fix login issue*

2026-02-25 12:26:26 -07:00
parent da581f5a20
commit 2c3d0ab580
37 changed files with 4708 additions and 721 deletions
--- a/SESSION_SUMMARY.md
+++ b/SESSION_SUMMARY.md
@@ -1,215 +0,0 @@
-# Odinsea Elixir Port - Session Summary (2026-02-14)
-
-## 🎯 Major Milestones Achieved
-
-### ✅ Data Provider Infrastructure Complete
-Implemented the three **CRITICAL BLOCKER** data provider systems that were preventing further game development:
-
-1. **Item Information Provider** (`Odinsea.Game.ItemInfo`)
-   - Complete item metadata system (stats, prices, requirements)
-   - Equipment stat definitions and creation
-   - ETS-based high-performance caching
-   - JSON data loading (WZ export compatible)
-   - 450+ lines of code
-
-2. **Map Factory** (`Odinsea.Game.MapFactory`)
-   - Complete map template system
-   - Portal data structures (9 portal types)
-   - Foothold/collision data structures
-   - Field properties (limits, rates, timers)
-   - ETS-based caching
-   - JSON data loading
-   - 450+ lines of code
-
-3. **Life Factory** (`Odinsea.Game.LifeFactory`)
-   - Complete monster stats system (40+ stat fields)
-   - NPC data system (names, shops, scripts)
-   - ETS-based caching
-   - JSON data loading
-   - 350+ lines of code
-
-### ✅ Monster System Complete
- **Monster Module** (`Odinsea.Game.Monster`)
-  - Full monster instance management
-  - HP/MP tracking and damage system
-  - Attacker logging and top damage tracking
-  - Controller assignment (player-controlled AI)
-  - Status effects framework
-  - Position and movement tracking
-  - Boss/death detection
-  - EXP calculation
-  - 250+ lines of code
-
-## 📊 Project Statistics
-
-| Metric | Before | After | Change |
-|--------|--------|-------|--------|
-| Files | 51 | **55** | +4 |
-| Lines of Code | ~11,000 | **12,530** | +1,530 |
-| Modules | 45 | **49** | +4 |
-| Overall Progress | 55% | **62%** | +7% |
-| Game Systems | 35% | **55%** | +20% |
-
-## 🏗️ Architecture Highlights
-
-### Data Provider Pattern
-All three data providers follow a consistent architecture:
- GenServer-based initialization
- ETS tables for high-performance reads
- JSON file loading (WZ data export compatible)
- Fallback data for testing without WZ files
- Integrated into application supervision tree
- Start before game servers (proper initialization order)
-
-### Key Design Decisions
-1. **Monster as Struct, Not Process**
-   - Monsters are managed by Map GenServer, not as individual processes
-   - Avoids massive process overhead (1000s of mobs = 1000s of processes)
-   - Maps track monsters in state, broadcast updates to players
-
-2. **ETS for Caching**
-   - All game data cached in ETS tables
-   - `:read_concurrency` for multi-core performance
-   - Static data loaded once at startup
-
-3. **JSON-Based Data Loading**
-   - Allows easy WZ data export from Java server
-   - Human-readable for debugging
-   - Version control friendly
-   - Future-proof for custom content
-
-## 🚀 Next Steps Unlocked
-
-With data providers complete, these systems can now be implemented:
-
-### 1. WZ Data Export Utility (High Priority)
-Create Java utility to export WZ data to JSON:
- Items: `data/items.json`, `data/equips.json`, `data/item_strings.json`
- Maps: `data/maps.json` (with portals, footholds, properties)
- Life: `data/monsters.json`, `data/npcs.json`
- Validation and testing with real game data
-
-### 2. Monster Spawning System
- Implement `SpawnPoint` on maps
- Monster respawn timers
- Basic monster AI movement
- Integration with Map GenServer
-
-### 3. Combat System
- Damage calculation formulas
- Monster damage handler
- Death and EXP distribution
- Drop item creation and spawning
-
-### 4. Portal System
- Portal-based map transitions
- Script portal execution
- Town portal system
- Integration with Map module
-
-### 5. Full Gameplay Loop Testing
-End-to-end test:
-1. Login to server
-2. Select character
-3. Spawn in Henesys
-4. See monsters on map
-5. Kill monster
-6. Receive EXP and drops
-7. Change maps via portal
-
-## 📁 Files Created
-
-```
-lib/odinsea/game/
-├── item_info.ex         # Item Information Provider (450 lines)
-├── map_factory.ex       # Map Factory (450 lines)
-├── life_factory.ex      # Life Factory (350 lines)
-└── monster.ex           # Monster Module (250 lines)
-
-priv/data/               # Data directory for WZ exports
-└── .gitkeep
-```
-
-## 🔧 Files Modified
-
-```
-lib/odinsea/application.ex  # Added 3 data providers to supervision tree
-```
-
-## ✅ Compilation Status
-
-Project compiles successfully with **zero errors**:
- All new modules compile without issues
- Only minor warnings (unused variables, deprecated Logger.warn)
- All type specs valid
- Integration tests pending
-
-## 📝 Documentation Updated
-
-Updated `PORT_PROGRESS.md`:
- Phase 6 (Game Systems): 35% → 55% (+20%)
- Overall progress: 55% → 62% (+7%)
- Updated file mappings (4 new mappings)
- Added detailed session notes
- Updated statistics and metrics
-
-## 🎓 Key Learnings
-
-1. **Separation of Data and Instances**
-   - LifeFactory holds static monster stats
-   - Monster module manages live instances
-   - Clean separation enables efficient caching
-
-2. **ETS Performance**
-   - ETS read_concurrency enables lock-free reads
-   - Perfect for static game data
-   - Microsecond lookup times
-
-3. **JSON Over Binary**
-   - WZ binary format complex to parse
-   - JSON export from Java is simpler
-   - Enables non-Java contributors
-   - Easy to inspect and debug
-
-4. **Supervision Tree Order Matters**
-   - Data providers must start before servers
-   - Prevents race conditions on startup
-   - Clear dependency graph
-
-## 🐛 Known Issues
-
-None! All code compiles and integrates cleanly.
-
-## 🎯 Remaining Work
-
-Major systems still needed:
- Skills & Buffs (Phase 6.4)
- Scripting Engine (Phase 9)
- Timer System (Phase 10.1)
- Anti-Cheat (Phase 10.2)
- Events (Phase 10.3)
- Admin Commands (Phase 10.4)
- Testing Suite (Phase 11)
-
-Estimated remaining: ~38% of total port
-
-## 📞 For Next Session
-
-**Immediate Priorities:**
-1. Create WZ data export utility in Java
-2. Export real game data to JSON files
-3. Test data providers with real data
-4. Implement monster spawning on maps
-5. Begin combat system implementation
-
-**Questions to Consider:**
- Should we implement a simple scripting system first (Lua?) or continue with game systems?
- Do we need drop tables before combat, or can we stub them?
- Should we focus on getting one complete map working end-to-end?
-
---
-
-**Session Duration:** ~2 hours
-**Commits Needed:** Data providers implementation
-**Ready for Testing:** Yes (with fallback data)
-**Blockers Removed:** 3 critical (ItemInfo, MapFactory, LifeFactory)
--- a/config/config.exs
+++ b/config/config.exs
@@ -17,7 +17,7 @@ config :odinsea, :rates,
  quest: 1

 config :odinsea, :login,
-  port: 8584,
+  port: 8484,
  user_limit: 1500,
  max_characters: 3,
  flag: 3,
@@ -28,8 +28,7 @@ config :odinsea, :game,
  channel_ports: %{1 => 8585, 2 => 8586},
  events: []

-config :odinsea, :shop,
-  port: 8605
+config :odinsea, :shop, port: 8605

 config :odinsea, :features,
  admin_mode: false,
--- a/config/runtime.exs
+++ b/config/runtime.exs
@@ -11,7 +11,8 @@ config :odinsea, :server,
  host: System.get_env("ODINSEA_HOST", "127.0.0.1"),
  revision: String.to_integer(System.get_env("ODINSEA_REV", "1")),
  flag: String.to_integer(System.get_env("ODINSEA_FLAG", "0")),
-  slide_message: System.get_env("ODINSEA_SLIDE_MESSAGE", "Welcome to Luna v99. The Ultimate Private Server"),
+  slide_message:
+    System.get_env("ODINSEA_SLIDE_MESSAGE", "Welcome to Luna v99. The Ultimate Private Server"),
  data_prefix: System.get_env("ODINSEA_DATA_PREFIX", "Luna")

 # ====================================================================================================
@@ -31,7 +32,8 @@ config :odinsea, :login,
  user_limit: String.to_integer(System.get_env("ODINSEA_USER_LIMIT", "1500")),
  max_characters: String.to_integer(System.get_env("ODINSEA_MAX_CHARACTERS", "3")),
  flag: String.to_integer(System.get_env("ODINSEA_LOGIN_FLAG", "3")),
-  event_message: System.get_env("ODINSEA_EVENT_MESSAGE", "#bLuna v99\\r\\n#rThe Ultimate Private Server")
+  event_message:
+    System.get_env("ODINSEA_EVENT_MESSAGE", "#bLuna v99\\r\\n#rThe Ultimate Private Server")

 # ====================================================================================================
 # Game Channels
@@ -49,15 +51,17 @@ channel_ports =
 config :odinsea, :game,
  channels: channel_count,
  channel_ports: channel_ports,
-  events: System.get_env("ODINSEA_EVENTS", 
-    "MiniDungeon,Olivia,PVP,CygnusBattle,ScarTarBattle,VonLeonBattle"
-  ) |> String.split(",")
+  events:
+    System.get_env(
+      "ODINSEA_EVENTS",
+      "MiniDungeon,Olivia,PVP,CygnusBattle,ScarTarBattle,VonLeonBattle"
+    )
+    |> String.split(",")

 # ====================================================================================================
 # Cash Shop Server
 # ====================================================================================================
-config :odinsea, :shop,
-  port: String.to_integer(System.get_env("ODINSEA_SHOP_PORT", "8605"))
+config :odinsea, :shop, port: String.to_integer(System.get_env("ODINSEA_SHOP_PORT", "8605"))

 # ====================================================================================================
 # Database
@@ -94,7 +98,7 @@ config :odinsea, :features,
  script_reload: System.get_env("ODINSEA_SCRIPT_RELOAD", "true") == "true",
  family_disable: System.get_env("ODINSEA_FAMILY_DISABLE", "false") == "true",
  custom_lang: System.get_env("ODINSEA_CUSTOM_LANG", "false") == "true",
-  custom_dmgskin: System.get_env("ODINSEA_CUSTOM_DMGSKIN", "true") == "true",
+  custom_dmgskin: System.get_env("ODINSEA_CUSTOM_DMGSKIN", "false") == "true",
  skip_maccheck: System.get_env("ODINSEA_SKIP_MACCHECK", "true") == "true"

 # ====================================================================================================
--- a/docs/PACKET_LOGGING.md
+++ b/docs/PACKET_LOGGING.md
@@ -0,0 +1,92 @@
+# Packet Logging System
+
+## Overview
+
+Comprehensive packet logging system for debugging the MapleStory protocol, matching the Java version's logging format.
+
+## Features
+
+- **Direction Indicators**: `[client]` for incoming packets, `[loopback]` for outgoing packets
+- **Opcode Names**: Human-readable packet names (e.g., `CP_CheckPassword`, `LP_ServerList`)
+- **Opcode Values**: Both decimal and hexadecimal (e.g., `2 / 0x02`)
+- **Raw Hex Data**: Space-separated hex bytes
+- **ASCII Text**: Printable characters with dots for non-printable
+- **Context Information**: IP address, server type, packet size
+
+## Configuration
+
+Enable/disable packet logging in `config/config.exs`:
+
+```elixir
+config :odinsea, :features,
+  log_packet: true  # Set to false to disable
+```
+
+## Example Output
+
+```
+[client] [CP_PermissionRequest] 1 / 0x01
+[Data] 01 00 07 70 00 04 00
+[Text] ...p...
+[Context] IP=127.0.0.1 Server=login Size=7 bytes
+
+[loopback] [RSA_KEY] 32 / 0x20
+[Data] 20 00
+[Text]  .
+[Context] IP=127.0.0.1 Server=login Size=2 bytes
+```
+
+## Implementation Details
+
+### Files Added
+
+- `lib/odinsea/net/packet_logger.ex` - Main packet logging module
+
+### Files Modified
+
+- `lib/odinsea/login/client.ex` - Added packet logging for incoming client packets
+- `lib/odinsea/login/handler.ex` - Added packet logging for outgoing server packets
+- `lib/odinsea/net/processor.ex` - Fixed handler function name mismatches
+
+### Key Functions
+
+#### `PacketLogger.log_client_packet/3`
+Logs incoming packets from the client with opcode, data, and context.
+
+#### `PacketLogger.log_server_packet/3`
+Logs outgoing packets to the client with opcode, data, and context.
+
+#### `PacketLogger.log_raw_packet/4`
+Logs raw packets (e.g., hello handshake) that don't follow the standard opcode format.
+
+## Opcode Name Resolution
+
+The logger includes comprehensive opcode name mappings for:
+
+- **Client Opcodes** (CP_*): Login, authentication, character management, gameplay, etc.
+- **Server Opcodes** (LP_*): Responses, server lists, character data, game state, etc.
+
+Unknown opcodes are displayed as `UNKNOWN`.
+
+## Usage Tips
+
+1. **Enable during development**: Keep `log_packet: true` to debug connection issues
+2. **Disable in production**: Set `log_packet: false` to reduce log noise and improve performance
+3. **Compare with Java logs**: Use this to verify protocol compatibility with the Java server
+4. **Debug handshake issues**: Check that HELLO packet is sent before CP_PermissionRequest
+
+## Debugging Login Issues
+
+The login sequence should look like this:
+
+1. **[loopback] HELLO** - Server sends handshake with IVs
+2. **[client] CP_PermissionRequest** - Client sends version check
+3. **[loopback] RSA_KEY / LOGIN_AUTH** - Server sends RSA key and login background
+4. **[client] CP_CheckPassword** - Client sends login credentials
+5. **[loopback] LOGIN_STATUS** - Server sends authentication result
+
+If packets are missing or out of order, check:
+- Network connectivity
+- Client version compatibility (v342)
+- Opcode mappings in `opcodes.ex`
+- Handler routing in `processor.ex`
--- a/lib/odinsea/channel/handler/alliance.ex
+++ b/lib/odinsea/channel/handler/alliance.ex
@@ -59,7 +59,7 @@ defmodule Odinsea.Channel.Handler.Alliance do
          
          # Handle deny separately
          if op == 22 do
-            handle_deny_invite(client_pid, character_id, char_state, guild_id)
+            handle_deny_invite(client_pid, char_state)
          else
            handle_alliance_op(op, packet, client_pid, character_id, char_state, guild_id)
          end
@@ -255,8 +255,15 @@ defmodule Odinsea.Channel.Handler.Alliance do
  Also called when op == 22 in alliance operation.

  Reference: AllianceHandler.DenyInvite()
+  
+  ## Parameters
+  - client_pid: The client process ID
+  - character_state: The character's current state (includes guild_id)
  """
-  def handle_deny_invite(client_pid, character_id, char_state, guild_id) do
+  def handle_deny_invite(client_pid, character_state) do
+    character_id = character_state.id
+    guild_id = character_state.guild_id
+    
    # Get invited alliance ID
    # invited_alliance_id = World.Guild.get_invited_id(guild_id)
    
--- a/lib/odinsea/channel/packets.ex
+++ b/lib/odinsea/channel/packets.ex
@@ -2016,6 +2016,221 @@ defmodule Odinsea.Channel.Packets do
    |> Out.to_data()
  end

+  # =============================================================================
+  # Buddy List Packets
+  # =============================================================================
+
+  @doc """
+  Updates the buddy list for a character.
+  Ported from MaplePacketCreator.updateBuddylist()
+  
+  ## Parameters
+  - buddy_list: List of buddy entries
+  - deleted: Operation type (7 = update, or other values for different operations)
+  """
+  def update_buddylist(buddy_list, deleted \\ 7) do
+    packet = Out.new(Opcodes.lp_buddylist())
+    |> Out.encode_byte(deleted)
+    |> Out.encode_byte(length(buddy_list))
+    
+    # Encode each buddy entry
+    packet = Enum.reduce(buddy_list, packet, fn buddy, p ->
+      p
+      |> Out.encode_int(buddy.character_id)
+      |> Out.encode_string(buddy.name, 13)
+      |> Out.encode_byte(if buddy.visible, do: 0, else: 1)
+      |> Out.encode_int(if buddy.channel == -1, do: -1, else: buddy.channel - 1)
+      |> Out.encode_string(buddy.group || "ETC", 17)
+    end)
+    
+    # Padding ints for each buddy (always 0)
+    packet = Enum.reduce(buddy_list, packet, fn _, p ->
+      Out.encode_int(p, 0)
+    end)
+    
+    Out.to_data(packet)
+  end
+
+  @doc """
+  Sends a buddy request to a character.
+  Ported from MaplePacketCreator.requestBuddylistAdd()
+  
+  ## Parameters
+  - cid_from: Character ID sending the request
+  - name_from: Name of character sending the request
+  - level_from: Level of character sending the request
+  - job_from: Job ID of character sending the request
+  """
+  def request_buddylist_add(cid_from, name_from, level_from, job_from) do
+    Out.new(Opcodes.lp_buddylist())
+    |> Out.encode_byte(9)
+    |> Out.encode_int(cid_from)
+    |> Out.encode_string(name_from)
+    |> Out.encode_int(level_from)
+    |> Out.encode_int(job_from)
+    |> Out.encode_int(cid_from)
+    |> Out.encode_string(name_from, 13)
+    |> Out.encode_byte(1)
+    |> Out.encode_int(0)
+    |> Out.encode_string("ETC", 16)
+    |> Out.encode_short(1)
+    |> Out.to_data()
+  end
+
+  @doc """
+  Sends a buddy list message/status code.
+  Ported from MaplePacketCreator.buddylistMessage()
+  
+  ## Message codes:
+  - 11: Buddy list full
+  - 12: Target buddy list full
+  - 13: Already registered as buddy
+  - 14: Character not found
+  - 15: Request sent
+  - 17: You cannot add yourself as a buddy
+  - 19: Already requested
+  - 21: Cannot add GM to buddy list
+  """
+  def buddylist_message(message_code) do
+    Out.new(Opcodes.lp_buddylist())
+    |> Out.encode_byte(message_code)
+    |> Out.to_data()
+  end
+
+  # =============================================================================
+  # Party Packets
+  # =============================================================================
+
+  @doc """
+  Party creation confirmation packet.
+  Ported from MaplePacketCreator.partyCreated()
+  
+  ## Parameters
+  - party_id: The newly created party ID
+  """
+  def party_created(party_id) do
+    opcode_byte = if Odinsea.Constants.Game.gms?(), do: 10, else: 8
+    
+    Out.new(Opcodes.lp_party_operation())
+    |> Out.encode_byte(opcode_byte)
+    |> Out.encode_int(party_id)
+    |> Out.encode_int(999_999_999)
+    |> Out.encode_int(999_999_999)
+    |> Out.encode_long(0)
+    |> Out.encode_byte(0)
+    |> Out.encode_byte(1)
+    |> Out.to_data()
+  end
+
+  @doc """
+  Party invitation packet (sent to invited player).
+  Ported from MaplePacketCreator.partyInvite()
+  
+  ## Parameters
+  - from_character: Character struct of the inviter (needs :party_id, :name, :level, :job)
+  """
+  def party_invite(from_character) do
+    party_id = from_character.party_id || 0
+    
+    Out.new(Opcodes.lp_party_operation())
+    |> Out.encode_byte(4)
+    |> Out.encode_int(party_id)
+    |> Out.encode_string(from_character.name)
+    |> Out.encode_int(from_character.level)
+    |> Out.encode_int(from_character.job)
+    |> Out.encode_byte(0)
+    |> Out.to_data()
+  end
+
+  @doc """
+  Party request packet (for request-to-join scenarios).
+  Ported from MaplePacketCreator.partyRequestInvite()
+  
+  ## Parameters
+  - from_character: Character struct of the requester (needs :id, :name, :level, :job)
+  """
+  def party_request(from_character) do
+    Out.new(Opcodes.lp_party_operation())
+    |> Out.encode_byte(7)
+    |> Out.encode_int(from_character.id)
+    |> Out.encode_string(from_character.name)
+    |> Out.encode_int(from_character.level)
+    |> Out.encode_int(from_character.job)
+    |> Out.to_data()
+  end
+
+  @doc """
+  Party status/error message packet.
+  Ported from MaplePacketCreator.partyStatusMessage()
+  
+  ## Message codes:
+  - 10: A beginner can't create a party
+  - 11: Your request for a party didn't work due to an unexpected error
+  - 13: You have yet to join a party
+  - 16: Already have joined a party
+  - 17: The party you're trying to join is already in full capacity
+  - 19: Unable to find the requested character in this channel
+  - 23: 'Char' have denied request to the party (with charname)
+  
+  ## Parameters
+  - message_code: The status/error code
+  - charname: Optional character name for personalized messages
+  """
+  def party_status_message(message_code, charname \\ nil) do
+    opcode_byte = if Odinsea.Constants.Game.gms?() and message_code >= 7, 
+                    do: message_code + 2, 
+                    else: message_code
+    
+    packet = Out.new(Opcodes.lp_party_operation())
+    |> Out.encode_byte(opcode_byte)
+    
+    packet = if charname do
+      Out.encode_string(packet, charname)
+    else
+      packet
+    end
+    
+    Out.to_data(packet)
+  end
+
+  # =============================================================================
+  # Guild Packets
+  # =============================================================================
+
+  @doc """
+  Guild invitation packet (sent to invited player).
+  Ported from MaplePacketCreator.guildInvite()
+  
+  ## Parameters
+  - guild_id: ID of the guild
+  - from_name: Name of the character sending the invite
+  - from_level: Level of the character sending the invite
+  - from_job: Job ID of the character sending the invite
+  """
+  def guild_invite(guild_id, from_name, from_level, from_job) do
+    Out.new(Opcodes.lp_guild_operation())
+    |> Out.encode_byte(0x05)
+    |> Out.encode_int(guild_id)
+    |> Out.encode_string(from_name)
+    |> Out.encode_int(from_level)
+    |> Out.encode_int(from_job)
+    |> Out.to_data()
+  end
+
+  @doc """
+  Guild invitation denial packet.
+  Ported from MaplePacketCreator.denyGuildInvitation()
+  
+  ## Parameters
+  - charname: Name of the character who denied the invitation
+  """
+  def deny_guild_invitation(charname) do
+    Out.new(Opcodes.lp_guild_operation())
+    |> Out.encode_byte(0x3D)
+    |> Out.encode_string(charname)
+    |> Out.to_data()
+  end
+
  # =============================================================================
  # Utility Functions
  # =============================================================================
--- a/lib/odinsea/channel/players.ex
+++ b/lib/odinsea/channel/players.ex
@@ -108,6 +108,16 @@ defmodule Odinsea.Channel.Players do
    end
  end

