Handle GV2 addresses.

app/src/main/AndroidManifest.xml

@@ -223,6 +223,14 @@
             <category android:name="android.intent.category.MULTIWINDOW_LAUNCHER" />
         </intent-filter>
 
+        <intent-filter>
+            <action android:name="android.intent.action.VIEW" />
+            <category android:name="android.intent.category.DEFAULT" />
+            <category android:name="android.intent.category.BROWSABLE" />
+            <data android:scheme="https"
+                  android:host="group.signal.org"/>
+        </intent-filter>
+
         <meta-data android:name="com.sec.minimode.icon.portrait.normal"
                    android:resource="@mipmap/ic_launcher" />
         <meta-data android:name="com.sec.minimode.icon.landscape.normal"

app/src/main/java/org/thoughtcrime/securesms/BindableConversationItem.java

@@ -1,14 +1,14 @@
 package org.thoughtcrime.securesms;
 
+import android.view.View;
+
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
-import android.view.View;
 
 import org.thoughtcrime.securesms.contactshare.Contact;
 import org.thoughtcrime.securesms.conversation.ConversationMessage;
 import org.thoughtcrime.securesms.database.model.MessageRecord;
 import org.thoughtcrime.securesms.database.model.MmsMessageRecord;
-import org.thoughtcrime.securesms.database.model.ReactionRecord;
 import org.thoughtcrime.securesms.groups.GroupId;
 import org.thoughtcrime.securesms.linkpreview.LinkPreview;
 import org.thoughtcrime.securesms.mms.GlideRequests;
@@ -49,5 +49,8 @@ public interface BindableConversationItem extends Unbindable {
     void onReactionClicked(@NonNull View reactionTarget, long messageId, boolean isMms);
     void onGroupMemberClicked(@NonNull RecipientId recipientId, @NonNull GroupId groupId);
     void onMessageWithErrorClicked(@NonNull MessageRecord messageRecord);
+
+    /** @return true if handled, false if you want to let the normal url handling continue */
+    boolean onUrlClicked(@NonNull String url);
   }
 }

app/src/main/java/org/thoughtcrime/securesms/MainActivity.java

@@ -1,9 +1,12 @@
 package org.thoughtcrime.securesms;
 
+import android.content.Intent;
+import android.net.Uri;
 import android.os.Bundle;
 
 import androidx.annotation.NonNull;
 
+import org.thoughtcrime.securesms.util.CommunicationActions;
 import org.thoughtcrime.securesms.util.DynamicNoActionBarTheme;
 import org.thoughtcrime.securesms.util.DynamicTheme;
 
@@ -18,6 +21,14 @@ public class MainActivity extends PassphraseRequiredActivity {
     setContentView(R.layout.main_activity);
 
     navigator.onCreate(savedInstanceState);
+
+    handleGroupLinkInIntent(getIntent());
+  }
+
+  @Override
+  protected void onNewIntent(Intent intent) {
+    super.onNewIntent(intent);
+    handleGroupLinkInIntent(intent);
   }
 
   @Override
@@ -42,4 +53,11 @@ public class MainActivity extends PassphraseRequiredActivity {
   public @NonNull MainNavigator getNavigator() {
     return navigator;
   }
+
+  private void handleGroupLinkInIntent(Intent intent) {
+    Uri data = intent.getData();
+    if (data != null) {
+      CommunicationActions.handlePotentialGroupLinkUrl(this, data.toString());
+    }
+  }
 }

app/src/main/java/org/thoughtcrime/securesms/components/reminder/ExpiredBuildReminder.java

@@ -1,33 +1,17 @@
 package org.thoughtcrime.securesms.components.reminder;
 
 import android.content.Context;
-import android.content.Intent;
-import android.net.Uri;
-import org.thoughtcrime.securesms.logging.Log;
-import android.widget.Toast;
 
 import org.thoughtcrime.securesms.R;
+import org.thoughtcrime.securesms.util.PlayStoreUtil;
 import org.thoughtcrime.securesms.util.Util;
 
 public class ExpiredBuildReminder extends Reminder {
-  @SuppressWarnings("unused")
-  private static final String TAG = ExpiredBuildReminder.class.getSimpleName();
 
   public ExpiredBuildReminder(final Context context) {
     super(context.getString(R.string.reminder_header_expired_build),
           context.getString(R.string.reminder_header_expired_build_details));
-    setOkListener(v -> {
+    setOkListener(v -> PlayStoreUtil.openPlayStoreOrOurApkDownloadPage(context));
-      try {
-        context.startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("market://details?id=" + context.getPackageName())));
-      } catch (android.content.ActivityNotFoundException anfe) {
-        try {
-          context.startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("https://play.google.com/store/apps/details?id=" + context.getPackageName())));
-        } catch (android.content.ActivityNotFoundException anfe2) {
-          Log.w(TAG, anfe2);
-          Toast.makeText(context, R.string.OutdatedBuildReminder_no_web_browser_installed, Toast.LENGTH_SHORT).show();
-        }
-      }
-    });
   }
 
   @Override

app/src/main/java/org/thoughtcrime/securesms/components/reminder/OutdatedBuildReminder.java

@@ -1,35 +1,17 @@
 package org.thoughtcrime.securesms.components.reminder;
 
