1 files changed, 106 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/modes/cfb/cfb.h b/comm/third_party/botan/src/lib/modes/cfb/cfb.h
new file mode 100644
index 0000000000..1f9e554872
--- /dev/null
+++ b/comm/third_party/botan/src/lib/modes/cfb/cfb.h
@@ -0,0 +1,106 @@
+/*
+* CFB mode
+* (C) 1999-2007,2013 Jack Lloyd
+* (C) 2016 Daniel Neus, Rohde & Schwarz Cybersecurity
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#ifndef BOTAN_MODE_CFB_H_
+#define BOTAN_MODE_CFB_H_
+
+#include <botan/cipher_mode.h>
+#include <botan/block_cipher.h>
+
+BOTAN_FUTURE_INTERNAL_HEADER(cfb.h)
+
+namespace Botan {
+
+/**
+* CFB Mode
+*/
+class BOTAN_PUBLIC_API(2,0) CFB_Mode : public Cipher_Mode
+   {
+   public:
+      std::string name() const override final;
+
+      size_t update_granularity() const override final;
+
+      size_t minimum_final_size() const override final;
+
+      Key_Length_Specification key_spec() const override final;
+
+      size_t output_length(size_t input_length) const override final;
+
+      size_t default_nonce_length() const override final;
+
+      bool valid_nonce_length(size_t n) const override final;
+
+      void clear() override final;
+
+      void reset() override final;
+   protected:
+      CFB_Mode(BlockCipher* cipher, size_t feedback_bits);
+
+      void shift_register();
+
+      size_t feedback() const { return m_feedback_bytes; }
+      const BlockCipher& cipher() const { return *m_cipher; }
+      size_t block_size() const { return m_block_size; }
+
+      secure_vector<uint8_t> m_state;
+      secure_vector<uint8_t> m_keystream;
+      size_t m_keystream_pos = 0;
+
+   private:
+      void start_msg(const uint8_t nonce[], size_t nonce_len) override;
+      void key_schedule(const uint8_t key[], size_t length) override;
+
+      std::unique_ptr<BlockCipher> m_cipher;
+      const size_t m_block_size;
+      const size_t m_feedback_bytes;
+   };
+
+/**
+* CFB Encryption
+*/
+class BOTAN_PUBLIC_API(2,0) CFB_Encryption final : public CFB_Mode
+   {
+   public:
+      /**
+      * If feedback_bits is zero, cipher->block_size() bytes will be used.
+      * @param cipher block cipher to use
+      * @param feedback_bits number of bits fed back into the shift register,
+      * must be a multiple of 8
+      */
+      CFB_Encryption(BlockCipher* cipher, size_t feedback_bits) :
+         CFB_Mode(cipher, feedback_bits) {}
+
+      size_t process(uint8_t buf[], size_t size) override;
+
+      void finish(secure_vector<uint8_t>& final_block, size_t offset = 0) override;
+   };
+
+/**
+* CFB Decryption
+*/
+class BOTAN_PUBLIC_API(2,0) CFB_Decryption final : public CFB_Mode
+   {
+   public:
+      /**
+      * If feedback_bits is zero, cipher->block_size() bytes will be used.
+      * @param cipher block cipher to use
+      * @param feedback_bits number of bits fed back into the shift register,
+      * must be a multiple of 8
+      */
+      CFB_Decryption(BlockCipher* cipher, size_t feedback_bits) :
+         CFB_Mode(cipher, feedback_bits) {}
+
+      size_t process(uint8_t buf[], size_t size) override;
+
+      void finish(secure_vector<uint8_t>& final_block, size_t offset = 0) override;
+   };
+
+}
+
+#endif