Basic filetransfer http delete implementation; Exceptions for IqPacketError added

22 files changed, 547 insertions, 15 deletions

diff --git a/src/main/java/de/thedevstack/conversationsplus/ConversationsPlusApplication.java b/src/main/java/de/thedevstack/conversationsplus/ConversationsPlusApplication.java
index 26854205..8f970a09 100644
--- a/src/main/java/de/thedevstack/conversationsplus/ConversationsPlusApplication.java
+++ b/src/main/java/de/thedevstack/conversationsplus/ConversationsPlusApplication.java
@@ -10,6 +10,7 @@ import java.io.File;
 import java.security.SecureRandom;
 
 import de.duenndns.ssl.MemorizingTrustManager;
+import de.thedevstack.conversationsplus.http.HttpClient;
 import de.thedevstack.conversationsplus.http.HttpConnectionManager;
 import de.thedevstack.conversationsplus.persistance.FileBackend;
 import de.thedevstack.conversationsplus.services.filetransfer.FileTransferManager;
@@ -18,6 +19,7 @@ import de.thedevstack.conversationsplus.services.filetransfer.jingle.JingleFileT
 import de.thedevstack.conversationsplus.utils.ImageUtil;
 import de.thedevstack.conversationsplus.utils.PRNGFixes;
 import de.thedevstack.conversationsplus.utils.SerialSingleThreadExecutor;
+import okhttp3.OkHttpClient;
 
 /**
  * This class is used to provide static access to the applicationcontext.
@@ -46,6 +48,7 @@ public class ConversationsPlusApplication extends Application {
         FileBackend.init();
         FileTransferManager.init(new HttpUploadFileTransferService(), new JingleFileTransferService());
         HttpConnectionManager.init();
+        HttpClient.init();
     }
 
     /**
@@ -147,6 +150,11 @@ public class ConversationsPlusApplication extends Application {
         getInstance().setMemorizingTrustManager(tm);
     }
 
+    private static void initHttpClient() {
+        OkHttpClient client = new OkHttpClient.Builder()
+                .build();
+    }
+
     public static SecureRandom getSecureRandom() {
         return getInstance().secureRandom;
     }
diff --git a/src/main/java/de/thedevstack/conversationsplus/entities/Message.java b/src/main/java/de/thedevstack/conversationsplus/entities/Message.java
index b0a5bb3b..f081e82a 100644
--- a/src/main/java/de/thedevstack/conversationsplus/entities/Message.java
+++ b/src/main/java/de/thedevstack/conversationsplus/entities/Message.java
@@ -27,6 +27,9 @@ public class Message extends AbstractEntity {
 	public static final int STATUS_SEND_RECEIVED = 7;
 	public static final int STATUS_SEND_DISPLAYED = 8;
 
+    public static final int STATUS_REMOTE_FILE_DELETE_FAILED = 101;
+    public static final int STATUS_REMOTE_FILE_DELETED = 102;
+
 	public static final int ENCRYPTION_NONE = 0;
 	public static final int ENCRYPTION_PGP = 1;
 	public static final int ENCRYPTION_OTR = 2;
diff --git a/src/main/java/de/thedevstack/conversationsplus/entities/RemoteFile.java b/src/main/java/de/thedevstack/conversationsplus/entities/RemoteFile.java
new file mode 100644
index 00000000..76c1dbc9
--- /dev/null
+++ b/src/main/java/de/thedevstack/conversationsplus/entities/RemoteFile.java
@@ -0,0 +1,37 @@
+package de.thedevstack.conversationsplus.entities;
+
+import android.support.annotation.NonNull;
+
+import java.io.Serializable;
+
+/**
+ * Created by steckbrief on 22.08.2016.
+ */
+public class RemoteFile implements Serializable {
+    private static final long serialVersionUID = 34564871234564L;
+    private final String path;
+
+    public RemoteFile(@NonNull String path) {
+        this.path = path;
+    }
+
+    public String getPath() {
+        return path;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        RemoteFile that = (RemoteFile) o;
+
+        return path.equals(that.path);
+
+    }
+
+    @Override
+    public int hashCode() {
+        return path.hashCode();
+    }
+}
diff --git a/src/main/java/de/thedevstack/conversationsplus/http/HttpClient.java b/src/main/java/de/thedevstack/conversationsplus/http/HttpClient.java
new file mode 100644
index 00000000..7e12a890
--- /dev/null
+++ b/src/main/java/de/thedevstack/conversationsplus/http/HttpClient.java
@@ -0,0 +1,81 @@
+package de.thedevstack.conversationsplus.http;
+
+import org.apache.http.conn.ssl.StrictHostnameVerifier;
+
+import java.security.KeyManagementException;
+import java.security.NoSuchAlgorithmException;
+
+import javax.net.ssl.HostnameVerifier;
+import javax.net.ssl.HttpsURLConnection;
+import javax.net.ssl.SSLContext;
+import javax.net.ssl.SSLSocketFactory;
+import javax.net.ssl.X509TrustManager;
+
+import de.thedevstack.conversationsplus.ConversationsPlusApplication;
+import de.thedevstack.conversationsplus.utils.CryptoHelper;
+import de.thedevstack.conversationsplus.utils.SSLSocketHelper;
+import okhttp3.OkHttpClient;
+
+/**
+ * Created by steckbrief on 22.08.2016.