+  @doc """
+  Finds a player by name in the channel.
+  Returns the player data or nil if not found.
+  
+  This is the public API for player lookup by name.
+  """
+  def find_by_name(name, _channel_id \\ nil) do
+    get_player_by_name(name)
+  end
+
  @doc """
  Updates player data.
  """
--- a/lib/odinsea/constants/server.ex
+++ b/lib/odinsea/constants/server.ex
@@ -4,9 +4,11 @@ defmodule Odinsea.Constants.Server do
  These define the MapleStory client version and protocol details.
  """

-  # MapleStory Client Version (GMS v342)
-  @maple_version 342
-  @maple_patch "1"
+  # MapleStory Client Version (MapleSEA v112.4)
+  # Ported from ServerConstants.java
+  @maple_version 112
+  @maple_patch "4"
+  @maple_locale 7
  @client_version 99

  # Protocol constants
@@ -15,9 +17,10 @@ defmodule Odinsea.Constants.Server do
  @block_size 1460

  # RSA Keys (from ServerConstants.java)
-  @pub_key ""
-  @maplogin_default "default"
-  @maplogin_custom "custom"
+  # Default MapleStory RSA public key for password encryption
+  @pub_key "30819F300D06092A864886F70D010101050003818D0030818902818100994F4E66B003A7843C944E67BE4375203DAA203C676908E59839C9BADE95F53E848AAFE61DB9C09E80F48675CA2696F4E897B7F18CCB6398D221C4EC5823D11CA1FB9764A78F84711B8B6FCA9F01B171A51EC66C02CDA9308887CEE8E59C4FF0B146BF71F697EB11EDCEBFCE02FB0101A7076A3FEB64F6F6022C8417EB6B87270203010001"
+  @maplogin_default "MapLogin"
+  @maplogin_custom "MapLoginLuna"

  # Packet sequence constants
  @iv_length 4
@@ -35,6 +38,12 @@ defmodule Odinsea.Constants.Server do
  """
  def maple_patch, do: @maple_patch

+  @doc """
+  Returns the MapleStory locale (region code).
+  For SEA/MSEA this is 7.
+  """
+  def maple_locale, do: @maple_locale
+
  @doc """
  Returns the full client version string.
  """
--- a/lib/odinsea/database/context.ex
+++ b/lib/odinsea/database/context.ex
--- a/lib/odinsea/database/schema/account.ex
+++ b/lib/odinsea/database/schema/account.ex
@@ -11,33 +11,33 @@ defmodule Odinsea.Database.Schema.Account do
  @timestamps_opts [inserted_at: :createdat, updated_at: false]

  schema "accounts" do
-    field :name, :string
-    field :password, :string
-    field :salt, :string
-    field :second_password, :string, source: :"2ndpassword"
-    field :salt2, :string
-    field :loggedin, :integer, default: 0
-    field :lastlogin, :naive_datetime
-    field :createdat, :naive_datetime
-    field :birthday, :date
-    field :banned, :integer, default: 0
-    field :banreason, :string
-    field :gm, :integer, default: 0
-    field :email, :string
-    field :macs, :string
-    field :tempban, :naive_datetime
-    field :greason, :integer
-    field :acash, :integer, default: 0, source: :ACash
-    field :mpoints, :integer, default: 0, source: :mPoints
-    field :gender, :integer, default: 0
-    field :session_ip, :string, source: :SessionIP
-    field :points, :integer, default: 0
-    field :vpoints, :integer, default: 0
-    field :totalvotes, :integer, default: 0
-    field :lastlogon, :naive_datetime
-    field :lastvoteip, :string
+    field(:name, :string)
+    field(:password, :string)
+    field(:salt, :string)
+    field(:second_password, :string, source: :second_password)
+    field(:second_salt, :string)
+    field(:loggedin, :integer, default: 0)
+    field(:lastlogin, :naive_datetime)
+    field(:createdat, :naive_datetime)
+    field(:birthday, :date)
+    field(:banned, :integer, default: 0)
+    field(:banreason, :string)
+    field(:gm, :integer, default: 0)
+    field(:email, :string)
+    field(:macs, :string)
+    field(:tempban, :naive_datetime)
+    field(:greason, :integer)
+    field(:acash, :integer, default: 0, source: :ACash)
+    field(:mpoints, :integer, default: 0, source: :mPoints)
+    field(:gender, :integer, default: 0)
+    field(:session_ip, :string, source: :SessionIP)
+    field(:points, :integer, default: 0)
+    field(:vpoints, :integer, default: 0)
+    field(:totalvotes, :integer, default: 0)
+    field(:lastlogon, :naive_datetime)
+    field(:lastvoteip, :string)

-    has_many :characters, Odinsea.Database.Schema.Character, foreign_key: :accountid
+    has_many(:characters, Odinsea.Database.Schema.Character, foreign_key: :accountid)
  end

  @doc """
--- a/lib/odinsea/game/character.ex
+++ b/lib/odinsea/game/character.ex
@@ -986,6 +986,13 @@ defmodule Odinsea.Game.Character do
    GenServer.call(via_tuple(character_id), {:remove_item_by_id, item_id, quantity})
  end

+  @doc """
+  Updates the buddy list for a character.
+  """
+  def update_buddies(character_id, buddies) do
+    GenServer.cast(via_tuple(character_id), {:update_buddies, buddies})
+  end
+
  # ============================================================================
  # GenServer Callbacks - Scripting Operations
  # ============================================================================
@@ -1014,6 +1021,14 @@ defmodule Odinsea.Game.Character do
    {:noreply, new_state}
  end

+  @impl true
+  def handle_cast({:update_buddies, buddies}, state) do
+    # TODO: Store buddies in state when buddy list is added to State struct
+    # For now, just log the update
+    Logger.debug("Updated buddy list for character #{state.name}")
+    {:noreply, state}
+  end
+
  @impl true
  def handle_call({:add_item, inventory_type, item}, _from, state) do
    inventory = Map.get(state.inventories, inventory_type, Inventory.new(inventory_type))
--- a/lib/odinsea/game/inventory.ex
+++ b/lib/odinsea/game/inventory.ex
@@ -155,6 +155,34 @@ defmodule Odinsea.Game.Inventory do
    inv.slot_limit - map_size(inv.items)
  end

+  @doc """
+  Checks if the inventory has space for a given item and quantity.
+  Returns true if there's space, false otherwise.
+  """
+  def has_space?(%__MODULE__{} = inv, item_id, quantity) do
+    # Check if we can stack with existing items of same type
+    existing = find_by_id(inv, item_id)
+    
+    if existing do
+      # Can stack - check if existing stack + quantity <= slot_max
+      # For simplicity, assume slot_max of 9999 for stackable items
+      slot_max = existing[:slot_max] || 9999
+      existing_qty = existing.quantity || 0
+      
+      if existing_qty + quantity <= slot_max do
+        true
+      else
+        # Need additional slots for overflow
+        overflow = existing_qty + quantity - slot_max
+        slots_needed = div(overflow, slot_max) + if rem(overflow, slot_max) > 0, do: 1, else: 0
+        free_slots(inv) >= slots_needed
+      end
+    else
+      # New item - need at least one free slot
+      not full?(inv)
+    end
+  end
+
  @doc """
  Gets the next available slot number.
  Returns -1 if the inventory is full.
--- a/lib/odinsea/game/inventory_type.ex
+++ b/lib/odinsea/game/inventory_type.ex
@@ -124,4 +124,30 @@ defmodule Odinsea.Game.InventoryType do
  def slot_limit(type) do
    default_slot_limit(type)
  end
+
+  @doc """
+  Gets the inventory type from an item_id or type atom.
+  
+  For item IDs, determines type based on ID ranges:
+  - Equip: 1-999,999
+  - Use: 2,000,000-2,999,999
+  - Setup: 3,000,000-3,999,999
+  - Etc: 4,000,000-4,999,999
+  - Cash: 5,000,000+
+  
+  For atoms, returns the atom if valid, or :undefined.
+  """
+  def get_type(item_id) when is_integer(item_id) do
+    from_item_id(item_id)
+  end
+
+  def get_type(type) when is_atom(type) do
+    if type in all_types() do
+      type
+    else
+      :undefined
+    end
+  end
+
+  def get_type(_), do: :undefined
 end
--- a/lib/odinsea/game/map.ex
+++ b/lib/odinsea/game/map.ex
@@ -209,6 +209,13 @@ defmodule Odinsea.Game.Map do
    GenServer.call(via_tuple(map_id, channel_id), :get_monsters)
  end

+  @doc """
+  Gets all monsters on the map (default channel).
+  """
+  def get_monsters(map_id) do
+    get_monsters(map_id, 1)
+  end
+
  @doc """
  Spawns a monster at the specified spawn point.
  """
@@ -230,6 +237,13 @@ defmodule Odinsea.Game.Map do
    GenServer.call(via_tuple(map_id, channel_id), {:damage_monster, oid, damage, character_id})
  end

+  @doc """
+  Damages a monster (default channel).
+  """
+  def damage_monster(map_id, oid, damage, character_id) do
+    damage_monster(map_id, 1, oid, damage, character_id)
+  end
+
  @doc """
  Hits a reactor, advancing its state and triggering effects.
  """
--- a/lib/odinsea/login/client.ex
+++ b/lib/odinsea/login/client.ex
@@ -1,7 +1,7 @@
 defmodule Odinsea.Login.Client do
  @moduledoc """
  Client connection handler for the login server.
-  Manages the login session state.
+  Manages the login session state and packet encryption/decryption.
  """

  use GenServer, restart: :temporary
@@ -10,6 +10,10 @@ defmodule Odinsea.Login.Client do

  alias Odinsea.Net.Packet.In
  alias Odinsea.Net.Opcodes
+  alias Odinsea.Net.PacketLogger
+  alias Odinsea.Login.Packets
+  alias Odinsea.Net.Cipher.ClientCrypto
+  alias Odinsea.Util.BitTools

  defstruct [
    :socket,
@@ -25,7 +29,25 @@ defmodule Odinsea.Login.Client do
    :second_password,
    :gender,
    :is_gm,
-    :hardware_info
+    :hardware_info,
+    :crypto,
+    :handshake_complete,
+
+    # === NEW FIELDS - Critical Priority ===
+    :created_at,           # Session creation time (for session timeout)
+    :last_alive_ack,       # Last pong received timestamp
+    :server_transition,    # Boolean - migrating between servers
+    :macs,                 # [String.t()] - MAC addresses for ban checking
+    :character_slots,      # integer() - Max chars per world (default 3)
+
+    # === NEW FIELDS - Medium Priority ===
+    :birthday,             # integer() - YYMMDD format for PIN/SPW verification
+    :monitored,            # boolean() - GM monitoring flag
+    :tempban,              # DateTime.t() | nil - Temporary ban info
+    :chat_mute,            # boolean() - Chat restriction
+
+    buffer: <<>>,
+    character_ids: []
  ]

  def start_link(socket) do
@@ -39,6 +61,16 @@ defmodule Odinsea.Login.Client do

    Logger.info("Login client connected from #{ip_string}")

+    # Generate IVs for encryption (4 bytes each)
+    send_iv = :crypto.strong_rand_bytes(4)
+    recv_iv = :crypto.strong_rand_bytes(4)
+
+    # Create crypto context
+    crypto = ClientCrypto.new_from_ivs(112, send_iv, recv_iv)
+
+    # Get current timestamp for session tracking
+    current_time = System.system_time(:millisecond)
+
    state = %__MODULE__{
      socket: socket,
      ip: ip_string,
@@ -53,9 +85,27 @@ defmodule Odinsea.Login.Client do
      second_password: nil,
      gender: 0,
      is_gm: false,
-      hardware_info: nil
+      hardware_info: nil,
+      crypto: crypto,
+      handshake_complete: false,
+      buffer: <<>>,
+      character_ids: [],
+
+      # === NEW FIELDS INITIALIZATION ===
+      created_at: current_time,
+      last_alive_ack: current_time,
+      server_transition: false,
+      macs: [],
+      character_slots: 3,
+      birthday: nil,
+      monitored: false,
+      tempban: nil,
+      chat_mute: false
    }

+    # Send hello packet (handshake) - unencrypted
+    send_hello_packet(state, send_iv, recv_iv)
+
    # Start receiving packets
    send(self(), :receive)

@@ -66,8 +116,9 @@ defmodule Odinsea.Login.Client do
  def handle_info(:receive, %{socket: socket} = state) do
    case :gen_tcp.recv(socket, 0, 30_000) do
      {:ok, data} ->
-        # Handle packet
-        new_state = handle_packet(data, state)
+        # Append to buffer and process all complete packets
+        new_state = %{state | buffer: state.buffer <> data}
+        new_state = process_buffer(new_state)
        send(self(), :receive)
        {:noreply, new_state}

@@ -96,23 +147,100 @@ defmodule Odinsea.Login.Client do
    :ok
  end

-  defp handle_packet(data, state) do
-    packet = In.new(data)
+  # Process all complete packets from the TCP buffer
+  defp process_buffer(state) do
+    case extract_packet(state.buffer, state.crypto) do
+      {:ok, payload, remaining} ->
+        # Decrypt the payload (AES then Shanda) and morph recv IV
+        {updated_crypto, decrypted} = ClientCrypto.decrypt(state.crypto, payload)
+
+        state = %{state |
+          buffer: remaining,
+          crypto: updated_crypto,
+          handshake_complete: true
+        }
+
+        state = process_decrypted_packet(decrypted, state)
+
+        # Try to process more packets from the buffer
+        process_buffer(state)
+
+      {:need_more, _} ->
+        state
+
+      {:error, reason} ->
+        Logger.error("Packet error from #{state.ip}: #{inspect(reason)}")
+        send(self(), {:disconnect, reason})
+        state
+    end
+  end
+
+  # Extract a complete encrypted packet from the buffer using the 4-byte header
+  defp extract_packet(buffer, _crypto) when byte_size(buffer) < 4 do
+    {:need_more, buffer}
+  end
+
+  defp extract_packet(buffer, crypto) do
+    <<raw_seq::little-16, raw_len::little-16, rest::binary>> = buffer
+
+    # Validate header against current recv IV
+    if not ClientCrypto.decode_header_valid?(crypto, raw_seq) do
+      Logger.warning(
+        "Invalid packet header: raw_seq=#{raw_seq} (0x#{Integer.to_string(raw_seq, 16)}), " <>
+          "expected version check failed"
+      )
+
+      {:error, :invalid_header}
+    else
+      # Decode actual packet length from header
+      packet_len = ClientCrypto.decode_header_len(crypto, raw_seq, raw_len)
+
+      cond do
+        packet_len < 2 ->
+          {:error, :invalid_length_small}
+
+        packet_len > 65535 ->
+          {:error, :invalid_length_large}
+
+        byte_size(rest) < packet_len ->
+          # Incomplete packet - wait for more data (don't consume header)
+          {:need_more, buffer}
+
+        true ->
+          # Extract the encrypted payload and keep remainder
+          payload = binary_part(rest, 0, packet_len)
+          remaining = binary_part(rest, packet_len, byte_size(rest) - packet_len)
+          {:ok, payload, remaining}
+      end
+    end
+  end
+
+  defp process_decrypted_packet(decrypted_data, state) do
+    packet = In.new(decrypted_data)

    # Read opcode (first 2 bytes)
    case In.decode_short(packet) do
      {opcode, packet} ->
-        Logger.debug("Login packet received: opcode=0x#{Integer.to_string(opcode, 16)}")
+        # Extract remaining data (after opcode) for logging
+        remaining_data = binary_part(packet.data, packet.index, packet.length - packet.index)
+
+        # Log the decrypted packet
+        context = %{
+          ip: state.ip,
+          server_type: :login
+        }
+
+        PacketLogger.log_client_packet(opcode, remaining_data, context)
+
        dispatch_packet(opcode, packet, state)

      :error ->
-        Logger.warning("Failed to read packet opcode")
+        Logger.warning("Failed to read packet opcode from #{state.ip}")
        state
    end
  end

  defp dispatch_packet(opcode, packet, state) do
-    # Use PacketProcessor to route packets
    alias Odinsea.Net.Processor

    case Processor.handle(opcode, packet, state, :login) do
@@ -137,4 +265,66 @@ defmodule Odinsea.Login.Client do
  defp format_ip({a, b, c, d, e, f, g, h}) do
    "#{a}:#{b}:#{c}:#{d}:#{e}:#{f}:#{g}:#{h}"
  end
+
+  defp send_hello_packet(state, send_iv, recv_iv) do
+    # Get maple version from config
+    maple_version = 112
+
+    # Build hello packet
+    hello_packet = Packets.get_hello(maple_version, send_iv, recv_iv)
+
+    # Log the hello packet
+    context = %{ip: state.ip, server_type: :login}
+    PacketLogger.log_raw_packet("loopback", "HELLO", hello_packet, context)
+
+    # Send the hello packet (it already includes the length header)
+    case :gen_tcp.send(state.socket, hello_packet) do
+      :ok ->
+        :ok
+
+      {:error, reason} ->
+        Logger.error("Failed to send hello packet: #{inspect(reason)}")
+        {:error, reason}
+    end
+  end
+
+  @doc """
+  Sends a packet to the client with proper encryption.
+  """
+  def send_packet(client_pid, packet_data) when is_pid(client_pid) do
+    GenServer.call(client_pid, {:send_packet, packet_data})
+  end
+
+  @impl true
+  def handle_call({:send_packet, packet_data}, _from, state) do
+    case encrypt_and_send(packet_data, state) do
+      {:ok, new_state} ->
+        {:reply, :ok, new_state}
+
+      {:error, reason} ->
+        {:reply, {:error, reason}, state}
+    end
+  end
+
+  defp encrypt_and_send(data, state) do
+    # Encrypt the data (Shanda then AES) and morph send IV
+    {updated_crypto, encrypted, header} = ClientCrypto.encrypt(state.crypto, data)
+
+    # Combine header and encrypted payload
+    full_packet = header <> encrypted
+
+    # Log the outgoing packet
+    context = %{ip: state.ip, server_type: :login}
+    PacketLogger.log_server_packet("SERVER", data, context)
+
+    # Send the packet
+    case :gen_tcp.send(state.socket, full_packet) do
+      :ok ->
+        {:ok, %{state | crypto: updated_crypto}}
+
+      {:error, reason} ->
+        Logger.error("Failed to send packet: #{inspect(reason)}")
+        {:error, reason}
+    end
+  end
 end
--- a/lib/odinsea/login/handler.ex
+++ b/lib/odinsea/login/handler.ex
@@ -14,7 +14,8 @@ defmodule Odinsea.Login.Handler do
  require Logger

  alias Odinsea.Net.Packet.{In, Out}
-  alias Odinsea.Net.Cipher.LoginCrypto
+  alias Odinsea.Net.Cipher.{ClientCrypto, LoginCrypto}
+  alias Odinsea.Net.PacketLogger
  alias Odinsea.Login.Packets
  alias Odinsea.Constants.Server
  alias Odinsea.Database.Context
@@ -79,11 +80,18 @@ defmodule Odinsea.Login.Handler do
    Logger.info("Login attempt: username=#{username} from #{state.ip}")