-import android.content.ActivityNotFoundException;
 import android.content.Context;
-import android.content.Intent;
-import android.net.Uri;
-import org.thoughtcrime.securesms.logging.Log;
-
-import android.widget.Toast;
 
 import org.thoughtcrime.securesms.R;
+import org.thoughtcrime.securesms.util.PlayStoreUtil;
 import org.thoughtcrime.securesms.util.Util;
 
 public class OutdatedBuildReminder extends Reminder {
 
-  private static final String TAG = OutdatedBuildReminder.class.getSimpleName();
-
   public OutdatedBuildReminder(final Context context) {
     super(context.getString(R.string.reminder_header_outdated_build),
           getPluralsText(context));
-    setOkListener(v -> {
+    setOkListener(v -> PlayStoreUtil.openPlayStoreOrOurApkDownloadPage(context));
-      try {
-        context.startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("market://details?id=" + context.getPackageName())));
-      } catch (ActivityNotFoundException anfe) {
-        try {
-          context.startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("https://play.google.com/store/apps/details?id=" + context.getPackageName())));
-        } catch (ActivityNotFoundException anfe2) {
-          Log.w(TAG, anfe2);
-          Toast.makeText(context, R.string.OutdatedBuildReminder_no_web_browser_installed, Toast.LENGTH_LONG).show();
-        }
-      }
-    });
   }
 
   private static CharSequence getPluralsText(final Context context) {

app/src/main/java/org/thoughtcrime/securesms/conversation/ConversationFragment.java

@@ -1388,6 +1388,11 @@ public class ConversationFragment extends LoggingFragment {
     public void onMessageWithErrorClicked(@NonNull MessageRecord messageRecord) {
       listener.onMessageWithErrorClicked(messageRecord);
     }
+
+    @Override
+    public boolean onUrlClicked(@NonNull String url) {
+      return CommunicationActions.handlePotentialGroupLinkUrl(requireActivity(), url);
+    }
   }
 
   @Override

app/src/main/java/org/thoughtcrime/securesms/conversation/ConversationItem.java

@@ -110,12 +110,13 @@ import org.thoughtcrime.securesms.revealable.ViewOnceUtil;
 import org.thoughtcrime.securesms.stickers.StickerUrl;
 import org.thoughtcrime.securesms.util.DateUtils;
 import org.thoughtcrime.securesms.util.DynamicTheme;
-import org.thoughtcrime.securesms.util.LongClickCopySpan;
+import org.thoughtcrime.securesms.util.InterceptableLongClickCopyLinkSpan;
 import org.thoughtcrime.securesms.util.LongClickMovementMethod;
 import org.thoughtcrime.securesms.util.SearchUtil;
 import org.thoughtcrime.securesms.util.TextSecurePreferences;
 import org.thoughtcrime.securesms.util.ThemeUtil;
 import org.thoughtcrime.securesms.util.VibrateUtil;
+import org.thoughtcrime.securesms.util.UrlClickHandler;
 import org.thoughtcrime.securesms.util.ViewUtil;
 import org.thoughtcrime.securesms.util.views.Stub;
 import org.whispersystems.libsignal.util.guava.Optional;
@@ -194,6 +195,7 @@ public class ConversationItem extends LinearLayout implements BindableConversati
   private final SharedContactClickListener      sharedContactClickListener  = new SharedContactClickListener();
   private final LinkPreviewClickListener        linkPreviewClickListener    = new LinkPreviewClickListener();
   private final ViewOnceMessageClickListener    revealableClickListener     = new ViewOnceMessageClickListener();
+  private final UrlClickListener                urlClickListener            = new UrlClickListener();
 
   private final Context context;
 
@@ -580,7 +582,9 @@ public class ConversationItem extends LinearLayout implements BindableConversati
     return messageRecord.isMms() && ((MmsMessageRecord) messageRecord).isViewOnce();
   }
 
-  private void setBodyText(MessageRecord messageRecord, @Nullable String searchQuery) {
+  private void setBodyText(@NonNull MessageRecord messageRecord,
+                           @Nullable String searchQuery)
+  {
     bodyText.setClickable(false);
     bodyText.setFocusable(false);
     bodyText.setTextSize(TypedValue.COMPLEX_UNIT_SP, TextSecurePreferences.getMessageBodyTextSize(context));
@@ -916,7 +920,9 @@ public class ConversationItem extends LinearLayout implements BindableConversati
     contactPhoto.setAvatar(glideRequests, recipient, false);
   }
 
-  private SpannableString linkifyMessageBody(SpannableString messageBody, boolean shouldLinkifyAllLinks) {
+  private SpannableString linkifyMessageBody(@NonNull SpannableString messageBody,
+                                             boolean shouldLinkifyAllLinks)
+  {
     int     linkPattern = Linkify.WEB_URLS | Linkify.EMAIL_ADDRESSES | Linkify.PHONE_NUMBERS;
     boolean hasLinks    = Linkify.addLinks(messageBody, shouldLinkifyAllLinks ? linkPattern : 0);
 
@@ -930,7 +936,8 @@ public class ConversationItem extends LinearLayout implements BindableConversati
       for (URLSpan urlSpan : urlSpans) {
         int     start = messageBody.getSpanStart(urlSpan);
         int     end   = messageBody.getSpanEnd(urlSpan);
-        messageBody.setSpan(new LongClickCopySpan(urlSpan.getURL()), start, end, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
+        URLSpan span  = new InterceptableLongClickCopyLinkSpan(urlSpan.getURL(), urlClickListener);
+        messageBody.setSpan(span, start, end, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
       }
     }
 
@@ -1473,6 +1480,14 @@ public class ConversationItem extends LinearLayout implements BindableConversati
     }
   }
 
+  private final class UrlClickListener implements UrlClickHandler {
+
+    @Override
+    public boolean handleOnClick(@NonNull String url) {
+      return eventListener != null && eventListener.onUrlClicked(url);
+    }
+  }
+
   private class MentionClickableSpan extends ClickableSpan {
     private final RecipientId mentionedRecipientId;
 

app/src/main/java/org/thoughtcrime/securesms/groups/ui/invitesandrequests/joining/GroupJoinUpdateRequiredBottomSheetDialogFragment.java

