1 files changed, 86 insertions, 0 deletions
diff --git a/src/lib/modes/xts/xts.h b/src/lib/modes/xts/xts.h
new file mode 100644
index 000000000..21bc495e1
--- /dev/null
+++ b/src/lib/modes/xts/xts.h
@@ -0,0 +1,86 @@
+/*
+* XTS mode, from IEEE P1619
+* (C) 2009,2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_MODE_XTS_H__
+#define BOTAN_MODE_XTS_H__
+
+#include <botan/cipher_mode.h>
+#include <botan/block_cipher.h>
+#include <memory>
+
+namespace Botan {
+
+/**
+* IEEE P1619 XTS Mode
+*/
+class BOTAN_DLL XTS_Mode : public Cipher_Mode
+   {
+   public:
+      std::string name() const override;
+
+      secure_vector<byte> start(const byte nonce[], size_t nonce_len) override;
+
+      size_t update_granularity() const override;
+
+      size_t minimum_final_size() const override;
+
+      Key_Length_Specification key_spec() const override;
+
+      size_t default_nonce_length() const override;
+
+      bool valid_nonce_length(size_t n) const override;
+
+      void clear();
+   protected:
+      XTS_Mode(BlockCipher* cipher);
+
+      const byte* tweak() const { return &m_tweak[0]; }
+
+      const BlockCipher& cipher() const { return *m_cipher; }
+
+      void update_tweak(size_t last_used);
+
+   private:
+      void key_schedule(const byte key[], size_t length) override;
+
+      std::unique_ptr<BlockCipher> m_cipher, m_tweak_cipher;
+      secure_vector<byte> m_tweak;
+   };
+
+/**
+* IEEE P1619 XTS Encryption
+*/
+class BOTAN_DLL XTS_Encryption : public XTS_Mode
+   {
+   public:
+      XTS_Encryption(BlockCipher* cipher) : XTS_Mode(cipher) {}
+
+      void update(secure_vector<byte>& blocks, size_t offset = 0) override;
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+
+      size_t output_length(size_t input_length) const override;
+   };
+
+/**
+* IEEE P1619 XTS Decryption
+*/
+class BOTAN_DLL XTS_Decryption : public XTS_Mode
+   {
+   public:
+      XTS_Decryption(BlockCipher* cipher) : XTS_Mode(cipher) {}
+
+      void update(secure_vector<byte>& blocks, size_t offset = 0) override;
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+
+      size_t output_length(size_t input_length) const override;
+   };
+
+}
+
+#endif