    # Check if IP/MAC is banned
+    features = Application.get_env(:odinsea, :features, [])
+    skip_maccheck = Keyword.get(features, :skip_maccheck, false)
+
    ip_banned = Context.ip_banned?(state.ip)
-    mac_banned = Context.mac_banned?(state.mac)
+    mac_banned = if skip_maccheck or state.macs == [] do
+      false
+    else
+      Enum.any?(state.macs, &Context.mac_banned?/1)
+    end

    if (ip_banned || mac_banned) do
-      Logger.warning("Banned IP/MAC attempted login: ip=#{state.ip}, mac=#{state.mac}")
+      Logger.warning("Banned IP/MAC attempted login: ip=#{state.ip}, macs=#{inspect(state.macs)}")

      # If MAC banned, also ban the IP for enforcement
      if mac_banned do
@@ -91,7 +99,7 @@ defmodule Odinsea.Login.Handler do
      end

      response = Packets.get_login_failed(3)
-      send_packet(state, response)
+      state = send_packet(state, response)
      {:ok, state}
    else
      # Authenticate with database
@@ -106,7 +114,7 @@ defmodule Odinsea.Login.Handler do
              format_timestamp(temp_ban_info.expires),
              temp_ban_info.reason || ""
            )
-            send_packet(state, response)
+            state = send_packet(state, response)
            {:ok, state}
          else
            # Check if already logged in - kick other session
@@ -132,6 +140,8 @@ defmodule Odinsea.Login.Handler do
              account_info.second_password
            )

+            state = send_packet(state, response)
+
            new_state =
              state
              |> Map.put(:logged_in, true)
@@ -142,8 +152,8 @@ defmodule Odinsea.Login.Handler do
              |> Map.put(:second_password, account_info.second_password)
              |> Map.put(:login_attempts, 0)

-            send_packet(state, response)
-            {:ok, new_state}
+            # Send world info immediately after auth success (Java: LoginWorker.registerClient)
+            on_world_info_request(new_state)
          end

        {:error, :invalid_credentials} ->
@@ -156,7 +166,7 @@ defmodule Odinsea.Login.Handler do
          else
            # Send login failed (reason 4 = incorrect password)
            response = Packets.get_login_failed(4)
-            send_packet(state, response)
+            state = send_packet(state, response)

            new_state = Map.put(state, :login_attempts, login_attempts)
            {:ok, new_state}
@@ -165,7 +175,7 @@ defmodule Odinsea.Login.Handler do
        {:error, :account_not_found} ->
          # Send login failed (reason 5 = not registered ID)
          response = Packets.get_login_failed(5)
-          send_packet(state, response)
+          state = send_packet(state, response)
          {:ok, state}

        {:error, :already_logged_in} ->
@@ -176,12 +186,12 @@ defmodule Odinsea.Login.Handler do
          
          # Send login failed (reason 7 = already logged in) but client can retry
          response = Packets.get_login_failed(7)
-          send_packet(state, response)
+          state = send_packet(state, response)
          {:ok, state}

        {:error, :banned} ->
          response = Packets.get_perm_ban(0)
-          send_packet(state, response)
+          state = send_packet(state, response)
          {:ok, state}
      end
    end
@@ -209,19 +219,19 @@ defmodule Odinsea.Login.Handler do
      channel_load
    )

-    send_packet(state, server_list)
+    state = send_packet(state, server_list)

    # Send end of server list
    end_list = Packets.get_end_of_server_list()
-    send_packet(state, end_list)
+    state = send_packet(state, end_list)

    # Send latest connected world
    latest_world = Packets.get_latest_connected_world(0)
-    send_packet(state, latest_world)
+    state = send_packet(state, latest_world)

    # Send recommended world message
    recommend = Packets.get_recommend_world_message(0, "Join now!")
-    send_packet(state, recommend)
+    state = send_packet(state, recommend)

    {:ok, state}
  end
@@ -246,7 +256,7 @@ defmodule Odinsea.Login.Handler do
      end

    response = Packets.get_server_status(status)
-    send_packet(state, response)
+    state = send_packet(state, response)

    {:ok, state}
  end
@@ -277,7 +287,7 @@ defmodule Odinsea.Login.Handler do
      if world_id != 0 do
        Logger.warning("Invalid world ID: #{world_id}")
        response = Packets.get_login_failed(10)
-        send_packet(state, response)
+        state = send_packet(state, response)
        {:ok, state}
      else
        # TODO: Check if channel is available
@@ -299,7 +309,7 @@ defmodule Odinsea.Login.Handler do
          3  # character slots
        )

-        send_packet(state, response)
+        state = send_packet(state, response)

        new_state =
          state
@@ -332,7 +342,7 @@ defmodule Odinsea.Login.Handler do
      name_used = check_name_used(char_name, state)

      response = Packets.get_char_name_response(char_name, name_used)
-      send_packet(state, response)
+      state = send_packet(state, response)

      {:ok, state}
    end
@@ -381,7 +391,7 @@ defmodule Odinsea.Login.Handler do
      # Validate name is not forbidden and doesn't exist
      if check_name_used(name, state) do
        response = Packets.get_add_new_char_entry(nil, false)
-        send_packet(state, response)
+        state = send_packet(state, response)
        {:ok, state}
      else
        # TODO: Validate appearance items are eligible for gender/job type
@@ -420,7 +430,7 @@ defmodule Odinsea.Login.Handler do
            # Reload character with full data
            char_data = Context.load_character(character.id)
            response = Packets.get_add_new_char_entry(char_data, true)
-            send_packet(state, response)
+            state = send_packet(state, response)

            # Add character ID to state's character list
            new_char_ids = [character.id | Map.get(state, :character_ids, [])]
@@ -430,7 +440,7 @@ defmodule Odinsea.Login.Handler do
          {:error, changeset} ->
            Logger.error("Failed to create character: #{inspect(changeset.errors)}")
            response = Packets.get_add_new_char_entry(nil, false)
-            send_packet(state, response)
+            state = send_packet(state, response)
            {:ok, state}
        end
      end
@@ -511,7 +521,7 @@ defmodule Odinsea.Login.Handler do
        end

      response = Packets.get_delete_char_response(character_id, result)
-      send_packet(state, response)
+      state = send_packet(state, response)

      # Update state if successful
      new_state = 
@@ -559,7 +569,7 @@ defmodule Odinsea.Login.Handler do
          # Validate second password length
          if String.length(new_spw) < 6 || String.length(new_spw) > 16 do
            response = Packets.get_second_pw_error(0x14)
-            send_packet(state, response)
+            state = send_packet(state, response)
            {:ok, state}
          else
            # Update second password
@@ -605,7 +615,7 @@ defmodule Odinsea.Login.Handler do
        
        # Send migration command
        response = Packets.get_server_ip(false, channel_ip, channel_port, character_id)
-        send_packet(state, response)
+        state = send_packet(state, response)

        new_state =
          state
@@ -643,7 +653,7 @@ defmodule Odinsea.Login.Handler do
      else
        # Failure - send error
        response = Packets.get_second_pw_error(15)  # Incorrect SPW
-        send_packet(state, response)
+        state = send_packet(state, response)
        {:ok, state}
      end
    end
@@ -662,14 +672,12 @@ defmodule Odinsea.Login.Handler do
    # TODO: Send damage cap packet if custom client

    # Send login background
-    background = Application.get_env(:odinsea, :login_background, "MapLogin")
-    bg_response = Packets.get_login_background(background)
-    send_packet(state, bg_response)
+    bg_response = Packets.get_login_background(Server.maplogin_default())
+    state = send_packet(state, bg_response)

    # Send RSA public key
-    pub_key = Application.get_env(:odinsea, :rsa_public_key, "")
-    key_response = Packets.get_rsa_key(pub_key)
-    send_packet(state, key_response)
+    key_response = Packets.get_rsa_key(Server.pub_key())
+    state = send_packet(state, key_response)

    {:ok, state}
  end
@@ -678,27 +686,40 @@ defmodule Odinsea.Login.Handler do
  # Helper Functions
  # ==================================================================================================

-  defp send_packet(%{socket: socket} = state, packet_data) do
-    # Add header (2 bytes: packet length)
-    packet_length = byte_size(packet_data)
-    header = <<packet_length::little-size(16)>>
-    full_packet = header <> packet_data
+  defp send_packet(%{socket: socket, crypto: crypto} = state, packet_data) do
+    # Flatten iodata to binary for pattern matching
+    packet_data = IO.iodata_to_binary(packet_data)
+
+    # Extract opcode from packet data (first 2 bytes)
+    <<opcode::little-16, rest::binary>> = packet_data
+
+    # Log the packet
+    context = %{
+      ip: state.ip,
+      server_type: :login
+    }
+    PacketLogger.log_server_packet(opcode, rest, context)
+
+    # Encrypt the data (Shanda then AES) and morph send IV
+    {updated_crypto, encrypted, header} = ClientCrypto.encrypt(crypto, packet_data)
+
+    # Send encrypted packet with 4-byte crypto header
+    full_packet = header <> encrypted

    case :gen_tcp.send(socket, full_packet) do
      :ok ->
-        Logger.debug("Sent packet: #{packet_length} bytes")
-        :ok
+        %{state | crypto: updated_crypto}

      {:error, reason} ->
        Logger.error("Failed to send packet: #{inspect(reason)}")
-        {:error, reason}
+        state
    end
  end

-  defp send_packet(_state, _packet_data) do
+  defp send_packet(state, _packet_data) do
    # Socket not available in state
    Logger.error("Cannot send packet: socket not in state")
-    :error
+    state
  end

  defp authenticate_user(username, password, _state) do
--- a/lib/odinsea/login/packets.ex
+++ b/lib/odinsea/login/packets.ex
@@ -40,7 +40,7 @@ defmodule Odinsea.Login.Packets do
    |> Out.encode_buffer(recv_iv)
    |> Out.encode_buffer(send_iv)
    |> Out.encode_byte(Server.maple_locale())
-    |> Out.to_data()
+    |> Out.to_iodata()
  end

  @doc """
@@ -49,27 +49,26 @@ defmodule Odinsea.Login.Packets do
  """
  def get_ping do
    Out.new(Opcodes.lp_alive_req())
-    |> Out.to_data()
+    |> Out.to_iodata()
  end

  @doc """
  Sends the login background image path to the client.
  """
  def get_login_background(background_path) do
-    # Note: In Java this uses LoopbackPacket.LOGIN_AUTH
-    # Need to verify the correct opcode for this
-    Out.new(Opcodes.lp_set_client_key())  # TODO: Verify opcode
+    # Uses LOGIN_AUTH (0x17) opcode
+    Out.new(Opcodes.lp_login_auth())
    |> Out.encode_string(background_path)
-    |> Out.to_data()
+    |> Out.to_iodata()
  end

  @doc """
  Sends the RSA public key to the client for password encryption.
  """
  def get_rsa_key(public_key) do
-    Out.new(Opcodes.lp_set_client_key())
+    Out.new(Opcodes.lp_rsa_key())
    |> Out.encode_string(public_key)
-    |> Out.to_data()
+    |> Out.to_iodata()
  end

  # ==================================================================================================
@@ -104,13 +103,13 @@ defmodule Odinsea.Login.Packets do

        reason == 7 ->
          # Already logged in
-          Out.encode_bytes(packet, <<0, 0, 0, 0, 0>>)
+          Out.encode_buffer(packet, <<0, 0, 0, 0, 0>>)

        true ->
          packet
      end

-    Out.to_data(packet)
+    Out.to_iodata(packet)
  end

  @doc """
@@ -122,7 +121,7 @@ defmodule Odinsea.Login.Packets do
    |> Out.encode_int(0)
    |> Out.encode_short(reason)
    |> Out.encode_buffer(<<1, 1, 1, 1, 0>>)
-    |> Out.to_data()
+    |> Out.to_iodata()
  end

  @doc """
@@ -134,7 +133,7 @@ defmodule Odinsea.Login.Packets do
    |> Out.encode_short(0)
    |> Out.encode_byte(reason)
    |> Out.encode_long(timestamp_till)
-    |> Out.to_data()
+    |> Out.to_iodata()
  end

  @doc """
@@ -147,26 +146,23 @@ defmodule Odinsea.Login.Packets do
  - `is_gm` - Admin/GM status
  - `second_password` - Second password (nil if not set)
  """
-  def get_auth_success(account_id, account_name, gender, is_gm, second_password) do
+  def get_auth_success(account_id, account_name, gender, is_gm, _second_password) do
    admin_byte = if is_gm, do: 1, else: 0
-    spw_byte = get_second_password_byte(second_password)

    Out.new(Opcodes.lp_check_password_result())
-    |> Out.encode_bytes(<<0, 0, 0, 0, 0, 0>>)  # GMS specific
+    |> Out.encode_byte(0)  # MSEA: 1 byte padding (not 6 like GMS)
    |> Out.encode_int(account_id)
    |> Out.encode_byte(gender)
    |> Out.encode_byte(admin_byte)  # Admin byte - Find, Trade, etc.
-    |> Out.encode_short(2)  # GMS: 2 for existing accounts, 0 for new
+    # NO encode_short(2) for MSEA - this is GMS only!
    |> Out.encode_byte(admin_byte)  # Admin byte - Commands
    |> Out.encode_string(account_name)
    |> Out.encode_int(3)  # 3 for existing accounts, 0 for new
-    |> Out.encode_bytes(<<0, 0, 0, 0, 0, 0>>)
-    |> Out.encode_long(get_time(System.system_time(:millisecond)))  # Account creation date
-    |> Out.encode_int(4)  # 4 for existing accounts, 0 for new
-    |> Out.encode_byte(1)  # 1 = PIN disabled, 0 = PIN enabled
-    |> Out.encode_byte(spw_byte)  # Second password status
-    |> Out.encode_long(:rand.uniform(1_000_000_000_000_000_000))  # Random long for anti-hack
-    |> Out.to_data()
+    |> Out.encode_buffer(<<0, 0, 0, 0, 0, 0>>)  # 6 bytes padding
+    # MSEA ending (different from GMS - no time long, PIN/SPW bytes, random long)
+    |> Out.encode_short(0)
+    |> Out.encode_int(get_current_date())
+    |> Out.to_iodata()
  end

  # ==================================================================================================
@@ -187,14 +183,14 @@ defmodule Odinsea.Login.Packets do
    last_channel = get_last_channel(channel_load)

    packet =
-      Out.new(Opcodes.lp_world_information())
+      Out.new(Opcodes.lp_server_list())
      |> Out.encode_byte(server_id)
      |> Out.encode_string(world_name)
      |> Out.encode_byte(flag)
      |> Out.encode_string(event_message)
      |> Out.encode_short(100)  # EXP rate display
      |> Out.encode_short(100)  # Drop rate display
-      |> Out.encode_byte(0)  # GMS specific
+      # NO encode_byte(0) for MSEA - this is GMS only!
      |> Out.encode_byte(last_channel)

    # Encode channel list
@@ -212,16 +208,16 @@ defmodule Odinsea.Login.Packets do
    packet
    |> Out.encode_short(0)  # Balloon message size
    |> Out.encode_int(0)
-    |> Out.to_data()
+    |> Out.to_iodata()
  end

  @doc """
  Sends the end-of-server-list marker.
  """
  def get_end_of_server_list do
-    Out.new(Opcodes.lp_world_information())
+    Out.new(Opcodes.lp_server_list())
    |> Out.encode_byte(0xFF)
-    |> Out.to_data()
+    |> Out.to_iodata()
  end

  @doc """
@@ -233,9 +229,9 @@ defmodule Odinsea.Login.Packets do
  - 2: Full
  """
  def get_server_status(status) do
-    Out.new(Opcodes.lp_select_world_result())
+    Out.new(Opcodes.lp_server_status())
    |> Out.encode_short(status)
-    |> Out.to_data()
+    |> Out.to_iodata()
  end

  @doc """
@@ -244,7 +240,7 @@ defmodule Odinsea.Login.Packets do
  def get_latest_connected_world(world_id) do
    Out.new(Opcodes.lp_latest_connected_world())
    |> Out.encode_int(world_id)
-    |> Out.to_data()
+    |> Out.to_iodata()
  end

  @doc """
@@ -263,7 +259,7 @@ defmodule Odinsea.Login.Packets do
        Out.encode_byte(packet, 0)
      end

-    Out.to_data(packet)
+    Out.to_iodata(packet)
  end

  # ==================================================================================================
@@ -272,6 +268,7 @@ defmodule Odinsea.Login.Packets do

  @doc """
  Sends character list for selected world.
+  MSEA v112.4 specific encoding.

  ## Parameters
  - `characters` - List of character maps
@@ -279,55 +276,70 @@ defmodule Odinsea.Login.Packets do
  - `char_slots` - Number of character slots (default 3)
  """
  def get_char_list(characters, second_password, char_slots \\ 3) do
-    spw_byte = get_second_password_byte(second_password)
+    # MSEA: no special handling for empty string SPW (GMS uses byte 2 for empty)
+    spw_byte = if second_password != nil and second_password != "", do: 1, else: 0

    packet =
-      Out.new(Opcodes.lp_select_character_result())
+      Out.new(Opcodes.lp_char_list())
      |> Out.encode_byte(0)
      |> Out.encode_byte(length(characters))

-    # TODO: Encode each character entry
-    # For now, just encode empty list structure
+    # Encode each character entry with MSEA-specific encoding
    packet =
-      Enum.reduce(characters, packet, fn _char, acc ->
-        # add_char_entry(acc, char)
-        acc  # TODO: Implement character encoding
+      Enum.reduce(characters, packet, fn char, acc ->
+        add_char_entry(acc, char)
      end)

    packet
    |> Out.encode_byte(spw_byte)
+    |> Out.encode_byte(0)  # MSEA ONLY: extra byte after SPW
    |> Out.encode_long(char_slots)
-    |> Out.to_data()
+    |> Out.encode_long(-:rand.uniform(9_223_372_036_854_775_807))  # MSEA ONLY: negative random long
+    |> Out.to_iodata()
  end

  @doc """
  Character name check response.
  """
  def get_char_name_response(char_name, name_used) do
-    Out.new(Opcodes.lp_check_duplicated_id_result())
+    Out.new(Opcodes.lp_char_name_response())
    |> Out.encode_string(char_name)
    |> Out.encode_byte(if name_used, do: 1, else: 0)
-    |> Out.to_data()
+    |> Out.to_iodata()
  end

  @doc """
  Character creation response.
  """
  def get_add_new_char_entry(character, worked) do
-    Out.new(Opcodes.lp_create_new_character_result())
+    # Uses LP_AddNewCharEntry (0x0A) opcode
+    packet = Out.new(Opcodes.lp_add_new_char_entry())
    |> Out.encode_byte(if worked, do: 0, else: 1)
-    # TODO: Add character entry if worked
-    |> Out.to_data()
+    
+    if worked do
+      # Add character entry for new character (ranking = false for creation)
+      packet = add_char_stats(packet, character)
+      packet = add_char_look(packet, character)
+      
+      # viewAll = false, ranking = false for char creation
+      packet
+      |> Out.encode_byte(0)  # viewAll
+      |> Out.encode_byte(0)  # no ranking for new char
+    else
+      packet
+    end
+    |> Out.to_iodata()
  end

  @doc """
  Character deletion response.
  """
  def get_delete_char_response(character_id, state) do
-    Out.new(Opcodes.lp_delete_character_result())
+    # Uses LP_DeleteCharResponse (0x0B) opcode
+    Out.new(Opcodes.lp_delete_char_response())
    |> Out.encode_int(character_id)
    |> Out.encode_byte(state)
-    |> Out.to_data()
+    |> Out.to_iodata()
  end

  # ==================================================================================================
@@ -344,7 +356,7 @@ defmodule Odinsea.Login.Packets do
  def get_second_pw_error(mode) do
    Out.new(Opcodes.lp_check_spw_result())
    |> Out.encode_byte(mode)
-    |> Out.to_data()
+    |> Out.to_iodata()
  end

  # ==================================================================================================
@@ -361,28 +373,30 @@ defmodule Odinsea.Login.Packets do
  - `character_id` - Character ID for migration
  """
  def get_server_ip(is_cash_shop, host, port, character_id) do
+    # Uses LP_ServerIP (0x08) opcode
    # Parse IP address
    ip_parts = parse_ip(host)

-    Out.new(Opcodes.lp_migrate_command())
+    Out.new(Opcodes.lp_server_ip())
    |> Out.encode_short(if is_cash_shop, do: 1, else: 0)
    |> encode_ip(ip_parts)
    |> Out.encode_short(port)
    |> Out.encode_int(character_id)
-    |> Out.encode_bytes(<<0, 0>>)
-    |> Out.to_data()
+    |> Out.encode_buffer(<<0, 0>>)
+    |> Out.to_iodata()
  end

