword(auth.getPassword());
            authBuilder.addPrivateKey(auth.getPrivateKey(), auth.getPassphrase());
            result = authBuilder.build();
        }
        return result;
    }

                Server server = servers.get(i);
                String serverField = "servers.server[" + i + "]";
                validateStringEmpty(problems, serverField + ".username", server.getUsername(), msgS);
                validateStringEmpty(problems, serverField + ".password", server.getPassword(), msgS);
                validateStringEmpty(problems, serverField + ".privateKey", server.getPrivateKey(), msgS);

        for (Proxy proxy : decrypted.getProxies()) {
            AuthenticationBuilder authBuilder = new AuthenticationBuilder();
            authBuilder.addUsername(proxy.getUsername()).addPassword(proxy.getPassword());
            proxySelector.add(
                    new org.eclipse.aether.repository.Proxy(