Crypto++  5.6.4
Free C++ class library of cryptographic schemes
vmac.h
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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 // Clang 3.3 integrated assembler crash on Linux
14 // http://github.com/weidai11/cryptopp/issues/264
15 #if (defined(CRYPTOPP_LLVM_CLANG_VERSION) && (CRYPTOPP_LLVM_CLANG_VERSION < 30400)) || CRYPTOPP_BOOL_X32
16 # define CRYPTOPP_DISABLE_VMAC_ASM
17 #endif
18 
19 NAMESPACE_BEGIN(CryptoPP)
20 
21 //! \class VMAC_Base
22 //! \brief VMAC message authentication code base class
24 {
25 public:
26  std::string AlgorithmName() const {return std::string("VMAC(") + GetCipher().AlgorithmName() + ")-" + IntToString(DigestSize()*8);}
27  unsigned int IVSize() const {return GetCipher().BlockSize();}
28  unsigned int MinIVLength() const {return 1;}
29  void Resynchronize(const byte *nonce, int length=-1);
30  void GetNextIV(RandomNumberGenerator &rng, byte *IV);
31  unsigned int DigestSize() const {return m_is128 ? 16 : 8;};
32  void UncheckedSetKey(const byte *userKey, unsigned int keylength, const NameValuePairs &params);
33  void TruncatedFinal(byte *mac, size_t size);
34  unsigned int BlockSize() const {return m_L1KeyLength;}
35  ByteOrder GetByteOrder() const {return LITTLE_ENDIAN_ORDER;}
36  unsigned int OptimalDataAlignment() const;
37 
38 protected:
39  virtual BlockCipher & AccessCipher() =0;
40  virtual int DefaultDigestSize() const =0;
41  const BlockCipher & GetCipher() const {return const_cast<VMAC_Base *>(this)->AccessCipher();}
42  void HashEndianCorrectedBlock(const word64 *data);
43  size_t HashMultipleBlocks(const word64 *input, size_t length);
44  void Init() {}
45  word64* StateBuf() {return NULL;}
46  word64* DataBuf() {return (word64 *)(void*)m_data();}
47 
48  void VHASH_Update_SSE2(const word64 *data, size_t blocksRemainingInWord64, int tagPart);
49 #if !(defined(_MSC_VER) && _MSC_VER < 1300) // can't use function template here with VC6
50  template <bool T_128BitTag>
51 #endif
52  void VHASH_Update_Template(const word64 *data, size_t blockRemainingInWord128);
53  void VHASH_Update(const word64 *data, size_t blocksRemainingInWord128);
54 
55  CRYPTOPP_BLOCK_1(polyState, word64, 4*(m_is128+1))
56  CRYPTOPP_BLOCK_2(nhKey, word64, m_L1KeyLength/sizeof(word64) + 2*m_is128)
57  CRYPTOPP_BLOCK_3(data, byte, m_L1KeyLength)
58  CRYPTOPP_BLOCK_4(l3Key, word64, 2*(m_is128+1))
59  CRYPTOPP_BLOCK_5(nonce, byte, IVSize())
60  CRYPTOPP_BLOCK_6(pad, byte, IVSize())
61  CRYPTOPP_BLOCKS_END(6)
62 
63  bool m_is128, m_padCached, m_isFirstBlock;
64  int m_L1KeyLength;
65 };
66 
67 //! \class VMAC
68 //! \brief VMAC message authentication code
69 //! \tparam T_BlockCipher block cipher
70 //! \tparam T_DigestBitSize digest size, in bits
71 //! \details VMAC is a block cipher-based message authentication code algorithm
72 //! using a universal hash proposed by Ted Krovetz and Wei Dai in April 2007. The
73 //! algorithm was designed for high performance backed by a formal analysis.
74 //! \details The implementation is based on Ted Krovetz's public domain vmac.c
75 //! and <a href="http://tools.ietf.org/html/draft-krovetz-vmac-01">draft-krovetz-vmac-01.txt</a>.
76 //! \sa <a href="http://www.cryptolounge.org/wiki/VMAC">VMAC</a>.
77 template <class T_BlockCipher, int T_DigestBitSize = 128>
78 class VMAC : public SimpleKeyingInterfaceImpl<VMAC_Base, SameKeyLengthAs<T_BlockCipher, SimpleKeyingInterface::UNIQUE_IV, T_BlockCipher::BLOCKSIZE> >
79 {
80 public:
81  static std::string StaticAlgorithmName() {return std::string("VMAC(") + T_BlockCipher::StaticAlgorithmName() + ")-" + IntToString(T_DigestBitSize);}
82 
83 private:
84  BlockCipher & AccessCipher() {return m_cipher;}
85  int DefaultDigestSize() const {return T_DigestBitSize/8;}
86  typename T_BlockCipher::Encryption m_cipher;
87 };
88 
89 NAMESPACE_END
90 
91 #endif
std::string AlgorithmName() const
Provides the name of this algorithm.
Definition: vmac.h:26
VMAC message authentication code.
Definition: vmac.h:78
const char * DigestSize()
int, in bytes
Definition: argnames.h:78
Interface for message authentication codes.
Definition: cryptlib.h:1114
ByteOrder
Provides the byte ordering.
Definition: cryptlib.h:128
unsigned int DigestSize() const
Provides the digest size of the hash.
Definition: vmac.h:31
VMAC message authentication code base class.
Definition: vmac.h:23
Provides a base implementation of SimpleKeyingInterface.
Definition: seckey.h:278
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:34
Interface for random number generators.
Definition: cryptlib.h:1193
byte order is little-endian
Definition: cryptlib.h:130
Interface for one direction (encryption or decryption) of a block cipher.
Definition: cryptlib.h:1098
Classes and functions for implementing secret key algorithms.
Interface for algorithms that take byte strings as keys.
Definition: cryptlib.h:529
Provides key lengths based on another class's key length.
Definition: seckey.h:237
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:28
unsigned int IVSize() const
Returns length of the IV accepted by this object.
Definition: vmac.h:27
Iterated hash base class.
Definition: iterhash.h:27
std::string IntToString(T value, unsigned int base=10)
Converts a value to a string.
Definition: misc.h:530
Crypto++ library namespace.
Interface for retrieving values given their names.
Definition: cryptlib.h:282