1 files changed, 128 insertions, 0 deletions
diff --git a/src/lib/modes/aead/ccm/ccm.h b/src/lib/modes/aead/ccm/ccm.h
new file mode 100644
index 000000000..87dd5805c
--- /dev/null
+++ b/src/lib/modes/aead/ccm/ccm.h
@@ -0,0 +1,128 @@
+/*
+* CCM Mode
+* (C) 2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_AEAD_CCM_H__
+#define BOTAN_AEAD_CCM_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 CCM encryption and decryption
+* @see RFC 3610
+*/
+class BOTAN_DLL CCM_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(const byte ad[], size_t ad_len) override;
+
+      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;
+
+      size_t default_nonce_length() const override;
+
+      void clear();
+
+      size_t tag_size() const { return m_tag_size; }
+
+   protected:
+      const size_t BS = 16; // intrinsic to CCM definition
+
+      CCM_Mode(BlockCipher* cipher, size_t tag_size, size_t L);
+
+      size_t L() const { return m_L; }
+
+      const BlockCipher& cipher() const { return *m_cipher; }
+
+      void encode_length(size_t len, byte out[]);
+
+      void inc(secure_vector<byte>& C);
+
+      const secure_vector<byte>& ad_buf() const { return m_ad_buf; }
+
+      secure_vector<byte>& msg_buf() { return m_msg_buf; }
+
+      secure_vector<byte> format_b0(size_t msg_size);
+      secure_vector<byte> format_c0();
+   private:
+      void key_schedule(const byte key[], size_t length) override;
+
+      const size_t m_tag_size;
+      const size_t m_L;
+
+      std::unique_ptr<BlockCipher> m_cipher;
+      secure_vector<byte> m_nonce, m_msg_buf, m_ad_buf;
+   };
+
+/**
+* CCM Encryption
+*/
+class BOTAN_DLL CCM_Encryption : public CCM_Mode
+   {
+   public:
+      /**
+      * @param cipher a 128-bit block cipher
+      * @param tag_size is how big the auth tag will be (even values
+      *                 between 4 and 16 are accepted)
+      * @param L length of L parameter. The total message length
+      *           must be less than 2**L bytes, and the nonce is 15-L bytes.
+      */
+      CCM_Encryption(BlockCipher* cipher, size_t tag_size = 16, size_t L = 3) :
+         CCM_Mode(cipher, tag_size, L) {}
+
+      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; }
+   };
+
+/**
+* CCM Decryption
+*/
+class BOTAN_DLL CCM_Decryption : public CCM_Mode
+   {
+   public:
+      /**
+      * @param cipher a 128-bit block cipher
+      * @param tag_size is how big the auth tag will be (even values
+      *                 between 4 and 16 are accepted)
+      * @param L length of L parameter. The total message length
+      *           must be less than 2**L bytes, and the nonce is 15-L bytes.
+      */
+      CCM_Decryption(BlockCipher* cipher, size_t tag_size = 16, size_t L = 3) :
+         CCM_Mode(cipher, tag_size, L) {}
+
+      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