@@ -0,0 +1,55 @@
+package org.thoughtcrime.securesms.groups.ui.invitesandrequests.joining;
+
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.fragment.app.DialogFragment;
+import androidx.fragment.app.FragmentManager;
+
+import com.google.android.material.bottomsheet.BottomSheetDialogFragment;
+
+import org.thoughtcrime.securesms.R;
+import org.thoughtcrime.securesms.util.BottomSheetUtil;
+import org.thoughtcrime.securesms.util.PlayStoreUtil;
+import org.thoughtcrime.securesms.util.ThemeUtil;
+
+public final class GroupJoinUpdateRequiredBottomSheetDialogFragment extends BottomSheetDialogFragment {
+
+  public static void show(@NonNull FragmentManager manager) {
+    new GroupJoinUpdateRequiredBottomSheetDialogFragment().show(manager, BottomSheetUtil.STANDARD_BOTTOM_SHEET_FRAGMENT_TAG);
+  }
+
+  @Override
+  public void onCreate(@Nullable Bundle savedInstanceState) {
+    setStyle(DialogFragment.STYLE_NORMAL,
+             ThemeUtil.isDarkTheme(requireContext()) ? R.style.Theme_Signal_RoundedBottomSheet
+                                                     : R.style.Theme_Signal_RoundedBottomSheet_Light);
+
+    super.onCreate(savedInstanceState);
+  }
+
+  @Override
+  public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
+    return inflater.inflate(R.layout.group_join_update_needed_bottom_sheet, container, false);
+  }
+
+  @Override
+  public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
+    super.onViewCreated(view, savedInstanceState);
+
+    view.findViewById(R.id.group_join_update_button)
+        .setOnClickListener(v -> {
+          PlayStoreUtil.openPlayStoreOrOurApkDownloadPage(requireContext());
+          dismiss();
+        });
+  }
+
+  @Override
+  public void show(@NonNull FragmentManager manager, @Nullable String tag) {
+    BottomSheetUtil.show(manager, tag, this);
+  }
+}

app/src/main/java/org/thoughtcrime/securesms/groups/v2/GroupInviteLinkUrl.java

@@ -0,0 +1,115 @@
+package org.thoughtcrime.securesms.groups.v2;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+import com.google.protobuf.ByteString;
+
+import org.signal.storageservice.protos.groups.GroupInviteLink;
+import org.signal.zkgroup.InvalidInputException;
+import org.signal.zkgroup.groups.GroupMasterKey;
+import org.thoughtcrime.securesms.util.Base64UrlSafe;
+
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URL;
+
+public final class GroupInviteLinkUrl {
+
+  private static final String GROUP_URL_HOST   = "group.signal.org";
+  private static final String GROUP_URL_PREFIX = "https://" + GROUP_URL_HOST + "/#";
+
+  private final GroupMasterKey    groupMasterKey;
+  private final GroupLinkPassword password;
+  private final String            url;
+
+  public static @Nullable GroupInviteLinkUrl fromUrl(@NonNull String urlString)
+      throws InvalidGroupLinkException, UnknownGroupLinkVersionException
+  {
+    URL url;
+    try {
+      url = new URL(urlString);
+    } catch (MalformedURLException e) {
+      return null;
+    }
+
+    try {
+      if (!GROUP_URL_HOST.equalsIgnoreCase(url.getHost())) {
+        return null;
+      }
+
+      if (!"/".equals(url.getPath()) && url.getPath().length() > 0) {
+        throw new InvalidGroupLinkException("No path was expected in url");
+      }
+
+      String encoding = url.getRef();
+
+      if (encoding == null || encoding.length() == 0) {
+        throw new InvalidGroupLinkException("No reference was in the url");
+      }
+
+      byte[]          bytes           = Base64UrlSafe.decodePaddingAgnostic(encoding);
+      GroupInviteLink groupInviteLink = GroupInviteLink.parseFrom(bytes);
+
+      //noinspection SwitchStatementWithTooFewBranches
+      switch (groupInviteLink.getContentsCase()) {
+        case V1CONTENTS: {
+            GroupInviteLink.GroupInviteLinkContentsV1 groupInviteLinkContentsV1 = groupInviteLink.getV1Contents();
+            GroupMasterKey                            groupMasterKey            = new GroupMasterKey(groupInviteLinkContentsV1.getGroupMasterKey().toByteArray());
+            GroupLinkPassword                         password                  = GroupLinkPassword.fromBytes(groupInviteLinkContentsV1.getInviteLinkPassword().toByteArray());
+
+            return new GroupInviteLinkUrl(groupMasterKey, password);
+        }
+        default: throw new UnknownGroupLinkVersionException("Url contains no known group link content");
+      }
+    } catch (GroupLinkPassword.InvalidLengthException | InvalidInputException | IOException e){
+      throw new InvalidGroupLinkException(e);
+    }
+  }
+
+  private GroupInviteLinkUrl(@NonNull GroupMasterKey groupMasterKey, @NonNull GroupLinkPassword password) {
+    this.groupMasterKey = groupMasterKey;
+    this.password       = password;
+    this.url            = createUrl(groupMasterKey, password);
+  }
+
+  protected static @NonNull String createUrl(@NonNull GroupMasterKey groupMasterKey, @NonNull GroupLinkPassword password) {
+    GroupInviteLink groupInviteLink = GroupInviteLink.newBuilder()
+                                                     .setV1Contents(GroupInviteLink.GroupInviteLinkContentsV1.newBuilder()
+                                                                                   .setGroupMasterKey(ByteString.copyFrom(groupMasterKey.serialize()))
+                                                                                   .setInviteLinkPassword(ByteString.copyFrom(password.serialize())))
+                                                     .build();
+
+    String encoding = Base64UrlSafe.encodeBytesWithoutPadding(groupInviteLink.toByteArray());
+
+    return GROUP_URL_PREFIX + encoding;
+  }
+
+  public @NonNull String getUrl() {
+    return url;
+  }
+
+  public @NonNull GroupMasterKey getGroupMasterKey() {
+    return groupMasterKey;
+  }
+
+  public @NonNull GroupLinkPassword getPassword() {
+    return password;
+  }
+
+  public final static class InvalidGroupLinkException extends Exception {
+    public InvalidGroupLinkException(String message) {
+      super(message);
+    }
+
+    public InvalidGroupLinkException(Throwable cause) {
+      super(cause);
+    }
+  }
+
+  public final static class UnknownGroupLinkVersionException extends Exception {
+    public UnknownGroupLinkVersionException(String message) {
+      super(message);
+    }
+  }
+}

