diff --git a/ncsmsgo/ncsmsgo.aar b/ncsmsgo/ncsmsgo.aar
index df3d685..f74d3d5 100644
Binary files a/ncsmsgo/ncsmsgo.aar and b/ncsmsgo/ncsmsgo.aar differ
diff --git a/src/main/java/fr/unix_experience/owncloud_sms/engine/ASyncContactLoad.java b/src/main/java/fr/unix_experience/owncloud_sms/engine/ASyncContactLoad.java
index 4f50c4a..66cff1a 100644
--- a/src/main/java/fr/unix_experience/owncloud_sms/engine/ASyncContactLoad.java
+++ b/src/main/java/fr/unix_experience/owncloud_sms/engine/ASyncContactLoad.java
@@ -12,15 +12,13 @@ import android.view.View;
 import android.widget.LinearLayout;
 import android.widget.ProgressBar;
 
-import org.json.JSONArray;
-import org.json.JSONException;
-
 import java.util.ArrayList;
 import java.util.Collections;
 
 import fr.unix_experience.owncloud_sms.R;
 import fr.unix_experience.owncloud_sms.adapters.ContactListAdapter;
 import fr.unix_experience.owncloud_sms.exceptions.OCSyncException;
+import ncsmsgo.SmsPhoneListResponse;
 
 public interface ASyncContactLoad {
 	class ContactLoadTask extends AsyncTask<Void, Void, Boolean> {
@@ -68,10 +66,15 @@ public interface ASyncContactLoad {
 
 				ArrayList<String> serverPhoneList = new ArrayList<>();
 
-				JSONArray phoneNumbers = _client.getServerPhoneNumbers();
-				for (int i = 0; i < phoneNumbers.length(); i++) {
-					String phone = phoneNumbers.getString(i);
-					serverPhoneList.add(phone);
+				SmsPhoneListResponse splr = _client.getServerPhoneNumbers();
+				if (splr == null) {
+					_objects.add(_context.getString(R.string.err_fetch_phonelist));
+					return false;
+				}
+
+				String phoneNumber;
+				while (!(phoneNumber = splr.getNextEntry()).equals("")) {
+					serverPhoneList.add(phoneNumber);
 				}
 
 				// Read all contacts
@@ -81,9 +84,6 @@ public interface ASyncContactLoad {
 
 				// Sort phone numbers
 				Collections.sort(_objects);
-			} catch (JSONException e) {
-				_objects.add(_context.getString(R.string.err_fetch_phonelist));
-				return false;
 			} catch (OCSyncException e) {
 				_objects.add(_context.getString(e.getErrorId()));
 				return false;
diff --git a/src/main/java/fr/unix_experience/owncloud_sms/engine/OCHttpClient.java b/src/main/java/fr/unix_experience/owncloud_sms/engine/OCHttpClient.java
index 5daa9a1..3095d12 100644
--- a/src/main/java/fr/unix_experience/owncloud_sms/engine/OCHttpClient.java
+++ b/src/main/java/fr/unix_experience/owncloud_sms/engine/OCHttpClient.java
@@ -47,6 +47,7 @@ import fr.unix_experience.owncloud_sms.exceptions.OCSyncException;
 import fr.unix_experience.owncloud_sms.providers.AndroidVersionProvider;
 import ncsmsgo.SmsBuffer;
 import ncsmsgo.SmsHTTPClient;
+import ncsmsgo.SmsPhoneListResponse;
 import ncsmsgo.SmsPushResponse;
 
 public class OCHttpClient {
@@ -108,17 +109,13 @@ public class OCHttpClient {
 		return new Pair<>(0, null);
 	}
 
-	private Pair<Integer, JSONObject> post(String oc_call, String data) throws OCSyncException {
-		Log.i(OCHttpClient.TAG, "Perform POST " + _url + oc_call);
-		try {
-			return execute("POST",
-					new URL(_url.toString() + oc_call), data, false);
-		} catch (MalformedURLException e) {
-			Log.e(OCHttpClient.TAG, "Malformed URL provided, aborting. URL was: "
-					+ _url.toExternalForm() + oc_call);
+	private void handleEarlyHTTPStatus(int httpStatus) throws OCSyncException {
+		switch (httpStatus) {
+			case 403: {
+				// Authentication failed
+				throw new OCSyncException(R.string.err_sync_auth_failed, OCSyncErrorType.AUTH);
+			}
 		}
-
-		return new Pair<>(0, null);
 	}
 
