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iterhash.h

00001 #ifndef CRYPTOPP_ITERHASH_H
00002 #define CRYPTOPP_ITERHASH_H
00003 
00004 #include "cryptlib.h"
00005 #include "secblock.h"
00006 #include "misc.h"
00007 #include "simple.h"
00008 
00009 NAMESPACE_BEGIN(CryptoPP)
00010 
00011 //! _
00012 template <class T, class BASE>
00013 class CRYPTOPP_NO_VTABLE IteratedHashBase : public BASE
00014 {
00015 public:
00016         typedef T HashWordType;
00017 
00018         IteratedHashBase() : m_countHi(0), m_countLo(0) {}
00019         unsigned int BlockSize() const {return m_data.size() * sizeof(T);}
00020         unsigned int OptimalBlockSize() const {return BlockSize();}
00021         unsigned int OptimalDataAlignment() const {return sizeof(T);}
00022         void Update(const byte *input, unsigned int length);
00023         byte * CreateUpdateSpace(unsigned int &size);
00024         void Restart();
00025 
00026 protected:
00027         void SetBlockSize(unsigned int blockSize) {m_data.resize(blockSize / sizeof(HashWordType));}
00028         void SetStateSize(unsigned int stateSize) {m_digest.resize(stateSize / sizeof(HashWordType));}
00029 
00030         T GetBitCountHi() const {return (m_countLo >> (8*sizeof(T)-3)) + (m_countHi << 3);}
00031         T GetBitCountLo() const {return m_countLo << 3;}
00032 
00033         virtual unsigned int HashMultipleBlocks(const T *input, unsigned int length);
00034         void PadLastBlock(unsigned int lastBlockSize, byte padFirst=0x80);
00035         virtual void Init() =0;
00036         virtual void HashBlock(const T *input) =0;
00037 
00038         SecBlock<T> m_data;                     // Data buffer
00039         SecBlock<T> m_digest;           // Message digest
00040 
00041 private:
00042         T m_countLo, m_countHi;
00043 };
00044 
00045 #ifdef WORD64_AVAILABLE
00046 CRYPTOPP_STATIC_TEMPLATE_CLASS IteratedHashBase<word64, HashTransformation>;
00047 CRYPTOPP_STATIC_TEMPLATE_CLASS IteratedHashBase<word64, MessageAuthenticationCode>;
00048 #endif
00049 
00050 CRYPTOPP_DLL_TEMPLATE_CLASS IteratedHashBase<word32, HashTransformation>;
00051 CRYPTOPP_STATIC_TEMPLATE_CLASS IteratedHashBase<word32, MessageAuthenticationCode>;
00052 
00053 //! _
00054 template <class T, class B, class BASE>
00055 class CRYPTOPP_NO_VTABLE IteratedHashBase2 : public IteratedHashBase<T, BASE>
00056 {
00057 public:
00058         typedef B ByteOrderClass;
00059         typedef typename IteratedHashBase<T, BASE>::HashWordType HashWordType;
00060 
00061         inline static void CorrectEndianess(HashWordType *out, const HashWordType *in, unsigned int byteCount)
00062         {
00063                 ConditionalByteReverse(B::ToEnum(), out, in, byteCount);
00064         }
00065 
00066         void TruncatedFinal(byte *digest, unsigned int size);
00067 
00068 protected:
00069         void HashBlock(const HashWordType *input);
00070         virtual void HashEndianCorrectedBlock(const HashWordType *data) =0;
00071 };
00072 
00073 //! _
00074 template <class T_HashWordType, class T_Endianness, unsigned int T_BlockSize, class T_Base = HashTransformation>
00075 class CRYPTOPP_NO_VTABLE IteratedHash : public IteratedHashBase2<T_HashWordType, T_Endianness, T_Base>
00076 {
00077 public:
00078         enum {BLOCKSIZE = T_BlockSize};
00079         CRYPTOPP_COMPILE_ASSERT((BLOCKSIZE & (BLOCKSIZE - 1)) == 0);            // blockSize is a power of 2
00080 
00081 protected:
00082         IteratedHash() {this->SetBlockSize(T_BlockSize);}
00083 };
00084 
00085 //! _
00086 template <class T_HashWordType, class T_Endianness, unsigned int T_BlockSize, unsigned int T_StateSize, class T_Transform, unsigned int T_DigestSize = T_StateSize>
00087 class CRYPTOPP_NO_VTABLE IteratedHashWithStaticTransform
00088         : public ClonableImpl<T_Transform, AlgorithmImpl<IteratedHash<T_HashWordType, T_Endianness, T_BlockSize>, T_Transform> >
00089 {
00090 public:
00091         enum {DIGESTSIZE = T_DigestSize};
00092         unsigned int DigestSize() const {return DIGESTSIZE;};
00093 
00094 protected:
00095         IteratedHashWithStaticTransform()
00096         {
00097                 this->SetStateSize(T_StateSize);
00098                 Init();
00099         }
00100         void HashEndianCorrectedBlock(const T_HashWordType *data) {T_Transform::Transform(this->m_digest, data);}
00101         void Init() {T_Transform::InitState(this->m_digest);}
00102 };
00103 
00104 // *************************************************************
00105 
00106 template <class T, class B, class BASE> void IteratedHashBase2<T, B, BASE>::TruncatedFinal(byte *digest, unsigned int size)
00107 {
00108         this->ThrowIfInvalidTruncatedSize(size);
00109 
00110         PadLastBlock(this->BlockSize() - 2*sizeof(HashWordType));
00111         CorrectEndianess(this->m_data, this->m_data, this->BlockSize() - 2*sizeof(HashWordType));
00112 
00113         this->m_data[this->m_data.size()-2] = B::ToEnum() ? this->GetBitCountHi() : this->GetBitCountLo();
00114         this->m_data[this->m_data.size()-1] = B::ToEnum() ? this->GetBitCountLo() : this->GetBitCountHi();
00115 
00116         HashEndianCorrectedBlock(this->m_data);
00117         CorrectEndianess(this->m_digest, this->m_digest, this->DigestSize());
00118         memcpy(digest, this->m_digest, size);
00119 
00120         this->Restart();                // reinit for next use
00121 }
00122 
00123 template <class T, class B, class BASE> void IteratedHashBase2<T, B, BASE>::HashBlock(const HashWordType *input)
00124 {
00125         if (NativeByteOrderIs(B::ToEnum()))
00126                 HashEndianCorrectedBlock(input);
00127         else
00128         {
00129                 ByteReverse(this->m_data.begin(), input, this->BlockSize());
00130                 HashEndianCorrectedBlock(this->m_data);
00131         }
00132 }
00133 
00134 NAMESPACE_END
00135 
00136 #endif

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