app/src/main/java/org/thoughtcrime/securesms/groups/v2/GroupLinkPassword.java

@@ -0,0 +1,51 @@
+package org.thoughtcrime.securesms.groups.v2;
+
+import androidx.annotation.NonNull;
+
+import org.thoughtcrime.securesms.util.Util;
+
+import java.util.Arrays;
+
+public final class GroupLinkPassword {
+
+  private static final int SIZE = 16;
+
+  private final byte[] bytes;
+
+  public static @NonNull GroupLinkPassword createNew() {
+    return new GroupLinkPassword(Util.getSecretBytes(SIZE));
+  }
+
+  public static @NonNull GroupLinkPassword fromBytes(@NonNull byte[] bytes) throws InvalidLengthException {
+    if (bytes.length != SIZE) {
+      throw new InvalidLengthException();
+    }
+
+    return new GroupLinkPassword(bytes);
+  }
+
+  private GroupLinkPassword(@NonNull byte[] bytes) {
+    this.bytes = bytes;
+  }
+
+  public @NonNull byte[] serialize() {
+    return bytes.clone();
+  }
+
+  @Override
+  public boolean equals(Object other) {
+    if (!(other instanceof GroupLinkPassword)) {
+      return false;
+    }
+
+    return Arrays.equals(bytes, ((GroupLinkPassword) other).bytes);
+  }
+
+  @Override
+  public int hashCode() {
+    return Arrays.hashCode(bytes);
+  }
+
+  public static class InvalidLengthException extends Exception {
+  }
+}

app/src/main/java/org/thoughtcrime/securesms/util/Base64UrlSafe.java

@@ -0,0 +1,38 @@
+package org.thoughtcrime.securesms.util;
+
+import androidx.annotation.NonNull;
+
+import org.whispersystems.util.Base64;
+
+import java.io.IOException;
+
+public final class Base64UrlSafe {
+
+  private Base64UrlSafe() {
+  }
+
+  public static @NonNull byte[] decode(@NonNull String s) throws IOException {
+    return Base64.decode(s, Base64.URL_SAFE);
+  }
+
+  public static @NonNull byte[] decodePaddingAgnostic(@NonNull String s) throws IOException {
+    switch (s.length() % 4) {
+      case 1:
+      case 3: s = s + "="; break;
+      case 2: s = s + "=="; break;
+    }
+    return decode(s);
+  }
+
+  public static @NonNull String encodeBytes(@NonNull byte[] source) {
+    try {
+      return Base64.encodeBytes(source, Base64.URL_SAFE);
+    } catch (IOException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  public static @NonNull String encodeBytesWithoutPadding(@NonNull byte[] source) {
+    return encodeBytes(source).replace("=", "");
+  }
+}

app/src/main/java/org/thoughtcrime/securesms/util/CommunicationActions.java

@@ -24,12 +24,17 @@ import org.thoughtcrime.securesms.R;
 import org.thoughtcrime.securesms.WebRtcCallActivity;
 import org.thoughtcrime.securesms.conversation.ConversationActivity;
 import org.thoughtcrime.securesms.database.DatabaseFactory;
+import org.thoughtcrime.securesms.groups.GroupId;
+import org.thoughtcrime.securesms.groups.ui.invitesandrequests.joining.GroupJoinUpdateRequiredBottomSheetDialogFragment;
+import org.thoughtcrime.securesms.groups.v2.GroupInviteLinkUrl;
 import org.thoughtcrime.securesms.logging.Log;
 import org.thoughtcrime.securesms.permissions.Permissions;
 import org.thoughtcrime.securesms.recipients.Recipient;
 import org.thoughtcrime.securesms.ringrtc.RemotePeer;
 import org.thoughtcrime.securesms.service.WebRtcCallService;
 import org.thoughtcrime.securesms.sms.MessageSender;
+import org.thoughtcrime.securesms.util.concurrent.SignalExecutors;
+import org.thoughtcrime.securesms.util.concurrent.SimpleTask;
 import org.whispersystems.signalservice.api.messages.calls.OfferMessage;
 
 public class CommunicationActions {
@@ -162,6 +167,47 @@ public class CommunicationActions {
     context.startActivity(intent);
   }
 
