1 files changed, 137 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/modes/aead/ocb/ocb.h b/comm/third_party/botan/src/lib/modes/aead/ocb/ocb.h
new file mode 100644
index 0000000000..4029fcda25
--- /dev/null
+++ b/comm/third_party/botan/src/lib/modes/aead/ocb/ocb.h
@@ -0,0 +1,137 @@
+/*
+* OCB Mode
+* (C) 2013,2014 Jack Lloyd
+* (C) 2016 Daniel Neus, Rohde & Schwarz Cybersecurity
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#ifndef BOTAN_AEAD_OCB_H_
+#define BOTAN_AEAD_OCB_H_
+
+#include <botan/aead.h>
+
+BOTAN_FUTURE_INTERNAL_HEADER(ocb.h)
+
+namespace Botan {
+
+class BlockCipher;
+class L_computer;
+
+/**
+* OCB Mode (base class for OCB_Encryption and OCB_Decryption). Note
+* that OCB is patented, but is freely licensed in some circumstances.
+*
+* @see "The OCB Authenticated-Encryption Algorithm" RFC 7253
+*      https://tools.ietf.org/html/rfc7253
+* @see "OCB For Block Ciphers Without 128-Bit Blocks"
+*      (draft-krovetz-ocb-wide-d3) for the extension of OCB to
+*      block ciphers with larger block sizes.
+* @see Free Licenses http://www.cs.ucdavis.edu/~rogaway/ocb/license.htm
+* @see OCB home page http://www.cs.ucdavis.edu/~rogaway/ocb
+*/
+class BOTAN_PUBLIC_API(2,0) OCB_Mode : public AEAD_Mode
+   {
+   public:
+      void set_associated_data(const uint8_t ad[], size_t ad_len) override;
+
+      std::string name() const override;
+
+      size_t update_granularity() const override;
+
+      Key_Length_Specification key_spec() const override;
+
+      bool valid_nonce_length(size_t) const override;
+
+      size_t tag_size() const override { return m_tag_size; }
+
+      void clear() override;
+
+      void reset() override;
+
+      ~OCB_Mode();
+   protected:
+      /**
+      * @param cipher the block cipher to use
+      * @param tag_size is how big the auth tag will be
+      */
+      OCB_Mode(BlockCipher* cipher, size_t tag_size);
+
+      size_t block_size() const { return m_block_size; }
+      size_t par_blocks() const { return m_par_blocks; }
+      size_t par_bytes() const { return m_checksum.size(); }
+
+      // fixme make these private
+      std::unique_ptr<BlockCipher> m_cipher;
+      std::unique_ptr<L_computer> m_L;
+
+      size_t m_block_index = 0;
+
+      secure_vector<uint8_t> m_checksum;
+      secure_vector<uint8_t> m_ad_hash;
+   private:
+      void start_msg(const uint8_t nonce[], size_t nonce_len) override;
+
+      void key_schedule(const uint8_t key[], size_t length) override;
+
+      const secure_vector<uint8_t>& update_nonce(const uint8_t nonce[], size_t nonce_len);
+
+      const size_t m_tag_size;
+      const size_t m_block_size;
+      const size_t m_par_blocks;
+      secure_vector<uint8_t> m_last_nonce;
+      secure_vector<uint8_t> m_stretch;
+      secure_vector<uint8_t> m_nonce_buf;
+      secure_vector<uint8_t> m_offset;
+   };
+
+class BOTAN_PUBLIC_API(2,0) OCB_Encryption final : public OCB_Mode
+   {
+   public:
+      /**
+      * @param cipher the block cipher to use
+      * @param tag_size is how big the auth tag will be
+      */
+      OCB_Encryption(BlockCipher* cipher, size_t tag_size = 16) :
+         OCB_Mode(cipher, tag_size) {}
+
+      size_t output_length(size_t input_length) const override
+         { return input_length + tag_size(); }
+
+      size_t minimum_final_size() const override { return 0; }
+
+      size_t process(uint8_t buf[], size_t size) override;
+
+      void finish(secure_vector<uint8_t>& final_block, size_t offset = 0) override;
+   private:
+      void encrypt(uint8_t input[], size_t blocks);
+   };
+
+class BOTAN_PUBLIC_API(2,0) OCB_Decryption final : public OCB_Mode
+   {
+   public:
+      /**
+      * @param cipher the block cipher to use
+      * @param tag_size is how big the auth tag will be
+      */
+      OCB_Decryption(BlockCipher* cipher, size_t tag_size = 16) :
+         OCB_Mode(cipher, tag_size) {}
+
+      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(); }
+
+      size_t process(uint8_t buf[], size_t size) override;
+
+      void finish(secure_vector<uint8_t>& final_block, size_t offset = 0) override;
+   private:
+      void decrypt(uint8_t input[], size_t blocks);
+   };
+
+}
+
+#endif