+ */
+public final class HttpClient {
+    private static HttpClient INSTANCE;
+    private boolean interactive = false;
+    private OkHttpClient client;
+
+    public static void init() {
+        INSTANCE = new HttpClient();
+    }
+
+    public static synchronized OkHttpClient getClient(boolean interactive) {
+        if (INSTANCE.interactive != interactive) {
+            INSTANCE.interactive = interactive;
+            INSTANCE.buildClient();
+        }
+        return INSTANCE.client;
+    }
+
+    private HttpClient() {
+        this.buildClient();
+    }
+
+    private void buildClient() {
+        OkHttpClient.Builder builder = new OkHttpClient.Builder();
+        this.initTrustManager(builder);
+        this.client = builder.build();
+    }
+
+    public void initTrustManager(final OkHttpClient.Builder builder) {
+        final X509TrustManager trustManager;
+        final HostnameVerifier hostnameVerifier;
+        if (interactive) {
+            trustManager = ConversationsPlusApplication.getMemorizingTrustManager();
+            hostnameVerifier = ConversationsPlusApplication.getMemorizingTrustManager().wrapHostnameVerifier(
+                    new StrictHostnameVerifier());
+        } else {
+            trustManager = ConversationsPlusApplication.getMemorizingTrustManager()
+                    .getNonInteractive();
+            hostnameVerifier = ConversationsPlusApplication.getMemorizingTrustManager()
+                    .wrapHostnameVerifierNonInteractive(
+                            new StrictHostnameVerifier());
+        }
+        try {
+            final SSLContext sc = SSLSocketHelper.getSSLContext();
+            sc.init(null, new X509TrustManager[]{trustManager},
+                    ConversationsPlusApplication.getSecureRandom());
+
+            final SSLSocketFactory sf = sc.getSocketFactory();
+            final String[] cipherSuites = CryptoHelper.getOrderedCipherSuites(
+                    sf.getSupportedCipherSuites());
+            if (cipherSuites.length > 0) {
+                sc.getDefaultSSLParameters().setCipherSuites(cipherSuites);
+
+            }
+
+            builder.sslSocketFactory(sf, trustManager);
+            builder.hostnameVerifier(hostnameVerifier);
+        } catch (final KeyManagementException | NoSuchAlgorithmException ignored) {
+        }
+    }
+}
diff --git a/src/main/java/de/thedevstack/conversationsplus/services/filetransfer/http/DeleteRemoteFile.java b/src/main/java/de/thedevstack/conversationsplus/services/filetransfer/http/DeleteRemoteFile.java
new file mode 100644
index 00000000..9f6b3bbd
--- /dev/null
+++ b/src/main/java/de/thedevstack/conversationsplus/services/filetransfer/http/DeleteRemoteFile.java
@@ -0,0 +1,22 @@
+package de.thedevstack.conversationsplus.services.filetransfer.http;
+
+import android.support.annotation.NonNull;
+
+import de.thedevstack.conversationsplus.entities.Message;
+import de.thedevstack.conversationsplus.entities.RemoteFile;
+
+/**
+ * Created by steckbrief on 22.08.2016.
+ */
+public class DeleteRemoteFile extends RemoteFile {
+    private final Message message;
+
+    public DeleteRemoteFile(@NonNull String path, @NonNull Message message) {
+        super(path);
+        this.message = message;
+    }
+
+    public Message getMessage() {
+        return message;
+    }
+}
diff --git a/src/main/java/de/thedevstack/conversationsplus/services/filetransfer/http/DeleteRemoteFileService.java b/src/main/java/de/thedevstack/conversationsplus/services/filetransfer/http/DeleteRemoteFileService.java
new file mode 100644
index 00000000..57f408cc
--- /dev/null
+++ b/src/main/java/de/thedevstack/conversationsplus/services/filetransfer/http/DeleteRemoteFileService.java
@@ -0,0 +1,30 @@
+package de.thedevstack.conversationsplus.services.filetransfer.http;
+
+import de.thedevstack.conversationsplus.entities.Account;
+import de.thedevstack.conversationsplus.entities.Message;
+import de.thedevstack.conversationsplus.utils.XmppSendUtil;
+import de.thedevstack.conversationsplus.xmpp.filetransfer.http.FileTransferHttp;
+import de.thedevstack.conversationsplus.xmpp.filetransfer.http.FileTransferHttpDeleteSlotRequestPacketGenerator;
+import de.thedevstack.conversationsplus.xmpp.jid.Jid;
+import de.thedevstack.conversationsplus.xmpp.stanzas.IqPacket;
+
+/**
+ * Created by steckbrief on 21.08.2016.