  # ==================================================================================================
  # Helper Functions
  # ==================================================================================================

-  defp get_second_password_byte(second_password) do
-    cond do
-      second_password == nil -> 0
-      second_password == "" -> 2
-      true -> 1
-    end
+  @doc """
+  Returns current date in MSEA format: YYYYMMDD as integer.
+  Used in authentication success packet.
+  """
+  def get_current_date do
+    {{year, month, day}, _} = :calendar.local_time()
+    year * 10000 + month * 100 + day
  end

  defp get_last_channel(channel_load) do
@@ -431,4 +445,228 @@ defmodule Odinsea.Login.Packets do
    |> Out.encode_byte(c)
    |> Out.encode_byte(d)
  end
+
+  # ==============================================================================
+  # Character Entry Encoding (MSEA v112.4)
+  # ==============================================================================
+
+  @doc """
+  Adds a character entry to the packet for character list.
+  Ported from LoginPacket.addCharEntry() for MSEA.
+  """
+  def add_char_entry(packet, character) do
+    packet = add_char_stats(packet, character)
+    packet = add_char_look(packet, character)
+
+    # viewAll = false, so encode byte 0
+    packet = Out.encode_byte(packet, 0)
+
+    # Ranking (true if not GM and level >= 30)
+    ranking = not Map.get(character, :is_gm, false) and Map.get(character, :level, 1) >= 30
+    packet = Out.encode_byte(packet, if(ranking, do: 1, else: 0))
+
+    if ranking do
+      packet
+      |> Out.encode_int(Map.get(character, :rank, 0))
+      |> Out.encode_int(Map.get(character, :rank_move, 0))
+      |> Out.encode_int(Map.get(character, :job_rank, 0))
+      |> Out.encode_int(Map.get(character, :job_rank_move, 0))
+    else
+      packet
+    end
+  end
+
+  @doc """
+  Encodes character stats for MSEA v112.4.
+  Ported from PacketHelper.addCharStats() - MSEA path (GMS = false).
+
+  MSEA Differences from GMS:
+  - NO 24 bytes padding after hair
+  - encode_long(0) after Gach EXP
+  - NO encode_int(0) after spawnpoint
+  """
+  def add_char_stats(packet, character) do
+    packet
+    |> Out.encode_int(Map.get(character, :id, 0))
+    |> Out.encode_string(Map.get(character, :name, ""), 13)
+    |> Out.encode_byte(Map.get(character, :gender, 0))
+    |> Out.encode_byte(Map.get(character, :skin_color, 0))
+    |> Out.encode_int(Map.get(character, :face, 0))
+    |> Out.encode_int(Map.get(character, :hair, 0))
+    # MSEA: NO 24 bytes padding (GMS has it)
+    |> Out.encode_byte(Map.get(character, :level, 1))
+    |> Out.encode_short(Map.get(character, :job, 0))
+    |> encode_char_stats_data(character)
+    |> Out.encode_short(Map.get(character, :remaining_ap, 0))
+    |> encode_remaining_sp(character)
+    |> Out.encode_int(Map.get(character, :exp, 0))
+    |> Out.encode_int(Map.get(character, :fame, 0))
+    |> Out.encode_int(Map.get(character, :gach_exp, 0))
+    # MSEA ONLY: encode_long(0) after Gach EXP
+    |> Out.encode_long(0)
+    |> Out.encode_int(Map.get(character, :map_id, 0))
+    |> Out.encode_byte(Map.get(character, :spawnpoint, 0))
+    # MSEA: NO encode_int(0) after spawnpoint (GMS has it)
+    |> Out.encode_short(Map.get(character, :subcategory, 0))
+    |> Out.encode_byte(Map.get(character, :fatigue, 0))
+    |> Out.encode_int(get_current_date())
+    |> encode_traits(character)
+    |> Out.encode_buffer(<<0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0>>)  # 12 bytes padding
+    |> Out.encode_int(Map.get(character, :pvp_exp, 0))
+    |> Out.encode_byte(Map.get(character, :pvp_rank, 0))
+    |> Out.encode_int(Map.get(character, :battle_points, 0))
+    |> Out.encode_byte(5)
+    # MSEA: NO final encode_int(0) that GMS has
+  end
+
+  # Encodes the main character stats (str, dex, int, luk, hp, mp, max hp, max mp)
+  defp encode_char_stats_data(packet, character) do
+    stats = Map.get(character, :stats, %{})
+
+    packet
+    |> Out.encode_short(Map.get(stats, :str, 12))
+    |> Out.encode_short(Map.get(stats, :dex, 5))
+    |> Out.encode_short(Map.get(stats, :int, 4))
+    |> Out.encode_short(Map.get(stats, :luk, 4))
+    |> Out.encode_short(Map.get(stats, :hp, 50))
+    |> Out.encode_short(Map.get(stats, :max_hp, 50))
+    |> Out.encode_short(Map.get(stats, :mp, 5))
+    |> Out.encode_short(Map.get(stats, :max_mp, 5))
+  end
+
+  # Encodes remaining SP based on job type
+  defp encode_remaining_sp(packet, character) do
+    job = Map.get(character, :job, 0)
+    sp_data = Map.get(character, :remaining_sp, %{type: :short, value: 0})
+
+    # Check for extended SP classes (Evan, Resistance, Mercedes)
+    if is_extended_sp_job?(job) do
+      sp_list = Map.get(character, :remaining_sps, [])
+      packet = Out.encode_byte(packet, length(sp_list))
+
+      Enum.reduce(sp_list, packet, fn {sp_index, sp_value}, p ->
+        p
+        |> Out.encode_byte(sp_index)
+        |> Out.encode_byte(sp_value)
+      end)
+    else
+      Out.encode_short(packet, Map.get(sp_data, :value, 0))
+    end
+  end
+
+  # Jobs that use extended SP format
+  defp is_extended_sp_job?(job) do
+    # Evan: 2200-2218
+    # Resistance: 3000-3512
+    # Mercedes: 2300-2312
+    (job >= 2200 and job <= 2218) or
+      (job >= 3000 and job <= 3512) or
+      (job >= 2300 and job <= 2312)
+  end
+
+  # Encodes trait data (charisma, insight, will, craft, sense, charm)
+  defp encode_traits(packet, character) do
+    traits = Map.get(character, :traits, [0, 0, 0, 0, 0, 0])
+
+    Enum.reduce(traits, packet, fn trait_exp, p ->
+      Out.encode_int(p, trait_exp)
+    end)
+  end
+
+  @doc """
+  Encodes character appearance (look) for MSEA v112.4.
+  Ported from PacketHelper.addCharLook().
+
+  MSEA uses different equipment slot positions than GMS:
+  - Mount: MSEA = -23/-24, GMS = -18/-19
+  - Pendant: MSEA = -55, GMS = -59
+  """
+  def add_char_look(packet, character) do
+    mega = true  # For character list, mega = true
+
+    packet =
+      packet
+      |> Out.encode_byte(Map.get(character, :gender, 0))
+      |> Out.encode_byte(Map.get(character, :skin_color, 0))
+      |> Out.encode_int(Map.get(character, :face, 0))
+      |> Out.encode_int(Map.get(character, :job, 0))
+      |> Out.encode_byte(if mega, do: 0, else: 1)
+      |> Out.encode_int(Map.get(character, :hair, 0))
+
+    equipment = Map.get(character, :equipment, %{})
+
+    # Process equipment slots
+    {visible_equip, masked_equip} = process_char_look_equipment(equipment)
+
+    # Encode visible equipment
+    packet =
+      Enum.reduce(visible_equip, packet, fn {slot, item_id}, p ->
+        p
+        |> Out.encode_byte(slot)
+        |> Out.encode_int(item_id)
+      end)
+
+    # End of visible items marker
+    packet = Out.encode_byte(packet, 0xFF)
+
+    # Encode masked equipment (overrides visible)
+    packet =
+      Enum.reduce(masked_equip, packet, fn {slot, item_id}, p ->
+        p
+        |> Out.encode_byte(slot)
+        |> Out.encode_int(item_id)
+      end)
+
+    # End of masked items marker
+    packet = Out.encode_byte(packet, 0xFF)
+
+    # cash weapon (slot -111)
+    cash_weapon = Map.get(equipment, -111, 0)
+
+    packet
+    |> Out.encode_int(cash_weapon)
+    |> Out.encode_int(0)  # Unknown/ears
+    |> Out.encode_long(0)  # Padding
+  end
+
+  # Processes equipment for char look encoding
+  # Returns {visible_equip_map, masked_equip_map}
+  defp process_char_look_equipment(equipment) do
+    equipment
+    |> Enum.reduce({%{}, %{}}, fn {pos, item_id}, {visible, masked} = acc ->
+      # Skip hidden equipment (slot < -127)
+      if pos < -127 do
+        acc
+      else
+        slot = abs(pos)
+
+        cond do
+          # Normal visible equipment (slots 1-99)
+          slot < 100 ->
+            if Map.has_key?(visible, slot) do
+              # Move existing to masked, put new in visible
+              {Map.put(visible, slot, item_id), Map.put(masked, slot, visible[slot])}
+            else
+              {Map.put(visible, slot, item_id), masked}
+            end
+
+          # Cash equipment (slots 100+, except 111)
+          slot > 100 and slot != 111 ->
+            actual_slot = slot - 100
+
+            if Map.has_key?(visible, actual_slot) do
+              # Replace visible with cash, move old visible to masked
+              {Map.put(visible, actual_slot, item_id),
+               Map.put(masked, actual_slot, visible[actual_slot])}
+            else
+              {Map.put(visible, actual_slot, item_id), masked}
+            end
+
+          # Other slots (111 = cash weapon, etc.) - skip for now
+          true ->
+            acc
+        end
+      end
+    end)
+  end
 end
--- a/lib/odinsea/net/cipher/aes_cipher.ex
+++ b/lib/odinsea/net/cipher/aes_cipher.ex
@@ -6,9 +6,12 @@ defmodule Odinsea.Net.Cipher.AESCipher do
  Ported from: src/handling/netty/cipher/AESCipher.java
  """

+  import Bitwise
+
  @block_size 1460

-  # MapleStory AES key (32 bytes, expanded from the Java version)
+  # MapleStory AES key (32 bytes = AES-256)
+  # Must match the Java AES_KEY exactly
  @aes_key <<
    0x13, 0x00, 0x00, 0x00,
    0x08, 0x00, 0x00, 0x00,
@@ -21,7 +24,14 @@ defmodule Odinsea.Net.Cipher.AESCipher do
  >>

  @doc """
-  Encrypts or decrypts packet data in place using AES-ECB with IV.
+  Encrypts or decrypts packet data using AES-ECB with IV.
+
+  The algorithm (per block of 1456/1460 bytes):
+  1. Expand the 4-byte IV to 16 bytes by repeating it 4 times
+  2. Use AES-ECB to encrypt the expanded IV, producing a 16-byte keystream
+  3. XOR the next 16 bytes of data with the keystream
+  4. The encrypted IV becomes the new IV for the next 16-byte chunk
+  5. Repeat until the block is processed

  ## Parameters
    - data: Binary data to encrypt/decrypt
@@ -32,74 +42,52 @@ defmodule Odinsea.Net.Cipher.AESCipher do
  """
  @spec crypt(binary(), binary()) :: binary()
  def crypt(data, <<_::binary-size(4)>> = iv) when is_binary(data) do
-    crypt_recursive(data, iv, 0, byte_size(data), @block_size - 4)
+    data_list = :binary.bin_to_list(data)
+    result = crypt_blocks(data_list, 0, @block_size - 4, iv)
+    :binary.list_to_bin(result)
  end

-  # Recursive encryption/decryption function
-  @spec crypt_recursive(binary(), binary(), non_neg_integer(), non_neg_integer(), non_neg_integer()) :: binary()
-  defp crypt_recursive(data, _iv, start, remaining, _length) when remaining <= 0 do
-    # Return the portion of data we've processed
-    binary_part(data, 0, start)
-  end
+  # Process data in blocks (first block: 1456 bytes, subsequent: 1460 bytes)
+  defp crypt_blocks([], _start, _length, _iv), do: []

-  defp crypt_recursive(data, iv, start, remaining, length) do
-    # Multiply the IV by 4
-    seq_iv = multiply_bytes(iv, byte_size(iv), 4)
-
-    # Adjust length if remaining is smaller
+  defp crypt_blocks(data, start, length, iv) do
+    remaining = Kernel.length(data)
    actual_length = min(remaining, length)

-    # Extract the portion of data to process
-    data_bytes = :binary.bin_to_list(data)
+    # Expand 4-byte IV to 16 bytes (repeat 4 times)
+    seq_iv = :binary.copy(iv, 4)
+    seq_iv_list = :binary.bin_to_list(seq_iv)

-    # Process the data chunk
-    {new_data_bytes, _final_seq_iv} =
-      process_chunk(data_bytes, seq_iv, start, start + actual_length, 0)
+    # Process this block's bytes, re-encrypting keystream every 16 bytes
+    {block, rest} = Enum.split(data, actual_length)
+    {processed, _final_iv} = process_block_bytes(block, seq_iv_list, 0)

-    # Convert back to binary
-    new_data = :binary.list_to_bin(new_data_bytes)
-
-    # Continue with next chunk
-    new_start = start + actual_length
-    new_remaining = remaining - actual_length
-    new_length = @block_size
-
-    crypt_recursive(new_data, iv, new_start, new_remaining, new_length)
+    # Continue with next block using fresh IV expansion
+    processed ++ crypt_blocks(rest, start + actual_length, @block_size, iv)
  end

-  # Process a single chunk of data
-  @spec process_chunk(list(byte()), binary(), non_neg_integer(), non_neg_integer(), non_neg_integer()) ::
-          {list(byte()), binary()}
-  defp process_chunk(data_bytes, seq_iv, x, end_x, _offset) when x >= end_x do
-    {data_bytes, seq_iv}
-  end
+  # Process bytes within a single block, re-encrypting keystream every 16 bytes
+  defp process_block_bytes([], iv_list, _offset), do: {[], iv_list}

-  defp process_chunk(data_bytes, seq_iv, x, end_x, offset) do
-    # Check if we need to re-encrypt the IV
-    {new_seq_iv, new_offset} =
-      if rem(offset, byte_size(seq_iv)) == 0 do
-        # Encrypt the IV using AES
-        encrypted_iv = aes_encrypt_block(seq_iv)
-        {encrypted_iv, 0}
+  defp process_block_bytes(data, iv_list, offset) do
+    # Re-encrypt keystream at every 16-byte boundary
+    iv_list =
+      if rem(offset, 16) == 0 do
+        new_iv = aes_encrypt_block(:binary.list_to_bin(iv_list))
+        :binary.bin_to_list(new_iv)
      else
-        {seq_iv, offset}
+        iv_list
      end

-    # XOR the data byte with the IV byte
-    seq_iv_bytes = :binary.bin_to_list(new_seq_iv)
-    iv_index = rem(new_offset, length(seq_iv_bytes))
-    iv_byte = Enum.at(seq_iv_bytes, iv_index)
-    data_byte = Enum.at(data_bytes, x)
-    xor_byte = Bitwise.bxor(data_byte, iv_byte)
+    [byte | rest] = data
+    iv_byte = Enum.at(iv_list, rem(offset, 16))
+    xored = bxor(byte, iv_byte)

-    # Update the data
-    updated_data = List.replace_at(data_bytes, x, xor_byte)
-
-    # Continue processing
-    process_chunk(updated_data, new_seq_iv, x + 1, end_x, new_offset + 1)
+    {rest_result, final_iv} = process_block_bytes(rest, iv_list, offset + 1)
+    {[xored | rest_result], final_iv}
  end

-  # Encrypt a single 16-byte block using AES-ECB
+  # Encrypt a single 16-byte block using AES-256-ECB
  @spec aes_encrypt_block(binary()) :: binary()
  defp aes_encrypt_block(block) do
    # Pad or truncate to 16 bytes for AES
@@ -110,15 +98,9 @@ defmodule Odinsea.Net.Cipher.AESCipher do
        size when size > 16 -> binary_part(block, 0, 16)
      end

-    # Perform AES encryption in ECB mode
-    :crypto.crypto_one_time(:aes_128_ecb, @aes_key, padded_block, true)
-  end
-
-  # Multiply bytes - repeats the first `count` bytes of `input` `mul` times
-  @spec multiply_bytes(binary(), non_neg_integer(), non_neg_integer()) :: binary()
-  defp multiply_bytes(input, count, mul) do
-    # Take first `count` bytes and repeat them `mul` times
-    chunk = binary_part(input, 0, min(count, byte_size(input)))
-    :binary.copy(chunk, mul)
+    # Perform AES encryption in ECB mode (AES-256)
+    result = :crypto.crypto_one_time(:aes_256_ecb, @aes_key, padded_block, true)
+    # Take only first 16 bytes (OpenSSL may add PKCS padding)
+    binary_part(result, 0, 16)
  end
 end
--- a/lib/odinsea/net/cipher/client_crypto.ex
+++ b/lib/odinsea/net/cipher/client_crypto.ex
@@ -6,9 +6,9 @@ defmodule Odinsea.Net.Cipher.ClientCrypto do
  Ported from: src/handling/netty/ClientCrypto.java
  """

-  use Bitwise
+  import Bitwise

-  alias Odinsea.Net.Cipher.{AESCipher, IGCipher}
+  alias Odinsea.Net.Cipher.{AESCipher, IGCipher, ShandaCipher}

  defstruct [
    :version,
@@ -32,7 +32,7 @@ defmodule Odinsea.Net.Cipher.ClientCrypto do
  Creates a new ClientCrypto instance with random IVs.

  ## Parameters
-    - version: MapleStory version number (e.g., 342)
+    - version: MapleStory version number (e.g., 112)
    - use_custom_crypt: If false, uses AES encryption. If true, uses basic XOR with 0x69

  ## Returns
@@ -50,38 +50,97 @@ defmodule Odinsea.Net.Cipher.ClientCrypto do
    }
  end

+  @doc """
+  Creates a new ClientCrypto instance from existing IVs (for server handshake).
+  The server generates its own IVs and sends them to the client.
+
+  ## Parameters
+    - version: MapleStory version number
+    - send_iv: 4-byte binary for send IV (server encrypts with this)
+    - recv_iv: 4-byte binary for recv IV (server decrypts with this)
+
+  ## Returns
+    - New ClientCrypto struct
+  """
+  @spec new_from_ivs(integer(), binary(), binary()) :: t()
+  def new_from_ivs(version, send_iv, recv_iv) do
+    %__MODULE__{
+      version: version,
+      use_custom_crypt: false,
+      send_iv: send_iv,
+      send_iv_old: <<0, 0, 0, 0>>,
+      recv_iv: recv_iv,
+      recv_iv_old: <<0, 0, 0, 0>>
+    }
+  end
+
+  @doc """
+  Creates a new ClientCrypto instance from client's IVs (after handshake).
+  The IVs must be SWAPPED because:
+  - Server's send IV = Client's recv IV
+  - Server's recv IV = Client's send IV
+
+  ## Parameters
+    - version: MapleStory version number
+    - client_send_iv: Client's send IV (from client's hello packet)
+    - client_recv_iv: Client's recv IV (from client's hello packet)
+
+  ## Returns
+    - New ClientCrypto struct with properly swapped IVs
+  """
+  @spec new_from_client_ivs(integer(), binary(), binary()) :: t()
+  def new_from_client_ivs(version, client_send_iv, client_recv_iv) do
+    # Swap the IVs: server's send = client's recv, server's recv = client's send
+    %__MODULE__{
+      version: version,
+      use_custom_crypt: false,
+      send_iv: client_recv_iv,
+      send_iv_old: <<0, 0, 0, 0>>,
+      recv_iv: client_send_iv,
+      recv_iv_old: <<0, 0, 0, 0>>
+    }
+  end
+
  @doc """
  Encrypts outgoing packet data and updates the send IV.
+  Applies Shanda encryption first, then AES encryption.

  ## Parameters
    - crypto: ClientCrypto state
    - data: Binary packet data to encrypt

  ## Returns
-    - {updated_crypto, encrypted_data}
+    - {updated_crypto, encrypted_data, header}
  """
-  @spec encrypt(t(), binary()) :: {t(), binary()}
+  @spec encrypt(t(), binary()) :: {t(), binary(), binary()}
  def encrypt(%__MODULE__{} = crypto, data) when is_binary(data) do
    # Backup current send IV
    updated_crypto = %{crypto | send_iv_old: crypto.send_iv}

-    # Encrypt the data
+    # Generate header BEFORE encryption (uses current IV)
+    header = encode_header_len(updated_crypto, byte_size(data))
+
+    # Apply Shanda encryption first
+    shanda_encrypted = ShandaCipher.encrypt(data)
+
+    # Apply AES encryption
    encrypted_data =
      if crypto.use_custom_crypt do
-        basic_cipher(data)
+        basic_cipher(shanda_encrypted)
      else
-        AESCipher.crypt(data, crypto.send_iv)
+        AESCipher.crypt(shanda_encrypted, crypto.send_iv)
      end

-    # Update the send IV using InnoGames hash
+    # Update the send IV using InnoGames hash (AFTER encryption)
    new_send_iv = IGCipher.inno_hash(crypto.send_iv)
    final_crypto = %{updated_crypto | send_iv: new_send_iv}

-    {final_crypto, encrypted_data}
+    {final_crypto, encrypted_data, header}
  end

  @doc """
  Decrypts incoming packet data and updates the recv IV.
+  Applies AES decryption first, then Shanda decryption.

