Botan  2.8.0
Crypto and TLS for C++11
eax.h
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1 /*
2 * EAX Mode
3 * (C) 1999-2007,2013 Jack Lloyd
4 * (C) 2016 Daniel Neus, Rohde & Schwarz Cybersecurity
5 *
6 * Botan is released under the Simplified BSD License (see license.txt)
7 */
8 
9 #ifndef BOTAN_AEAD_EAX_H_
10 #define BOTAN_AEAD_EAX_H_
11 
12 #include <botan/aead.h>
13 #include <botan/block_cipher.h>
14 #include <botan/stream_cipher.h>
15 #include <botan/mac.h>
16 
17 namespace Botan {
18 
19 /**
20 * EAX base class
21 */
22 class BOTAN_PUBLIC_API(2,0) EAX_Mode : public AEAD_Mode
23  {
24  public:
25  void set_associated_data(const uint8_t ad[], size_t ad_len) override;
26 
27  std::string name() const override;
28 
29  size_t update_granularity() const override;
30 
31  Key_Length_Specification key_spec() const override;
32 
33  // EAX supports arbitrary nonce lengths
34  bool valid_nonce_length(size_t) const override { return true; }
35 
36  size_t tag_size() const override { return m_tag_size; }
37 
38  void clear() override;
39 
40  void reset() override;
41 
42  protected:
43  /**
44  * @param cipher the cipher to use
45  * @param tag_size is how big the auth tag will be
46  */
47  EAX_Mode(BlockCipher* cipher, size_t tag_size);
48 
49  size_t block_size() const { return m_cipher->block_size(); }
50 
51  size_t m_tag_size;
52 
53  std::unique_ptr<BlockCipher> m_cipher;
54  std::unique_ptr<StreamCipher> m_ctr;
55  std::unique_ptr<MessageAuthenticationCode> m_cmac;
56 
58 
60  private:
61  void start_msg(const uint8_t nonce[], size_t nonce_len) override;
62 
63  void key_schedule(const uint8_t key[], size_t length) override;
64  };
65 
66 /**
67 * EAX Encryption
68 */
70  {
71  public:
72  /**
73  * @param cipher a 128-bit block cipher
74  * @param tag_size is how big the auth tag will be
75  */
76  EAX_Encryption(BlockCipher* cipher, size_t tag_size = 0) :
77  EAX_Mode(cipher, tag_size) {}
78 
79  size_t output_length(size_t input_length) const override
80  { return input_length + tag_size(); }
81 
82  size_t minimum_final_size() const override { return 0; }
83 
84  size_t process(uint8_t buf[], size_t size) override;
85 
86  void finish(secure_vector<uint8_t>& final_block, size_t offset = 0) override;
87  };
88 
89 /**
90 * EAX Decryption
91 */
93  {
94  public:
95  /**
96  * @param cipher a 128-bit block cipher
97  * @param tag_size is how big the auth tag will be
98  */
99  EAX_Decryption(BlockCipher* cipher, size_t tag_size = 0) :
100  EAX_Mode(cipher, tag_size) {}
101 
102  size_t output_length(size_t input_length) const override
103  {
104  BOTAN_ASSERT(input_length >= tag_size(), "Sufficient input");
105  return input_length - tag_size();
106  }
107 
108  size_t minimum_final_size() const override { return tag_size(); }
109 
110  size_t process(uint8_t buf[], size_t size) override;
111 
112  void finish(secure_vector<uint8_t>& final_block, size_t offset = 0) override;
113  };
114 
115 }
116 
117 #endif
EAX_Decryption(BlockCipher *cipher, size_t tag_size=0)
Definition: eax.h:99
size_t block_size() const
Definition: eax.h:49
size_t output_length(size_t input_length) const override
Definition: eax.h:102
int(* final)(unsigned char *, CTX *)
#define BOTAN_PUBLIC_API(maj, min)
Definition: compiler.h:27
secure_vector< uint8_t > m_ad_mac
Definition: eax.h:57
secure_vector< uint8_t > m_nonce_mac
Definition: eax.h:59
EAX_Encryption(BlockCipher *cipher, size_t tag_size=0)
Definition: eax.h:76
size_t m_tag_size
Definition: eax.h:51
#define BOTAN_ASSERT(expr, assertion_made)
Definition: assert.h:55
std::string name
size_t output_length(size_t input_length) const override
Definition: eax.h:79
bool valid_nonce_length(size_t) const override
Definition: eax.h:34
Definition: alg_id.cpp:13
std::unique_ptr< BlockCipher > m_cipher
Definition: eax.h:53
size_t minimum_final_size() const override
Definition: eax.h:82
size_t tag_size() const override
Definition: eax.h:36
std::unique_ptr< MessageAuthenticationCode > m_cmac
Definition: eax.h:55
std::vector< T, secure_allocator< T > > secure_vector
Definition: secmem.h:88
std::unique_ptr< StreamCipher > m_ctr
Definition: eax.h:54
size_t minimum_final_size() const override
Definition: eax.h:108