Crypto++  5.6.3
Free C++ class library of cryptographic schemes
vmac.h
Go to the documentation of this file.
1 // vmac.h - written and placed in the public domain by Wei Dai
2 
3 //! \file vmac.h
4 //! \brief Classes for the VMAC message authentication code
5 
6 #ifndef CRYPTOPP_VMAC_H
7 #define CRYPTOPP_VMAC_H
8 
9 #include "cryptlib.h"
10 #include "iterhash.h"
11 #include "seckey.h"
12 
13 #if CRYPTOPP_BOOL_X32
14 # define CRYPTOPP_DISABLE_VMAC_ASM
15 #endif
16 
17 NAMESPACE_BEGIN(CryptoPP)
18 
19 //! \class VMAC_Base
20 //! \brief VMAC message authentication code base class
22 {
23 public:
24  std::string AlgorithmName() const {return std::string("VMAC(") + GetCipher().AlgorithmName() + ")-" + IntToString(DigestSize()*8);}
25  unsigned int IVSize() const {return GetCipher().BlockSize();}
26  unsigned int MinIVLength() const {return 1;}
27  void Resynchronize(const byte *nonce, int length=-1);
28  void GetNextIV(RandomNumberGenerator &rng, byte *IV);
29  unsigned int DigestSize() const {return m_is128 ? 16 : 8;};
30  void UncheckedSetKey(const byte *userKey, unsigned int keylength, const NameValuePairs &params);
31  void TruncatedFinal(byte *mac, size_t size);
32  unsigned int BlockSize() const {return m_L1KeyLength;}
33  ByteOrder GetByteOrder() const {return LITTLE_ENDIAN_ORDER;}
34  unsigned int OptimalDataAlignment() const;
35 
36 protected:
37  virtual BlockCipher & AccessCipher() =0;
38  virtual int DefaultDigestSize() const =0;
39  const BlockCipher & GetCipher() const {return const_cast<VMAC_Base *>(this)->AccessCipher();}
40  void HashEndianCorrectedBlock(const word64 *data);
41  size_t HashMultipleBlocks(const word64 *input, size_t length);
42  void Init() {}
43  word64* StateBuf() {return NULL;}
44  word64* DataBuf() {return (word64 *)(void*)m_data();}
45 
46  void VHASH_Update_SSE2(const word64 *data, size_t blocksRemainingInWord64, int tagPart);
47 #if !(defined(_MSC_VER) && _MSC_VER < 1300) // can't use function template here with VC6
48  template <bool T_128BitTag>
49 #endif
50  void VHASH_Update_Template(const word64 *data, size_t blockRemainingInWord128);
51  void VHASH_Update(const word64 *data, size_t blocksRemainingInWord128);
52 
53  CRYPTOPP_BLOCK_1(polyState, word64, 4*(m_is128+1))
54  CRYPTOPP_BLOCK_2(nhKey, word64, m_L1KeyLength/sizeof(word64) + 2*m_is128)
55  CRYPTOPP_BLOCK_3(data, byte, m_L1KeyLength)
56  CRYPTOPP_BLOCK_4(l3Key, word64, 2*(m_is128+1))
57  CRYPTOPP_BLOCK_5(nonce, byte, IVSize())
58  CRYPTOPP_BLOCK_6(pad, byte, IVSize())
59  CRYPTOPP_BLOCKS_END(6)
60 
61  bool m_is128, m_padCached, m_isFirstBlock;
62  int m_L1KeyLength;
63 };
64 
65 //! \class VMAC
66 //! \brief VMAC message authentication code
67 //! \tparam T_BlockCipher block cipher
68 //! \tparam T_DigestBitSize digest size, in bits
69 //! \details VMAC is a block cipher-based message authentication code algorithm
70 //! using a universal hash proposed by Ted Krovetz and Wei Dai in April 2007. The
71 //! algorithm was designed for high performance backed by a formal analysis.
72 //! \details The implementation is based on Ted Krovetz's public domain vmac.c
73 //! and <a href="http://tools.ietf.org/html/draft-krovetz-vmac-01">draft-krovetz-vmac-01.txt</a>.
74 //! \sa <a href="http://www.cryptolounge.org/wiki/VMAC">VMAC</a>.
75 template <class T_BlockCipher, int T_DigestBitSize = 128>
76 class VMAC : public SimpleKeyingInterfaceImpl<VMAC_Base, SameKeyLengthAs<T_BlockCipher, SimpleKeyingInterface::UNIQUE_IV, T_BlockCipher::BLOCKSIZE> >
77 {
78 public:
79  static std::string StaticAlgorithmName() {return std::string("VMAC(") + T_BlockCipher::StaticAlgorithmName() + ")-" + IntToString(T_DigestBitSize);}
80 
81 private:
82  BlockCipher & AccessCipher() {return m_cipher;}
83  int DefaultDigestSize() const {return T_DigestBitSize/8;}
84  typename T_BlockCipher::Encryption m_cipher;
85 };
86 
87 NAMESPACE_END
88 
89 #endif
std::string AlgorithmName() const
Provides the name of this algorithm.
Definition: vmac.h:24
VMAC message authentication code.
Definition: vmac.h:76
const char * DigestSize()
int, in bytes
Definition: argnames.h:78
Interface for message authentication codes.
Definition: cryptlib.h:1107
ByteOrder
Provides the byte ordering.
Definition: cryptlib.h:123
unsigned int DigestSize() const
Provides the digest size of the hash.
Definition: vmac.h:29
VMAC message authentication code base class.
Definition: vmac.h:21
Provides a base implementation of SimpleKeyingInterface.
Definition: seckey.h:258
Abstract base classes that provide a uniform interface to this library.
unsigned int BlockSize() const
Provides the block size of the compression function.
Definition: vmac.h:32
Interface for random number generators.
Definition: cryptlib.h:1186
byte order is little-endian
Definition: cryptlib.h:125
Interface for one direction (encryption or decryption) of a block cipher.
Definition: cryptlib.h:1091
Classes and functions for implementing secret key algorithms.
Interface for algorithms that take byte strings as keys.
Definition: cryptlib.h:524
Provides key lengths based on another class's key length.
Definition: seckey.h:219
const char * IV()
ConstByteArrayParameter, also accepts const byte * for backwards compatibility.
Definition: argnames.h:21
unsigned int MinIVLength() const
Provides the minimum size of an IV.
Definition: vmac.h:26
unsigned int IVSize() const
Returns length of the IV accepted by this object.
Definition: vmac.h:25
std::string IntToString(T value, unsigned int base=10)
Converts a value to a string.
Definition: misc.h:494
Crypto++ library namespace.
Interface for retrieving values given their names.
Definition: cryptlib.h:277