From 3a7c3c0fe99df82f464bdeb4144d10d351ed68ff Mon Sep 17 00:00:00 2001
From: Martin Michelsen <fuzziqersoftware+g@gmail.com>
Date: Fri, 2 Sep 2022 17:29:19 -0700
Subject: [PATCH] implement BB encryption in --cat-client

---
 src/CatSession.cc | 23 ++++++++++++++---------
 src/CatSession.hh |  4 +++-
 src/Main.cc       | 13 +++++++++++--
 3 files changed, 28 insertions(+), 12 deletions(-)

diff --git a/src/CatSession.cc b/src/CatSession.cc
index 4b8bc072..f9cd9691 100644
--- a/src/CatSession.cc
+++ b/src/CatSession.cc
@@ -36,7 +36,8 @@ using namespace std;
 CatSession::CatSession(
     shared_ptr<struct event_base> base,
     const struct sockaddr_storage& remote,
-    GameVersion version)
+    GameVersion version,
+    shared_ptr<const PSOBBEncryption::KeyFile> bb_key_file)
   : Shell(base),
     log("[CatSession] ", proxy_server_log.min_level),
     channel(
@@ -44,7 +45,8 @@ CatSession::CatSession(
       CatSession::dispatch_on_channel_input,
       CatSession::dispatch_on_channel_error,
       this,
-      "CatSession") {
+      "CatSession"),
+    bb_key_file(bb_key_file) {
   if (remote.ss_family != AF_INET) {
     throw runtime_error("remote is not AF_INET");
   }
@@ -91,13 +93,16 @@ void CatSession::on_channel_input(
       }
     }
   } else { // BB
-    // TODO: This can easily be done; I'm just lazy. We need to have the user
-    // pass in a key name, then get that key file from this->state, then create
-    // the crypts.
-    // TODO: We really should just move encryption handling into the Channel
-    // abstraction instead of the above, but this is a bit harder because then
-    // Channels would have to know about BB key files.
-    throw runtime_error("CatSession does not implement BB encryption yet");
+    if (command == 0x03 || command == 0x9B) {
+      if (!this->bb_key_file) {
+        throw runtime_error("BB encryption requires a key file");
+      }
+      const auto& cmd = check_size_t<S_ServerInit_BB_03_9B>(data,
+          offsetof(S_ServerInit_DC_PC_V3_02_17_91_9B, after_message), 0xFFFF);
+      this->channel.crypt_in.reset(new PSOBBEncryption(*this->bb_key_file, &cmd.server_key[0], sizeof(cmd.server_key)));
+      this->channel.crypt_out.reset(new PSOBBEncryption(*this->bb_key_file, &cmd.client_key[0], sizeof(cmd.client_key)));
+      this->log.info("Enabled BB encryption");
+    }
   }
 
   string full_cmd = prepend_command_header(
diff --git a/src/CatSession.hh b/src/CatSession.hh
index e69df6b0..01013831 100644
--- a/src/CatSession.hh
+++ b/src/CatSession.hh
@@ -23,12 +23,14 @@ public:
   CatSession(
       std::shared_ptr<struct event_base> base,
       const struct sockaddr_storage& remote,
-      GameVersion version);
+      GameVersion version,
+      std::shared_ptr<const PSOBBEncryption::KeyFile> bb_key_file);
   virtual ~CatSession() = default;
 
 protected:
   PrefixedLogger log;
   Channel channel;
+  std::shared_ptr<const PSOBBEncryption::KeyFile> bb_key_file;
 
   virtual void print_prompt();
   virtual void execute_command(const std::string& command);
diff --git a/src/Main.cc b/src/Main.cc
index c64bd504..393a7016 100644
--- a/src/Main.cc
+++ b/src/Main.cc
@@ -245,7 +245,8 @@ Specifically:\n\
       commands to stdout, and forward any commands typed into stdin to the\n\
       remote server. It is assumed that the input and output are terminals, so\n\
       all commands are hex-encoded. The --patch, --dc, --pc, --gc, and --bb\n\
-      options can be used to select the command format end encryption.\n\
+      options can be used to select the command format and encryption. If --bb\n\
+      is used, the --key option is also required (as in --decrypt-data above).\n\
   --replay-log=FILENAME\n\
       This option makes newserv replay terminal log as if it were a client\n\
       session. This is used for regression testing, to make sure client\n\
@@ -438,8 +439,16 @@ int main(int argc, char** argv) {
     }
 
     case Behavior::CAT_CLIENT: {
+      shared_ptr<PSOBBEncryption::KeyFile> key;
+      if (cli_version == GameVersion::BB) {
+        if (key_file_name.empty()) {
+          throw runtime_error("a key filename is required for BB client emulation");
+        }
+        key.reset(new PSOBBEncryption::KeyFile(
+            load_object_file<PSOBBEncryption::KeyFile>("system/blueburst/keys/" + key_file_name + ".nsk")));
+      }
       shared_ptr<struct event_base> base(event_base_new(), event_base_free);
-      CatSession session(base, cat_client_remote, cli_version);
+      CatSession session(base, cat_client_remote, cli_version, key);
       event_base_dispatch(base.get());
       break;
     }