+  /**
+   * If the url is a group link it will handle it.
+   * If the url is a malformed group link, it will assume Signal needs to update.
+   * Otherwise returns false, indicating was not a group link.
+   */
+  public static boolean handlePotentialGroupLinkUrl(@NonNull FragmentActivity activity, @NonNull String potentialGroupLinkUrl) {
+    try {
+      GroupInviteLinkUrl groupInviteLinkUrl = GroupInviteLinkUrl.fromUrl(potentialGroupLinkUrl);
+
+      if (groupInviteLinkUrl == null) {
+        return false;
+      }
+
+      handleGroupLinkUrl(activity, groupInviteLinkUrl);
+      return true;
+    } catch (GroupInviteLinkUrl.InvalidGroupLinkException | GroupInviteLinkUrl.UnknownGroupLinkVersionException e) {
+      Log.w(TAG, "Could not parse group URL", e);
+      GroupJoinUpdateRequiredBottomSheetDialogFragment.show(activity.getSupportFragmentManager());
+      return true;
+    }
+  }
+
+  public static void handleGroupLinkUrl(@NonNull FragmentActivity activity,
+                                        @NonNull GroupInviteLinkUrl groupInviteLinkUrl)
+  {
+    GroupId.V2 groupId = GroupId.v2(groupInviteLinkUrl.getGroupMasterKey());
+
+    SimpleTask.run(SignalExecutors.BOUNDED, () ->
+      DatabaseFactory.getGroupDatabase(activity)
+                     .getGroup(groupId)
+                     .transform(groupRecord -> Recipient.resolved(groupRecord.getRecipientId()))
+                     .orNull(),
+      recipient -> {
+        if (recipient != null) {
+          CommunicationActions.startConversation(activity, recipient, null);
+          Toast.makeText(activity, R.string.GroupJoinBottomSheetDialogFragment_you_are_already_a_member, Toast.LENGTH_SHORT).show();
+        } else {
+          GroupJoinUpdateRequiredBottomSheetDialogFragment.show(activity.getSupportFragmentManager());
+        }
+      });
+  }
 
   private static void startInsecureCallInternal(@NonNull Activity activity, @NonNull Recipient recipient) {
     try {

app/src/main/java/org/thoughtcrime/securesms/util/Hex.java

@@ -75,6 +75,14 @@ public class Hex {
     return out;
   }
 
+  public static byte[] fromStringOrThrow(String encoded) {
+    try {
+      return fromStringCondensed(encoded);
+    } catch (IOException e) {
+      throw new AssertionError(e);
+    }
+  }
+
   public static String dump(byte[] bytes) {
     return dump(bytes, 0, bytes.length);
   }

app/src/main/java/org/thoughtcrime/securesms/util/InterceptableLongClickCopyLinkSpan.java

@@ -0,0 +1,29 @@
+package org.thoughtcrime.securesms.util;
+
+import android.view.View;
+
+import androidx.annotation.NonNull;
+
+import org.thoughtcrime.securesms.groups.v2.GroupInviteLinkUrl;
+
+/**
+ * Passes clicked Urls to the supplied {@link UrlClickHandler}.
+ */
+public final class InterceptableLongClickCopyLinkSpan extends LongClickCopySpan {
+
+  private final UrlClickHandler onClickListener;
+
+  public InterceptableLongClickCopyLinkSpan(@NonNull String url,
+                                            @NonNull UrlClickHandler onClickListener)
+  {
+    super(url);
+    this.onClickListener = onClickListener;
+  }
+
+  @Override
+  public void onClick(View widget) {
+    if (!onClickListener.handleOnClick(getURL())) {
+      super.onClick(widget);
+    }
+  }
+}

app/src/main/java/org/thoughtcrime/securesms/util/PlayStoreUtil.java

@@ -0,0 +1,34 @@
+package org.thoughtcrime.securesms.util;
+
+import android.content.ActivityNotFoundException;
+import android.content.Context;
+import android.content.Intent;
+import android.net.Uri;
+
+import androidx.annotation.NonNull;
+
+import org.thoughtcrime.securesms.BuildConfig;
+
+public final class PlayStoreUtil {
+
+  private PlayStoreUtil() {
+  }
+
+  public static void openPlayStoreOrOurApkDownloadPage(@NonNull Context context) {
+    if (BuildConfig.PLAY_STORE_DISABLED) {
+      CommunicationActions.openBrowserLink(context, "https://signal.org/android/apk");
+    } else {
+      openPlayStore(context);
+    }
+  }
+
+  private static void openPlayStore(@NonNull Context context) {
+    String packageName = context.getPackageName();
+
+    try {
+      context.startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("market://details?id=" + packageName)));
+    } catch (ActivityNotFoundException e) {
+      CommunicationActions.openBrowserLink(context, "https://play.google.com/store/apps/details?id=" + packageName);
+    }
+  }
+}

app/src/main/java/org/thoughtcrime/securesms/util/UrlClickHandler.java

@@ -0,0 +1,11 @@
+package org.thoughtcrime.securesms.util;
+
+import androidx.annotation.NonNull;
+
+public interface UrlClickHandler {
+
+  /**
+   * @return true if you have handled it, false if you want to allow the standard Url handling.
+   */
+  boolean handleOnClick(@NonNull String url);
+}