+ */
+public class DeleteRemoteFileService {
+    public void deleteRemoteFile(Message message) {
+        if (message.isHttpUploaded()) {
+            String path = message.getBody();
+            if (message.hasFileOnRemoteHost()) {
+                path = message.getFileParams().url.toString();
+            }
+
+            DeleteRemoteFile remoteFile = new DeleteRemoteFile(path, message);
+            Account account = message.getConversation().getAccount();
+            Jid host = account.getXmppConnection().findDiscoItemByFeature(FileTransferHttp.NAMESPACE);
+            IqPacket request = FileTransferHttpDeleteSlotRequestPacketGenerator.generate(host, path);
+
+            XmppSendUtil.sendIqPacket(account, request, new DeleteTokenReceived(remoteFile));
+        }
+    }
+}
diff --git a/src/main/java/de/thedevstack/conversationsplus/services/filetransfer/http/DeleteTokenReceived.java b/src/main/java/de/thedevstack/conversationsplus/services/filetransfer/http/DeleteTokenReceived.java
new file mode 100644
index 00000000..fb83219b
--- /dev/null
+++ b/src/main/java/de/thedevstack/conversationsplus/services/filetransfer/http/DeleteTokenReceived.java
@@ -0,0 +1,83 @@
+package de.thedevstack.conversationsplus.services.filetransfer.http;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.io.IOException;
+
+import de.thedevstack.android.logcat.Logging;
+import de.thedevstack.conversationsplus.entities.Account;
+import de.thedevstack.conversationsplus.entities.Message;
+import de.thedevstack.conversationsplus.http.HttpClient;
+import de.thedevstack.conversationsplus.utils.MessageUtil;
+import de.thedevstack.conversationsplus.xmpp.OnIqPacketReceived;
+import de.thedevstack.conversationsplus.xmpp.exceptions.XmppException;
+import de.thedevstack.conversationsplus.xmpp.filetransfer.http.DeleteSlotPacketParser;
+import de.thedevstack.conversationsplus.xmpp.stanzas.IqPacket;
+import okhttp3.Call;
+import okhttp3.Callback;
+import okhttp3.OkHttpClient;
+import okhttp3.Request;
+import okhttp3.Response;
+
+/**
+ * Created by steckbrief on 21.08.2016.
+ */
+public class DeleteTokenReceived implements OnIqPacketReceived {
+    private static final String HEADER_NAME_DELETE_TOKEN = "X-FILETRANSFER-HTTP-DELETE-TOKEN";
+    private final DeleteRemoteFile remoteFile;
+
+    public DeleteTokenReceived(DeleteRemoteFile remoteFile) {
+        this.remoteFile = remoteFile;
+    }
+
+    @Override
+    public void onIqPacketReceived(Account account, IqPacket packet) {
+        try {
+            String url = this.remoteFile.getPath();
+            String deleteToken = DeleteSlotPacketParser.parseDeleteToken(packet);
+            Logging.d("filetransfer.http.delete", "Got delete token '" + deleteToken + "' for remote file '" + remoteFile.getPath() + "'");
+            OkHttpClient client = HttpClient.getClient(true);
+            Request request = new Request.Builder()
+                    .url(url)
+                    .addHeader(HEADER_NAME_DELETE_TOKEN, deleteToken)
+                    .delete()
+                    .build();
+            client.newCall(request).enqueue(new Callback() {
+                @Override
+                public void onFailure(Call call, IOException e) {
+                    Logging.e("filetransfer.http.delete", "Error while connecting to '" + call.request().url() + "': " + e.getMessage());
+                    MessageUtil.markMessage(remoteFile.getMessage(), Message.STATUS_REMOTE_FILE_DELETE_FAILED);
+                }
+
+                @Override
+                public void onResponse(Call call, Response response) throws IOException {
+                    if (response.isSuccessful()) {
+                        MessageUtil.markMessage(remoteFile.getMessage(), Message.STATUS_REMOTE_FILE_DELETED);
+                        Logging.i("filetransfer.http.delete", "Remote file successfully deleted '" + remoteFile.getPath() + "'");
+                    } else {
+                        String detailedMessage = response.body().string();
+                        switch (response.code()) {
+                            case 403:
+                            case 404:
+                            case 500:
+                                try {
+                                    JSONObject jsonObject = new JSONObject(detailedMessage);
+                                    detailedMessage = jsonObject.getString("msg");
