Botan  2.6.0
Crypto and TLS for C++11
lion.h
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1 /*
2 * Lion
3 * (C) 1999-2007,2014 Jack Lloyd
4 *
5 * Botan is released under the Simplified BSD License (see license.txt)
6 */
7 
8 #ifndef BOTAN_LION_H_
9 #define BOTAN_LION_H_
10 
11 #include <botan/block_cipher.h>
12 #include <botan/stream_cipher.h>
13 #include <botan/hash.h>
14 
15 namespace Botan {
16 
17 /**
18 * Lion is a block cipher construction designed by Ross Anderson and
19 * Eli Biham, described in "Two Practical and Provably Secure Block
20 * Ciphers: BEAR and LION". It has a variable block size and is
21 * designed to encrypt very large blocks (up to a megabyte)
22 
23 * https://www.cl.cam.ac.uk/~rja14/Papers/bear-lion.pdf
24 */
25 class BOTAN_PUBLIC_API(2,0) Lion final : public BlockCipher
26  {
27  public:
28  void encrypt_n(const uint8_t in[], uint8_t out[], size_t blocks) const override;
29  void decrypt_n(const uint8_t in[], uint8_t out[], size_t blocks) const override;
30 
31  size_t block_size() const override { return m_block_size; }
32 
34  {
35  return Key_Length_Specification(2, 2*m_hash->output_length(), 2);
36  }
37 
38  void clear() override;
39  std::string name() const override;
40  BlockCipher* clone() const override;
41 
42  /**
43  * @param hash the hash to use internally
44  * @param cipher the stream cipher to use internally
45  * @param block_size the size of the block to use
46  */
48  StreamCipher* cipher,
49  size_t block_size);
50  private:
51  void key_schedule(const uint8_t[], size_t) override;
52 
53  size_t left_size() const { return m_hash->output_length(); }
54  size_t right_size() const { return m_block_size - left_size(); }
55 
56  const size_t m_block_size;
57  std::unique_ptr<HashFunction> m_hash;
58  std::unique_ptr<StreamCipher> m_cipher;
59  secure_vector<uint8_t> m_key1, m_key2;
60  };
61 
62 }
63 
64 #endif
Key_Length_Specification key_spec() const override
Definition: lion.h:33
#define BOTAN_PUBLIC_API(maj, min)
Definition: compiler.h:27
size_t block_size() const override
Definition: lion.h:31
Definition: alg_id.cpp:13
MechanismType hash