aboutsummaryrefslogtreecommitdiffstats
path: root/src/lib/stream/ofb/ofb.h
blob: f8beb4956c7d92d97d26a8589c788ce2b963c203 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
/*
* OFB Mode
* (C) 1999-2007 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/

#ifndef BOTAN_OUTPUT_FEEDBACK_MODE_H__
#define BOTAN_OUTPUT_FEEDBACK_MODE_H__

#include <botan/stream_cipher.h>
#include <botan/block_cipher.h>

namespace Botan {

/**
* Output Feedback Mode
*/
class BOTAN_DLL OFB final : public StreamCipher
   {
   public:
      void cipher(const byte in[], byte out[], size_t length) override;

      void set_iv(const byte iv[], size_t iv_len) override;

      bool valid_iv_length(size_t iv_len) const override
         { return (iv_len <= m_cipher->block_size()); }

      Key_Length_Specification key_spec() const override
         {
         return m_cipher->key_spec();
         }

      std::string name() const override;

      OFB* clone() const override
         { return new OFB(m_cipher->clone()); }

      void clear() override;

      /**
      * @param cipher the block cipher to use
      */
      explicit OFB(BlockCipher* cipher);

      void seek(u64bit offset) override;
   private:
      void key_schedule(const byte key[], size_t key_len) override;

      std::unique_ptr<BlockCipher> m_cipher;
      secure_vector<byte> m_buffer;
      size_t m_buf_pos;
   };

}

#endif