+                                } catch (JSONException e) {
+                                    Logging.e("filetransfer.http.delete", "Failed to get error message from expected json response: " + detailedMessage);
+                                }
+                                break;
+                        }
+                        Logging.e("filetransfer.http.delete", "Could not delete remote file '" + remoteFile.getPath() + "'. Response Code: " + response.code() + ", details: " + detailedMessage);
+                        MessageUtil.markMessage(remoteFile.getMessage(), Message.STATUS_REMOTE_FILE_DELETE_FAILED);
+                    }
+                }
+            });
+
+        } catch (XmppException e) {
+            Logging.e("filetransfer.http.delete", "Error while trying to get the delete token: " + e.getMessage());
+            MessageUtil.markMessage(remoteFile.getMessage(), Message.STATUS_REMOTE_FILE_DELETE_FAILED);
+        }
+    }
+}
diff --git a/src/main/java/de/thedevstack/conversationsplus/ui/ConversationFragment.java b/src/main/java/de/thedevstack/conversationsplus/ui/ConversationFragment.java
index d6e6f34c..934f16b6 100644
--- a/src/main/java/de/thedevstack/conversationsplus/ui/ConversationFragment.java
+++ b/src/main/java/de/thedevstack/conversationsplus/ui/ConversationFragment.java
@@ -8,7 +8,6 @@ import android.content.ActivityNotFoundException;
 import android.content.Context;
 import android.content.DialogInterface;
 import android.content.Intent;
-import android.content.IntentSender;
 import android.content.IntentSender.SendIntentException;
 import android.os.Bundle;
 import android.support.annotation.Nullable;
@@ -24,8 +23,6 @@ import android.view.View.OnClickListener;
 import android.view.ViewGroup;
 import android.view.inputmethod.EditorInfo;
 import android.view.inputmethod.InputMethodManager;
-import android.widget.AbsListView;
-import android.widget.AbsListView.OnScrollListener;
 import android.widget.AdapterView;
 import android.widget.AdapterView.AdapterContextMenuInfo;
 import android.widget.ImageButton;
@@ -48,6 +45,7 @@ import java.util.List;
 import de.thedevstack.conversationsplus.ConversationsPlusPreferences;
 import de.thedevstack.conversationsplus.http.HttpConnectionManager;
 import de.thedevstack.conversationsplus.http.HttpDownloadConnection;
+import de.thedevstack.conversationsplus.services.filetransfer.http.DeleteRemoteFileService;
 import de.thedevstack.conversationsplus.ui.dialogs.MessageDetailsDialog;
 import de.thedevstack.conversationsplus.Config;
 import de.thedevstack.conversationsplus.R;
@@ -576,12 +574,19 @@ public class ConversationFragment extends Fragment implements EditMessage.Keyboa
 				deleteFile.setVisible(true);
 				deleteFile.setTitle(activity.getString(R.string.delete_x_file,UIHelper.getFileDescriptionString(activity, m)));
 			}
+            if (m.isHttpUploaded() && (MessageUtil.isMessageSent(m) || m.getStatus() == Message.STATUS_REMOTE_FILE_DELETE_FAILED)) {
+                MenuItem deleteRemoteFile = menu.findItem(R.id.msg_ctx_menu_delete_remote_file);
+                deleteRemoteFile.setVisible(true);
+            }
 		}
 	}
 
 	@Override
 	public boolean onContextItemSelected(MenuItem item) {
 		switch (item.getItemId()) {
+            case R.id.msg_ctx_menu_delete_remote_file:
+                new DeleteRemoteFileService().deleteRemoteFile(selectedMessage);
+                return true;
             case R.id.msg_ctx_mnu_details:
                 new MessageDetailsDialog(getActivity(), selectedMessage).show();
                 return true;
diff --git a/src/main/java/de/thedevstack/conversationsplus/utils/MessageUtil.java b/src/main/java/de/thedevstack/conversationsplus/utils/MessageUtil.java
index 67433b31..626b1bf3 100644
--- a/src/main/java/de/thedevstack/conversationsplus/utils/MessageUtil.java
+++ b/src/main/java/de/thedevstack/conversationsplus/utils/MessageUtil.java
@@ -18,6 +18,16 @@ import de.thedevstack.conversationsplus.persistance.FileBackend;
  */
 public final class MessageUtil {
 
+    public static boolean isMessageSent(Message message) {
+        switch (message.getStatus()) {
+            case Message.STATUS_SEND:
+            case Message.STATUS_SEND_DISPLAYED:
+            case Message.STATUS_SEND_RECEIVED:
+                return true;
+            default:
+                return false;
