8 files changed, 83 insertions, 3 deletions
diff --git a/src/map/chrif.cpp b/src/map/chrif.cpp
index 42a13cf..9361c2e 100644
--- a/src/map/chrif.cpp
+++ b/src/map/chrif.cpp
@@ -340,6 +340,30 @@ int chrif_charselectreq(dumb_ptr<map_session_data> sd)
     return 0;
 }
 
+void chrif_parse_preauth(Session *s, const Packet_Fixed<0x3829>& fixed)
+{
+    if (auth_fifo_iter == auth_fifo.end())
+        auth_fifo_iter = auth_fifo.begin();
+    auth_fifo_iter->account_id = fixed.account_id;
+    auth_fifo_iter->char_id = fixed.char_id;
+    auth_fifo_iter->login_id1 = fixed.login_id1;
+    auth_fifo_iter->login_id2 = fixed.login_id2;
+    auth_fifo_iter->ip = fixed.ip;
+    auth_fifo_iter->delflag = 0;
+    auth_fifo_iter++;
+
+    // tell char server we accepted the auth details
+    Packet_Fixed<0x3830> fixed_3830;
+    fixed_3830.account_id = fixed.account_id;
+    fixed_3830.char_id = fixed.char_id;
+    fixed_3830.login_id1 = fixed.login_id1;
+    fixed_3830.login_id2 = fixed.login_id2;
+    fixed_3830.ip = fixed.ip;
+    send_fpacket<0x3830, 22>(s, fixed_3830);
+
+    MAP_LOG_AND_ECHO("Received pre-auth details for account %d [%s], replying to char server\n"_fmt, fixed.account_id, fixed.ip);
+}
+
 /*==========================================
  * Change Email
  *------------------------------------------
diff --git a/src/map/chrif.hpp b/src/map/chrif.hpp
index 655103d..ea8096c 100644
--- a/src/map/chrif.hpp
+++ b/src/map/chrif.hpp
@@ -44,6 +44,8 @@ void chrif_char_ask_name(AccountId id, CharName character_name, short operation_
 int chrif_saveaccountreg2(dumb_ptr<map_session_data> sd);
 int chrif_send_divorce(CharId char_id);
 
+void chrif_parse_preauth(Session *s, const Packet_Fixed<0x3829>& fixed);
+
 void do_init_chrif(void);
 } // namespace map
 } // namespace tmwa
diff --git a/src/map/clif.cpp b/src/map/clif.cpp
index f2667ac..a2f3b3a 100644
--- a/src/map/clif.cpp
+++ b/src/map/clif.cpp
@@ -3539,15 +3539,36 @@ RecvResult clif_parse_WantToConnection(Session *s, dumb_ptr<map_session_data> sd
     if (rv != RecvResult::Complete)
         return rv;
 
-    {
-        account_id = fixed.account_id;
-    }
+    account_id = fixed.account_id;
 
     // formerly: account id
     Packet_Payload<0x8000> special;
     special.magic_packet_length = 4;
     send_ppacket<0x8000>(s, special);
 
+    bool is_valid = false;
+    for (AuthFifoEntry& afi : auth_fifo)
+    {
+        if (afi.account_id == fixed.account_id
+            && afi.char_id == fixed.char_id
+            && afi.login_id1 == fixed.login_id1
+            //&& afi.login_id2 == sd->login_id2
+            && afi.ip == s->client_ip
+            && afi.delflag == 0)
+        {
+            is_valid = true;
+            afi.delflag = 1;
+            break;
+        }
+    }
+
+    if (!is_valid)
+    {
+        MAP_LOG_AND_ECHO("Attempt to connect without correct authentication (REJECTED IP: %s)!\n"_fmt, s->client_ip);
+        s->set_eof();
+        return RecvResult::Complete;
+    }
+
     // if same account already connected, we disconnect the 2 sessions
     dumb_ptr<map_session_data> old_sd = map_id2sd(account_to_block(account_id));
     if (old_sd)
diff --git a/src/map/fwd.hpp b/src/map/fwd.hpp
index 74e0ccf..fc6b284 100644
--- a/src/map/fwd.hpp
+++ b/src/map/fwd.hpp
@@ -69,5 +69,7 @@ struct ScriptState;
 struct str_data_t;
 class SIR;
 
+struct AuthFifoEntry;
+
 } // namespace map
 } // namespace tmwa
diff --git a/src/map/globals.cpp b/src/map/globals.cpp
index 49d6074..97533c8 100644
--- a/src/map/globals.cpp
+++ b/src/map/globals.cpp
@@ -51,6 +51,9 @@ namespace tmwa
         Map<ItemNameId, item_data> item_db;
         Map<QuestId, quest_data> quest_db;
 
+        std::array<AuthFifoEntry, 256> auth_fifo;
+        decltype(auth_fifo)::iterator auth_fifo_iter = auth_fifo.begin();
+
         DMap<BlockId, dumb_ptr<block_list>> id_db;
         UPMap<MapName, map_abstract> maps_db;
         DMap<CharName, dumb_ptr<map_session_data>> nick_db;
diff --git a/src/map/globals.hpp b/src/map/globals.hpp
index 1c8e70d..acf52fd 100644
--- a/src/map/globals.hpp
+++ b/src/map/globals.hpp
@@ -95,5 +95,8 @@ namespace tmwa
         extern earray<skill_db_, SkillID, SkillID::MAX_SKILL_DB> skill_db;
         extern BlockId skill_area_temp_id;
         extern int skill_area_temp_hp;
+
+        extern std::array<AuthFifoEntry, 256> auth_fifo;
+        extern AuthFifoEntry *auth_fifo_iter;
     } // namespace map
 } // namespace tmwa
diff --git a/src/map/intif.cpp b/src/map/intif.cpp
index fc34a64..379bb1d 100644
--- a/src/map/intif.cpp
+++ b/src/map/intif.cpp
@@ -743,6 +743,16 @@ RecvResult intif_parse(Session *s, uint16_t packet_id)
             intif_parse_PartyLeaderChanged(s, fixed);
             break;
         }
+        case 0x3829:
+        {
+            Packet_Fixed<0x3829> fixed;
+            rv = recv_fpacket<0x3829, 22>(s, fixed);
+            if (rv != RecvResult::Complete)
+                return rv;
+
+            chrif_parse_preauth(s, fixed);
+            break;
+        }
         default:
             return RecvResult::Error;
     }
diff --git a/src/map/map.hpp b/src/map/map.hpp
index 24037e9..2f6ef21 100644
--- a/src/map/map.hpp
+++ b/src/map/map.hpp
@@ -584,6 +584,12 @@ void map_log(XString line);
 #define MAP_LOG(format, ...)    \
     map_log(STRPRINTF(format, ## __VA_ARGS__))
 
+#define MAP_LOG_AND_ECHO(...) \
+    do { \
+      PRINTF(__VA_ARGS__); \
+      MAP_LOG(__VA_ARGS__); \
+    } while (0)
+
 #define MAP_LOG_PC(sd, fmt, ...)    \
     MAP_LOG("PC%d %s:%d,%d " fmt,   \
             sd->status_key.char_id, (sd->bl_m->name_), sd->bl_x, sd->bl_y, ## __VA_ARGS__)
@@ -692,5 +698,14 @@ struct charid2nick
     CharName nick;
     int req_id;
 };
+
+struct AuthFifoEntry
+{
+    AccountId account_id;
+    CharId char_id;
+    int login_id1, login_id2;
+    IP4Address ip;
+    int delflag;
+};
 } // namespace map
 } // namespace tmwa