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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 //! exception thrown when trying to hash more data than is allowed by a hash function
    00012 class CRYPTOPP_DLL HashInputTooLong : public InvalidDataFormat
    00013 {
    00014 public:
    00015         explicit HashInputTooLong(const std::string &alg)
    00016                 : InvalidDataFormat("IteratedHashBase: input data exceeds maximum allowed by hash function " + alg) {}
    00017 };
    00018
    00019 //! _
    00020 template <class T, class BASE>
    00021 class CRYPTOPP_NO_VTABLE IteratedHashBase : public BASE
    00022 {
    00023 public:
    00024         typedef T HashWordType;
    00025
    00026         IteratedHashBase() : m_countLo(0), m_countHi(0) {}
    00027         unsigned int OptimalBlockSize() const {return this->BlockSize();}
    00028         unsigned int OptimalDataAlignment() const {return GetAlignmentOf<T>();}
    00029         void Update(const byte *input, size_t length);
    00030         byte * CreateUpdateSpace(size_t &size);
    00031         void Restart();
    00032         void TruncatedFinal(byte *digest, size_t size);
    00033
    00034 protected:
    00035         inline T GetBitCountHi() const {return (m_countLo >> (8*sizeof(T)-3)) + (m_countHi << 3);}
    00036         inline T GetBitCountLo() const {return m_countLo << 3;}
    00037
    00038         void PadLastBlock(unsigned int lastBlockSize, byte padFirst=0x80);
    00039         virtual void Init() =0;
    00040
    00041         virtual ByteOrder GetByteOrder() const =0;
    00042         virtual void HashEndianCorrectedBlock(const HashWordType *data) =0;
    00043         virtual size_t HashMultipleBlocks(const T *input, size_t length);
    00044         void HashBlock(const HashWordType *input) {HashMultipleBlocks(input, this->BlockSize());}
    00045
    00046         virtual T* DataBuf() =0;
    00047         virtual T* StateBuf() =0;
    00048
    00049 private:
    00050         T m_countLo, m_countHi;
    00051 };
    00052
    00053 //! _
    00054 template <class T_HashWordType, class T_Endianness, unsigned int T_BlockSize, class T_Base = HashTransformation>
    00055 class CRYPTOPP_NO_VTABLE IteratedHash : public IteratedHashBase<T_HashWordType, T_Base>
    00056 {
    00057 public:
    00058         typedef T_Endianness ByteOrderClass;
    00059         typedef T_HashWordType HashWordType;
    00060
    00061         CRYPTOPP_CONSTANT(BLOCKSIZE = T_BlockSize)
    00062         // BCB2006 workaround: can't use BLOCKSIZE here
    00063         CRYPTOPP_COMPILE_ASSERT((T_BlockSize & (T_BlockSize - 1)) == 0);        // blockSize is a power of 2
    00064         unsigned int BlockSize() const {return T_BlockSize;}
    00065
    00066         ByteOrder GetByteOrder() const {return T_Endianness::ToEnum();}
    00067
    00068         inline static void CorrectEndianess(HashWordType *out, const HashWordType *in, size_t byteCount)
    00069         {
    00070                 ConditionalByteReverse(T_Endianness::ToEnum(), out, in, byteCount);
    00071         }
    00072
    00073 protected:
    00074         T_HashWordType* DataBuf() {return this->m_data;}
    00075         FixedSizeSecBlock<T_HashWordType, T_BlockSize/sizeof(T_HashWordType)> m_data;
    00076 };
    00077
    00078 //! _
    00079 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>
    00080 class CRYPTOPP_NO_VTABLE IteratedHashWithStaticTransform
    00081         : public ClonableImpl<T_Transform, AlgorithmImpl<IteratedHash<T_HashWordType, T_Endianness, T_BlockSize>, T_Transform> >
    00082 {
    00083 public:
    00084         CRYPTOPP_CONSTANT(DIGESTSIZE = T_DigestSize ? T_DigestSize : T_StateSize)
    00085         unsigned int DigestSize() const {return DIGESTSIZE;};
    00086
    00087 protected:
    00088         IteratedHashWithStaticTransform() {this->Init();}
    00089         void HashEndianCorrectedBlock(const T_HashWordType *data) {T_Transform::Transform(this->m_state, data);}
    00090         void Init() {T_Transform::InitState(this->m_state);}
    00091
    00092         T_HashWordType* StateBuf() {return this->m_state;}
    00093         FixedSizeAlignedSecBlock<T_HashWordType, T_BlockSize/sizeof(T_HashWordType), T_StateAligned> m_state;
    00094 };
    00095
    00096 #ifndef __GNUC__
    00097         CRYPTOPP_DLL_TEMPLATE_CLASS IteratedHashBase<word64, HashTransformation>;
    00098         CRYPTOPP_STATIC_TEMPLATE_CLASS IteratedHashBase<word64, MessageAuthenticationCode>;
    00099
    00100         CRYPTOPP_DLL_TEMPLATE_CLASS IteratedHashBase<word32, HashTransformation>;
    00101         CRYPTOPP_STATIC_TEMPLATE_CLASS IteratedHashBase<word32, MessageAuthenticationCode>;
    00102 #endif
    00103
    00104 NAMESPACE_END
    00105
    00106 #endif