1 files changed, 114 insertions, 0 deletions
diff --git a/src/lib/modes/aead/siv/siv.h b/src/lib/modes/aead/siv/siv.h
new file mode 100644
index 000000000..31df4d049
--- /dev/null
+++ b/src/lib/modes/aead/siv/siv.h
@@ -0,0 +1,114 @@
+/*
+* SIV Mode
+* (C) 2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_AEAD_SIV_H__
+#define BOTAN_AEAD_SIV_H__
+
+#include <botan/aead.h>
+#include <botan/block_cipher.h>
+#include <botan/stream_cipher.h>
+#include <botan/mac.h>
+#include <memory>
+
+namespace Botan {
+
+/**
+* Base class for SIV encryption and decryption (@see RFC 5297)
+*/
+class BOTAN_DLL SIV_Mode : public AEAD_Mode
+   {
+   public:
+      secure_vector<byte> start(const byte nonce[], size_t nonce_len) override;
+
+      void update(secure_vector<byte>& blocks, size_t offset = 0) override;
+
+      void set_associated_data_n(size_t n, const byte ad[], size_t ad_len);
+
+      void set_associated_data(const byte ad[], size_t ad_len) override
+         {
+         set_associated_data_n(0, ad, ad_len);
+         }
+
+      std::string name() const override;
+
+      size_t update_granularity() const;
+
+      Key_Length_Specification key_spec() const override;
+
+      bool valid_nonce_length(size_t) const override;
+
+      void clear();
+
+      size_t tag_size() const { return 16; }
+
+   protected:
+      SIV_Mode(BlockCipher* cipher);
+
+      StreamCipher& ctr() { return *m_ctr; }
+
+      void set_ctr_iv(secure_vector<byte> V);
+
+      secure_vector<byte>& msg_buf() { return m_msg_buf; }
+
+      secure_vector<byte> S2V(const byte text[], size_t text_len);
+   private:
+      MessageAuthenticationCode& cmac() { return *m_cmac; }
+
+      void key_schedule(const byte key[], size_t length) override;
+
+      const std::string m_name;
+
+      std::unique_ptr<StreamCipher> m_ctr;
+      std::unique_ptr<MessageAuthenticationCode> m_cmac;
+      secure_vector<byte> m_nonce, m_msg_buf;
+      std::vector<secure_vector<byte>> m_ad_macs;
+   };
+
+/**
+* SIV Encryption
+*/
+class BOTAN_DLL SIV_Encryption : public SIV_Mode
+   {
+   public:
+      /**
+      * @param cipher a block cipher
+      */
+      SIV_Encryption(BlockCipher* cipher) : SIV_Mode(cipher) {}
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+
+      size_t output_length(size_t input_length) const override
+         { return input_length + tag_size(); }
+
+      size_t minimum_final_size() const override { return 0; }
+   };
+
+/**
+* SIV Decryption
+*/
+class BOTAN_DLL SIV_Decryption : public SIV_Mode
+   {
+   public:
+      /**
+      * @param cipher a 128-bit block cipher
+      */
+      SIV_Decryption(BlockCipher* cipher) : SIV_Mode(cipher) {}
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+
+      size_t output_length(size_t input_length) const override
+         {
+         BOTAN_ASSERT(input_length > tag_size(), "Sufficient input");
+         return input_length - tag_size();
+         }
+
+      size_t minimum_final_size() const override { return tag_size(); }
+   };
+
+}
+
+#endif