aboutsummaryrefslogtreecommitdiffstats
path: root/src/lib/mac/gmac/gmac.h
blob: ed586b4eada3e97ae68ef0f5886660576221e8f7 (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
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
/*
 * GMAC
 * (C) 2016 Matthias Gierlings, René Korthaus
 *
 * Botan is released under the Simplified BSD License (see license.txt)
 */

#ifndef BOTAN_GMAC_H_
#define BOTAN_GMAC_H_

#include <botan/mac.h>
#include <botan/gcm.h>

namespace Botan {

/**
* GMAC
*/
class BOTAN_PUBLIC_API(2,0) GMAC : public MessageAuthenticationCode, public GHASH
   {
   public:
      void clear() override;
      std::string name() const override;
      size_t output_length() const override;
      MessageAuthenticationCode* clone() const override;

      /**
      * Must be called to set the initialization vector prior to GMAC
      * calculation.
      *
      * @param nonce Initialization vector.
      * @param nonce_len size of initialization vector.
      */
      void start(const uint8_t nonce[], size_t nonce_len);

      /**
      * Must be called to set the initialization vector prior to GMAC
      * calculation.
      *
      * @param nonce Initialization vector.
      */
      void start(const secure_vector<uint8_t>& nonce);

      /**
      * Must be called to set the initialization vector prior to GMAC
      * calculation.
      *
      * @param nonce Initialization vector.
      */
      void start(const std::vector<uint8_t>& nonce);

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

      /**
      * Creates a new GMAC instance.
      *
      * @param cipher the underlying block cipher to use
      */
      explicit GMAC(BlockCipher* cipher);

      GMAC(const GMAC&) = delete;
      GMAC& operator=(const GMAC&) = delete;

   private:
      void add_data(const uint8_t[], size_t) override;
      void final_result(uint8_t[]) override;
      void start_msg(const uint8_t nonce[], size_t nonce_len) override;
      void key_schedule(const uint8_t key[], size_t size) override;

      static const size_t GCM_BS = 16;
      secure_vector<uint8_t> m_aad_buf;
      std::unique_ptr<BlockCipher> m_cipher;
      bool m_initialized;
   };

}
#endif