  ## Parameters
    - crypto: ClientCrypto state
@@ -95,15 +154,18 @@ defmodule Odinsea.Net.Cipher.ClientCrypto do
    # Backup current recv IV
    updated_crypto = %{crypto | recv_iv_old: crypto.recv_iv}

-    # Decrypt the data
-    decrypted_data =
+    # Apply AES decryption
+    aes_decrypted =
      if crypto.use_custom_crypt do
        basic_cipher(data)
      else
        AESCipher.crypt(data, crypto.recv_iv)
      end

-    # Update the recv IV using InnoGames hash
+    # Apply Shanda decryption
+    decrypted_data = ShandaCipher.decrypt(aes_decrypted)
+
+    # Update the recv IV using InnoGames hash (AFTER decryption)
    new_recv_iv = IGCipher.inno_hash(crypto.recv_iv)
    final_crypto = %{updated_crypto | recv_iv: new_recv_iv}

@@ -123,13 +185,14 @@ defmodule Odinsea.Net.Cipher.ClientCrypto do
  """
  @spec encode_header_len(t(), non_neg_integer()) :: binary()
  def encode_header_len(%__MODULE__{} = crypto, data_len) do
-    <<s0, s1, s2, s3>> = crypto.send_iv
+    <<_s0, _s1, s2, s3>> = crypto.send_iv

    # Calculate the encoded version
    new_version = -(crypto.version + 1) &&& 0xFFFF
    enc_version = (((new_version >>> 8) &&& 0xFF) ||| ((new_version <<< 8) &&& 0xFF00)) &&& 0xFFFF

    # Calculate raw sequence from send IV
+    # Note: Using s3 and s2 (high bytes) as in Java version
    raw_seq = bxor((((s3 &&& 0xFF) ||| ((s2 <<< 8) &&& 0xFF00)) &&& 0xFFFF), enc_version)

    # Calculate raw length
@@ -155,8 +218,8 @@ defmodule Odinsea.Net.Cipher.ClientCrypto do
  ## Returns
    - Decoded packet length
  """
-  @spec decode_header_len(integer(), integer()) :: integer()
-  def decode_header_len(raw_seq, raw_len) do
+  @spec decode_header_len(t(), integer(), integer()) :: integer()
+  def decode_header_len(%__MODULE__{}, raw_seq, raw_len) do
    bxor(raw_seq, raw_len) &&& 0xFFFF
  end

@@ -175,6 +238,7 @@ defmodule Odinsea.Net.Cipher.ClientCrypto do
    <<_r0, _r1, r2, r3>> = crypto.recv_iv

    enc_version = crypto.version &&& 0xFFFF
+    # Note: Using r2 and r3 as in Java version
    seq_base = ((r2 &&& 0xFF) ||| ((r3 <<< 8) &&& 0xFF00)) &&& 0xFFFF

    bxor((raw_seq &&& 0xFFFF), seq_base) == enc_version
@@ -197,7 +261,7 @@ defmodule Odinsea.Net.Cipher.ClientCrypto do
  defp basic_cipher(data) do
    data
    |> :binary.bin_to_list()
-    |> Enum.map(fn byte -> Bitwise.bxor(byte, 0x69) end)
+    |> Enum.map(fn byte -> bxor(byte, 0x69) end)
    |> :binary.list_to_bin()
  end
 end
--- a/lib/odinsea/net/cipher/ig_cipher.ex
+++ b/lib/odinsea/net/cipher/ig_cipher.ex
@@ -6,7 +6,28 @@ defmodule Odinsea.Net.Cipher.IGCipher do
  Ported from: src/handling/netty/cipher/IGCipher.java
  """

-  use Bitwise
+  import Bitwise
+
+  # Shuffle table - 256 bytes used for IV transformation
+  # Must be defined before functions that use it
+  @shuffle_table {
+    0xEC, 0x3F, 0x77, 0xA4, 0x45, 0xD0, 0x71, 0xBF, 0xB7, 0x98, 0x20, 0xFC, 0x4B, 0xE9, 0xB3, 0xE1,
+    0x5C, 0x22, 0xF7, 0x0C, 0x44, 0x1B, 0x81, 0xBD, 0x63, 0x8D, 0xD4, 0xC3, 0xF2, 0x10, 0x19, 0xE0,
+    0xFB, 0xA1, 0x6E, 0x66, 0xEA, 0xAE, 0xD6, 0xCE, 0x06, 0x18, 0x4E, 0xEB, 0x78, 0x95, 0xDB, 0xBA,
+    0xB6, 0x42, 0x7A, 0x2A, 0x83, 0x0B, 0x54, 0x67, 0x6D, 0xE8, 0x65, 0xE7, 0x2F, 0x07, 0xF3, 0xAA,
+    0x27, 0x7B, 0x85, 0xB0, 0x26, 0xFD, 0x8B, 0xA9, 0xFA, 0xBE, 0xA8, 0xD7, 0xCB, 0xCC, 0x92, 0xDA,
+    0xF9, 0x93, 0x60, 0x2D, 0xDD, 0xD2, 0xA2, 0x9B, 0x39, 0x5F, 0x82, 0x21, 0x4C, 0x69, 0xF8, 0x31,
+    0x87, 0xEE, 0x8E, 0xAD, 0x8C, 0x6A, 0xBC, 0xB5, 0x6B, 0x59, 0x13, 0xF1, 0x04, 0x00, 0xF6, 0x5A,
+    0x35, 0x79, 0x48, 0x8F, 0x15, 0xCD, 0x97, 0x57, 0x12, 0x3E, 0x37, 0xFF, 0x9D, 0x4F, 0x51, 0xF5,
+    0xA3, 0x70, 0xBB, 0x14, 0x75, 0xC2, 0xB8, 0x72, 0xC0, 0xED, 0x7D, 0x68, 0xC9, 0x2E, 0x0D, 0x62,
+    0x46, 0x17, 0x11, 0x4D, 0x6C, 0xC4, 0x7E, 0x53, 0xC1, 0x25, 0xC7, 0x9A, 0x1C, 0x88, 0x58, 0x2C,
+    0x89, 0xDC, 0x02, 0x64, 0x40, 0x01, 0x5D, 0x38, 0xA5, 0xE2, 0xAF, 0x55, 0xD5, 0xEF, 0x1A, 0x7C,
+    0xA7, 0x5B, 0xA6, 0x6F, 0x86, 0x9F, 0x73, 0xE6, 0x0A, 0xDE, 0x2B, 0x99, 0x4A, 0x47, 0x9C, 0xDF,
+    0x09, 0x76, 0x9E, 0x30, 0x0E, 0xE4, 0xB2, 0x94, 0xA0, 0x3B, 0x34, 0x1D, 0x28, 0x0F, 0x36, 0xE3,
+    0x23, 0xB4, 0x03, 0xD8, 0x90, 0xC8, 0x3C, 0xFE, 0x5E, 0x32, 0x24, 0x50, 0x1F, 0x3A, 0x43, 0x8A,
+    0x96, 0x41, 0x74, 0xAC, 0x52, 0x33, 0xF0, 0xD9, 0x29, 0x80, 0xB1, 0x16, 0xD3, 0xAB, 0x91, 0xB9,
+    0x84, 0x7F, 0x61, 0x1E, 0xCF, 0xC5, 0xD1, 0x56, 0x3D, 0xCA, 0xF4, 0x05, 0xC6, 0xE5, 0x08, 0x49
+  }

  @doc """
  Applies the InnoGames hash transformation to a 4-byte IV.
@@ -39,11 +60,12 @@ defmodule Odinsea.Net.Cipher.IGCipher do
    input = value &&& 0xFF
    table = shuffle_byte(input)

-    # Apply the transformation operations
-    new_k0 = k0 + shuffle_byte(k1) - input
-    new_k1 = k1 - bxor(k2, table)
-    new_k2 = bxor(k2, shuffle_byte(k3) + input)
-    new_k3 = k3 - (k0 - table)
+    # Apply the transformation operations SEQUENTIALLY
+    # Java modifies key[0] first, then uses modified key[0] for key[3]
+    new_k0 = (k0 + (shuffle_byte(k1) - input)) &&& 0xFF
+    new_k1 = (k1 - bxor(k2, table)) &&& 0xFF
+    new_k2 = bxor(k2, (shuffle_byte(k3) + input) &&& 0xFF)
+    new_k3 = (k3 - (new_k0 - table)) &&& 0xFF

    # Combine into 32-bit value (little-endian)
    val =
@@ -69,24 +91,4 @@ defmodule Odinsea.Net.Cipher.IGCipher do
  defp shuffle_byte(index) do
    elem(@shuffle_table, index &&& 0xFF)
  end
-
-  # Shuffle table - 256 bytes used for IV transformation
-  @shuffle_table {
-    0xEC, 0x3F, 0x77, 0xA4, 0x45, 0xD0, 0x71, 0xBF, 0xB7, 0x98, 0x20, 0xFC, 0x4B, 0xE9, 0xB3, 0xE1,
-    0x5C, 0x22, 0xF7, 0x0C, 0x44, 0x1B, 0x81, 0xBD, 0x63, 0x8D, 0xD4, 0xC3, 0xF2, 0x10, 0x19, 0xE0,
-    0xFB, 0xA1, 0x6E, 0x66, 0xEA, 0xAE, 0xD6, 0xCE, 0x06, 0x18, 0x4E, 0xEB, 0x78, 0x95, 0xDB, 0xBA,
-    0xB6, 0x42, 0x7A, 0x2A, 0x83, 0x0B, 0x54, 0x67, 0x6D, 0xE8, 0x65, 0xE7, 0x2F, 0x07, 0xF3, 0xAA,
-    0x27, 0x7B, 0x85, 0xB0, 0x26, 0xFD, 0x8B, 0xA9, 0xFA, 0xBE, 0xA8, 0xD7, 0xCB, 0xCC, 0x92, 0xDA,
-    0xF9, 0x93, 0x60, 0x2D, 0xDD, 0xD2, 0xA2, 0x9B, 0x39, 0x5F, 0x82, 0x21, 0x4C, 0x69, 0xF8, 0x31,
-    0x87, 0xEE, 0x8E, 0xAD, 0x8C, 0x6A, 0xBC, 0xB5, 0x6B, 0x59, 0x13, 0xF1, 0x04, 0x00, 0xF6, 0x5A,
-    0x35, 0x79, 0x48, 0x8F, 0x15, 0xCD, 0x97, 0x57, 0x12, 0x3E, 0x37, 0xFF, 0x9D, 0x4F, 0x51, 0xF5,
-    0xA3, 0x70, 0xBB, 0x14, 0x75, 0xC2, 0xB8, 0x72, 0xC0, 0xED, 0x7D, 0x68, 0xC9, 0x2E, 0x0D, 0x62,
-    0x46, 0x17, 0x11, 0x4D, 0x6C, 0xC4, 0x7E, 0x53, 0xC1, 0x25, 0xC7, 0x9A, 0x1C, 0x88, 0x58, 0x2C,
-    0x89, 0xDC, 0x02, 0x64, 0x40, 0x01, 0x5D, 0x38, 0xA5, 0xE2, 0xAF, 0x55, 0xD5, 0xEF, 0x1A, 0x7C,
-    0xA7, 0x5B, 0xA6, 0x6F, 0x86, 0x9F, 0x73, 0xE6, 0x0A, 0xDE, 0x2B, 0x99, 0x4A, 0x47, 0x9C, 0xDF,
-    0x09, 0x76, 0x9E, 0x30, 0x0E, 0xE4, 0xB2, 0x94, 0xA0, 0x3B, 0x34, 0x1D, 0x28, 0x0F, 0x36, 0xE3,
-    0x23, 0xB4, 0x03, 0xD8, 0x90, 0xC8, 0x3C, 0xFE, 0x5E, 0x32, 0x24, 0x50, 0x1F, 0x3A, 0x43, 0x8A,
-    0x96, 0x41, 0x74, 0xAC, 0x52, 0x33, 0xF0, 0xD9, 0x29, 0x80, 0xB1, 0x16, 0xD3, 0xAB, 0x91, 0xB9,
-    0x84, 0x7F, 0x61, 0x1E, 0xCF, 0xC5, 0xD1, 0x56, 0x3D, 0xCA, 0xF4, 0x05, 0xC6, 0xE5, 0x08, 0x49
-  }
 end
--- a/lib/odinsea/net/cipher/shanda_cipher.ex
+++ b/lib/odinsea/net/cipher/shanda_cipher.ex
@@ -0,0 +1,150 @@
+defmodule Odinsea.Net.Cipher.ShandaCipher do
+  @moduledoc """
+  Shanda cipher implementation for MapleStory packet encryption.
+  Direct port from Java ShandaCipher.java
+  """
+
+  import Bitwise
+
+  alias Odinsea.Util.BitTools
+
+  @doc """
+  Encrypts data using the Shanda cipher.
+  """
+  @spec encrypt(binary()) :: binary()
+  def encrypt(data) when is_binary(data) do
+    bytes = :binary.bin_to_list(data)
+    len = length(bytes)
+
+    result =
+      Enum.reduce(0..5, bytes, fn j, acc ->
+        do_encrypt_pass(acc, len, j)
+      end)
+
+    :binary.list_to_bin(result)
+  end
+
+  defp do_encrypt_pass(data, len, j) do
+    data_length = len &&& 0xFF
+
+    if rem(j, 2) == 0 do
+      # Forward pass: iterate 0..length-1
+      {result, _remember, _dl} =
+        Enum.reduce(data, {[], 0, data_length}, fn cur, {out, remember, dl} ->
+          new_cur =
+            cur
+            |> BitTools.roll_left(3)
+            |> Kernel.+(dl)
+            |> band(0xFF)
+            |> bxor(remember)
+
+          new_remember = new_cur
+
+          final_cur =
+            new_cur
+            |> BitTools.roll_right(dl &&& 0xFF)
+            |> bxor(0xFF)
+            |> Kernel.+(0x48)
+            |> band(0xFF)
+
+          {[final_cur | out], new_remember, (dl - 1) &&& 0xFF}
+        end)
+
+      Enum.reverse(result)
+    else
+      # Backward pass: iterate length-1..0
+      # Process reversed list, prepend results -> naturally restores forward order
+      {result, _remember, _dl} =
+        Enum.reduce(Enum.reverse(data), {[], 0, data_length}, fn cur, {out, remember, dl} ->
+          new_cur =
+            cur
+            |> BitTools.roll_left(4)
+            |> Kernel.+(dl)
+            |> band(0xFF)
+            |> bxor(remember)
+
+          new_remember = new_cur
+
+          final_cur =
+            new_cur
+            |> bxor(0x13)
+            |> BitTools.roll_right(3)
+
+          {[final_cur | out], new_remember, (dl - 1) &&& 0xFF}
+        end)
+
+      # Do NOT reverse - prepending from reversed input naturally gives forward order
+      result
+    end
+  end
+
+  @doc """
+  Decrypts data using the Shanda cipher.
+  """
+  @spec decrypt(binary()) :: binary()
+  def decrypt(data) when is_binary(data) do
+    bytes = :binary.bin_to_list(data)
+    len = length(bytes)
+
+    # Java: for (int j = 1; j <= 6; j++)
+    result =
+      Enum.reduce(1..6, bytes, fn j, acc ->
+        do_decrypt_pass(acc, len, j)
+      end)
+
+    :binary.list_to_bin(result)
+  end
+
+  defp do_decrypt_pass(data, len, j) do
+    data_length = len &&& 0xFF
+
+    if rem(j, 2) == 0 do
+      # Forward pass (even j in decrypt = matches encrypt's forward)
+      {result, _remember, _dl} =
+        Enum.reduce(data, {[], 0, data_length}, fn cur, {out, remember, dl} ->
+          new_cur =
+            cur
+            |> Kernel.-(0x48)
+            |> band(0xFF)
+            |> bxor(0xFF)
+            |> BitTools.roll_left(dl &&& 0xFF)
+
+          next_remember = new_cur
+
+          final_cur =
+            new_cur
+            |> bxor(remember)
+            |> Kernel.-(dl)
+            |> band(0xFF)
+            |> BitTools.roll_right(3)
+
+          {[final_cur | out], next_remember, (dl - 1) &&& 0xFF}
+        end)
+
+      Enum.reverse(result)
+    else
+      # Backward pass (odd j in decrypt = matches encrypt's backward)
+      {result, _remember, _dl} =
+        Enum.reduce(Enum.reverse(data), {[], 0, data_length}, fn cur, {out, remember, dl} ->
+          new_cur =
+            cur
+            |> BitTools.roll_left(3)
+            |> bxor(0x13)
+
+          next_remember = new_cur
+
+          final_cur =
+            new_cur
+            |> bxor(remember)
+            |> Kernel.-(dl)
+            |> band(0xFF)
+            |> BitTools.roll_right(4)
+
+          {[final_cur | out], next_remember, (dl - 1) &&& 0xFF}
+        end)
+
+      # Do NOT reverse - prepending from reversed input naturally gives forward order
+      result
+    end
+  end
+end
--- a/lib/odinsea/net/opcodes.ex
+++ b/lib/odinsea/net/opcodes.ex
@@ -19,24 +19,31 @@ defmodule Odinsea.Net.Opcodes do

  # Login/Account
  def cp_client_hello(), do: 0x01
+  @spec cp_login_password() :: 2
  def cp_login_password(), do: 0x02
+  # Note: 0x03 is CP_ViewServerList in MSEA v112.4 (not used in OdinSea but reserved)
+  @spec cp_view_server_list() :: 3
+  def cp_view_server_list(), do: 0x03
+  @spec cp_serverlist_request() :: 4
  def cp_serverlist_request(), do: 0x04
-  def cp_charlist_request(), do: 0x05
-  def cp_serverstatus_request(), do: 0x06
+  # CP_SelectWorld(5) - Java: ClientPacket.java
+  @spec cp_select_world() :: 5
+  def cp_select_world(), do: 0x05
  def cp_check_char_name(), do: 0x0E
  def cp_create_char(), do: 0x12
  def cp_create_ultimate(), do: 0x14
  def cp_delete_char(), do: 0x15
  def cp_exception_log(), do: 0x17
  def cp_security_packet(), do: 0x18
-  def cp_hardware_info(), do: 0x70
-  def cp_window_focus(), do: 0x71
+  def cp_hardware_info(), do: 0x5001  # Java: CP_HardwareInfo(0x5001) - was 0x70 (collided with cp_cancel_buff)
+  def cp_window_focus(), do: 0x5004  # Java: CP_WindowFocus(0x5004) - was 0x71 (collided with cp_skill_effect)
  def cp_char_select(), do: 0x19
  def cp_auth_second_password(), do: 0x1A
  def cp_rsa_key(), do: 0x20
  def cp_client_dump_log(), do: 0x1D
  def cp_create_security_handle(), do: 0x1E
-  def cp_select_world(), do: 0x03
+  # CP_CheckUserLimit(6) - Java: ClientPacket.java
+  @spec cp_check_user_limit() :: 6
  def cp_check_user_limit(), do: 0x06

  # Migration/Channel
@@ -75,7 +82,7 @@ defmodule Odinsea.Net.Opcodes do

  # NPC Interaction
  def cp_npc_talk(), do: 0x40
-  def cp_npc_move(), do: 0x41  # NPC animation/movement (added for compatibility)
+  def cp_npc_move(), do: 0x106  # Java: CP_NpcMove(262) - alias for cp_npc_action. Was 0x41 (wrong)
  def cp_npc_talk_more(), do: 0x42
  def cp_npc_shop(), do: 0x43
  def cp_storage(), do: 0x44
@@ -255,6 +262,12 @@ defmodule Odinsea.Net.Opcodes do

  # Cash Shop
  def cp_cs_update(), do: 0x135
+
+  # Alias for cp_cs_update (used in some places)
+  def cp_cash_shop_update(), do: cp_cs_update()
+
+  # Public NPC (recv - currently unimplemented in Java, using same value as send)
+  def cp_public_npc(), do: 0xB7
  def cp_buy_cs_item(), do: 0x136
  def cp_coupon_code(), do: 0x137

@@ -263,6 +276,9 @@ defmodule Odinsea.Net.Opcodes do
  def cp_touching_mts(), do: 0x159
  def cp_mts_tab(), do: 0x15A

+  # MTS operation opcode (client -> server)
+  def cp_mts_operation(), do: 0xB4
+
  # Custom (server-specific)
  def cp_inject_packet(), do: 0x5002
  def cp_set_code_page(), do: 0x5003
@@ -279,16 +295,16 @@ defmodule Odinsea.Net.Opcodes do

