1 files changed, 31 insertions, 0 deletions

diff --git a/src/core/crypto/ctr_encryption_layer.h b/src/core/crypto/ctr_encryption_layer.h
new file mode 100644
index 000000000..fe53e714b
--- /dev/null
+++ b/src/core/crypto/ctr_encryption_layer.h
@@ -0,0 +1,31 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "aes_util.h"
+#include "encryption_layer.h"
+#include "key_manager.h"
+
+namespace Crypto {
+
+// Sits on top of a VirtualFile and provides CTR-mode AES decription.
+struct CTREncryptionLayer : public EncryptionLayer {
+    CTREncryptionLayer(FileSys::VirtualFile base, Key128 key, size_t base_offset);
+
+    size_t Read(u8* data, size_t length, size_t offset) const override;
+
+    void SetIV(std::vector<u8> iv);
+
+private:
+    size_t base_offset;
+
+    // Must be mutable as operations modify cipher contexts.
+    mutable AESCipher<Key128> cipher;
+    mutable std::vector<u8> iv;
+
+    void UpdateIV(size_t offset) const;
+};
+
+} // namespace Crypto