+        }
+    }
 
     public static boolean markMessage(Conversation conversation, String uuid, int status) {
         if (uuid == null) {
diff --git a/src/main/java/de/thedevstack/conversationsplus/xmpp/AbstractIqPacketParser.java b/src/main/java/de/thedevstack/conversationsplus/xmpp/IqPacketParser.java
index d777cb64..7c198ce9 100644
--- a/src/main/java/de/thedevstack/conversationsplus/xmpp/AbstractIqPacketParser.java
+++ b/src/main/java/de/thedevstack/conversationsplus/xmpp/IqPacketParser.java
@@ -7,19 +7,23 @@ import de.thedevstack.conversationsplus.xmpp.exceptions.MissingRequiredElementEx
 /**
  *
  */
-public abstract class AbstractIqPacketParser {
-    protected static Element findRequiredChild(Element element, String elementName, String namespace) throws MissingRequiredElementException {
-        if (null == element) {
-            return null;
-        }
-        Element child = element.findChild(elementName, namespace);
+public abstract class IqPacketParser {
+    public static Element findRequiredChild(Element element, String elementName, String namespace) throws MissingRequiredElementException {
+        Element child = findChild(element, elementName, namespace);
         if (child == null) {
             throw new MissingRequiredElementException(elementName, namespace, element);
         }
         return child;
     }
 
-    protected static String findRequiredChildContent(Element element, String elementName) throws MissingRequiredContentException {
+    public static Element findChild(Element element, String elementName, String namespace) {
+        if (null == element) {
+            return null;
+        }
+        return element.findChild(elementName, namespace);
+    }
+
+    public static String findRequiredChildContent(Element element, String elementName) throws MissingRequiredContentException {
         if (null == element) {
             return null;
         }
@@ -30,14 +34,18 @@ public abstract class AbstractIqPacketParser {
         return childContent;
     }
 
-    protected static String findRequiredChildContent(Element element, String elementName, String namespace) throws MissingRequiredContentException {
-        if (null == element) {
-            return null;
-        }
-        String childContent = element.findChildContent(elementName, namespace);
+    public static String findRequiredChildContent(Element element, String elementName, String namespace) throws MissingRequiredContentException {
+        String childContent = findChildContent(element, elementName, namespace);
         if (null == childContent) {
             throw new MissingRequiredContentException(elementName, namespace, element);
         }
         return childContent;
     }
+
+    public static String findChildContent(Element element, String elementName, String namespace) {
+        if (null == element) {
+            return null;
+        }
+        return element.findChildContent(elementName, namespace);
+    }
 }
diff --git a/src/main/java/de/thedevstack/conversationsplus/xmpp/exceptions/BadRequestIqErrorException.java b/src/main/java/de/thedevstack/conversationsplus/xmpp/exceptions/BadRequestIqErrorException.java
new file mode 100644
index 00000000..69fb893b
--- /dev/null
+++ b/src/main/java/de/thedevstack/conversationsplus/xmpp/exceptions/BadRequestIqErrorException.java
@@ -0,0 +1,17 @@
+package de.thedevstack.conversationsplus.xmpp.exceptions;
+
+import de.thedevstack.conversationsplus.xml.Element;
+
+/**
+ * Created by steckbrief on 22.08.2016.
+ */
+public class BadRequestIqErrorException extends IqPacketErrorException {
+    public BadRequestIqErrorException(Element context, String errorMessage) {
+        super(context, errorMessage);
+    }
+
+    @Override
+    public String getMessage() {
+        return "Bad Request: " + super.getMessage();
+    }
+}
diff --git a/src/main/java/de/thedevstack/conversationsplus/xmpp/exceptions/InternalServerErrorException.java b/src/main/java/de/thedevstack/conversationsplus/xmpp/exceptions/InternalServerErrorException.java
new file mode 100644
index 00000000..7925c423
--- /dev/null
+++ b/src/main/java/de/thedevstack/conversationsplus/xmpp/exceptions/InternalServerErrorException.java
@@ -0,0 +1,17 @@
+package de.thedevstack.conversationsplus.xmpp.exceptions;
+
+import de.thedevstack.conversationsplus.xml.Element;
+
+/**
+ * Created by steckbrief on 22.08.2016.
