Botan  2.4.0
Crypto and TLS for C++11
ctr.h
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1 /*
2 * CTR-BE Mode
3 * (C) 1999-2007 Jack Lloyd
4 *
5 * Botan is released under the Simplified BSD License (see license.txt)
6 */
7 
8 #ifndef BOTAN_CTR_BE_H_
9 #define BOTAN_CTR_BE_H_
10 
11 #include <botan/block_cipher.h>
12 #include <botan/stream_cipher.h>
13 
14 namespace Botan {
15 
16 /**
17 * CTR-BE (Counter mode, big-endian)
18 */
19 class BOTAN_PUBLIC_API(2,0) CTR_BE final : public StreamCipher
20  {
21  public:
22  void cipher(const uint8_t in[], uint8_t out[], size_t length) override;
23 
24  void set_iv(const uint8_t iv[], size_t iv_len) override;
25 
26  bool valid_iv_length(size_t iv_len) const override
27  { return (iv_len <= m_cipher->block_size()); }
28 
30  {
31  return m_cipher->key_spec();
32  }
33 
34  std::string name() const override;
35 
36  CTR_BE* clone() const override
37  { return new CTR_BE(m_cipher->clone(), m_ctr_size); }
38 
39  void clear() override;
40 
41  /**
42  * @param cipher the block cipher to use
43  */
44  explicit CTR_BE(BlockCipher* cipher);
45 
46  CTR_BE(BlockCipher* cipher, size_t ctr_size);
47 
48  void seek(uint64_t offset) override;
49  private:
50  void key_schedule(const uint8_t key[], size_t key_len) override;
51  void add_counter(const uint64_t counter);
52 
53  std::unique_ptr<BlockCipher> m_cipher;
54 
55  const size_t m_block_size;
56  const size_t m_ctr_size;
57  const size_t m_ctr_blocks;
58 
59  secure_vector<uint8_t> m_counter, m_pad;
60  std::vector<uint8_t> m_iv;
61  size_t m_pad_pos;
62  };
63 
64 }
65 
66 #endif
#define BOTAN_PUBLIC_API(maj, min)
Definition: compiler.h:27
Definition: alg_id.cpp:13
Key_Length_Specification key_spec() const override
Definition: ctr.h:29
CTR_BE * clone() const override
Definition: ctr.h:36
std::vector< T, secure_allocator< T > > secure_vector
Definition: secmem.h:88
bool valid_iv_length(size_t iv_len) const override
Definition: ctr.h:26