 	Pair<Integer, JSONObject> getAllSmsIds() throws OCSyncException {
@@ -130,6 +127,8 @@ public class OCHttpClient {
 		Integer serverAPIVersion = (int) _smsHttpClient.doVersionCall();
 		int httpStatus = (int) _smsHttpClient.getLastHTTPStatus();
 
+		handleEarlyHTTPStatus(httpStatus);
+
 		// If last status is not 200, send the wrong status now
 		if (httpStatus != 200) {
 			return new Pair<>(httpStatus, 0);
@@ -153,11 +152,16 @@ public class OCHttpClient {
 
 	Pair<Integer, SmsPushResponse> pushSms(SmsBuffer smsBuf) throws OCSyncException {
 		SmsPushResponse spr = _smsHttpClient.doPushCall(smsBuf);
-		return new Pair<>((int) _smsHttpClient.getLastHTTPStatus(), spr);
+		int httpStatus = (int) _smsHttpClient.getLastHTTPStatus();
+		handleEarlyHTTPStatus(httpStatus);
+		return new Pair<>(httpStatus, spr);
 	}
 
-	Pair<Integer, JSONObject> getPhoneList() throws OCSyncException {
-		return get(_smsHttpClient.getPhoneListCall(), true);
+	Pair<Integer, SmsPhoneListResponse> getPhoneList() throws OCSyncException {
+		SmsPhoneListResponse splr = _smsHttpClient.doGetPhoneList();
+		int httpStatus = (int) _smsHttpClient.getLastHTTPStatus();
+		handleEarlyHTTPStatus(httpStatus);
+		return new Pair<>(httpStatus, splr);
 	}
 
 	Pair<Integer, JSONObject> getMessages(Long start, Integer limit) throws OCSyncException {
diff --git a/src/main/java/fr/unix_experience/owncloud_sms/engine/OCSMSOwnCloudClient.java b/src/main/java/fr/unix_experience/owncloud_sms/engine/OCSMSOwnCloudClient.java
index 3f1a921..640e6d0 100644
--- a/src/main/java/fr/unix_experience/owncloud_sms/engine/OCSMSOwnCloudClient.java
+++ b/src/main/java/fr/unix_experience/owncloud_sms/engine/OCSMSOwnCloudClient.java
@@ -23,8 +23,6 @@ import android.content.Context;
 import android.util.Log;
 import android.util.Pair;
 
-import org.json.JSONArray;
-import org.json.JSONException;
 import org.json.JSONObject;
 
 import java.net.MalformedURLException;
@@ -35,6 +33,7 @@ import fr.unix_experience.owncloud_sms.enums.OCSyncErrorType;
 import fr.unix_experience.owncloud_sms.exceptions.OCSyncException;
 import fr.unix_experience.owncloud_sms.prefs.OCSMSSharedPrefs;
 import ncsmsgo.SmsBuffer;
+import ncsmsgo.SmsPhoneListResponse;
 import ncsmsgo.SmsPushResponse;
 
 @SuppressWarnings("deprecation")
@@ -74,18 +73,13 @@ public class OCSMSOwnCloudClient {
 		return 0;
 	}
 
-	JSONArray getServerPhoneNumbers() throws OCSyncException {
-		Pair<Integer, JSONObject> response = _http.getPhoneList();
-		if (response.second == null) {
+	SmsPhoneListResponse getServerPhoneNumbers() throws OCSyncException {
+		Pair<Integer, SmsPhoneListResponse> response = _http.getPhoneList();
+		if (response.second == null || response.first != 200) {
 			return null;
 		}
 
-		try {
-			return response.second.getJSONArray("phoneList");
-		} catch (JSONException e) {
-			Log.e(OCSMSOwnCloudClient.TAG, "No phonelist received from server, empty it", e);
-			return null;
-		}
+		return response.second;
 	}
 
 	public void doPushRequest(SmsBuffer smsBuffer) throws OCSyncException {