+ */
+public class InternalServerErrorException extends IqPacketErrorException {
+    public InternalServerErrorException(Element packet, String errorText) {
+        super(packet, errorText);
+    }
+
+    @Override
+    public String getMessage() {
+        return "Internal Server Error: " + super.getMessage();
+    }
+}
diff --git a/src/main/java/de/thedevstack/conversationsplus/xmpp/exceptions/IqPacketErrorException.java b/src/main/java/de/thedevstack/conversationsplus/xmpp/exceptions/IqPacketErrorException.java
new file mode 100644
index 00000000..d4d932b7
--- /dev/null
+++ b/src/main/java/de/thedevstack/conversationsplus/xmpp/exceptions/IqPacketErrorException.java
@@ -0,0 +1,20 @@
+package de.thedevstack.conversationsplus.xmpp.exceptions;
+
+import de.thedevstack.conversationsplus.xml.Element;
+
+/**
+ * Created by steckbrief on 22.08.2016.
+ */
+public class IqPacketErrorException extends XmppException {
+    private final String iqErrorText;
+
+    public IqPacketErrorException(Element context, String errorMessage) {
+        super(context);
+        this.iqErrorText = errorMessage;
+    }
+
+    @Override
+    public String getMessage() {
+        return this.iqErrorText + " in context: " + this.getContext();
+    }
+}
diff --git a/src/main/java/de/thedevstack/conversationsplus/xmpp/exceptions/ServiceUnavailableException.java b/src/main/java/de/thedevstack/conversationsplus/xmpp/exceptions/ServiceUnavailableException.java
new file mode 100644
index 00000000..7e503aa9
--- /dev/null
+++ b/src/main/java/de/thedevstack/conversationsplus/xmpp/exceptions/ServiceUnavailableException.java
@@ -0,0 +1,17 @@
+package de.thedevstack.conversationsplus.xmpp.exceptions;
+
+import de.thedevstack.conversationsplus.xml.Element;
+
+/**
+ * Created by steckbrief on 22.08.2016.
+ */
+public class ServiceUnavailableException extends IqPacketErrorException {
+    public ServiceUnavailableException(Element context, String errorMessage) {
+        super(context, errorMessage);
+    }
+
+    @Override
+    public String getMessage() {
+        return "Service unavailable: " + super.getMessage();
+    }
+}
diff --git a/src/main/java/de/thedevstack/conversationsplus/xmpp/exceptions/UndefinedConditionException.java b/src/main/java/de/thedevstack/conversationsplus/xmpp/exceptions/UndefinedConditionException.java
new file mode 100644
index 00000000..38e1f6d2
--- /dev/null
+++ b/src/main/java/de/thedevstack/conversationsplus/xmpp/exceptions/UndefinedConditionException.java
@@ -0,0 +1,17 @@
+package de.thedevstack.conversationsplus.xmpp.exceptions;
+
+import de.thedevstack.conversationsplus.xml.Element;
+
+/**
+ * Created by steckbrief on 22.08.2016.
+ */
+public class UndefinedConditionException extends IqPacketErrorException {
+    public UndefinedConditionException(Element packet, String errorText) {
+        super(packet, errorText);
+    }
+
+    @Override
+    public String getMessage() {
+        return "Undefined Condition: " + super.getMessage();
+    }
+}
diff --git a/src/main/java/de/thedevstack/conversationsplus/xmpp/filetransfer/http/DeleteSlotPacketParser.java b/src/main/java/de/thedevstack/conversationsplus/xmpp/filetransfer/http/DeleteSlotPacketParser.java
new file mode 100644
index 00000000..d7e136fc
--- /dev/null
+++ b/src/main/java/de/thedevstack/conversationsplus/xmpp/filetransfer/http/DeleteSlotPacketParser.java
@@ -0,0 +1,28 @@
+package de.thedevstack.conversationsplus.xmpp.filetransfer.http;
+
+import de.thedevstack.conversationsplus.xml.Element;
+import de.thedevstack.conversationsplus.xmpp.IqPacketParser;
+import de.thedevstack.conversationsplus.xmpp.exceptions.UnexpectedIqPacketTypeException;
+import de.thedevstack.conversationsplus.xmpp.exceptions.XmppException;
+import de.thedevstack.conversationsplus.xmpp.stanzas.IqPacket;
+import de.thedevstack.conversationsplus.xmpp.utils.ErrorIqPacketExceptionHelper;
+
+/**
+ * Created by steckbrief on 21.08.2016.
