Crypto++  5.6.5
Free C++ class library of cryptographic schemes
iterhash.h
1 #ifndef CRYPTOPP_ITERHASH_H
2 #define CRYPTOPP_ITERHASH_H
3 
4 #include "cryptlib.h"
5 #include "secblock.h"
6 #include "misc.h"
7 #include "simple.h"
8 
9 NAMESPACE_BEGIN(CryptoPP)
10 
11 //! \class HashInputTooLong
12 //! \brief Exception thrown when trying to hash more data than is allowed by a hash function
13 class CRYPTOPP_DLL HashInputTooLong : public InvalidDataFormat
14 {
15 public:
16  explicit HashInputTooLong(const std::string &alg)
17  : InvalidDataFormat("IteratedHashBase: input data exceeds maximum allowed by hash function " + alg) {}
18 };
19 
20 //! \class IteratedHashBase
21 //! \brief Iterated hash base class
22 //! \tparam T Hash word type
23 //! \tparam BASE HashTransformation derived class
24 //! \details IteratedHashBase provides an interface for block-based iterated hashes
25 //! \sa HashTransformation, MessageAuthenticationCode
26 template <class T, class BASE>
27 class CRYPTOPP_NO_VTABLE IteratedHashBase : public BASE
28 {
29 public:
30  typedef T HashWordType;
31 
32  //! \brief Construct an IteratedHashBase
33  IteratedHashBase() : m_countLo(0), m_countHi(0) {}
34 
35  //! \brief Provides the input block size most efficient for this cipher.
36  //! \return The input block size that is most efficient for the cipher
37  //! \details The base class implementation returns MandatoryBlockSize().
38  //! \note Optimal input length is
39  //! <tt>n * OptimalBlockSize() - GetOptimalBlockSizeUsed()</tt> for any <tt>n > 0</tt>.
40  unsigned int OptimalBlockSize() const {return this->BlockSize();}
41 
42  //! \brief Provides input and output data alignment for optimal performance.
43  //! \return the input data alignment that provides optimal performance
44  //! \details OptimalDataAlignment returnes the natural alignment of the hash word.
45  unsigned int OptimalDataAlignment() const {return GetAlignmentOf<T>();}
46 
47  //! \brief Updates a hash with additional input
48  //! \param input the additional input as a buffer
49  //! \param length the size of the buffer, in bytes
50  void Update(const byte *input, size_t length);
51 
52  //! \brief Requests space which can be written into by the caller
53  //! \param size the requested size of the buffer
54  //! \details The purpose of this method is to help avoid extra memory allocations.
55  //! \details size is an \a IN and \a OUT parameter and used as a hint. When the call is made,
56  //! size is the requested size of the buffer. When the call returns, size is the size of
57  //! the array returned to the caller.
58  //! \details The base class implementation sets size to 0 and returns NULL.
59  //! \note Some objects, like ArraySink, cannot create a space because its fixed.
60  byte * CreateUpdateSpace(size_t &size);
61 
62  //! \brief Restart the hash
63  //! \details Discards the current state, and restart for a new message
64  void Restart();
65 
66  //! \brief Computes the hash of the current message
67  //! \param digest a pointer to the buffer to receive the hash
68  //! \param digestSize the size of the truncated digest, in bytes
69  //! \details TruncatedFinal() call Final() and then copies digestSize bytes to digest.
70  //! The hash is restarted the hash for the next message.
71  void TruncatedFinal(byte *digest, size_t digestSize);
72 
73 protected:
74  inline T GetBitCountHi() const {return (m_countLo >> (8*sizeof(T)-3)) + (m_countHi << 3);}
75  inline T GetBitCountLo() const {return m_countLo << 3;}
76 
77  void PadLastBlock(unsigned int lastBlockSize, byte padFirst=0x80);
78  virtual void Init() =0;
79 
80  virtual ByteOrder GetByteOrder() const =0;
81  virtual void HashEndianCorrectedBlock(const HashWordType *data) =0;
82  virtual size_t HashMultipleBlocks(const T *input, size_t length);
83  void HashBlock(const HashWordType *input) {HashMultipleBlocks(input, this->BlockSize());}
84 
85  virtual T* DataBuf() =0;
86  virtual T* StateBuf() =0;
87 
88 private:
89  T m_countLo, m_countHi;
90 };
91 
92 //! \class IteratedHash
93 //! \brief Iterated hash base class
94 //! \tparam T_HashWordType Hash word type
95 //! \tparam T_Endianness Endianness type of hash
96 //! \tparam T_BlockSize Block size of the hash
97 //! \tparam T_Base HashTransformation derived class
98 //! \details IteratedHash provides a default implementation for block-based iterated hashes
99 //! \sa HashTransformation, MessageAuthenticationCode
100 template <class T_HashWordType, class T_Endianness, unsigned int T_BlockSize, class T_Base = HashTransformation>
101 class CRYPTOPP_NO_VTABLE IteratedHash : public IteratedHashBase<T_HashWordType, T_Base>
102 {
103 public:
104  typedef T_Endianness ByteOrderClass;
105  typedef T_HashWordType HashWordType;
106 
107 #ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
108  virtual ~IteratedHash() { }
109 #endif
110 
111  CRYPTOPP_CONSTANT(BLOCKSIZE = T_BlockSize)
112  // BCB2006 workaround: can't use BLOCKSIZE here
113  CRYPTOPP_COMPILE_ASSERT((T_BlockSize & (T_BlockSize - 1)) == 0); // blockSize is a power of 2
114 
115  //! \brief Provides the block size of the hash
116  //! \return the block size of the hash, in bytes
117  //! \details BlockSize() returns <tt>T_BlockSize</tt>.