app/src/main/res/layout/group_join_update_needed_bottom_sheet.xml

@@ -0,0 +1,52 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    tools:theme="@style/Theme.Signal.RoundedBottomSheet.Light">
+
+    <TextView
+        android:id="@+id/group_join_update_title"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="24dp"
+        android:layout_marginTop="16dp"
+        android:text="@string/GroupJoinUpdateRequiredBottomSheetDialogFragment_update_signal_to_use_group_links"
+        android:textAppearance="@style/TextAppearance.Signal.Title2"
+        android:textColor="?title_text_color_primary"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
+    <TextView
+        android:id="@+id/group_join_update_explain"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="24dp"
+        android:layout_marginTop="16dp"
+        android:layout_marginEnd="24dp"
+        android:text="@string/GroupJoinUpdateRequiredBottomSheetDialogFragment_update_message"
+        android:textAppearance="@style/TextAppearance.Signal.Body1"
+        android:textColor="?title_text_color_secondary"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/group_join_update_title" />
+
+    <Button
+        android:id="@+id/group_join_update_button"
+        style="@style/Button.Primary"
+        android:layout_width="0dp"
+        android:layout_height="64dp"
+        android:layout_marginStart="16dp"
+        android:layout_marginTop="32dp"
+        android:layout_marginEnd="16dp"
+        android:layout_marginBottom="16dp"
+        android:text="@string/GroupJoinUpdateRequiredBottomSheetDialogFragment_update_signal"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintHorizontal_bias="0.5"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/group_join_update_explain"
+        app:layout_constraintVertical_bias="0" />
+
+</androidx.constraintlayout.widget.ConstraintLayout>

app/src/main/res/values/strings.xml

@@ -644,6 +644,14 @@
         <item quantity="other">Do you want to revoke %2$d invites sent by %1$s?</item>
     </plurals>
 
+    <!-- GroupJoinBottomSheetDialogFragment -->
+    <string name="GroupJoinBottomSheetDialogFragment_you_are_already_a_member">You are already a member</string>
+
+    <!-- GroupJoinUpdateRequiredBottomSheetDialogFragment -->
+    <string name="GroupJoinUpdateRequiredBottomSheetDialogFragment_update_signal_to_use_group_links">Update Signal to use group links</string>
+    <string name="GroupJoinUpdateRequiredBottomSheetDialogFragment_update_message">The version of Signal you’re using does not support sharable group links. Update to the latest version to join this group via link.</string>
+    <string name="GroupJoinUpdateRequiredBottomSheetDialogFragment_update_signal">Update Signal</string>
+
     <!-- CropImageActivity -->
     <string name="CropImageActivity_group_avatar">Group avatar</string>
     <string name="CropImageActivity_profile_avatar">Avatar</string>
@@ -1312,9 +1320,6 @@
     <!-- MuteDialog -->
     <string name="MuteDialog_mute_notifications">Mute notifications</string>
 
-    <!-- OutdatedBuildReminder -->
-    <string name="OutdatedBuildReminder_no_web_browser_installed">No web browser installed!</string>
-
     <!-- ApplicationMigrationService -->
     <string name="ApplicationMigrationService_import_in_progress">Import in progress</string>
     <string name="ApplicationMigrationService_importing_text_messages">Importing text messages</string>

app/src/test/java/org/thoughtcrime/securesms/groups/v2/GroupInviteLinkUrlTest.java

@@ -0,0 +1,101 @@
+package org.thoughtcrime.securesms.groups.v2;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.signal.zkgroup.InvalidInputException;
+import org.signal.zkgroup.groups.GroupMasterKey;
+import org.thoughtcrime.securesms.util.Hex;
+
+import java.util.Arrays;
+import java.util.Collection;
+
+import static org.junit.Assert.assertEquals;
+
+@RunWith(Parameterized.class)
+public final class GroupInviteLinkUrlTest {
+
+  private final GroupMasterKey    groupMasterKey;
+  private final GroupLinkPassword password;
+  private final String            expectedUrl;
+
+  @Parameterized.Parameters
+  public static Collection<Object[]> data() {
+    return Arrays.asList(
+
+      givenGroup().withMasterKey("a501335111fa04e3756c24b6eb87264e2dfb622e8e1d339179765410776c0488")
+                  .andPassword("f08b7e22fb938c025e6c158b7d544956")
+                  .expectUrl("https://group.signal.org/#CjQKIKUBM1ER-gTjdWwktuuHJk4t-2Iujh0zkXl2VBB3bASIEhDwi34i-5OMAl5sFYt9VElW"),
+
+      givenGroup().withMasterKey("2ca23c04d7cf60fe04039ae76d1912202c2a463d345d9cd48cf27f260dd37f6f")
+                  .andPassword("2734457c02ce51da71ad0b62f3c222f7")
+                  .expectUrl("https://group.signal.org/#CjQKICyiPATXz2D-BAOa520ZEiAsKkY9NF2c1IzyfyYN039vEhAnNEV8As5R2nGtC2LzwiL3"),
+
+      givenGroup().withMasterKey("00f7e0c2a71ab064cc3ced4c04f08d7b7ef4b84b2c2206f69833be6cfe34df80")
+                  .andPassword("9bc324eec437cfda6ae5b8aefbf47ee8")
+                  .expectUrl("https://group.signal.org/#CjQKIAD34MKnGrBkzDztTATwjXt-9LhLLCIG9pgzvmz-NN-AEhCbwyTuxDfP2mrluK779H7o")
+    );
+  }
+
+  public GroupInviteLinkUrlTest(GroupMasterKey groupMasterKey, GroupLinkPassword password, String expectedUrl) {
+    this.groupMasterKey = groupMasterKey;
+    this.password       = password;
+    this.expectedUrl    = expectedUrl;
+  }
+
+  @Test
+  public void can_extract_group_master_key_from_url() throws GroupInviteLinkUrl.InvalidGroupLinkException, GroupInviteLinkUrl.UnknownGroupLinkVersionException {
+    assertEquals(groupMasterKey, GroupInviteLinkUrl.fromUrl(expectedUrl).getGroupMasterKey());
+  }
+
+  @Test
+  public void can_extract_group_master_key_from_url_padded() throws GroupInviteLinkUrl.InvalidGroupLinkException, GroupInviteLinkUrl.UnknownGroupLinkVersionException {
+    assertEquals(groupMasterKey, GroupInviteLinkUrl.fromUrl(expectedUrl + "=").getGroupMasterKey());
+  }
+
+  @Test
+  public void can_extract_password_from_url() throws GroupInviteLinkUrl.InvalidGroupLinkException, GroupInviteLinkUrl.UnknownGroupLinkVersionException {
+    assertEquals(password, GroupInviteLinkUrl.fromUrl(expectedUrl).getPassword());
+  }
+
+  @Test
+  public void can_extract_password_from_url_padded() throws GroupInviteLinkUrl.InvalidGroupLinkException, GroupInviteLinkUrl.UnknownGroupLinkVersionException {
+    assertEquals(password, GroupInviteLinkUrl.fromUrl(expectedUrl + "=").getPassword());
+  }
+
+  @Test
+  public void can_reconstruct_url() {
+    assertEquals(expectedUrl, GroupInviteLinkUrl.createUrl(groupMasterKey, password));
+  }
+
+  private static TestBuilder givenGroup() {
+    return new TestBuilder();
+  }
+
+  private static class TestBuilder {
+    private GroupMasterKey groupMasterKey;
+    private byte[]         passwordBytes;
+
+    public TestBuilder withMasterKey(String groupMasterKeyAsHex) {
+      try {
+        groupMasterKey = new GroupMasterKey(Hex.fromStringOrThrow(groupMasterKeyAsHex));
+      } catch (InvalidInputException e) {
+        throw new AssertionError(e);
+      }
+      return this;
+    }
+
+    public TestBuilder andPassword(String passwordAsHex) {
+      passwordBytes = Hex.fromStringOrThrow(passwordAsHex);
+      return this;
+    }
+
+    public Object[] expectUrl(String url) {
+      try {
+        return new Object[]{ groupMasterKey, GroupLinkPassword.fromBytes(passwordBytes), url };
+      } catch (GroupLinkPassword.InvalidLengthException e) {
+        throw new AssertionError(e);
+      }
+    }
+  }
+}