+ */
+public class DeleteSlotPacketParser extends IqPacketParser {
+    public static String parseDeleteToken(IqPacket packet) throws XmppException {
+        String deletetoken = null;
+        if (packet.getType() == IqPacket.TYPE.RESULT) {
+            Element slot = findRequiredChild(packet, "slot", FileTransferHttp.NAMESPACE);
+
+            deletetoken = findRequiredChildContent(slot, "deletetoken");
+        } else if (packet.getType() == IqPacket.TYPE.ERROR) {
+            ErrorIqPacketExceptionHelper.throwIqErrorException(packet);
+        } else {
+            throw new UnexpectedIqPacketTypeException(packet, packet.getType(), IqPacket.TYPE.RESULT, IqPacket.TYPE.ERROR);
+        }
+
+        return deletetoken;
+    }
+}
diff --git a/src/main/java/de/thedevstack/conversationsplus/xmpp/filetransfer/http/DeleteSlotRequestPacket.java b/src/main/java/de/thedevstack/conversationsplus/xmpp/filetransfer/http/DeleteSlotRequestPacket.java
new file mode 100644
index 00000000..6adc3aac
--- /dev/null
+++ b/src/main/java/de/thedevstack/conversationsplus/xmpp/filetransfer/http/DeleteSlotRequestPacket.java
@@ -0,0 +1,33 @@
+package de.thedevstack.conversationsplus.xmpp.filetransfer.http;
+
+import de.thedevstack.conversationsplus.xml.Element;
+import de.thedevstack.conversationsplus.xmpp.stanzas.IqPacket;
+
+/**
+ * Created by steckbrief on 21.08.2016.
+ */
+public class DeleteSlotRequestPacket extends IqPacket {
+    public static final String ELEMENT_NAME = "request";
+    public static final String FILEURL_ELEMENT_NAME = "fileurl";
+    private Element requestElement;
+    private String fileurl;
+
+    private DeleteSlotRequestPacket() {
+        super(TYPE.GET);
+        this.requestElement = super.addChild(DeleteSlotRequestPacket.ELEMENT_NAME, FileTransferHttp.NAMESPACE);
+        this.requestElement.setAttribute("type", "delete");
+    }
+
+    public DeleteSlotRequestPacket(String fileurl) {
+        this();
+        this.setFileURL(fileurl);
+    }
+
+    public void setFileURL(String fileurl) {
+        if (null == fileurl || fileurl.isEmpty()) {
+            throw new IllegalArgumentException("fileurl must not be null or empty.");
+        }
+        this.fileurl = fileurl;
+        this.requestElement.addChild(FILEURL_ELEMENT_NAME).setContent(fileurl);
+    }
+}
diff --git a/src/main/java/de/thedevstack/conversationsplus/xmpp/filetransfer/http/FileTransferHttp.java b/src/main/java/de/thedevstack/conversationsplus/xmpp/filetransfer/http/FileTransferHttp.java
new file mode 100644
index 00000000..28f4f870
--- /dev/null
+++ b/src/main/java/de/thedevstack/conversationsplus/xmpp/filetransfer/http/FileTransferHttp.java
@@ -0,0 +1,8 @@
+package de.thedevstack.conversationsplus.xmpp.filetransfer.http;
+
+/**
+ * Created by steckbrief on 21.08.2016.
+ */
+public interface FileTransferHttp {
+    String NAMESPACE = "urn:xmpp:filetransfer:http";
+}
diff --git a/src/main/java/de/thedevstack/conversationsplus/xmpp/filetransfer/http/FileTransferHttpDeleteSlotRequestPacketGenerator.java b/src/main/java/de/thedevstack/conversationsplus/xmpp/filetransfer/http/FileTransferHttpDeleteSlotRequestPacketGenerator.java
new file mode 100644
index 00000000..bc4380fe
--- /dev/null
+++ b/src/main/java/de/thedevstack/conversationsplus/xmpp/filetransfer/http/FileTransferHttpDeleteSlotRequestPacketGenerator.java
@@ -0,0 +1,39 @@
+package de.thedevstack.conversationsplus.xmpp.filetransfer.http;
+
+import de.thedevstack.conversationsplus.xmpp.jid.Jid;
+import de.thedevstack.conversationsplus.xmpp.stanzas.IqPacket;
+
+/**
+ * Created by steckbrief on 21.08.2016.
+ */
+public final class FileTransferHttpDeleteSlotRequestPacketGenerator {
+    /**
+     * Generates the IqPacket to request a slot to delete a file previously uploaded via http upload.
+     * The attributes from and id are not set in here - this is added while sending the packet.