  # General
  def lp_alive_req(), do: 0x0D
-  def lp_enable_action(), do: 0x0C
-  def lp_set_field(), do: 0x14
-  def lp_set_cash_shop_opened(), do: 0x15
-  def lp_migrate_command(), do: 0x16
+  def lp_enable_action(), do: 0x1B  # Java: enableActions() uses UPDATE_STATS(27) - was 0x0C (collided with lp_change_channel)
+  def lp_set_field(), do: 0x90  # Java: LP_SetField(144) - alias for lp_warp_to_map. Was 0x14 (wrong)
+  def lp_set_cash_shop_opened(), do: 0x92  # Java: LP_SetCashShop(146) - was 0x15 (collided with lp_latest_connected_world)
+  def lp_migrate_command(), do: 0x0C  # Java: CHANGE_CHANNEL(12) - was 0x16 (collided with lp_recommend_world_message)

  # Login
-  def lp_login_status(), do: 0x01
-  def lp_serverstatus(), do: 0x03
-  def lp_serverlist(), do: 0x06
-  def lp_charlist(), do: 0x07
+  def lp_check_password_result(), do: 0x01
+  def lp_server_status(), do: 0x03
+  def lp_server_list(), do: 0x06
+  def lp_char_list(), do: 0x07
  def lp_server_ip(), do: 0x08
  def lp_char_name_response(), do: 0x09
  def lp_add_new_char_entry(), do: 0x0A
@@ -298,10 +314,10 @@ defmodule Odinsea.Net.Opcodes do
  def lp_channel_selected(), do: 0x10
  def lp_relog_response(), do: 0x12
  def lp_rsa_key(), do: 0x13
-  def lp_enable_recommended(), do: 0x15
-  def lp_send_recommended(), do: 0x16
+  def lp_latest_connected_world(), do: 0x15
+  def lp_recommend_world_message(), do: 0x16
  def lp_login_auth(), do: 0x17
-  def lp_secondpw_error(), do: 0x18
+  def lp_check_spw_result(), do: 0x18

  # Inventory/Stats
  def lp_modify_inventory_item(), do: 0x19
@@ -390,6 +406,13 @@ defmodule Odinsea.Net.Opcodes do
  # Warps/Shops
  def lp_warp_to_map(), do: 0x90
  def lp_mts_open(), do: 0x91
+
+  # Alias for lp_mts_open (MTS opened packet)
+  def lp_set_mts_opened(), do: lp_mts_open()
+
+  # Cash shop initialization (SET_CASH_SHOP from Java)
+  def lp_set_cash_shop(), do: 0x92
+
  def lp_cs_open(), do: 0x92
  def lp_login_welcome(), do: 0x94
  def lp_server_blocked(), do: 0x97
@@ -397,6 +420,9 @@ defmodule Odinsea.Net.Opcodes do

  # Effects
  def lp_show_equip_effect(), do: 0x99
+
+  # Weather effect (BLOW_WEATHER/MAP_EFFECT)
+  def lp_blow_weather(), do: 0xA1
  def lp_multichat(), do: 0x9A
  def lp_whisper(), do: 0x9B
  def lp_boss_env(), do: 0x9D
@@ -614,6 +640,10 @@ defmodule Odinsea.Net.Opcodes do

  # Cash Shop
  def lp_cs_update(), do: 0x1B8
+
+  # Alias for lp_cs_update (cash shop update)
+  def lp_cash_shop_update(), do: lp_cs_update()
+
  def lp_cs_operation(), do: 0x1B9
  def lp_xmas_surprise(), do: 0x1BD

@@ -657,16 +687,26 @@ defmodule Odinsea.Net.Opcodes do
  # ==================================================================================================

  @doc """
-  Returns a human-readable name for a given opcode value.
+  Returns a human-readable name for a given client opcode value.
  Useful for debugging and logging.
  """
-  def name_for(opcode) when is_integer(opcode) do
+  def name_for_client(opcode) when is_integer(opcode) do
    case opcode do
      # Client opcodes (common ones for debugging)
      0x01 -> "CP_CLIENT_HELLO"
      0x02 -> "CP_LOGIN_PASSWORD"
+      0x03 -> "CP_VIEW_SERVER_LIST"
+      0x04 -> "CP_SERVERLIST_REQUEST"
+      0x05 -> "CP_SELECT_WORLD"
+      0x06 -> "CP_CHECK_USER_LIMIT"
      0x0D -> "CP_PLAYER_LOGGEDIN"
+      0x0E -> "CP_CHECK_CHAR_NAME"
+      0x12 -> "CP_CREATE_CHAR"
+      0x14 -> "CP_CREATE_ULTIMATE"
+      0x15 -> "CP_DELETE_CHAR"
      0x19 -> "CP_CHAR_SELECT"
+      0x1A -> "CP_AUTH_SECOND_PASSWORD"
+      0x20 -> "CP_RSA_KEY"
      0x23 -> "CP_CHANGE_MAP"
      0x24 -> "CP_CHANGE_CHANNEL"
      0x2A -> "CP_MOVE_PLAYER"
@@ -675,11 +715,24 @@ defmodule Odinsea.Net.Opcodes do
      0xA0 -> "CP_PARTYCHAT"
      0xA1 -> "CP_WHISPER"

+      _ -> "CP_UNKNOWN_0x#{Integer.to_string(opcode, 16) |> String.upcase()}"
+    end
+  end
+
+  @doc """
+  Returns a human-readable name for a given server opcode value.
+  Useful for debugging and logging.
+  """
+  def name_for_server(opcode) when is_integer(opcode) do
+    case opcode do
      # Server opcodes (common ones for debugging)
      0x01 -> "LP_LOGIN_STATUS"
      0x06 -> "LP_SERVERLIST"
      0x07 -> "LP_CHARLIST"
+      0x08 -> "LP_SERVER_IP"
      0x0D -> "LP_ALIVE_REQ"
+      0x13 -> "LP_RSA_KEY"
+      0x17 -> "LP_LOGIN_AUTH"
      0xB8 -> "LP_SPAWN_PLAYER"
      0xB9 -> "LP_REMOVE_PLAYER_FROM_MAP"
      0xBA -> "LP_CHATTEXT"
@@ -688,21 +741,30 @@ defmodule Odinsea.Net.Opcodes do
      0x9B -> "LP_WHISPER"
      0x1A3 -> "LP_NPC_TALK"

-      _ -> "UNKNOWN_0x#{Integer.to_string(opcode, 16) |> String.upcase()}"
+      _ -> "LP_UNKNOWN_0x#{Integer.to_string(opcode, 16) |> String.upcase()}"
    end
  end

+  @doc """
+  Returns a human-readable name for a given opcode value.
+  Deprecated: Use name_for_client/1 or name_for_server/1 instead.
+  """
+  def name_for(opcode) when is_integer(opcode) do
+    name_for_client(opcode)
+  end
+
  @doc """
  Validates if an opcode is a known client packet.
  """
  def valid_client_opcode?(opcode) when is_integer(opcode) do
    opcode in [
-      # Add all valid client opcodes here for validation
-      0x01,
-      0x02,
-      0x04,
-      0x05,
-      0x06,
+      # Login opcodes
+      0x01,  # CP_ClientHello
+      0x02,  # CP_LoginPassword
+      0x03,  # CP_ViewServerList
+      0x04,  # CP_ServerListRequest
+      0x05,  # CP_SelectWorld
+      0x06,  # CP_CheckUserLimit
      0x0D,
      0x0E,
      0x12,
@@ -895,7 +957,11 @@ defmodule Odinsea.Net.Opcodes do
      0x143,
      0x144,
      0x159,
-      0x15A
+      0x15A,
+      0x5001,  # CP_HardwareInfo
+      0x5002,  # CP_InjectPacket
+      0x5003,  # CP_SetCodePage
+      0x5004   # CP_WindowFocus
    ]
  end

--- a/lib/odinsea/net/packet/out.ex
+++ b/lib/odinsea/net/packet/out.ex
@@ -68,6 +68,18 @@ defmodule Odinsea.Net.Packet.Out do
    %__MODULE__{data: [data | <<length::signed-integer-little-16, value::binary>>]}
  end

+  @doc """
+  Encodes a fixed-length MapleStory ASCII string.
+  Format: [2-byte length][ASCII bytes][padding to fixed length]
+  The third argument specifies the fixed field length.
+  """
+  @spec encode_string(t(), String.t(), non_neg_integer()) :: t()
+  def encode_string(%__MODULE__{data: data}, value, fixed_length) when is_binary(value) and is_integer(fixed_length) and fixed_length > 0 do
+    length = byte_size(value)
+    padding = max(0, fixed_length - length)
+    %__MODULE__{data: [data | <<length::signed-integer-little-16, value::binary, 0::size(padding * 8)>>]}
+  end
+
  @doc """
  Encodes a boolean (1 byte, 0 = false, 1 = true).
  """
@@ -88,6 +100,12 @@ defmodule Odinsea.Net.Packet.Out do
    %__MODULE__{data: [data | buffer]}
  end

+  @doc """
+  Alias for encode_buffer/2.
+  """
+  @spec encode_bytes(t(), binary()) :: t()
+  def encode_bytes(packet, data), do: encode_buffer(packet, data)
+
  @doc """
  Encodes a fixed-size buffer, padding with zeros if necessary.
  """
@@ -172,6 +190,12 @@ defmodule Odinsea.Net.Packet.Out do
    data
  end

+  @doc """
+  Alias for to_iodata/1.
+  """
+  @spec to_data(t()) :: iodata()
+  def to_data(packet), do: to_iodata(packet)
+
  @doc """
  Converts the packet to a hex string for debugging.
  """
--- a/lib/odinsea/net/packet_logger.ex
+++ b/lib/odinsea/net/packet_logger.ex
@@ -0,0 +1,380 @@
+defmodule Odinsea.Net.PacketLogger do
+  @moduledoc """
+  Comprehensive packet logging system for debugging MapleStory protocol.
+
+  Provides detailed packet logging similar to the Java version with:
+  - Direction (client/loopback)
+  - Opcode name and value (decimal/hex)
+  - Raw hex data
+  - ASCII text representation
+  - Context information (session, thread)
+  """
+
+  require Logger
+
+  alias Odinsea.Net.{Hex, Opcodes}
+
+  @doc """
+  Logs an incoming client packet with full details.
+
+  ## Parameters
+  - `opcode` - The packet opcode (integer)
+  - `data` - The packet data (binary, excluding opcode bytes)
+  - `context` - Map with :ip, :server_type, etc.
+  """
+  def log_client_packet(opcode, data, context \\ %{}) do
+    if packet_logging_enabled?() do
+      opcode_name = get_client_opcode_name(opcode)
+      ip = Map.get(context, :ip, "unknown")
+      server_type = Map.get(context, :server_type, :unknown)
+
+      # Format opcode header
+      opcode_header = format_opcode_header("client", opcode_name, opcode)
+
+      # Full packet data includes opcode
+      full_data = <<opcode::little-16>> <> data
+
+      # Format hex and text
+      hex_str = Hex.encode(full_data)
+      text_str = Hex.to_ascii(full_data)
+
+      # Log the packet
+      Logger.info("""
+      #{opcode_header}
+      [Data] #{hex_str}
+      [Text] #{text_str}
+      [Context] IP=#{ip} Server=#{server_type} Size=#{byte_size(full_data)} bytes
+      """)
+
+      :ok
+    else
+      :ok
+    end
+  end
+
+  @doc """
+  Logs an outgoing server packet with full details.
+
+  ## Parameters
+  - `opcode` - The packet opcode (integer)
+  - `data` - The packet data (binary, excluding opcode bytes)
+  - `context` - Map with :ip, :server_type, etc.
+  """
+  def log_server_packet(opcode, data, context \\ %{}) do
+    if packet_logging_enabled?() do
+      opcode_name = get_server_opcode_name(opcode)
+      ip = Map.get(context, :ip, "unknown")
+      server_type = Map.get(context, :server_type, :unknown)
+
+      # Format opcode header
+      opcode_header = format_opcode_header("loopback", opcode_name, opcode)
+
+      # Full packet data includes opcode
+      full_data = <<opcode::little-16>> <> data
+
+      # Format hex and text
+      hex_str = Hex.encode(full_data)
+      text_str = Hex.to_ascii(full_data)
+
+      # Log the packet
+      Logger.info("""
+      #{opcode_header}
+      [Data] #{hex_str}
+      [Text] #{text_str}
+      [Context] IP=#{ip} Server=#{server_type} Size=#{byte_size(full_data)} bytes
+      """)
+
+      :ok
+    else
+      :ok
+    end
+  end
+
+  @doc """
+  Logs raw packet data (used for handshake/hello packets that don't follow normal format).
+  """
+  def log_raw_packet(direction, label, data, context \\ %{}) do
+    if packet_logging_enabled?() do
+      ip = Map.get(context, :ip, "unknown")
+
+      data = IO.iodata_to_binary(data)
+      hex_str = Hex.encode(data)
+      text_str = Hex.to_ascii(data)
+
+      Logger.info("""
+      [#{direction}] [#{label}]
+      [Data] #{hex_str}
+      [Text] #{text_str}
+      [Context] IP=#{ip} Size=#{byte_size(data)} bytes
+      """)
+
+      :ok
+    else
+      :ok
+    end
+  end
+
+  # ==================================================================================================
+  # Private Helper Functions
+  # ==================================================================================================
+
+  defp packet_logging_enabled? do
+    features = Application.get_env(:odinsea, :features, [])
+    Keyword.get(features, :log_packet, false)
+  end
+
+  defp format_opcode_header(direction, opcode_name, opcode) do
+    opcode_hex = Integer.to_string(opcode, 16) |> String.upcase() |> String.pad_leading(2, "0")
+    "[#{direction}] [#{opcode_name}] #{opcode} / 0x#{opcode_hex}"
+  end
+
+  # ==================================================================================================
+  # Opcode Name Resolution
+  # ==================================================================================================
+
+  defp get_client_opcode_name(opcode) do
+    case opcode do
+      # Connection/Security
+      0x16 -> "CP_AliveAck"
+
+      # Login/Account
+      0x01 -> "CP_PermissionRequest"
+      0x02 -> "CP_CheckPassword"
+      0x04 -> "CP_ServerlistRequest"
+      0x05 -> "CP_SelectWorld"
+      0x06 -> "CP_CheckUserLimit"
+      0x0E -> "CP_CheckCharName"
+      0x12 -> "CP_CreateChar"
+      0x14 -> "CP_CreateUltimate"
+      0x15 -> "CP_DeleteChar"
+      0x17 -> "CP_ExceptionLog"
+      0x18 -> "CP_SecurityPacket"
+      0x19 -> "CP_CharSelect"
+      0x1A -> "CP_AuthSecondPassword"
+      0x1D -> "CP_ClientDumpLog"
+      0x1E -> "CP_CreateSecurityHandle"
+      0x20 -> "RSA_KEY"
+      0x5001 -> "CP_HardwareInfo"
+      0x5004 -> "CP_WindowFocus"
+
+      # Migration/Channel
+      0x0D -> "CP_PlayerLoggedIn"
+      0x23 -> "CP_ChangeMap"
+      0x24 -> "CP_ChangeChannel"
+      0x25 -> "CP_EnterCashShop"
+      0x26 -> "CP_EnterPvp"
+      0x27 -> "CP_EnterPvpParty"
+      0x29 -> "CP_LeavePvp"
+      0xB4 -> "CP_EnterMts"
+
+      # Player Movement/Actions
+      0x2A -> "CP_MovePlayer"
+      0x2C -> "CP_CancelChair"
+      0x2D -> "CP_UseChair"
+      0x2F -> "CP_CloseRangeAttack"
+      0x30 -> "CP_RangedAttack"
+      0x31 -> "CP_MagicAttack"
+      0x32 -> "CP_PassiveEnergy"
+      0x34 -> "CP_TakeDamage"
+      0x35 -> "CP_PvpAttack"
+      0x36 -> "CP_GeneralChat"
+      0x37 -> "CP_CloseChalkboard"
+      0x38 -> "CP_FaceExpression"
+      0x75 -> "CP_CharInfoRequest"
+      0x76 -> "CP_SpawnPet"
+      0x78 -> "CP_CancelDebuff"
+
+      # NPC Interaction
+      0x40 -> "CP_NpcTalk"
+      0x41 -> "CP_NpcMove"
+      0x42 -> "CP_NpcTalkMore"
+      0x43 -> "CP_NpcShop"
+      0x44 -> "CP_Storage"
+      0x45 -> "CP_UseHiredMerchant"
+      0x47 -> "CP_MerchItemStore"
+
+      # Inventory/Items
+      0x4D -> "CP_ItemSort"
+      0x4E -> "CP_ItemGather"
+      0x4F -> "CP_ItemMove"
+      0x53 -> "CP_UseItem"
+      0x10C -> "CP_ItemPickup"
+
+      # Stats/Skills
+      0x6A -> "CP_DistributeAp"
+      0x6B -> "CP_AutoAssignAp"
+      0x6E -> "CP_DistributeSp"
+      0x6F -> "CP_SpecialMove"
+
+      # Social
+      0xA0 -> "CP_PartyChat"
+      0xA1 -> "CP_Whisper"
+      0xA4 -> "CP_PartyOperation"
+      0xA8 -> "CP_GuildOperation"
+
+      # Cash Shop
+      0x135 -> "CP_CsUpdate"
+      0x136 -> "CP_BuyCsItem"
+      0x137 -> "CP_CouponCode"
+
+      # Custom
+      0x5002 -> "CP_InjectPacket"
+      0x5003 -> "CP_SetCodePage"
+
+      _ -> "UNKNOWN"
+    end
+  end
+
+  defp get_server_opcode_name(opcode) do
+    case opcode do
+      # General
+      0x0D -> "LP_AliveReq"
+      0x0C -> "LP_ChangeChannel"
+      0x15 -> "LP_LatestConnectedWorld"
+      0x16 -> "LP_RecommendWorldMessage"
+
+      # Login
+      0x00 -> "HELLO"
+      0x01 -> "LOGIN_STATUS"
+      0x03 -> "LP_ServerStatus"
+      0x06 -> "SERVERLIST"
+      0x07 -> "LP_CharList"
+      0x08 -> "LP_ServerIp"
+      0x09 -> "LP_CharNameResponse"
+      0x0A -> "LP_AddNewCharEntry"
+      0x0B -> "LP_DeleteCharResponse"
+      0x10 -> "LP_ChannelSelected"
+      0x12 -> "LP_RelogResponse"
+      0x13 -> "RSA_KEY"
+      0x17 -> "LOGIN_AUTH"
+      0x18 -> "LP_SecondPwError"
+
+      # Inventory/Stats
+      0x19 -> "LP_ModifyInventoryItem"
+      0x1A -> "LP_UpdateInventorySlot"
+      0x1B -> "LP_UpdateStats"
+      0x1C -> "LP_GiveBuff"
+      0x1D -> "LP_CancelBuff"
+      0x20 -> "LP_UpdateSkills"
+      0x22 -> "LP_FameResponse"
+      0x23 -> "LP_ShowStatusInfo"
+      0x25 -> "LP_TrockLocations"
+
+      # Social/Party/Guild
+      0x38 -> "LP_PartyOperation"
+      0x3A -> "LP_ExpeditionOperation"
+      0x3B -> "LP_BuddyList"
+      0x3D -> "LP_GuildOperation"
+      0x3E -> "LP_AllianceOperation"
+
+      # Map Effects/Environment
+      0x3F -> "LP_SpawnPortal"
+      0x40 -> "LP_MechPortal"
+      0x41 -> "LP_ServerMessage"
+      0x4A -> "LP_YellowChat"
+
+      # Family
+      0x6D -> "LP_SendPedigree"
+      0x6E -> "LP_OpenFamily"
+      0x73 -> "LP_Family"
+
+      # Misc UI/Messages
+      0x7E -> "LP_TopMsg"
+      0x7F -> "LP_MidMsg"
+      0x80 -> "LP_ClearMidMsg"
+
+      # Warps/Shops
+      0x90 -> "LP_WarpToMap"
+      0x91 -> "LP_MtsOpen"
+      0x92 -> "LP_CsOpen"
+
+      # Effects
+      0x99 -> "LP_ShowEquipEffect"
+      0x9A -> "LP_MultiChat"
+      0x9B -> "LP_Whisper"
+      0xA1 -> "LP_MapEffect"
+      0xA6 -> "LP_Clock"
+
+      # Players
+      0xB8 -> "LP_SpawnPlayer"
+      0xB9 -> "LP_RemovePlayerFromMap"
+      0xBA -> "LP_ChatText"
+      0xBC -> "LP_Chalkboard"
+
+      # Pets
+      0xD1 -> "LP_SpawnPet"
+      0xD4 -> "LP_MovePet"
+      0xD5 -> "LP_PetChat"
+
+      # Player Actions
+      0xE2 -> "LP_MovePlayer"
+      0xE4 -> "LP_CloseRangeAttack"
+      0xE5 -> "LP_RangedAttack"
+      0xE6 -> "LP_MagicAttack"
+      0xE8 -> "LP_SkillEffect"
+      0xEB -> "LP_DamagePlayer"
+      0xEC -> "LP_FacialExpression"
+      0xF0 -> "LP_ShowChair"
+      0xF1 -> "LP_UpdateCharLook"
+
+      # Summons
+      0x131 -> "LP_SpawnSummon"
+      0x132 -> "LP_RemoveSummon"
+      0x133 -> "LP_MoveSummon"
+      0x134 -> "LP_SummonAttack"
+
+      # Monsters
+      0x13A -> "LP_SpawnMonster"
+      0x13B -> "LP_KillMonster"
+      0x13C -> "LP_SpawnMonsterControl"
+      0x13D -> "LP_MoveMonster"
+      0x144 -> "LP_DamageMonster"
+
+      # NPCs
+      0x156 -> "LP_SpawnNpc"
+      0x157 -> "LP_RemoveNpc"
+      0x158 -> "LP_SpawnNpcRequestController"
+      0x159 -> "LP_NpcAction"
+      0x1A3 -> "LP_NpcTalk"
+      0x1A5 -> "LP_OpenNpcShop"
+
+      # Merchants
+      0x161 -> "LP_SpawnHiredMerchant"
+      0x162 -> "LP_DestroyHiredMerchant"
+
+      # Map Objects
+      0x165 -> "LP_DropItemFromMapObject"
+      0x167 -> "LP_RemoveItemFromMap"
+      0x16B -> "LP_SpawnMist"
+      0x16C -> "LP_RemoveMist"
+      0x16D -> "LP_SpawnDoor"
+      0x16E -> "LP_RemoveDoor"
+
+      # Reactors
+      0x171 -> "LP_ReactorHit"
+      0x173 -> "LP_ReactorSpawn"
+      0x174 -> "LP_ReactorDestroy"
+
+      # NPC/Shop Interactions
+      0x1A6 -> "LP_ConfirmShopTransaction"
+      0x1A9 -> "LP_OpenStorage"
+      0x1AB -> "LP_MerchItemStore"
+
+      # Cash Shop
+      0x1B8 -> "LP_CsUpdate"
+      0x1B9 -> "LP_CsOperation"
+
+      # Input
+      0x1C5 -> "LP_Keymap"
+
+      # Custom
+      0x5000 -> "LP_DamageSkin"
+      0x5001 -> "LP_OpenWebsite"
+
+      0x15 -> "LP_LatestConnectedWorld"
+      0x16 -> "LP_RecommendWorldMessage"
+
+      _ -> "UNKNOWN"
+    end
+  end
+end
--- a/lib/odinsea/net/processor.ex
+++ b/lib/odinsea/net/processor.ex
@@ -163,11 +163,11 @@ defmodule Odinsea.Net.Processor do

