Crypto++  8.2
Free C++ class library of cryptographic schemes
cmac.h
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1 // cmac.h - originally written and placed in the public domain by Wei Dai
2 
3 /// \file cmac.h
4 /// \brief Classes for CMAC message authentication code
5 /// \since Crypto++ 5.6.0
6 
7 #ifndef CRYPTOPP_CMAC_H
8 #define CRYPTOPP_CMAC_H
9 
10 #include "seckey.h"
11 #include "secblock.h"
12 
13 /// \brief Enable CMAC and wide block ciphers
14 /// \details CMAC is only defined for AES. The library can support wide
15 /// block ciphers like Kaylna and Threefish since we know the polynomials.
16 #ifndef CRYPTOPP_CMAC_WIDE_BLOCK_CIPHERS
17 # define CRYPTOPP_CMAC_WIDE_BLOCK_CIPHERS 1
18 #endif // CRYPTOPP_CMAC_WIDE_BLOCK_CIPHERS
19 
20 NAMESPACE_BEGIN(CryptoPP)
21 
22 /// \brief CMAC base implementation
23 /// \since Crypto++ 5.6.0
24 class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE CMAC_Base : public MessageAuthenticationCode
25 {
26 public:
27 
28  virtual ~CMAC_Base() {}
29  CMAC_Base() : m_counter(0) {}
30 
31  void UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs &params);
32  void Update(const byte *input, size_t length);
33  void TruncatedFinal(byte *mac, size_t size);
34  unsigned int DigestSize() const {return GetCipher().BlockSize();}
35  unsigned int OptimalBlockSize() const {return GetCipher().BlockSize();}
36  unsigned int OptimalDataAlignment() const {return GetCipher().OptimalDataAlignment();}
37  std::string AlgorithmProvider() const {return GetCipher().AlgorithmProvider();}
38 
39 protected:
40  friend class EAX_Base;
41 
42  const BlockCipher & GetCipher() const {return const_cast<CMAC_Base*>(this)->AccessCipher();}
43  virtual BlockCipher & AccessCipher() =0;
44 
45  void ProcessBuf();
46  SecByteBlock m_reg;
47  unsigned int m_counter;
48 };
49 
50 /// \brief CMAC message authentication code
51 /// \tparam T block cipher
52 /// \details Template parameter T should be a class derived from BlockCipherDocumentation, for example AES, with a block size of 8, 16, or 32.
53 /// \sa <a href="http://www.cryptolounge.org/wiki/CMAC">CMAC</a>
54 /// \since Crypto++ 5.6.0
55 template <class T>
56 class CMAC : public MessageAuthenticationCodeImpl<CMAC_Base, CMAC<T> >, public SameKeyLengthAs<T>
57 {
58 public:
59  /// \brief Construct a CMAC
60  CMAC() {}
61  /// \brief Construct a CMAC
62  /// \param key the MAC key
63  /// \param length the key size, in bytes
64  CMAC(const byte *key, size_t length=SameKeyLengthAs<T>::DEFAULT_KEYLENGTH)
65  {this->SetKey(key, length);}
66 
67  static std::string StaticAlgorithmName() {return std::string("CMAC(") + T::StaticAlgorithmName() + ")";}
68 
69 private:
70  BlockCipher & AccessCipher() {return m_cipher;}
71  typename T::Encryption m_cipher;
72 };
73 
74 NAMESPACE_END
75 
76 #endif
CMAC_Base::AlgorithmProvider
std::string AlgorithmProvider() const
Retrieve the provider of this algorithm.
Definition: cmac.h:37
CMAC_Base::DigestSize
unsigned int DigestSize() const
Provides the digest size of the hash.
Definition: cmac.h:34
CMAC_Base::OptimalBlockSize
unsigned int OptimalBlockSize() const
Provides the input block size most efficient for this hash.
Definition: cmac.h:35
CMAC
CMAC message authentication code.
Definition: cmac.h:56
secblock.h
Classes and functions for secure memory allocations.
SecByteBlock
SecBlock<byte> typedef.
Definition: secblock.h:1091
CMAC_Base::OptimalDataAlignment
unsigned int OptimalDataAlignment() const
Provides input and output data alignment for optimal performance.
Definition: cmac.h:36
CMAC::CMAC
CMAC(const byte *key, size_t length=SameKeyLengthAs< T >::DEFAULT_KEYLENGTH)
Construct a CMAC.
Definition: cmac.h:64
SameKeyLengthAs
Provides key lengths based on another class's key length.
Definition: seckey.h:217
seckey.h
Classes and functions for implementing secret key algorithms.
MessageAuthenticationCodeImpl
Provides a base implementation of Algorithm and SimpleKeyingInterface for message authentication code...
Definition: seckey.h:362
CMAC_Base
CMAC base implementation.
Definition: cmac.h:24
CryptoPP
Crypto++ library namespace.
EAX_Base
EAX block cipher base implementation.
Definition: eax.h:18
CMAC::CMAC
CMAC()
Construct a CMAC.
Definition: cmac.h:60
SimpleKeyingInterface::SetKey
virtual void SetKey(const byte *key, size_t length, const NameValuePairs &params=g_nullNameValuePairs)
Sets or reset the key of this object.
Definition: cryptlib.cpp:58
BlockCipher
Interface for one direction (encryption or decryption) of a block cipher.
Definition: cryptlib.h:1278
MessageAuthenticationCode
Interface for message authentication codes.
Definition: cryptlib.h:1294
NameValuePairs
Interface for retrieving values given their names.
Definition: cryptlib.h:321