feat: Remove autogenerated key functionality

This commit removes the functionality that automatically generates and writes
keys to *_autogenerated files. The key derivation logic is preserved, but
derived keys are now only stored in memory and not written to disk.

Changes include:
- Remove loading from *_autogenerated key files
- Make WriteKeyToFile a no-op function
- Remove all file writing operations in SetKey methods
- Remove file writing for keyblobs and other derived keys
- Update copyright notices

This change improves security by not storing derived keys on disk and
simplifies the key management system.

2 files changed, 6 insertions, 91 deletions

diff --git a/src/core/crypto/key_manager.cpp b/src/core/crypto/key_manager.cpp
index d00188fad..e61a59fc9 100644
--- a/src/core/crypto/key_manager.cpp
+++ b/src/core/crypto/key_manager.cpp
@@ -1,4 +1,5 @@
 // SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project
+// SPDX-FileCopyrightText: Copyright 2025 citron Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include <algorithm>
@@ -648,17 +649,13 @@ void KeyManager::ReloadKeys() {
 
     if (Settings::values.use_dev_keys) {
         dev_mode = true;
-        LoadFromFile(citron_keys_dir / "dev.keys_autogenerated", false);
         LoadFromFile(citron_keys_dir / "dev.keys", false);
     } else {
         dev_mode = false;
-        LoadFromFile(citron_keys_dir / "prod.keys_autogenerated", false);
         LoadFromFile(citron_keys_dir / "prod.keys", false);
     }
 
-    LoadFromFile(citron_keys_dir / "title.keys_autogenerated", true);
     LoadFromFile(citron_keys_dir / "title.keys", true);
-    LoadFromFile(citron_keys_dir / "console.keys_autogenerated", false);
     LoadFromFile(citron_keys_dir / "console.keys", false);
 }
 
@@ -847,87 +844,15 @@ Key256 KeyManager::GetBISKey(u8 partition_id) const {
 template <size_t Size>
 void KeyManager::WriteKeyToFile(KeyCategory category, std::string_view keyname,
                                 const std::array<u8, Size>& key) {
-    const auto citron_keys_dir = Common::FS::GetCitronPath(Common::FS::CitronPath::KeysDir);
-
-    std::string filename = "title.keys_autogenerated";
-
-    if (category == KeyCategory::Standard) {
-        filename = dev_mode ? "dev.keys_autogenerated" : "prod.keys_autogenerated";
-    } else if (category == KeyCategory::Console) {
-        filename = "console.keys_autogenerated";
-    }
-
-    const auto path = citron_keys_dir / filename;
-    const auto add_info_text = !Common::FS::Exists(path);
-
-    Common::FS::IOFile file{path, Common::FS::FileAccessMode::Append,
-                            Common::FS::FileType::TextFile};
-
-    if (!file.IsOpen()) {
-        return;
-    }
-
-    if (add_info_text) {
-        void(file.WriteString(
-            "# This file is autogenerated by Citron\n"
-            "# It serves to store keys that were automatically generated from the normal keys\n"
-            "# If you are experiencing issues involving keys, it may help to delete this file\n"));
-    }
-
-    void(file.WriteString(fmt::format("\n{} = {}", keyname, Common::HexToString(key))));
-    LoadFromFile(path, category == KeyCategory::Title);
+    // Function is now a no-op - keys are no longer written to autogenerated files
 }
 
