From f794458cba94650464abef0f287db8ef6f881c9b Mon Sep 17 00:00:00 2001
From: SessionHero01 <180888785+SessionHero01@users.noreply.github.com>
Date: Mon, 21 Oct 2024 14:36:58 +1100
Subject: [PATCH] Kick handling

---
 .../messenger/libsession_util/util/Sodium.kt  |  2 -
 .../groups/RemoveGroupMemberHandler.kt        |  3 +-
 .../pollers/ClosedGroupPoller.kt              | 37 +++++++++++--------
 3 files changed, 24 insertions(+), 18 deletions(-)

diff --git a/libsession-util/src/main/java/network/loki/messenger/libsession_util/util/Sodium.kt b/libsession-util/src/main/java/network/loki/messenger/libsession_util/util/Sodium.kt
index f2a6cd02e2..a7f7e6f1c2 100644
--- a/libsession-util/src/main/java/network/loki/messenger/libsession_util/util/Sodium.kt
+++ b/libsession-util/src/main/java/network/loki/messenger/libsession_util/util/Sodium.kt
@@ -1,11 +1,9 @@
 package network.loki.messenger.libsession_util.util
 
-import java.util.regex.Pattern
 
 object Sodium {
 
     const val KICKED_DOMAIN = "SessionGroupKickedMessage"
-    val KICKED_REGEX: Pattern = Pattern.compile("^(05[a-zA-Z0-9]{64})(\\d+)$")
 
     init {
         System.loadLibrary("session_util")
diff --git a/libsession/src/main/java/org/session/libsession/messaging/groups/RemoveGroupMemberHandler.kt b/libsession/src/main/java/org/session/libsession/messaging/groups/RemoveGroupMemberHandler.kt
index 74b6b62779..601448a2f8 100644
--- a/libsession/src/main/java/org/session/libsession/messaging/groups/RemoveGroupMemberHandler.kt
+++ b/libsession/src/main/java/org/session/libsession/messaging/groups/RemoveGroupMemberHandler.kt
@@ -216,7 +216,8 @@ class RemoveGroupMemberHandler @Inject constructor(
         data = Base64.encodeBytes(
             Sodium.encryptForMultipleSimple(
                 messages = Array(pendingRemovals.size) {
-                    "${pendingRemovals[it].sessionId}${keys.currentGeneration()}".encodeToByteArray()
+                    AccountId(pendingRemovals[it].sessionId).pubKeyBytes
+                        .plus(keys.currentGeneration().toString().toByteArray())
                 },
                 recipients = Array(pendingRemovals.size) {
                     AccountId(pendingRemovals[it].sessionId).pubKeyBytes
diff --git a/libsession/src/main/java/org/session/libsession/messaging/sending_receiving/pollers/ClosedGroupPoller.kt b/libsession/src/main/java/org/session/libsession/messaging/sending_receiving/pollers/ClosedGroupPoller.kt
index c6f181591f..42cd01ba18 100644
--- a/libsession/src/main/java/org/session/libsession/messaging/sending_receiving/pollers/ClosedGroupPoller.kt
+++ b/libsession/src/main/java/org/session/libsession/messaging/sending_receiving/pollers/ClosedGroupPoller.kt
@@ -29,6 +29,7 @@ import org.session.libsession.utilities.getClosedGroup
 import org.session.libsignal.database.LokiAPIDatabaseProtocol
 import org.session.libsignal.exceptions.NonRetryableException
 import org.session.libsignal.utilities.AccountId
+import org.session.libsignal.utilities.IdPrefix
 import org.session.libsignal.utilities.Log
 import org.session.libsignal.utilities.Namespace
 import org.session.libsignal.utilities.Snode
@@ -299,23 +300,29 @@ class ClosedGroupPoller(
             )
 
             if (decoded != null) {
-                val message = decoded.decodeToString()
-                val matcher = Sodium.KICKED_REGEX.matcher(message)
-                if (matcher.matches()) {
-                    val sessionId = matcher.group(1)
-                    val messageGeneration = matcher.group(2)!!.toInt()
-                    val currentKeysGeneration = configFactoryProtocol.withGroupConfigs(closedGroupSessionId) {
-                        it.groupKeys.currentGeneration()
-                    }
+                // The message should be in the format of "<sessionIdPubKeyBinary><messageGenerationASCII>",
+                // where the pub key is 32 bytes, so we need to have at least 33 bytes of data
+                if (decoded.size < 33) {
+                    Log.w(TAG, "Received an invalid kicked message, expecting at least 33 bytes, got ${decoded.size}")
+                    return@forEach
+                }
 
-                    val isForMe = sessionId == storage.getUserPublicKey()
-                    Log.d(TAG, "Received kicked message, for us? ${sessionId == storage.getUserPublicKey()}, message key generation = $messageGeneration, our key generation = $currentKeysGeneration")
+                val sessionId = AccountId(IdPrefix.STANDARD, decoded.copyOfRange(0, 32))
+                val messageGeneration = decoded.copyOfRange(32, decoded.size).decodeToString().toIntOrNull()
+                if (messageGeneration == null) {
+                    Log.w(TAG, "Received an invalid kicked message: missing message generation")
+                    return@forEach
+                }
 
-                    if (isForMe && messageGeneration >= currentKeysGeneration) {
-                        groupManagerV2.handleKicked(closedGroupSessionId)
-                    }
-                } else {
-                    Log.w(TAG, "Received an invalid kicked message")
+                val currentKeysGeneration = configFactoryProtocol.withGroupConfigs(closedGroupSessionId) {
+                    it.groupKeys.currentGeneration()
+                }
+
+                val isForMe = sessionId.hexString == storage.getUserPublicKey()
+                Log.d(TAG, "Received kicked message, for us? ${isForMe}, message key generation = $messageGeneration, our key generation = $currentKeysGeneration")
+
+                if (isForMe && messageGeneration >= currentKeysGeneration) {
+                    groupManagerV2.handleKicked(closedGroupSessionId)
                 }
             }
         }