From 9f4b53178adaf01703edf44029385081a074a2c7 Mon Sep 17 00:00:00 2001
From: Martin Michelsen <fuzziqersoftware+g@gmail.com>
Date: Fri, 2 Dec 2022 23:35:02 -0800
Subject: [PATCH] add jsd0

---
 src/PSOEncryption.cc | 29 +++++++++++++++++++++++++++++
 src/PSOEncryption.hh | 16 ++++++++++++++++
 2 files changed, 45 insertions(+)

diff --git a/src/PSOEncryption.cc b/src/PSOEncryption.cc
index 31425291..c875972f 100644
--- a/src/PSOEncryption.cc
+++ b/src/PSOEncryption.cc
@@ -837,6 +837,35 @@ shared_ptr<PSOBBEncryption> PSOBBMultiKeyImitatorEncryption::ensure_crypt() {
 
 
 
+JSD0Encryption::JSD0Encryption(const void* seed, size_t seed_size) : key(0) {
+  const uint8_t* bytes = reinterpret_cast<const uint8_t*>(seed);
+  for (size_t z = 0; z < seed_size; z++) {
+    this->key ^= bytes[z];
+  }
+}
+
+void JSD0Encryption::decrypt(void* data, size_t size, bool) {
+  uint8_t* bytes = reinterpret_cast<uint8_t*>(data);
+  for (size_t z = 0; z < size; z++) {
+    bytes[z] ^= this->key;
+    bytes[z] -= this->key;
+  }
+}
+
+void JSD0Encryption::encrypt(void* data, size_t size, bool) {
+  uint8_t* bytes = reinterpret_cast<uint8_t*>(data);
+  for (size_t z = 0; z < size; z++) {
+    bytes[z] += this->key;
+    bytes[z] ^= this->key;
+  }
+}
+
+PSOEncryption::Type JSD0Encryption::type() const {
+  return Type::JSD0;
+}
+
+
+
 void decrypt_trivial_gci_data(void* data, size_t size, uint8_t basis) {
   uint8_t* bytes = reinterpret_cast<uint8_t*>(data);
   uint8_t key = basis + 0x80;
diff --git a/src/PSOEncryption.hh b/src/PSOEncryption.hh
index 9a7dc22b..2f23a61a 100644
--- a/src/PSOEncryption.hh
+++ b/src/PSOEncryption.hh
@@ -18,6 +18,7 @@ public:
     V2 = 0,
     V3,
     BB,
+    JSD0,
   };
 
   virtual ~PSOEncryption() = default;
@@ -229,4 +230,19 @@ protected:
 
 
 
+class JSD0Encryption : public PSOEncryption {
+public:
+  JSD0Encryption(const void* seed, size_t seed_size);
+
+  virtual void encrypt(void* data, size_t size, bool advance = true);
+  virtual void decrypt(void* data, size_t size, bool advance = true);
+
+  virtual Type type() const = 0;
+
+private:
+  uint8_t key;
+};
+
+
+
 void decrypt_trivial_gci_data(void* data, size_t size, uint8_t basis);