 void KeyManager::SetKey(S128KeyType id, Key128 key, u64 field1, u64 field2) {
     if (s128_keys.find({id, field1, field2}) != s128_keys.end() || key == Key128{}) {
         return;
     }
-    if (id == S128KeyType::Titlekey) {
-        Key128 rights_id;
-        std::memcpy(rights_id.data(), &field2, sizeof(u64));
-        std::memcpy(rights_id.data() + sizeof(u64), &field1, sizeof(u64));
-        WriteKeyToFile(KeyCategory::Title, Common::HexToString(rights_id), key);
-    }
-
-    auto category = KeyCategory::Standard;
-    if (id == S128KeyType::Keyblob || id == S128KeyType::KeyblobMAC || id == S128KeyType::TSEC ||
-        id == S128KeyType::SecureBoot || id == S128KeyType::SDSeed || id == S128KeyType::BIS) {
-        category = KeyCategory::Console;
-    }
-
-    const auto iter2 = std::find_if(
-        s128_file_id.begin(), s128_file_id.end(), [&id, &field1, &field2](const auto& elem) {
-            return std::tie(elem.second.type, elem.second.field1, elem.second.field2) ==
-                   std::tie(id, field1, field2);
-        });
-    if (iter2 != s128_file_id.end()) {
-        WriteKeyToFile(category, iter2->first, key);
-    }
-
-    // Variable cases
-    if (id == S128KeyType::KeyArea) {
-        static constexpr std::array<const char*, 3> kak_names = {
-            "key_area_key_application_{:02X}",
-            "key_area_key_ocean_{:02X}",
-            "key_area_key_system_{:02X}",
-        };
-        WriteKeyToFile(category, fmt::format(fmt::runtime(kak_names.at(field2)), field1), key);
-    } else if (id == S128KeyType::Master) {
-        WriteKeyToFile(category, fmt::format("master_key_{:02X}", field1), key);
-    } else if (id == S128KeyType::Package1) {
-        WriteKeyToFile(category, fmt::format("package1_key_{:02X}", field1), key);
-    } else if (id == S128KeyType::Package2) {
-        WriteKeyToFile(category, fmt::format("package2_key_{:02X}", field1), key);
-    } else if (id == S128KeyType::Titlekek) {
-        WriteKeyToFile(category, fmt::format("titlekek_{:02X}", field1), key);
-    } else if (id == S128KeyType::Keyblob) {
-        WriteKeyToFile(category, fmt::format("keyblob_key_{:02X}", field1), key);
-    } else if (id == S128KeyType::KeyblobMAC) {
-        WriteKeyToFile(category, fmt::format("keyblob_mac_key_{:02X}", field1), key);
-    } else if (id == S128KeyType::Source && field1 == static_cast<u64>(SourceKeyType::Keyblob)) {
-        WriteKeyToFile(category, fmt::format("keyblob_key_source_{:02X}", field2), key);
-    }
 
+    // Store the key in memory but don't write to file
     s128_keys[{id, field1, field2}] = key;
 }
 
@@ -935,14 +860,8 @@ void KeyManager::SetKey(S256KeyType id, Key256 key, u64 field1, u64 field2) {
     if (s256_keys.find({id, field1, field2}) != s256_keys.end() || key == Key256{}) {
         return;
     }
-    const auto iter = std::find_if(
-        s256_file_id.begin(), s256_file_id.end(), [&id, &field1, &field2](const auto& elem) {
-            return std::tie(elem.second.type, elem.second.field1, elem.second.field2) ==
-                   std::tie(id, field1, field2);
-        });
-    if (iter != s256_file_id.end()) {
-        WriteKeyToFile(KeyCategory::Standard, iter->first, key);
-    }
+
+    // Store the key in memory but don't write to file
     s256_keys[{id, field1, field2}] = key;
 }
 
@@ -1052,8 +971,6 @@ void KeyManager::DeriveBase() {
         // Decrypt keyblob
         if (keyblobs[i] == std::array<u8, 0x90>{}) {
             keyblobs[i] = DecryptKeyblob(encrypted_keyblobs[i], key);
-            WriteKeyToFile<0x90>(KeyCategory::Console, fmt::format("keyblob_{:02X}", i),
-                                 keyblobs[i]);
         }
 
         Key128 package1;
@@ -1183,7 +1100,6 @@ void KeyManager::DeriveETicket(PartitionDataManager& data,
     data.DecryptProdInfo(GetBISKey(0));
 
     eticket_extended_kek = data.GetETicketExtendedKek();
-    WriteKeyToFile(KeyCategory::Console, "eticket_extended_kek", eticket_extended_kek);
     DeriveETicketRSAKey();
     PopulateTickets();
 }
@@ -1261,8 +1177,6 @@ void KeyManager::PopulateFromPartitionData(PartitionDataManager& data) {
             continue;
         }
         encrypted_keyblobs[i] = data.GetEncryptedKeyblob(i);
-        WriteKeyToFile<0xB0>(KeyCategory::Console, fmt::format("encrypted_keyblob_{:02X}", i),
-                             encrypted_keyblobs[i]);
     }
 
     SetKeyWrapped(S128KeyType::Source, data.GetPackage2KeySource(),
diff --git a/src/core/crypto/key_manager.h b/src/core/crypto/key_manager.h
index 7de21f8a4..0adf3701f 100644
--- a/src/core/crypto/key_manager.h
+++ b/src/core/crypto/key_manager.h
@@ -1,4 +1,5 @@
 // SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project
+// SPDX-FileCopyrightText: Copyright 2025 citron Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once