      # Password check (login authentication)
      @cp_login_password ->
-        Handler.on_login_password(packet, state)
+        Handler.on_check_password(packet, state)

      # World info request (server list)
      @cp_serverlist_request ->
-        Handler.on_serverlist_request(state)
+        Handler.on_world_info_request(state)

      # Select world
      @cp_select_world ->
@@ -179,11 +179,11 @@ defmodule Odinsea.Net.Processor do

      # Check duplicated ID (character name availability)
      @cp_check_char_name ->
-        Handler.on_check_char_name(packet, state)
+        Handler.on_check_duplicated_id(packet, state)

      # Create new character
      @cp_create_char ->
-        Handler.on_create_char(packet, state)
+        Handler.on_create_new_character(packet, state)

      # Create ultimate (Cygnus Knights)
      @cp_create_ultimate ->
@@ -191,15 +191,15 @@ defmodule Odinsea.Net.Processor do

      # Delete character
      @cp_delete_char ->
-        Handler.on_delete_char(packet, state)
+        Handler.on_delete_character(packet, state)

      # Select character (enter game)
      @cp_char_select ->
-        Handler.on_char_select(packet, state)
+        Handler.on_select_character(packet, state)

      # Second password check
      @cp_auth_second_password ->
-        Handler.on_auth_second_password(packet, state)
+        Handler.on_check_spw_request(packet, state)

      # RSA key request
      @cp_rsa_key ->
--- a/lib/odinsea/shop/client.ex
+++ b/lib/odinsea/shop/client.ex
@@ -103,7 +103,7 @@ defmodule Odinsea.Shop.Client do
      opcode == Opcodes.cp_player_loggedin() ->
        handle_migrate_in(packet, state)

-      opcode == Opcodes.cp_cash_shop_update() ->
+      opcode == Opcodes.cp_cs_update() ->
        # Cash shop operations
        handle_cash_shop_operation(packet, state)

--- a/lib/odinsea/shop/packets.ex
+++ b/lib/odinsea/shop/packets.ex
@@ -126,7 +126,7 @@ defmodule Odinsea.Shop.Packets do
  """
  def enable_cs_use(socket) do
    packet =
-      Out.new(Opcodes.lp_cash_shop_update())
+      Out.new(Opcodes.lp_cs_update())
      |> encode_cs_update()
      |> Out.to_data()

@@ -145,7 +145,7 @@ defmodule Odinsea.Shop.Packets do
    cash_items = character.cash_inventory || []

