fix: return error early if the public key is not expected length or format with an appropriate message

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

@@ -1,5 +1,4 @@
-/*
- * Copyright (C) 2013 Open Whisper Systems
+/* Copyright (C) 2013 Open Whisper Systems
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by

app/src/main/java/org/thoughtcrime/securesms/loki/activities/JoinPublicChatActivity.kt

@@ -29,6 +29,7 @@ import org.session.libsession.utilities.DistributionTypes
 import org.session.libsession.utilities.recipients.Recipient
 import org.session.libsession.utilities.GroupUtil
 import org.session.libsignal.utilities.Log
+import org.session.libsignal.utilities.PublicKeyValidation
 import org.thoughtcrime.securesms.BaseActionBarActivity
 import org.thoughtcrime.securesms.PassphraseRequiredActionBarActivity
 import org.thoughtcrime.securesms.conversation.ConversationActivity
@@ -37,7 +38,6 @@ import org.thoughtcrime.securesms.loki.api.OpenGroupManager
 import org.thoughtcrime.securesms.loki.fragments.ScanQRCodeWrapperFragment
 import org.thoughtcrime.securesms.loki.fragments.ScanQRCodeWrapperFragmentDelegate
 import org.thoughtcrime.securesms.loki.protocol.MultiDeviceProtocol
-import org.thoughtcrime.securesms.loki.utilities.OpenGroupUtilities
 import org.thoughtcrime.securesms.loki.viewmodel.DefaultGroupsViewModel
 import org.thoughtcrime.securesms.loki.viewmodel.State
 
@@ -86,6 +86,9 @@ class JoinPublicChatActivity : PassphraseRequiredActionBarActivity(), ScanQRCode
         val room = url.pathSegments().firstOrNull()
         val publicKey = url.queryParameter("public_key")
         val isV2OpenGroup = !room.isNullOrEmpty()
+        if (isV2OpenGroup && (publicKey == null || !PublicKeyValidation.isValid(publicKey, 64,false))) {
+            return Toast.makeText(this, R.string.invalid_public_key, Toast.LENGTH_SHORT).show()
+        }
         showLoader()
         lifecycleScope.launch(Dispatchers.IO) {
             try {

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

@@ -842,5 +842,6 @@
     <string name="activity_prompt_passphrase_tap_to_unlock">Tap to Unlock</string>
 
     <string name="fragment_user_details_bottom_sheet_edit_text_hint">Enter a nickname</string>
+    <string name="invalid_public_key">Invalid Public Key</string>
 
 </resources>