1 files changed, 117 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/modes/aead/gcm/gcm.h b/comm/third_party/botan/src/lib/modes/aead/gcm/gcm.h
new file mode 100644
index 0000000000..fe3c405721
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+++ b/comm/third_party/botan/src/lib/modes/aead/gcm/gcm.h
@@ -0,0 +1,117 @@
+/*
+* GCM Mode
+* (C) 2013 Jack Lloyd
+* (C) 2016 Daniel Neus, Rohde & Schwarz Cybersecurity
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#ifndef BOTAN_AEAD_GCM_H_
+#define BOTAN_AEAD_GCM_H_
+
+#include <botan/aead.h>
+#include <botan/sym_algo.h>
+
+BOTAN_FUTURE_INTERNAL_HEADER(gcm.h)
+
+namespace Botan {
+
+class BlockCipher;
+class StreamCipher;
+class GHASH;
+
+/**
+* GCM Mode
+*/
+class BOTAN_PUBLIC_API(2,0) GCM_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 len) const override;
+
+      size_t tag_size() const override { return m_tag_size; }
+
+      void clear() override;
+
+      void reset() override;
+
+      std::string provider() const override;
+   protected:
+      GCM_Mode(BlockCipher* cipher, size_t tag_size);
+
+      ~GCM_Mode();
+
+      static const size_t GCM_BS = 16;
+
+      const size_t m_tag_size;
+      const std::string m_cipher_name;
+
+      std::unique_ptr<StreamCipher> m_ctr;
+      std::unique_ptr<GHASH> m_ghash;
+   private:
+      void start_msg(const uint8_t nonce[], size_t nonce_len) override;
+
+      void key_schedule(const uint8_t key[], size_t length) override;
+
+      secure_vector<uint8_t> m_y0;
+   };
+
+/**
+* GCM Encryption
+*/
+class BOTAN_PUBLIC_API(2,0) GCM_Encryption final : public GCM_Mode
+   {
+   public:
+      /**
+      * @param cipher the 128 bit block cipher to use
+      * @param tag_size is how big the auth tag will be
+      */
+      GCM_Encryption(BlockCipher* cipher, size_t tag_size = 16) :
+         GCM_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;
+   };
+
+/**
+* GCM Decryption
+*/
+class BOTAN_PUBLIC_API(2,0) GCM_Decryption final : public GCM_Mode
+   {
+   public:
+      /**
+      * @param cipher the 128 bit block cipher to use
+      * @param tag_size is how big the auth tag will be
+      */
+      GCM_Decryption(BlockCipher* cipher, size_t tag_size = 16) :
+         GCM_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;
+   };
+
+}
+
+#endif