+     * <pre>
+     * <iq from='romeo@montague.tld/garden'
+     *     id='step_01'
+     *     to='upload.montague.tld'
+     *     type='get'>
+     *   <request type='delete' xmlns='urn:xmpp:filetransfer:http'>
+     *     <fileurl>http://upload.montague.tld/files/1e56ee17-ee4c-4a9c-aedd-cb09cb3984a7/my_juliet.png</fileurl>
+     *   </request>
+     * </iq>
+     * </pre>
+     * @param host the jid of the host to request a slot from
+     * @param fileurl the URL of the file to be deleted
+     * @return the IqPacket
+     */
+    public static IqPacket generate(Jid host, String fileurl) {
+        DeleteSlotRequestPacket packet = new DeleteSlotRequestPacket(fileurl);
+        packet.setTo(host);
+        return packet;
+    }
+
+    /**
+     * Utility class - avoid instantiation
+     */
+    private FileTransferHttpDeleteSlotRequestPacketGenerator() {
+        // Helper class - avoid instantiation
+    }
+}
diff --git a/src/main/java/de/thedevstack/conversationsplus/xmpp/utils/ErrorIqPacketExceptionHelper.java b/src/main/java/de/thedevstack/conversationsplus/xmpp/utils/ErrorIqPacketExceptionHelper.java
new file mode 100644
index 00000000..f02d8d46
--- /dev/null
+++ b/src/main/java/de/thedevstack/conversationsplus/xmpp/utils/ErrorIqPacketExceptionHelper.java
@@ -0,0 +1,44 @@
+package de.thedevstack.conversationsplus.xmpp.utils;
+
+import de.thedevstack.conversationsplus.xml.Element;
+import de.thedevstack.conversationsplus.xmpp.IqPacketParser;
+import de.thedevstack.conversationsplus.xmpp.exceptions.BadRequestIqErrorException;
+import de.thedevstack.conversationsplus.xmpp.exceptions.InternalServerErrorException;
+import de.thedevstack.conversationsplus.xmpp.exceptions.IqPacketErrorException;
+import de.thedevstack.conversationsplus.xmpp.exceptions.ServiceUnavailableException;
+import de.thedevstack.conversationsplus.xmpp.exceptions.UndefinedConditionException;
+
+/**
+ * Created by steckbrief on 22.08.2016.
+ */
+public final class ErrorIqPacketExceptionHelper {
+    private final static String ERROR_NAMESPACE = "urn:ietf:params:xml:ns:xmpp-stanzas";
+
+    public static void throwIqErrorException(Element packet) throws IqPacketErrorException {
+        if (hasErrorElement(packet, "bad-request")) {
+            throw new BadRequestIqErrorException(packet, getErrorText(packet));
+        }
+        if (hasErrorElement(packet, "service-unavailable")) {
+            throw new ServiceUnavailableException(packet, getErrorText(packet));
+        }
+        if (hasErrorElement(packet, "internal-server-error")) {
+            throw new InternalServerErrorException(packet, getErrorText(packet));
+        }
+        if (hasErrorElement(packet, "undefined-condition")) {
+            throw new UndefinedConditionException(packet, getErrorText(packet));
+        }
+        throw new IqPacketErrorException(packet, "Unknown error packet.");
+    }
+
+    private static boolean hasErrorElement(Element packet, String elementName) {
+        return null != IqPacketParser.findChild(packet, elementName, ERROR_NAMESPACE);
+    }
+
+    private static String getErrorText(Element packet) {
+        return IqPacketParser.findChildContent(packet, "text", ERROR_NAMESPACE);
+    }
+
+    private ErrorIqPacketExceptionHelper() {
+
+    }
+}
diff --git a/src/main/res/menu/message_context.xml b/src/main/res/menu/message_context.xml
index 0c7d8eef..da7f0636 100644
--- a/src/main/res/menu/message_context.xml
+++ b/src/main/res/menu/message_context.xml
@@ -36,4 +36,8 @@
         android:id="@+id/delete_file"
         android:title="@string/delete_x_file"
         android:visible="false"/>
+    <item
+        android:id="@+id/msg_ctx_menu_delete_remote_file"
+        android:title="@string/delete_remote_file_x"
+        android:visible="false"/>
 </menu>
\ No newline at end of file
diff --git a/src/main/res/values/strings.xml b/src/main/res/values/strings.xml
index 3da33010..22b6c490 100644
--- a/src/main/res/values/strings.xml
+++ b/src/main/res/values/strings.xml
@@ -674,4 +674,5 @@
 	<string name="security_error_invalid_file_access">Security error: Invalid file access</string>
 	<string name="no_application_to_share_uri">No application found to share URI</string>
 	<string name="share_uri_with">Share URI with…</string>
+	<string name="delete_remote_file_x">Delete remote file</string>
 </resources>