Botan  2.13.0
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 
18 
19 namespace Botan {
20 
21 /**
22 * EAX base class
23 */
24 class BOTAN_PUBLIC_API(2,0) EAX_Mode : public AEAD_Mode
25  {
26  public:
27  void set_associated_data(const uint8_t ad[], size_t ad_len) override;
28 
29  std::string name() const override;
30 
31  size_t update_granularity() const override;
32 
33  Key_Length_Specification key_spec() const override;
34 
35  // EAX supports arbitrary nonce lengths
36  bool valid_nonce_length(size_t) const override { return true; }
37 
38  size_t tag_size() const override { return m_tag_size; }
39 
40  void clear() override;
41 
42  void reset() override;
43 
44  protected:
45  /**
46  * @param cipher the cipher to use
47  * @param tag_size is how big the auth tag will be
48  */
49  EAX_Mode(BlockCipher* cipher, size_t tag_size);
50 
51  size_t block_size() const { return m_cipher->block_size(); }
52 
53  size_t m_tag_size;
54 
55  std::unique_ptr<BlockCipher> m_cipher;
56  std::unique_ptr<StreamCipher> m_ctr;
57  std::unique_ptr<MessageAuthenticationCode> m_cmac;
58 
60 
62  private:
63  void start_msg(const uint8_t nonce[], size_t nonce_len) override;
64 
65  void key_schedule(const uint8_t key[], size_t length) override;
66  };
67 
68 /**
69 * EAX Encryption
70 */
72  {
73  public:
74  /**
75  * @param cipher a 128-bit block cipher
76  * @param tag_size is how big the auth tag will be
77  */
78  EAX_Encryption(BlockCipher* cipher, size_t tag_size = 0) :
79  EAX_Mode(cipher, tag_size) {}
80 
81  size_t output_length(size_t input_length) const override
82  { return input_length + tag_size(); }
83 
84  size_t minimum_final_size() const override { return 0; }
85 
86  size_t process(uint8_t buf[], size_t size) override;
87 
88  void finish(secure_vector<uint8_t>& final_block, size_t offset = 0) override;
89  };
90 
91 /**
92 * EAX Decryption
93 */
95  {
96  public:
97  /**
98  * @param cipher a 128-bit block cipher
99  * @param tag_size is how big the auth tag will be
100  */
101  EAX_Decryption(BlockCipher* cipher, size_t tag_size = 0) :
102  EAX_Mode(cipher, tag_size) {}
103 
104  size_t output_length(size_t input_length) const override
105  {
106  BOTAN_ASSERT(input_length >= tag_size(), "Sufficient input");
107  return input_length - tag_size();
108  }
109 
110  size_t minimum_final_size() const override { return tag_size(); }
111 
112  size_t process(uint8_t buf[], size_t size) override;
113 
114  void finish(secure_vector<uint8_t>& final_block, size_t offset = 0) override;
115  };
116 
117 }
118 
119 #endif
EAX_Decryption(BlockCipher *cipher, size_t tag_size=0)
Definition: eax.h:101
size_t block_size() const
Definition: eax.h:51
size_t output_length(size_t input_length) const override
Definition: eax.h:104
int(* final)(unsigned char *, CTX *)
virtual size_t update_granularity() const =0
#define BOTAN_PUBLIC_API(maj, min)
Definition: compiler.h:31
secure_vector< uint8_t > m_ad_mac
Definition: eax.h:59
secure_vector< uint8_t > m_nonce_mac
Definition: eax.h:61
virtual void start_msg(const uint8_t nonce[], size_t nonce_len)=0
EAX_Encryption(BlockCipher *cipher, size_t tag_size=0)
Definition: eax.h:78
virtual void reset()=0
size_t m_tag_size
Definition: eax.h:53
#define BOTAN_ASSERT(expr, assertion_made)
Definition: assert.h:55
size_t output_length(size_t input_length) const override
Definition: eax.h:81
virtual std::string name() const =0
bool valid_nonce_length(size_t) const override
Definition: eax.h:36
virtual void clear()=0
Definition: alg_id.cpp:13
std::unique_ptr< BlockCipher > m_cipher
Definition: eax.h:55
size_t minimum_final_size() const override
Definition: eax.h:84
virtual Key_Length_Specification key_spec() const =0
virtual size_t process(uint8_t msg[], size_t msg_len)=0
size_t tag_size() const override
Definition: eax.h:38
std::unique_ptr< MessageAuthenticationCode > m_cmac
Definition: eax.h:57
std::vector< T, secure_allocator< T > > secure_vector
Definition: secmem.h:65
virtual void set_associated_data(const uint8_t ad[], size_t ad_len)=0
std::unique_ptr< StreamCipher > m_ctr
Definition: eax.h:56
#define BOTAN_FUTURE_INTERNAL_HEADER(hdr)
Definition: compiler.h:139
virtual void finish(secure_vector< uint8_t > &final_block, size_t offset=0)=0
size_t minimum_final_size() const override
Definition: eax.h:110