118  unsigned int BlockSize() const {return T_BlockSize;}
119 
120  //! \brief Provides the byte order of the hash
121  //! \returns the byte order of the hash as an enumeration
122  //! \details GetByteOrder() returns <tt>T_Endianness::ToEnum()</tt>.
123  //! \sa ByteOrder()
124  ByteOrder GetByteOrder() const {return T_Endianness::ToEnum();}
125 
126  //! \brief Adjusts the byte ordering of the hash
127  //! \param out the output buffer
128  //! \param in the input buffer
129  //! \param byteCount the size of the buffers, in bytes
130  //! \details CorrectEndianess() calls ConditionalByteReverse() using <tt>T_Endianness</tt>.
131  inline void CorrectEndianess(HashWordType *out, const HashWordType *in, size_t byteCount)
132  {
133  ConditionalByteReverse(T_Endianness::ToEnum(), out, in, byteCount);
134  }
135 
136 protected:
137  T_HashWordType* DataBuf() {return this->m_data;}
138  FixedSizeSecBlock<T_HashWordType, T_BlockSize/sizeof(T_HashWordType)> m_data;
139 };
140 
141 //! \class IteratedHashWithStaticTransform
142 //! \brief Iterated hash with a static transformation function
143 //! \tparam T_HashWordType Hash word type
144 //! \tparam T_Endianness Endianness type of hash
145 //! \tparam T_BlockSize Block size of the hash
146 //! \tparam T_StateSize Internal state size of the hash
147 //! \tparam T_Transform HashTransformation derived class
148 //! \tparam T_DigestSize Digest size of the hash
149 //! \tparam T_StateAligned Flag indicating if state is 16-byte aligned
150 //! \sa HashTransformation, MessageAuthenticationCode
151 template <class T_HashWordType, class T_Endianness, unsigned int T_BlockSize, unsigned int T_StateSize, class T_Transform, unsigned int T_DigestSize = 0, bool T_StateAligned = false>
152 class CRYPTOPP_NO_VTABLE IteratedHashWithStaticTransform
153  : public ClonableImpl<T_Transform, AlgorithmImpl<IteratedHash<T_HashWordType, T_Endianness, T_BlockSize>, T_Transform> >
154 {
155 public:
156 
157 #ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
158  virtual ~IteratedHashWithStaticTransform() { }
159 #endif
160 
161  CRYPTOPP_CONSTANT(DIGESTSIZE = T_DigestSize ? T_DigestSize : T_StateSize)
162 
163  //! \brief Provides the digest size of the hash
164  //! \return the digest size of the hash, in bytes
165  //! \details DigestSize() returns <tt>DIGESTSIZE</tt>.
166  unsigned int DigestSize() const {return DIGESTSIZE;};
167 
168 protected:
169  IteratedHashWithStaticTransform() {this->Init();}
170  void HashEndianCorrectedBlock(const T_HashWordType *data) {T_Transform::Transform(this->m_state, data);}
171  void Init() {T_Transform::InitState(this->m_state);}
172 
173  T_HashWordType* StateBuf() {return this->m_state;}
174  FixedSizeAlignedSecBlock<T_HashWordType, T_BlockSize/sizeof(T_HashWordType), T_StateAligned> m_state;
175 };
176 
177 #ifndef __GNUC__
178  CRYPTOPP_DLL_TEMPLATE_CLASS IteratedHashBase<word64, HashTransformation>;
179  CRYPTOPP_STATIC_TEMPLATE_CLASS IteratedHashBase<word64, MessageAuthenticationCode>;
180 
181  CRYPTOPP_DLL_TEMPLATE_CLASS IteratedHashBase<word32, HashTransformation>;
182  CRYPTOPP_STATIC_TEMPLATE_CLASS IteratedHashBase<word32, MessageAuthenticationCode>;
183 #endif
184 
185 NAMESPACE_END
186 
187 #endif
const char * DigestSize()
int, in bytes
Definition: argnames.h:79
ByteOrder GetByteOrder() const
Provides the byte order of the hash.
Definition: iterhash.h:124
IteratedHashBase()
Construct an IteratedHashBase.
Definition: iterhash.h:33
Classes providing basic library services.
Utility functions for the Crypto++ library.
ByteOrder
Provides the byte ordering.
Definition: cryptlib.h:124
Base class for identifying alogorithm.
Definition: simple.h:26
Iterated hash with a static transformation function.
Definition: iterhash.h:152
Abstract base classes that provide a uniform interface to this library.
Exception thrown when trying to hash more data than is allowed by a hash function.
Definition: iterhash.h:13
Classes and functions for secure memory allocations.
#define CRYPTOPP_COMPILE_ASSERT(expr)
Compile time assertion.
Definition: misc.h:123
T ConditionalByteReverse(ByteOrder order, T value)
Reverses bytes in a value depending upon endianess.
Definition: misc.h:1862
Fixed size stack-based SecBlock with 16-byte alignment.
Definition: secblock.h:766
void CorrectEndianess(HashWordType *out, const HashWordType *in, size_t byteCount)
Adjusts the byte ordering of the hash.
Definition: iterhash.h:131
unsigned int OptimalBlockSize() const
Provides the input block size most efficient for this cipher.
Definition: iterhash.h:40
Fixed size stack-based SecBlock.
Definition: secblock.h:753
unsigned int OptimalDataAlignment() const
Provides input and output data alignment for optimal performance.
Definition: iterhash.h:45
const char * BlockSize()
int, in bytes
Definition: argnames.h:27
unsigned int BlockSize() const
Provides the block size of the hash.
Definition: iterhash.h:118
Iterated hash base class.
Definition: iterhash.h:27
Iterated hash base class.
Definition: iterhash.h:101
Crypto++ library namespace.
Input data was received that did not conform to expected format.
Definition: cryptlib.h:190