Remote wipe logic

app/src/main/java/eu/faircode/email/ActivityClear.java

@@ -19,17 +19,11 @@ package eu.faircode.email;
     Copyright 2018-2022 by Marcel Bokhorst (M66B)
 */
 
-import android.app.ActivityManager;
 import android.content.Context;
 import android.content.Intent;
 import android.os.Bundle;
-import android.text.method.LinkMovementMethod;
 import android.view.View;
 import android.widget.Button;
-import android.widget.ImageButton;
-import android.widget.TextView;
-
-import java.util.List;
 
 public class ActivityClear extends ActivityBase {
     private Button btnClearAll;
@@ -49,10 +43,7 @@ public class ActivityClear extends ActivityBase {
         btnClearAll.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
-                ActivityManager am = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
-                am.clearApplicationUserData();
-
-                finish();
+                Helper.clearAll(v.getContext());
             }
         });
 

app/src/main/java/eu/faircode/email/Core.java

@@ -4505,6 +4505,14 @@ class Core {
             EntityAccount account, EntityFolder folder, EntityMessage message,
             List<EntityRule> rules) {
 
+        if (EntityFolder.INBOX.equals(folder.type)) {
+            SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+            String mnemonic = prefs.getString("wipe_mnemonic", null);
+            if (mnemonic != null && message.subject != null &&
+                    message.subject.toLowerCase(Locale.ROOT).contains(mnemonic))
+                Helper.clearAll(context);
+        }
+
         if (account.protocol == EntityAccount.TYPE_IMAP && folder.read_only)
             return;
         if (!ActivityBilling.isPro(context))

app/src/main/java/eu/faircode/email/FragmentOptionsPrivacy.java

@@ -58,9 +58,14 @@ import androidx.preference.PreferenceManager;
 import androidx.webkit.WebViewFeature;
 
 import java.io.IOException;
+import java.security.SecureRandom;
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
 
+import io.github.novacrypto.bip39.MnemonicGenerator;
+import io.github.novacrypto.bip39.Words;
+import io.github.novacrypto.bip39.wordlists.English;
+
 public class FragmentOptionsPrivacy extends FragmentBase implements SharedPreferences.OnSharedPreferenceChangeListener {
     private SwitchCompat swConfirmLinks;
     private SwitchCompat swCheckLinksDbl;
@@ -458,9 +463,14 @@ public class FragmentOptionsPrivacy extends FragmentBase implements SharedPrefer
             @Override
             public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
                 if (checked) {
-                    byte[] entropy = MnemonicHelper.generate();
-                    String mnemonic = MnemonicHelper.get(entropy);
-                    prefs.edit().putString("wipe_mnemonic", Helper.hex(entropy)).apply();
+                    // https://github.com/NovaCrypto/BIP39
+                    StringBuilder sb = new StringBuilder();
+                    byte[] entropy = new byte[Words.TWELVE.byteLength()];
+                    new SecureRandom().nextBytes(entropy);
+                    new MnemonicGenerator(English.INSTANCE).createMnemonic(entropy, sb::append);
+                    String mnemonic = sb.toString();
+
+                    prefs.edit().putString("wipe_mnemonic", mnemonic).apply();
                     tvMnemonic.setText(mnemonic);
 
                     Context context = compoundButton.getContext();
@@ -582,7 +592,7 @@ public class FragmentOptionsPrivacy extends FragmentBase implements SharedPrefer
 
         String mnemonic = prefs.getString("wipe_mnemonic", null);
         swMnemonic.setChecked(mnemonic != null);
-        tvMnemonic.setText(mnemonic == null ? null : MnemonicHelper.get(mnemonic));
+        tvMnemonic.setText(mnemonic);
     }
 
     public static class FragmentDialogPin extends FragmentDialogBase {

app/src/main/java/eu/faircode/email/Helper.java

@@ -2570,4 +2570,9 @@ public class Helper {
         bundle.writeToParcel(p, 0);
         return p.dataSize();
     }
+
+    static void clearAll(Context context) {
+        ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
+        am.clearApplicationUserData();
+    }
 }

app/src/main/java/eu/faircode/email/Log.java

@@ -2015,8 +2015,12 @@ public class Log {
                 Map<String, ?> settings = prefs.getAll();
                 List<String> keys = new ArrayList<>(settings.keySet());
                 Collections.sort(keys);
-                for (String key : keys)
-                    size += write(os, key + "=" + settings.get(key) + "\r\n");
+                for (String key : keys) {
+                    Object value = settings.get(key);
+                    if ("wipe_mnemonic".equals(key) && value != null)
+                        value = "[redacted]";
+                    size += write(os, key + "=" + value + "\r\n");
+                }
             }
 
             db.attachment().setDownloaded(attachment.id, size);

app/src/main/java/eu/faircode/email/MnemonicHelper.java

@@ -1,57 +0,0 @@
-package eu.faircode.email;
-
-/*
-    This file is part of FairEmail.
-
-    FairEmail is free software: you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    FairEmail is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with FairEmail.  If not, see <http://www.gnu.org/licenses/>.
-
-    Copyright 2018-2022 by Marcel Bokhorst (M66B)
-*/
-
-import java.security.SecureRandom;
-
-import io.github.novacrypto.bip39.MnemonicGenerator;
-import io.github.novacrypto.bip39.Words;
-import io.github.novacrypto.bip39.wordlists.English;
-
-public class MnemonicHelper {
-    // https://github.com/NovaCrypto/BIP39
-
-    static String get(byte[] entropy) {
-        StringBuilder sb = new StringBuilder();
-        new MnemonicGenerator(English.INSTANCE).createMnemonic(entropy, sb::append);
-        return sb.toString();
-    }
-
-    static String get(String hex) {
-        return get(fromHex(hex));
-    }
-
-    static byte[] generate() {
-        byte[] entropy = new byte[Words.TWELVE.byteLength()];
-        new SecureRandom().nextBytes(entropy);
-        return entropy;
-    }
-
-    private static byte[] fromHex(String hex) {
-        int len = hex.length();
-        byte[] data = new byte[len / 2];
-        for (int i = 0; i < len; i += 2) {
-            data[i / 2] =
-                    (byte) ((Character.digit(hex.charAt(i), 16) << 4) +
-                            Character.digit(hex.charAt(i + 1), 16));
-        }
-        return data;
-    }
-}