1 files changed, 65 insertions, 0 deletions
diff --git a/src/core/file_sys/fssystem/fssystem_crypto_configuration.cpp b/src/core/file_sys/fssystem/fssystem_crypto_configuration.cpp
new file mode 100644
index 000000000..a4f0cde28
--- /dev/null
+++ b/src/core/file_sys/fssystem/fssystem_crypto_configuration.cpp
@@ -0,0 +1,65 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "core/crypto/aes_util.h"
+#include "core/crypto/key_manager.h"
+#include "core/file_sys/fssystem/fssystem_crypto_configuration.h"
+
+namespace FileSys {
+
+namespace {
+
+void GenerateKey(void* dst_key, size_t dst_key_size, const void* src_key, size_t src_key_size,
+                 s32 key_type) {
+    if (key_type == static_cast<s32>(KeyType::ZeroKey)) {
+        std::memset(dst_key, 0, dst_key_size);
+        return;
+    }
+
+    if (key_type == static_cast<s32>(KeyType::InvalidKey) ||
+        key_type < static_cast<s32>(KeyType::ZeroKey) ||
+        key_type >= static_cast<s32>(KeyType::NcaExternalKey)) {
+        std::memset(dst_key, 0xFF, dst_key_size);
+        return;
+    }
+
+    const auto& instance = Core::Crypto::KeyManager::Instance();
+
+    if (key_type == static_cast<s32>(KeyType::NcaHeaderKey1) ||
+        key_type == static_cast<s32>(KeyType::NcaHeaderKey2)) {
+        const s32 key_index = static_cast<s32>(KeyType::NcaHeaderKey2) == key_type;
+        const auto key = instance.GetKey(Core::Crypto::S256KeyType::Header);
+        std::memcpy(dst_key, key.data() + key_index * 0x10, std::min(dst_key_size, key.size() / 2));
+        return;
+    }
+
+    const s32 key_generation =
+        std::max(key_type / NcaCryptoConfiguration::KeyAreaEncryptionKeyIndexCount, 1) - 1;
+    const s32 key_index = key_type % NcaCryptoConfiguration::KeyAreaEncryptionKeyIndexCount;
+
+    Core::Crypto::AESCipher<Core::Crypto::Key128> cipher(
+        instance.GetKey(Core::Crypto::S128KeyType::KeyArea, key_generation, key_index),
+        Core::Crypto::Mode::ECB);
+    cipher.Transcode(reinterpret_cast<const u8*>(src_key), src_key_size,
+                     reinterpret_cast<u8*>(dst_key), Core::Crypto::Op::Decrypt);
+}
+
+} // namespace
+
+const NcaCryptoConfiguration& GetCryptoConfiguration() {
+    static const NcaCryptoConfiguration configuration = {
+        .header_1_sign_key_moduli{},
+        .header_1_sign_key_public_exponent{},
+        .key_area_encryption_key_source{},
+        .header_encryption_key_source{},
+        .header_encrypted_encryption_keys{},
+        .generate_key = GenerateKey,
+        .verify_sign1{},
+        .is_plaintext_header_available{},
+        .is_available_sw_key{},
+    };
+
+    return configuration;
+}
+
+} // namespace FileSys