app/src/test/java/org/thoughtcrime/securesms/groups/v2/GroupInviteLinkUrl_InvalidGroupLinkException_Test.java

@@ -0,0 +1,120 @@
+package org.thoughtcrime.securesms.groups.v2;
+
+import androidx.annotation.NonNull;
+
+import com.google.protobuf.ByteString;
+import com.google.protobuf.InvalidProtocolBufferException;
+
+import org.junit.Test;
+import org.signal.storageservice.protos.groups.GroupInviteLink;
+import org.signal.zkgroup.InvalidInputException;
+import org.signal.zkgroup.groups.GroupMasterKey;
+import org.thoughtcrime.securesms.util.Base64UrlSafe;
+import org.thoughtcrime.securesms.util.Util;
+
+import java.io.IOException;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertNull;
+
+public final class GroupInviteLinkUrl_InvalidGroupLinkException_Test {
+
+  @Test
+  public void empty_string() throws GroupInviteLinkUrl.InvalidGroupLinkException, GroupInviteLinkUrl.UnknownGroupLinkVersionException {
+    assertNull(GroupInviteLinkUrl.fromUrl(""));
+  }
+
+  @Test
+  public void not_a_url_string() throws GroupInviteLinkUrl.InvalidGroupLinkException, GroupInviteLinkUrl.UnknownGroupLinkVersionException {
+    assertNull(GroupInviteLinkUrl.fromUrl("abc"));
+  }
+
+  @Test
+  public void wrong_host() throws GroupInviteLinkUrl.InvalidGroupLinkException, GroupInviteLinkUrl.UnknownGroupLinkVersionException {
+    assertNull(GroupInviteLinkUrl.fromUrl("https://x.signal.org/#CAESNAogpQEzURH6BON1bCS264cmTi37Yi6OHTOReXZUEHdsBIgSEPCLfiL7k4wCXmwVi31USVY"));
+  }
+
+  @Test
+  public void has_path() {
+    assertThatThrownBy(() -> GroupInviteLinkUrl.fromUrl("https://group.signal.org/not_expected/#CAESNAogpQEzURH6BON1bCS264cmTi37Yi6OHTOReXZUEHdsBIgSEPCLfiL7k4wCXmwVi31USVY"))
+                      .isInstanceOf(GroupInviteLinkUrl.InvalidGroupLinkException.class)
+                      .hasMessage("No path was expected in url");
+  }
+
+  @Test
+  public void missing_ref() {
+    assertThatThrownBy(() -> GroupInviteLinkUrl.fromUrl("https://group.signal.org/"))
+                       .isInstanceOf(GroupInviteLinkUrl.InvalidGroupLinkException.class)
+                       .hasMessage("No reference was in the url");
+  }
+
+  @Test
+  public void empty_ref() {
+    assertThatThrownBy(() -> GroupInviteLinkUrl.fromUrl("https://group.signal.org/#"))
+                      .isInstanceOf(GroupInviteLinkUrl.InvalidGroupLinkException.class)
+                      .hasMessage("No reference was in the url");
+  }
+
+  @Test
+  public void bad_base64() {
+    assertThatThrownBy(() -> GroupInviteLinkUrl.fromUrl("https://group.signal.org/#CAESNAogpQEzURH6BON1bCS264cmTi37Yi6HTOReXZUEHdsBIgSEPCLfiL7k4wCX;mwVi31USVY"))
+                      .isInstanceOf(GroupInviteLinkUrl.InvalidGroupLinkException.class)
+                      .hasCauseExactlyInstanceOf(IOException.class);
+  }
+
+  @Test
+  public void bad_protobuf() {
+    assertThatThrownBy(() -> GroupInviteLinkUrl.fromUrl("https://group.signal.org/#CAESNAogpQEzURH6BON1bCS264cmTi37Yi6HTOReXZUEHdsBIgSEPCLfiL7k4wCXmwVi31USVY"))
+                      .isInstanceOf(GroupInviteLinkUrl.InvalidGroupLinkException.class)
+                      .hasCauseExactlyInstanceOf(InvalidProtocolBufferException.class);
+  }
+
+  @Test
+  public void version_999_url() {
+    String url = "https://group.signal.org/#uj4zCiDMSxlNUvF4bQ3z3fYzGyZTFbJ1xEqWbPE3uZSD8bjOrxIP8NxV-0GUz3jpxMLR1rN3";
+
+    assertThatThrownBy(() -> GroupInviteLinkUrl.fromUrl(url))
+                      .isInstanceOf(GroupInviteLinkUrl.UnknownGroupLinkVersionException.class)
+                      .hasMessage("Url contains no known group link content");
+  }
+
+  @Test
+  public void bad_master_key_length() {
+    byte[]            masterKeyBytes = Util.getSecretBytes(33);
+    GroupLinkPassword password       = GroupLinkPassword.createNew();
+
+    String encoding = createEncodedProtobuf(masterKeyBytes, password.serialize());
+
+    String url = "https://group.signal.org/#" + encoding;
+
+    assertThatThrownBy(() -> GroupInviteLinkUrl.fromUrl(url))
+                      .isInstanceOf(GroupInviteLinkUrl.InvalidGroupLinkException.class)
+                      .hasCauseExactlyInstanceOf(InvalidInputException.class);
+  }
+
+  @Test
+  public void bad_password_length() throws InvalidInputException {
+    GroupMasterKey groupMasterKey = new GroupMasterKey(Util.getSecretBytes(32));
+    byte[]         passwordBytes  = Util.getSecretBytes(15);
+
+    String encoding = createEncodedProtobuf(groupMasterKey.serialize(), passwordBytes);
+
+    String url = "https://group.signal.org/#" + encoding;
+
+    assertThatThrownBy(() -> GroupInviteLinkUrl.fromUrl(url))
+                      .isInstanceOf(GroupInviteLinkUrl.InvalidGroupLinkException.class)
+                      .hasCauseExactlyInstanceOf(GroupLinkPassword.InvalidLengthException.class);
+  }
+
+  private static String createEncodedProtobuf(@NonNull byte[] groupMasterKey,
+                                              @NonNull byte[] passwordBytes)
+  {
+    return Base64UrlSafe.encodeBytesWithoutPadding(GroupInviteLink.newBuilder()
+                                                 .setV1Contents(GroupInviteLink.GroupInviteLinkContentsV1.newBuilder()
+                                                                               .setGroupMasterKey(ByteString.copyFrom(groupMasterKey))
+                                                                               .setInviteLinkPassword(ByteString.copyFrom(passwordBytes)))
+                                                 .build()
+                                                 .toByteArray());
+  }
+
+}

