From 77cea58fc5a5abe531d10134c52fde17eda8b5b3 Mon Sep 17 00:00:00 2001
From: Martin Michelsen <fuzziqersoftware+g@gmail.com>
Date: Wed, 24 Aug 2022 00:48:49 -0700
Subject: [PATCH] clean up big-endian encryption

---
 src/PSOEncryption.cc | 26 ++++++++++++++++++++++----
 src/PSOEncryption.hh |  8 ++++++++
 src/SendCommands.cc  | 10 +---------
 3 files changed, 31 insertions(+), 13 deletions(-)

diff --git a/src/PSOEncryption.cc b/src/PSOEncryption.cc
index ca168069..f7db03e6 100644
--- a/src/PSOEncryption.cc
+++ b/src/PSOEncryption.cc
@@ -81,7 +81,8 @@ uint32_t PSOV2Encryption::next(bool advance) {
   return ret;
 }
 
-void PSOV2Encryption::encrypt(void* vdata, size_t size, bool advance) {
+template <typename LongT>
+void PSOV2Encryption::encrypt_t(void* vdata, size_t size, bool advance) {
   if (size & 3) {
     throw invalid_argument("size must be a multiple of 4");
   }
@@ -90,12 +91,20 @@ void PSOV2Encryption::encrypt(void* vdata, size_t size, bool advance) {
   }
   size >>= 2;
 
-  le_uint32_t* data = reinterpret_cast<le_uint32_t*>(vdata);
+  LongT* data = reinterpret_cast<LongT*>(vdata);
   for (size_t x = 0; x < size; x++) {
     data[x] ^= this->next(advance);
   }
 }
 
+void PSOV2Encryption::encrypt(void* vdata, size_t size, bool advance) {
+  this->encrypt_t<le_uint32_t>(vdata, size, advance);
+}
+
+void PSOV2Encryption::encrypt_big_endian(void* vdata, size_t size, bool advance) {
+  this->encrypt_t<be_uint32_t>(vdata, size, advance);
+}
+
 
 
 void PSOV3Encryption::update_stream() {
@@ -158,7 +167,8 @@ PSOV3Encryption::PSOV3Encryption(uint32_t seed) : offset(0) {
   }
 }
 
-void PSOV3Encryption::encrypt(void* vdata, size_t size, bool advance) {
+template <typename LongT>
+void PSOV3Encryption::encrypt_t(void* vdata, size_t size, bool advance) {
   if (size & 3) {
     throw invalid_argument("size must be a multiple of 4");
   }
@@ -167,12 +177,20 @@ void PSOV3Encryption::encrypt(void* vdata, size_t size, bool advance) {
   }
   size >>= 2;
 
-  le_uint32_t* data = reinterpret_cast<le_uint32_t*>(vdata);
+  LongT* data = reinterpret_cast<LongT*>(vdata);
   for (size_t x = 0; x < size; x++) {
     data[x] ^= this->next(advance);
   }
 }
 
+void PSOV3Encryption::encrypt(void* vdata, size_t size, bool advance) {
+  this->encrypt_t<le_uint32_t>(vdata, size, advance);
+}
+
+void PSOV3Encryption::encrypt_big_endian(void* vdata, size_t size, bool advance) {
+  this->encrypt_t<be_uint32_t>(vdata, size, advance);
+}
+
 
 
 void PSOBBEncryption::decrypt(void* vdata, size_t size, bool advance) {
diff --git a/src/PSOEncryption.hh b/src/PSOEncryption.hh
index 725ebb64..2fc4b3d8 100644
--- a/src/PSOEncryption.hh
+++ b/src/PSOEncryption.hh
@@ -39,10 +39,14 @@ public:
   explicit PSOV2Encryption(uint32_t seed);
 
   virtual void encrypt(void* data, size_t size, bool advance = true);
+  void encrypt_big_endian(void* data, size_t size, bool advance = true);
 
   uint32_t next(bool advance = true);
 
 protected:
+  template <typename LongT>
+  void encrypt_t(void* data, size_t size, bool advance);
+
   void update_stream();
 
   uint32_t stream[V2_STREAM_LENGTH + 1];
@@ -54,10 +58,14 @@ public:
   explicit PSOV3Encryption(uint32_t key);
 
   virtual void encrypt(void* data, size_t size, bool advance = true);
+  void encrypt_big_endian(void* data, size_t size, bool advance = true);
 
   uint32_t next(bool advance = true);
 
 protected:
+  template <typename LongT>
+  void encrypt_t(void* data, size_t size, bool advance);
+
   void update_stream();
 
   uint32_t stream[V3_STREAM_LENGTH];
diff --git a/src/SendCommands.cc b/src/SendCommands.cc
index 938caf89..e5d5b648 100644
--- a/src/SendCommands.cc
+++ b/src/SendCommands.cc
@@ -254,15 +254,7 @@ void send_function_call(
       data.resize((data.size() + 3) & ~3);
       PSOV2Encryption crypt(key);
       if (code->is_big_endian()) {
-        // The code section is decrypted without byteswapping on the client.
-        // Since PowerPC systems (including the GameCube) are usually
-        // big-endian, we have to treat the data the same way here (hence we
-        // can't just use crypt.encrypt).
-        StringReader compressed_r(data);
-        while (!compressed_r.eof()) {
-          w.put_u32b(compressed_r.get_u32b() ^ crypt.next());
-        }
-        data = move(w.str());
+        crypt.encrypt_big_endian(data.data(), data.size());
       } else {
         crypt.encrypt(data.data(), data.size());
       }