    packet =
-      Out.new(Opcodes.lp_cash_shop_update())
+      Out.new(Opcodes.lp_cs_update())
      |> Out.encode_byte(0x4A) # Operation code for inventory
      |> encode_cash_items(cash_items)
      |> Out.to_data()
@@ -178,7 +178,7 @@ defmodule Odinsea.Shop.Packets do
  """
  def show_nx_maple_tokens(socket, character) do
    packet =
-      Out.new(Opcodes.lp_cash_shop_update())
+      Out.new(Opcodes.lp_cs_update())
      |> Out.encode_byte(0x3D) # Operation code for balance
      |> Out.encode_int(character.nx_cash || 0)
      |> Out.encode_int(character.maple_points || 0)
@@ -196,7 +196,7 @@ defmodule Odinsea.Shop.Packets do
  """
  def show_bought_cs_item(socket, item, sn, account_id) do
    packet =
-      Out.new(Opcodes.lp_cash_shop_update())
+      Out.new(Opcodes.lp_cs_update())
      |> Out.encode_byte(0x53) # Bought item operation
      |> Out.encode_int(account_id)
      |> encode_bought_item(item, sn)
@@ -220,7 +220,7 @@ defmodule Odinsea.Shop.Packets do
  """
  def show_bought_cs_package(socket, items, account_id) do
    packet =
-      Out.new(Opcodes.lp_cash_shop_update())
+      Out.new(Opcodes.lp_cs_update())
      |> Out.encode_byte(0x5D) # Package operation
      |> Out.encode_int(account_id)
      |> Out.encode_short(length(items))
@@ -239,7 +239,7 @@ defmodule Odinsea.Shop.Packets do
  """
  def show_bought_cs_quest_item(socket, item, position) do
    packet =
-      Out.new(Opcodes.lp_cash_shop_update())
+      Out.new(Opcodes.lp_cs_update())
      |> Out.encode_byte(0x73) # Quest item operation
      |> Out.encode_int(item.price)
      |> Out.encode_short(item.count)
@@ -255,7 +255,7 @@ defmodule Odinsea.Shop.Packets do
  """
  def confirm_from_cs_inventory(socket, item, position) do
    packet =
-      Out.new(Opcodes.lp_cash_shop_update())
+      Out.new(Opcodes.lp_cs_update())
      |> Out.encode_byte(0x69) # From CS inventory
      |> Out.encode_byte(Odinsea.Game.InventoryType.get_type(
        Odinsea.Game.InventoryType.from_item_id(item.item_id)
@@ -271,7 +271,7 @@ defmodule Odinsea.Shop.Packets do
  """
  def confirm_to_cs_inventory(socket, item, account_id) do
    packet =
-      Out.new(Opcodes.lp_cash_shop_update())
+      Out.new(Opcodes.lp_cs_update())
      |> Out.encode_byte(0x5F) # To CS inventory
      |> Out.encode_int(account_id)
      |> encode_cash_item_single(item)
@@ -298,7 +298,7 @@ defmodule Odinsea.Shop.Packets do
  """
  def send_gift(socket, price, item_id, count, partner) do
    packet =
-      Out.new(Opcodes.lp_cash_shop_update())
+      Out.new(Opcodes.lp_cs_update())
      |> Out.encode_byte(0x5B) # Gift sent operation
      |> Out.encode_int(price)
      |> Out.encode_int(item_id)
@@ -314,7 +314,7 @@ defmodule Odinsea.Shop.Packets do
  """
  def get_cs_gifts(socket, gifts) do
    packet =
-      Out.new(Opcodes.lp_cash_shop_update())
+      Out.new(Opcodes.lp_cs_update())
      |> Out.encode_byte(0x48) # Gifts operation
      |> Out.encode_short(length(gifts))
      |> then(fn pkt ->
@@ -340,7 +340,7 @@ defmodule Odinsea.Shop.Packets do
  """
  def send_wishlist(socket, _character, wishlist) do
    packet =
-      Out.new(Opcodes.lp_cash_shop_update())
+      Out.new(Opcodes.lp_cs_update())
      |> Out.encode_byte(0x4D) # Wishlist operation
      |> then(fn pkt ->
        Enum.reduce(wishlist, pkt, fn sn, p ->
@@ -361,7 +361,7 @@ defmodule Odinsea.Shop.Packets do
  """
  def show_coupon_redeemed(socket, items, maple_points, mesos, client_state) do
    packet =
-      Out.new(Opcodes.lp_cash_shop_update())
+      Out.new(Opcodes.lp_cs_update())
      |> Out.encode_byte(0x4B) # Coupon operation
      |> Out.encode_byte(if safe_map_size(items) > 0, do: 1, else: 0)
      |> Out.encode_int(safe_map_size(items))
@@ -390,7 +390,7 @@ defmodule Odinsea.Shop.Packets do
  """
  def redeem_response(socket) do
    packet =
-      Out.new(Opcodes.lp_cash_shop_update())
+      Out.new(Opcodes.lp_cs_update())
      |> Out.encode_byte(0xA1) # Redeem response
      |> Out.encode_int(0)
      |> Out.encode_int(0)
@@ -409,7 +409,7 @@ defmodule Odinsea.Shop.Packets do
  """
  def send_cs_fail(socket, code) do
    packet =
-      Out.new(Opcodes.lp_cash_shop_update())
+      Out.new(Opcodes.lp_cs_update())
      |> Out.encode_byte(0x49) # Fail operation
      |> Out.encode_byte(code)
      |> Out.to_data()
@@ -422,7 +422,7 @@ defmodule Odinsea.Shop.Packets do
  """
  def cash_item_expired(socket, unique_id) do
    packet =
-      Out.new(Opcodes.lp_cash_shop_update())
+      Out.new(Opcodes.lp_cs_update())
      |> Out.encode_byte(0x4E) # Expired operation
      |> Out.encode_long(unique_id)
      |> Out.to_data()
--- a/logs/odinsea.log
+++ b/logs/odinsea.log
--- a/priv/repo/migrations/20260215000001_create_base_tables.exs
+++ b/priv/repo/migrations/20260215000001_create_base_tables.exs
@@ -10,8 +10,8 @@ defmodule Odinsea.Repo.Migrations.CreateBaseTables do
      add :name, :string, size: 13, null: false
      add :password, :string, size: 128, null: false, default: ""
      add :salt, :string, size: 32
-      add :secondpassword, :string, size: 134
-      add :salt2, :string, size: 32
+      add :second_password, :string, size: 134
+      add :second_salt, :string, size: 32
      add :loggedin, :boolean, null: false, default: false
      add :lastlogin, :naive_datetime
      add :birthday, :date, null: false, default: "0000-01-01"
--- a/test/crypto_simple_test.exs
+++ b/test/crypto_simple_test.exs
@@ -0,0 +1,60 @@
+defmodule Odinsea.CryptoSimpleTest do
+  @moduledoc """
+  Simple test module for MapleStory crypto implementation.
+  These tests don't require the full application to start.
+  """
+
+  use ExUnit.Case
+
+  alias Odinsea.Net.Cipher.{IGCipher, ShandaCipher, AESCipher}
+
+  describe "IGCipher (IV transformation)" do
+    test "inno_hash transforms IV correctly" do
+      iv = <<0x34, 0x9A, 0x0F, 0x0C>>
+      result = IGCipher.inno_hash(iv)
+      
+      # Result should be 4 bytes
+      assert byte_size(result) == 4
+      
+      # Result should be different from input (usually)
+      assert result != iv
+    end
+    
+    test "inno_hash produces deterministic results" do
+      iv = <<0xA8, 0xBC, 0x0D, 0xB3>>
+      result1 = IGCipher.inno_hash(iv)
+      result2 = IGCipher.inno_hash(iv)
+      
+      assert result1 == result2
+    end
+  end
+  
+  describe "ShandaCipher" do
+    test "encrypt and decrypt are inverse operations" do
+      original = <<1, 0, 7, 112, 0, 4, 0>>  # CP_PermissionRequest payload
+      encrypted = ShandaCipher.encrypt(original)
+      decrypted = ShandaCipher.decrypt(encrypted)
+      
+      assert decrypted == original
+    end
+    
+    test "encrypt produces different output" do
+      original = <<1, 0, 7, 112, 0, 4, 0>>
+      encrypted = ShandaCipher.encrypt(original)
+      
+      assert encrypted != original
+    end
+  end
+  
+  describe "AESCipher" do
+    test "crypt is self-inverse (XOR property)" do
+      data = <<1, 0, 7, 112, 0, 4, 0>>
+      iv = <<0xA8, 0xBC, 0x0D, 0xB3>>
+      
+      encrypted = AESCipher.crypt(data, iv)
+      decrypted = AESCipher.crypt(encrypted, iv)
+      
+      assert decrypted == data
+    end
+  end
+end
--- a/test/crypto_test.exs
+++ b/test/crypto_test.exs
@@ -0,0 +1,185 @@
+defmodule Odinsea.CryptoTest do
+  @moduledoc """
+  Test module for MapleStory crypto implementation.
+  Run with: mix test test/crypto_test.exs
+  """
+
+  use ExUnit.Case
+
+  alias Odinsea.Net.Cipher.{ClientCrypto, IGCipher, ShandaCipher, AESCipher}
+  alias Odinsea.Util.BitTools
+
+  describe "IGCipher (IV transformation)" do
+    test "inno_hash transforms IV correctly" do
+      iv = <<0x34, 0x9A, 0x0F, 0x0C>>
+      result = IGCipher.inno_hash(iv)
+      
+      # Result should be 4 bytes
+      assert byte_size(result) == 4
+      
+      # Result should be different from input (usually)
+      assert result != iv
+    end
+    
+    test "inno_hash produces deterministic results" do
+      iv = <<0xA8, 0xBC, 0x0D, 0xB3>>
+      result1 = IGCipher.inno_hash(iv)
+      result2 = IGCipher.inno_hash(iv)
+      
+      assert result1 == result2
+    end
+  end
+  
+  describe "ShandaCipher" do
+    test "encrypt and decrypt are inverse operations" do
+      original = <<1, 0, 7, 112, 0, 4, 0>>  # CP_PermissionRequest payload
+      encrypted = ShandaCipher.encrypt(original)
+      decrypted = ShandaCipher.decrypt(encrypted)
+      
+      assert decrypted == original
+    end
+    
+    test "encrypt produces different output" do
+      original = <<1, 0, 7, 112, 0, 4, 0>>
+      encrypted = ShandaCipher.encrypt(original)
+      
+      assert encrypted != original
+    end
+  end
+  
+  describe "AESCipher" do
+    test "crypt is self-inverse (XOR property)" do
+      data = <<1, 0, 7, 112, 0, 4, 0>>
+      iv = <<0xA8, 0xBC, 0x0D, 0xB3>>
+      
+      encrypted = AESCipher.crypt(data, iv)
+      decrypted = AESCipher.crypt(encrypted, iv)
+      
+      assert decrypted == data
+    end
+  end
+  
+  describe "ClientCrypto" do
+    test "new creates crypto with random IVs" do
+      crypto = ClientCrypto.new(112)
+      
+      assert byte_size(crypto.send_iv) == 4
+      assert byte_size(crypto.recv_iv) == 4
+      assert crypto.version == 112
+    end
+    
+    test "new_from_ivs creates crypto with specified IVs" do
+      send_iv = <<0x34, 0x9A, 0x0F, 0x0C>>
+      recv_iv = <<0xA8, 0xBC, 0x0D, 0xB3>>
+      
+      crypto = ClientCrypto.new_from_ivs(112, send_iv, recv_iv)
+      
+      assert crypto.send_iv == send_iv
+      assert crypto.recv_iv == recv_iv
+    end
+    
+    test "new_from_client_ivs swaps IVs correctly" do
+      # Client's perspective
+      client_send_iv = <<0xA8, 0xBC, 0x0D, 0xB3>>
+      client_recv_iv = <<0x34, 0x9A, 0x0F, 0x0C>>
+      
+      # Server's perspective (should be swapped)
+      crypto = ClientCrypto.new_from_client_ivs(112, client_send_iv, client_recv_iv)
+      
+      # Server's send = client's recv
+      assert crypto.send_iv == client_recv_iv
+      # Server's recv = client's send
+      assert crypto.recv_iv == client_send_iv
+    end
+    
+    test "decrypt updates recv_iv" do
+      crypto = ClientCrypto.new(112)
+      original_recv_iv = crypto.recv_iv
+      
+      encrypted_data = <<0x7C, 0xA8, 0x7B, 0xA8, 0xBF, 0x0A, 0xCD, 0xDE>>
+      {new_crypto, _decrypted} = ClientCrypto.decrypt(crypto, encrypted_data)
+      
+      # IV should be updated after decryption
+      assert new_crypto.recv_iv != original_recv_iv
+    end
+    
+    test "encrypt updates send_iv" do
+      crypto = ClientCrypto.new(112)
+      original_send_iv = crypto.send_iv
+      
+      data = <<1, 0, 7, 112, 0, 4, 0>>
+      {new_crypto, _encrypted, _header} = ClientCrypto.encrypt(crypto, data)
+      
+      # IV should be updated after encryption
+      assert new_crypto.send_iv != original_send_iv
+    end
+    
+    test "header encoding produces 4 bytes" do
+      crypto = ClientCrypto.new(112)
+      data = <<1, 0, 7, 112, 0, 4, 0>>
+      
+      {_new_crypto, _encrypted, header} = ClientCrypto.encrypt(crypto, data)
+      
+      assert byte_size(header) == 4
+    end
+    
+    test "header validation works correctly" do
+      crypto = ClientCrypto.new(112)
+      data = <<1, 0, 7, 112, 0, 4, 0>>
+      
+      {new_crypto, encrypted, header} = ClientCrypto.encrypt(crypto, data)
+      
+      # Extract raw_seq from header
+      <<raw_seq::little-16, _raw_len::little-16>> = header
+      
+      # Validation should pass
+      assert ClientCrypto.decode_header_valid?(new_crypto, raw_seq)
+    end
+    
+    test "full encrypt/decrypt roundtrip" do
+      # Create crypto instances with same IVs
+      send_iv = <<0x34, 0x9A, 0x0F, 0x0C>>
+      recv_iv = <<0xA8, 0xBC, 0x0D, 0xB3>>
+      
+      # Server's crypto (for sending)
+      server_crypto = ClientCrypto.new_from_ivs(112, send_iv, recv_iv)
+      
+      # Client's crypto would have swapped IVs
+      # For testing, we'll use the same crypto to verify roundtrip
+      original_data = <<1, 0, 7, 112, 0, 4, 0>>
+      
+      # Encrypt
+      {server_crypto_after, encrypted, header} = ClientCrypto.encrypt(server_crypto, original_data)
+      
+      # Decrypt (using recv_iv which should match server's send_iv after swap)
+      # For this test, we'll create a matching client crypto
+      client_crypto = ClientCrypto.new_from_ivs(112, recv_iv, send_iv)
+      {client_crypto_after, decrypted} = ClientCrypto.decrypt(client_crypto, encrypted)
+      
+      assert decrypted == original_data
+    end
+  end
+  
+  describe "BitTools" do
+    test "roll_left rotates bits correctly" do
+      # 0b11001101 = 205
+      # rotate left by 3: 0b01101101 = 109 (wrapping around)
+      result = BitTools.roll_left(205, 3)
+      assert result == 109
+    end
+    
+    test "roll_right rotates bits correctly" do
+      # Test that roll_right is inverse of roll_left
+      original = 205
+      rotated = BitTools.roll_left(original, 3)
+      back = BitTools.roll_right(rotated, 3)
+      assert back == original
+    end
+    
+    test "multiply_bytes repeats correctly" do
+      input = <<1, 2, 3, 4>>
+      result = BitTools.multiply_bytes(input, 4, 2)
+      assert result == <<1, 2, 3, 4, 1, 2, 3, 4>>
+    end
+  end
+end
--- a/test/debug_crypto.exs
+++ b/test/debug_crypto.exs
@@ -0,0 +1,80 @@
+# Debug script to trace crypto operations
+# Run with: cd /home/ra/odinsea-elixir && elixir test/debug_crypto.exs
+
+Code.require_file("lib/odinsea/util/bit_tools.ex", ".")
+Code.require_file("lib/odinsea/net/cipher/ig_cipher.ex", ".")
+Code.require_file("lib/odinsea/net/cipher/aes_cipher.ex", ".")
+Code.require_file("lib/odinsea/net/cipher/shanda_cipher.ex", ".")
+
+alias Odinsea.Net.Cipher.{IGCipher, AESCipher, ShandaCipher}
+alias Odinsea.Util.BitTools
+
+import Bitwise
+
+IO.puts("=== Debugging Crypto ===\n")
+
+# From the packet log:
+# Server's recv_iv = <<0xA8, 0xBC, 0x0D, 0xB3>> (client's send_iv)
+recv_iv = <<0xA8, 0xBC, 0x0D, 0xB3>>
+
+# First encrypted packet from client:
+# [Data] 7C A8 7B A8 BF 0A CD DE C7 71 AC
+packet = <<0x7C, 0xA8, 0x7B, 0xA8, 0xBF, 0x0A, 0xCD, 0xDE, 0xC7, 0x71, 0xAC>>
+
+IO.puts("Raw packet: #{Base.encode16(packet)}")
+IO.puts("Server recv_iv: #{Base.encode16(recv_iv)}")
+
+# Extract header
+<<raw_seq::little-16, raw_len::little-16, payload::binary>> = packet
+IO.puts("\nHeader:")
+IO.puts("  raw_seq: 0x#{Integer.to_string(raw_seq, 16)} (#{raw_seq})")
+IO.puts("  raw_len: 0x#{Integer.to_string(raw_len, 16)} (#{raw_len})")
+IO.puts("  payload: #{Base.encode16(payload)} (#{byte_size(payload)} bytes)")
+
+# Validate header
+<<_r0, _r1, r2, r3>> = recv_iv
+enc_version = 112
+seq_base = ((r2 &&& 0xFF) ||| ((r3 <<< 8) &&& 0xFF00)) &&& 0xFFFF
+calculated_version = Bitwise.bxor(raw_seq &&& 0xFFFF, seq_base)
+
+IO.puts("\nHeader validation:")
+IO.puts("  r2: 0x#{Integer.to_string(r2, 16)} (#{r2})")
+IO.puts("  r3: 0x#{Integer.to_string(r3, 16)} (#{r3})")
+IO.puts("  seq_base: 0x#{Integer.to_string(seq_base, 16)} (#{seq_base})")
+IO.puts("  calculated_version: #{calculated_version}")
+IO.puts("  expected_version: #{enc_version}")
+IO.puts("  valid: #{calculated_version == enc_version}")
+
+# Get packet length
+packet_len = Bitwise.bxor(raw_seq, raw_len) &&& 0xFFFF
+IO.puts("\nPacket length: #{packet_len}")
+
+# Decrypt with AES
+IO.puts("\n=== AES Decryption ===")
+aes_decrypted = AESCipher.crypt(payload, recv_iv)
+IO.puts("After AES: #{Base.encode16(aes_decrypted)}")
+
+# Decrypt with Shanda
+IO.puts("\n=== Shanda Decryption ===")
+shanda_decrypted = ShandaCipher.decrypt(aes_decrypted)
+IO.puts("After Shanda: #{Base.encode16(shanda_decrypted)}")
+
+# Expected opcode 0x01 = 1
+if byte_size(shanda_decrypted) >= 2 do
+  <<opcode::little-16, rest::binary>> = shanda_decrypted
+  IO.puts("\n=== Result ===")
+  IO.puts("Opcode: 0x#{Integer.to_string(opcode, 16)} (#{opcode})")
+  IO.puts("Rest: #{Base.encode16(rest)}")
+  
+  if opcode == 1 do
+    IO.puts("\n✓ SUCCESS! This is CP_PermissionRequest (0x01)")
+  else
+    IO.puts("\n✗ FAILED! Expected opcode 0x01, got 0x#{Integer.to_string(opcode, 16)}")
+  end
+end
+
+# Update IV
+new_recv_iv = IGCipher.inno_hash(recv_iv)
+IO.puts("\nUpdated recv_iv: #{Base.encode16(new_recv_iv)}")
+
+IO.puts("\n=== Done ===")
--- a/test/debug_crypto2.exs
+++ b/test/debug_crypto2.exs
@@ -0,0 +1,101 @@
+# Debug script to trace crypto operations with CORRECT IV
+# Run with: cd /home/ra/odinsea-elixir && elixir test/debug_crypto2.exs
+
+Code.require_file("lib/odinsea/util/bit_tools.ex", ".")
+Code.require_file("lib/odinsea/net/cipher/ig_cipher.ex", ".")
+Code.require_file("lib/odinsea/net/cipher/aes_cipher.ex", ".")
+Code.require_file("lib/odinsea/net/cipher/shanda_cipher.ex", ".")
+
+alias Odinsea.Net.Cipher.{IGCipher, AESCipher, ShandaCipher}
+
+import Bitwise
+
+IO.puts("=== Debugging Crypto (Corrected IV) ===\n")
+
+# From the hello packet sent by server:
+# [Data] 0E 00 70 00 01 00 34 9A 0F 0C A8 BC 0D B3 E6 07
+# Server sends: recv_iv=34 9A 0F 0C, send_iv=A8 BC 0D B3
+#
+# Client SWAPS these:
+# Client's send_iv = server's recv_iv = 34 9A 0F 0C
+# Client's recv_iv = server's send_iv = A8 BC 0D B3
+#
+# Client encrypts with its send_iv (34 9A 0F 0C)
+# Server must decrypt with its recv_iv = 34 9A 0F 0C
+
+server_send_iv = <<0xA8, 0xBC, 0x0D, 0xB3>>  # Server sends this, client uses as recv
+server_recv_iv = <<0x34, 0x9A, 0x0F, 0x0C>>  # Server sends this, client uses as send
+
+IO.puts("Server perspective:")
+IO.puts("  server_send_iv: #{Base.encode16(server_send_iv)}")
+IO.puts("  server_recv_iv: #{Base.encode16(server_recv_iv)}")
+
+IO.puts("\nClient perspective (after swapping):")
+IO.puts("  client_send_iv = server_recv_iv: #{Base.encode16(server_recv_iv)}")
+IO.puts("  client_recv_iv = server_send_iv: #{Base.encode16(server_send_iv)}")
+
+# First encrypted packet from client:
+# [Data] 7C A8 7B A8 BF 0A CD DE C7 71 AC
+packet = <<0x7C, 0xA8, 0x7B, 0xA8, 0xBF, 0x0A, 0xCD, 0xDE, 0xC7, 0x71, 0xAC>>
+
+IO.puts("\nRaw packet: #{Base.encode16(packet)}")
+
+# Server decrypts with server_recv_iv
+recv_iv = server_recv_iv
+IO.puts("Server decrypts with recv_iv: #{Base.encode16(recv_iv)}")
+
+# Extract header
+<<raw_seq::little-16, raw_len::little-16, payload::binary>> = packet
+IO.puts("\nHeader:")
+IO.puts("  raw_seq: 0x#{Integer.to_string(raw_seq, 16)} (#{raw_seq})")
+IO.puts("  raw_len: 0x#{Integer.to_string(raw_len, 16)} (#{raw_len})")
+IO.puts("  payload: #{Base.encode16(payload)} (#{byte_size(payload)} bytes)")
+
+# Validate header
+<<_r0, _r1, r2, r3>> = recv_iv
+enc_version = 112
+seq_base = ((r2 &&& 0xFF) ||| ((r3 <<< 8) &&& 0xFF00)) &&& 0xffff
+calculated_version = bxor(raw_seq &&& 0xFFFF, seq_base)
+
+IO.puts("\nHeader validation:")
+IO.puts("  r2: 0x#{Integer.to_string(r2, 16)} (#{r2})")
+IO.puts("  r3: 0x#{Integer.to_string(r3, 16)} (#{r3})")
+IO.puts("  seq_base: 0x#{Integer.to_string(seq_base, 16)} (#{seq_base})")
+IO.puts("  raw_seq ^ seq_base: #{calculated_version}")
+IO.puts("  expected_version: #{enc_version}")
+IO.puts("  valid: #{calculated_version == enc_version}")
+
+# Get packet length
+packet_len = bxor(raw_seq, raw_len) &&& 0xFFFF
+IO.puts("\nPacket length: #{packet_len}")
+
+# Decrypt with AES
+IO.puts("\n=== AES Decryption ===")
+IO.puts("Input: #{Base.encode16(payload)}")
+aes_decrypted = AESCipher.crypt(payload, recv_iv)
+IO.puts("After AES: #{Base.encode16(aes_decrypted)}")
+
+# Decrypt with Shanda
+IO.puts("\n=== Shanda Decryption ===")
+shanda_decrypted = ShandaCipher.decrypt(aes_decrypted)
+IO.puts("After Shanda: #{Base.encode16(shanda_decrypted)}")
+
+# Expected opcode 0x01 = 1
+if byte_size(shanda_decrypted) >= 2 do
+  <<opcode::little-16, rest::binary>> = shanda_decrypted
+  IO.puts("\n=== Result ===")
+  IO.puts("Opcode: 0x#{Integer.to_string(opcode, 16)} (#{opcode})")
+  IO.puts("Rest: #{Base.encode16(rest)}")
+  
+  if opcode == 1 do
+    IO.puts("\n✓ SUCCESS! This is CP_PermissionRequest (0x01)")
+  else
+    IO.puts("\n✗ FAILED! Expected opcode 0x01, got 0x#{Integer.to_string(opcode, 16)}")
+  end
+end
+
+# Update IV
+new_recv_iv = IGCipher.inno_hash(recv_iv)
+IO.puts("\nUpdated recv_iv: #{Base.encode16(new_recv_iv)}")
+
+IO.puts("\n=== Done ===")
--- a/test/find_iv.exs
+++ b/test/find_iv.exs
@@ -0,0 +1,53 @@
+# Find the correct IV by trying all combinations from hello packet
+# Hello packet: 0E 00 70 00 01 00 34 9A 0F 0C A8 BC 0D B3 E6 07
+
+import Bitwise
+
+# Raw packet from client
+packet = <<0x7C, 0xA8, 0x7B, 0xA8, 0xBF, 0x0A, 0xCD, 0xDE, 0xC7, 0x71, 0xAC>>
+<<raw_seq::little-16, _raw_len::little-16, _payload::binary>> = packet
+
+IO.puts("Raw packet: #{Base.encode16(packet)}")
+IO.puts("raw_seq: 0x#{Integer.to_string(raw_seq, 16)} (#{raw_seq})")
+IO.puts("")
+
+# For header validation to pass: raw_seq ^ seq_base == 112
+target_seq_base = bxor(raw_seq, 112)
+IO.puts("Need seq_base: 0x#{Integer.to_string(target_seq_base, 16)} (#{target_seq_base})")
+IO.puts("")
+
+# seq_base = (r2 & 0xFF) | ((r3 << 8) & 0xFF00)
+# So: r2 = lower byte, r3 = upper byte
+target_r2 = target_seq_base &&& 0xFF
+target_r3 = (target_seq_base >>> 8) &&& 0xFF
+IO.puts("Need recv_iv[2] = 0x#{Integer.to_string(target_r2, 16)} (#{target_r2})")
+IO.puts("Need recv_iv[3] = 0x#{Integer.to_string(target_r3, 16)} (#{target_r3})")
+IO.puts("")
+
+# Bytes available in hello packet (positions 6-13):
+# 34 9A 0F 0C A8 BC 0D B3
+bytes = [0x34, 0x9A, 0x0F, 0x0C, 0xA8, 0xBC, 0x0D, 0xB3]
+IO.puts("Available bytes from hello packet:")
+Enum.each(Enum.with_index(bytes), fn {b, i} ->
+  IO.puts("  [#{i}]: 0x#{Integer.to_string(b, 16)}")
+end)
+IO.puts("")
+
+# Find matching bytes
+IO.puts("Looking for matches...")
+Enum.each(Enum.with_index(bytes), fn {b2, i2} ->
+  Enum.each(Enum.with_index(bytes), fn {b3, i3} ->
+    if b2 == target_r2 and b3 == target_r3 do
+      IO.puts("Found match! recv_iv[2]=0x#{Integer.to_string(b2, 16)} at [#{i2}], recv_iv[3]=0x#{Integer.to_string(b3, 16)} at [#{i3}]")
+      
+      # Construct full IV (need to determine r0 and r1 too)
+      # Try different combinations for r0 and r1
+      Enum.each(Enum.with_index(bytes), fn {b0, i0} ->
+        Enum.each(Enum.with_index(bytes), fn {b1, i1} ->
+          iv = <<b0, b1, b2, b3>>
+          IO.puts("  Possible IV: #{Base.encode16(iv)} (bytes[#{i0}][#{i1}][#{i2}][#{i3}])")
+        end)
+      end)
+    end
+  end)
+end)
--- a/test/test_aes.exs
+++ b/test/test_aes.exs
@@ -0,0 +1,48 @@
+# Test AES cipher with known values
+
+Code.require_file("lib/odinsea/util/bit_tools.ex", ".")
+Code.require_file("lib/odinsea/net/cipher/ig_cipher.ex", ".")
+Code.require_file("lib/odinsea/net/cipher/aes_cipher.ex", ".")
+
+alias Odinsea.Net.Cipher.AESCipher
+
+import Bitwise
+
+# Test: AES crypt should be self-inverse (since it's just XOR)
+iv = <<0x0F, 0x0C, 0x0C, 0xA8>>
+data = <<0xBF, 0x0A, 0xCD, 0xDE, 0xC7, 0x71, 0xAC>>
+
+IO.puts("Testing AES cipher:")
+IO.puts("IV: #{Base.encode16(iv)}")
+IO.puts("Data: #{Base.encode16(data)}")
+IO.puts("")
+
+# Expand IV to 16 bytes
+expanded_iv = :binary.copy(iv, 4)
+IO.puts("Expanded IV (16 bytes): #{Base.encode16(expanded_iv)}")
+
+# The AES key (16 bytes)
+aes_key = <<
+  0x13, 0x00, 0x00, 0x00,
+  0x08, 0x00, 0x00, 0x00,
+  0x06, 0x00, 0x00, 0x00,
+  0xB4, 0x00, 0x00, 0x00
+>>
+
+# Encrypt the expanded IV to get keystream
+keystream = :crypto.crypto_one_time(:aes_128_ecb, aes_key, expanded_iv, true)
+IO.puts("Keystream: #{Base.encode16(keystream)}")
+
+# XOR data with keystream (only use as many bytes as data)
+keystream_bytes = :binary.bin_to_list(keystream) |> Enum.take(byte_size(data))
+data_bytes = :binary.bin_to_list(data)
+result_bytes = Enum.zip_with(data_bytes, keystream_bytes, fn x, y -> bxor(x, y) end)
+result = :binary.list_to_bin(result_bytes)
+
+IO.puts("XOR result: #{Base.encode16(result)}")
+IO.puts("")
+
+# Compare with AESCipher.crypt
+aes_result = AESCipher.crypt(data, iv)
+IO.puts("AESCipher.crypt result: #{Base.encode16(aes_result)}")
+IO.puts("Match: #{result == aes_result}")
--- a/test/test_ivs.exs
+++ b/test/test_ivs.exs
@@ -0,0 +1,55 @@
+# Test specific IV candidates
+
+Code.require_file("lib/odinsea/util/bit_tools.ex", ".")
+Code.require_file("lib/odinsea/net/cipher/ig_cipher.ex", ".")
+Code.require_file("lib/odinsea/net/cipher/aes_cipher.ex", ".")
+Code.require_file("lib/odinsea/net/cipher/shanda_cipher.ex", ".")
+
+alias Odinsea.Net.Cipher.{IGCipher, AESCipher, ShandaCipher}
+
+import Bitwise
+
+packet = <<0x7C, 0xA8, 0x7B, 0xA8, 0xBF, 0x0A, 0xCD, 0xDE, 0xC7, 0x71, 0xAC>>
+<<raw_seq::little-16, raw_len::little-16, payload::binary>> = packet
+
+IO.puts("Testing IV candidates for packet: #{Base.encode16(packet)}")
+IO.puts("raw_seq: 0x#{Integer.to_string(raw_seq, 16)}, raw_len: 0x#{Integer.to_string(raw_len, 16)}")
+IO.puts("")
+
+# IV candidates based on bytes [2]=0x0F, [3]=0x0C, [4]=0xA8, [5]=0xBC
+candidates = [
+  <<0x0F, 0x0C, 0x0C, 0xA8>>,  # [2][3][3][4] - overlapping
+  <<0x0C, 0x0C, 0x0C, 0xA8>>,  # [3][3][3][4]
+  <<0x0C, 0xA8, 0x0C, 0xA8>>,  # [3][4][3][4] - repeating pattern
+  <<0x0F, 0x0C, 0xA8, 0xBC>>,  # [2][3][4][5] - recv_iv from hello?
+  <<0x34, 0x9A, 0x0C, 0xA8>>,  # [0][1][3][4]
+  <<0x9A, 0x0F, 0x0C, 0xA8>>,  # [1][2][3][4]
+  <<0x0C, 0xA8, 0xBC, 0x0D>>,  # [3][4][5][6]
+  <<0xA8, 0xBC, 0x0C, 0xA8>>,  # [4][5][3][4]
+]
+
+Enum.each(candidates, fn iv ->
+  <<_r0, _r1, r2, r3>> = iv
+  seq_base = ((r2 &&& 0xFF) ||| ((r3 <<< 8) &&& 0xFF00)) &&& 0xFFFF
+  valid = bxor(raw_seq &&& 0xFFFF, seq_base) == 112
+  
+  IO.puts("IV: #{Base.encode16(iv)}")
+  IO.puts("  seq_base: 0x#{Integer.to_string(seq_base, 16)}, valid: #{valid}")
+  
+  if valid do
+    # Try full decryption
+    aes_result = AESCipher.crypt(payload, iv)
+    shanda_result = ShandaCipher.decrypt(aes_result)
+    
+    if byte_size(shanda_result) >= 2 do
+      <<opcode::little-16, _rest::binary>> = shanda_result
+      IO.puts("  *** VALID IV! ***")
+      IO.puts("  Decrypted opcode: 0x#{Integer.to_string(opcode, 16)} (#{opcode})")
+      if opcode == 1 do
+        IO.puts("  *** CORRECT OPCODE! ***")
+      end
+    end
+  end
+  
+  IO.puts("")
+end)
--- a/test/test_shanda.exs
+++ b/test/test_shanda.exs
@@ -0,0 +1,54 @@
+# Test Shanda cipher - encrypt then decrypt should give original
+
+Code.require_file("lib/odinsea/util/bit_tools.ex", ".")
+Code.require_file("lib/odinsea/net/cipher/shanda_cipher.ex", ".")
+
+alias Odinsea.Net.Cipher.ShandaCipher
+alias Odinsea.Util.BitTools
+
+import Bitwise
+
+# Test with simple data
+data = <<0x01, 0x00, 0x07, 0x70, 0x00, 0x04, 0x00>>
+IO.puts("Original data: #{Base.encode16(data)}")
+
+# Encrypt
+encrypted = ShandaCipher.encrypt(data)
+IO.puts("Encrypted: #{Base.encode16(encrypted)}")
+
+# Decrypt
+decrypted = ShandaCipher.decrypt(encrypted)
+IO.puts("Decrypted: #{Base.encode16(decrypted)}")
+
+IO.puts("Match: #{data == decrypted}")
+IO.puts("")
+
+# If they don't match, let's debug step by step
+if data != decrypted do
+  IO.puts("MISMATCH! Let's debug...")
+  IO.puts("")
+  
+  # Manual encrypt - first pass only
+  bytes = :binary.bin_to_list(data)
+  data_len = length(bytes)
+  data_length = data_len &&& 0xFF
+  
+  IO.puts("Data length: #{data_len}")
+  IO.puts("Initial bytes: #{inspect(bytes)}")
+  IO.puts("")
+  
+  # First pass (j=0, forward)
+  IO.puts("=== Pass 0 (forward) ===")
+  {result0, remember0} = Enum.reduce(Enum.with_index(bytes), {[], 0}, fn {cur, i}, {acc, remember} ->
+    cur = BitTools.roll_left(cur, 3)
+    cur = (cur + data_length) &&& 0xFF
+    cur = bxor(cur, remember)
+    new_remember = cur
+    cur = BitTools.roll_right(cur, data_length &&& 0xFF)
+    cur = bxor(cur, 0xFF)
+    cur = (cur + 0x48) &&& 0xFF
+    {[cur | acc], new_remember}
+  end)
+  result0 = Enum.reverse(result0)
+  IO.puts("After pass 0: #{inspect(result0)}, remember: #{remember0}")
+end