app/src/test/java/org/thoughtcrime/securesms/util/Base64UrlSafeTest.java

@@ -0,0 +1,66 @@
+package org.thoughtcrime.securesms.util;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collection;
+
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+
+@RunWith(Parameterized.class)
+public final class Base64UrlSafeTest {
+
+  private final byte[] data;
+  private final String encoded;
+  private final String encodedWithoutPadding;
+
+  @Parameterized.Parameters
+  public static Collection<Object[]> data() {
+    return Arrays.asList(new Object[][]{
+      { "", "", "" },
+      { "01", "AQ==", "AQ" },
+      { "0102", "AQI=", "AQI" },
+      { "010203", "AQID", "AQID" },
+      { "030405", "AwQF", "AwQF" },
+      { "03040506", "AwQFBg==", "AwQFBg" },
+      { "0304050708", "AwQFBwg=", "AwQFBwg" },
+      { "af4d6cff", "r01s_w==", "r01s_w" },
+      { "ffefde", "_-_e", "_-_e" },
+    });
+  }
+
+  public Base64UrlSafeTest(String hexData, String encoded, String encodedWithoutPadding) throws IOException {
+    this.data                  = Hex.fromStringCondensed(hexData);
+    this.encoded               = encoded;
+    this.encodedWithoutPadding = encodedWithoutPadding;
+  }
+
+  @Test
+  public void encodes_as_expected() {
+    assertEquals(encoded, Base64UrlSafe.encodeBytes(data));
+  }
+
+  @Test
+  public void encodes_as_expected_without_padding() {
+    assertEquals(encodedWithoutPadding, Base64UrlSafe.encodeBytesWithoutPadding(data));
+  }
+
+  @Test
+  public void decodes_as_expected() throws IOException {
+    assertArrayEquals(data, Base64UrlSafe.decode(encoded));
+  }
+
+  @Test
+  public void decodes_padding_agnostic_as_expected() throws IOException {
+    assertArrayEquals(data, Base64UrlSafe.decodePaddingAgnostic(encoded));
+  }
+
+  @Test
+  public void decodes_as_expected_without_padding() throws IOException {
+    assertArrayEquals(data, Base64UrlSafe.decodePaddingAgnostic(encodedWithoutPadding));
+  }
+}

libsignal/service/src/main/proto/Groups.proto

@@ -150,3 +150,14 @@ message GroupAttributeBlob {
     uint32 disappearingMessagesDuration = 3;
   }
 }
+
+message GroupInviteLink {
+  message GroupInviteLinkContentsV1 {
+      bytes groupMasterKey     = 1;
+      bytes inviteLinkPassword = 2;
+  }
+
+  oneof contents {
+    GroupInviteLinkContentsV1 v1Contents = 1;
+  }
+}