Botan  2.7.0
Crypto and TLS for C++11
mac.h
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1 /*
2 * Base class for message authentiction codes
3 * (C) 1999-2007 Jack Lloyd
4 *
5 * Botan is released under the Simplified BSD License (see license.txt)
6 */
7 
8 #ifndef BOTAN_MESSAGE_AUTH_CODE_BASE_H_
9 #define BOTAN_MESSAGE_AUTH_CODE_BASE_H_
10 
11 #include <botan/buf_comp.h>
12 #include <botan/sym_algo.h>
13 #include <string>
14 #include <memory>
15 
16 namespace Botan {
17 
18 /**
19 * This class represents Message Authentication Code (MAC) objects.
20 */
22  public SymmetricAlgorithm
23  {
24  public:
25  /**
26  * Create an instance based on a name
27  * If provider is empty then best available is chosen.
28  * @param algo_spec algorithm name
29  * @param provider provider implementation to use
30  * @return a null pointer if the algo/provider combination cannot be found
31  */
32  static std::unique_ptr<MessageAuthenticationCode>
33  create(const std::string& algo_spec,
34  const std::string& provider = "");
35 
36  /*
37  * Create an instance based on a name
38  * If provider is empty then best available is chosen.
39  * @param algo_spec algorithm name
40  * @param provider provider implementation to use
41  * Throws a Lookup_Error if algo/provider combination cannot be found
42  */
43  static std::unique_ptr<MessageAuthenticationCode>
44  create_or_throw(const std::string& algo_spec,
45  const std::string& provider = "");
46 
47  /**
48  * @return list of available providers for this algorithm, empty if not available
49  */
50  static std::vector<std::string> providers(const std::string& algo_spec);
51 
52  virtual ~MessageAuthenticationCode() = default;
53 
54  /**
55  * Prepare for processing a message under the specified nonce
56  *
57  * Most MACs neither require nor support a nonce; for these algorithms
58  * calling `start_msg` is optional and calling it with anything other than
59  * an empty string is an error. One MAC which *requires* a per-message
60  * nonce be specified is GMAC.
61  *
62  * @param nonce the message nonce bytes
63  * @param nonce_len the size of len in bytes
64  * Default implementation simply rejects all non-empty nonces
65  * since most hash/MAC algorithms do not support randomization
66  */
67  virtual void start_msg(const uint8_t nonce[], size_t nonce_len);
68 
69  /**
70  * Begin processing a message with a nonce
71  *
72  * @param nonce the per message nonce
73  */
74  template<typename Alloc>
75  void start(const std::vector<uint8_t, Alloc>& nonce)
76  {
77  start_msg(nonce.data(), nonce.size());
78  }
79 
80  /**
81  * Begin processing a message.
82  * @param nonce the per message nonce
83  * @param nonce_len length of nonce
84  */
85  void start(const uint8_t nonce[], size_t nonce_len)
86  {
87  start_msg(nonce, nonce_len);
88  }
89 
90  /**
91  * Begin processing a message.
92  */
93  void start()
94  {
95  return start_msg(nullptr, 0);
96  }
97 
98  /**
99  * Verify a MAC.
100  * @param in the MAC to verify as a byte array
101  * @param length the length of param in
102  * @return true if the MAC is valid, false otherwise
103  */
104  virtual bool verify_mac(const uint8_t in[], size_t length);
105 
106  /**
107  * Verify a MAC.
108  * @param in the MAC to verify as a byte array
109  * @return true if the MAC is valid, false otherwise
110  */
111  virtual bool verify_mac(const std::vector<uint8_t>& in)
112  {
113  return verify_mac(in.data(), in.size());
114  }
115 
116  /**
117  * Verify a MAC.
118  * @param in the MAC to verify as a byte array
119  * @return true if the MAC is valid, false otherwise
120  */
121  virtual bool verify_mac(const secure_vector<uint8_t>& in)
122  {
123  return verify_mac(in.data(), in.size());
124  }
125 
126  /**
127  * Get a new object representing the same algorithm as *this
128  */
129  virtual MessageAuthenticationCode* clone() const = 0;
130 
131  /**
132  * @return provider information about this implementation. Default is "base",
133  * might also return "sse2", "avx2", "openssl", or some other arbitrary string.
134  */
135  virtual std::string provider() const { return "base"; }
136 
137  };
138 
140 
141 }
142 
143 #endif
MessageAuthenticationCode MAC
Definition: mac.h:139
virtual std::string provider() const
Definition: mac.h:135
#define BOTAN_PUBLIC_API(maj, min)
Definition: compiler.h:27
Definition: alg_id.cpp:13
virtual bool verify_mac(const std::vector< uint8_t > &in)
Definition: mac.h:111
virtual bool verify_mac(const secure_vector< uint8_t > &in)
Definition: mac.h:121
void start(const std::vector< uint8_t, Alloc > &nonce)
Definition: mac.h:75
std::vector< T, secure_allocator< T > > secure_vector
Definition: secmem.h:88
void start(const uint8_t nonce[], size_t nonce_len)
Definition: mac.h:85