---

misc.h

#ifndef CRYPTOPP_MISC_H
#define CRYPTOPP_MISC_H

#include "config.h"
#include <assert.h>
#include <string.h>             // CodeWarrior doesn't have memory.h
#include <algorithm>
#include <string>

#ifdef INTEL_INTRINSICS
#include <stdlib.h>
#endif

NAMESPACE_BEGIN(CryptoPP)

// ************** misc functions ***************

#define GETBYTE(x, y) (unsigned int)(((x)>>(8*(y)))&255)
// this one may be faster on a Pentium
// #define GETBYTE(x, y) (((byte *)&(x))[y])

unsigned int Parity(unsigned long);
unsigned int BytePrecision(unsigned long);
unsigned int BitPrecision(unsigned long);
unsigned long Crop(unsigned long, unsigned int size);

inline unsigned int bitsToBytes(unsigned int bitCount)
{
        return ((bitCount+7)/(8));
}

inline unsigned int bytesToWords(unsigned int byteCount)
{
        return ((byteCount+WORD_SIZE-1)/WORD_SIZE);
}

inline unsigned int bitsToWords(unsigned int bitCount)
{
        return ((bitCount+WORD_BITS-1)/(WORD_BITS));
}

void xorbuf(byte *buf, const byte *mask, unsigned int count);
void xorbuf(byte *output, const byte *input, const byte *mask, unsigned int count);

inline unsigned int RoundDownToMultipleOf(unsigned int n, unsigned int m)
{
        return n - n%m;
}

inline unsigned int RoundUpToMultipleOf(unsigned int n, unsigned int m)
{
        return RoundDownToMultipleOf(n+m-1, m);
}

template <class T>
inline bool IsAligned(const void *p)
{
        return (unsigned int)p % sizeof(T) == 0;
}

inline bool CheckEndianess(bool highFirst)
{
#ifdef IS_LITTLE_ENDIAN
        return !highFirst;
#else
        return highFirst;
#endif
}

template <class T>              // can't use <sstream> because GCC 2.95.2 doesn't have it
std::string IntToString(T a)
{
        if (a == 0)
                return "0";
        bool negate = false;
        if (a < 0)
        {
                negate = true;
                a = -a;
        }
        std::string result;
        while (a > 0)
        {
                result = char('0' + a % 10) + result;
                a = a / 10;
        }
        if (negate)
                result = "-" + result;
        return result;
}

// ************** rotate functions ***************

template <class T> inline T rotlFixed(T x, unsigned int y)
{
        assert(y < sizeof(T)*8);
        return (x<<y) | (x>>(sizeof(T)*8-y));
}

template <class T> inline T rotrFixed(T x, unsigned int y)
{
        assert(y < sizeof(T)*8);
        return (x>>y) | (x<<(sizeof(T)*8-y));
}

template <class T> inline T rotlVariable(T x, unsigned int y)
{
        assert(y < sizeof(T)*8);
        return (x<<y) | (x>>(sizeof(T)*8-y));
}

template <class T> inline T rotrVariable(T x, unsigned int y)
{
        assert(y < sizeof(T)*8);
        return (x>>y) | (x<<(sizeof(T)*8-y));
}

template <class T> inline T rotlMod(T x, unsigned int y)
{
        y %= sizeof(T)*8;
        return (x<<y) | (x>>(sizeof(T)*8-y));
}

template <class T> inline T rotrMod(T x, unsigned int y)
{
        y %= sizeof(T)*8;
        return (x>>y) | (x<<(sizeof(T)*8-y));
}

#ifdef INTEL_INTRINSICS

template<> inline word32 rotlFixed<word32>(word32 x, unsigned int y)
{
        assert(y < 32);
        return y ? _lrotl(x, y) : x;
}

template<> inline word32 rotrFixed<word32>(word32 x, unsigned int y)
{
        assert(y < 32);
        return y ? _lrotr(x, y) : x;
}

template<> inline word32 rotlVariable<word32>(word32 x, unsigned int y)
{
        assert(y < 32);
        return _lrotl(x, y);
}

template<> inline word32 rotrVariable<word32>(word32 x, unsigned int y)
{
        assert(y < 32);
        return _lrotr(x, y);
}

template<> inline word32 rotlMod<word32>(word32 x, unsigned int y)
{
        return _lrotl(x, y);
}

template<> inline word32 rotrMod<word32>(word32 x, unsigned int y)
{
        return _lrotr(x, y);
}

#endif // #ifdef INTEL_INTRINSICS

#ifdef PPC_INTRINSICS

template<> inline word32 rotlFixed<word32>(word32 x, unsigned int y)
{
        assert(y < 32);
        return y ? __rlwinm(x,y,0,31) : x;
}

template<> inline word32 rotrFixed<word32>(word32 x, unsigned int y)
{
        assert(y < 32);
        return y ? __rlwinm(x,32-y,0,31) : x;
}

template<> inline word32 rotlVariable<word32>(word32 x, unsigned int y)
{
        assert(y < 32);
        return (__rlwnm(x,y,0,31));
}

template<> inline word32 rotrVariable<word32>(word32 x, unsigned int y)
{
        assert(y < 32);
        return (__rlwnm(x,32-y,0,31));
}

template<> inline word32 rotlMod<word32>(word32 x, unsigned int y)
{
        return (__rlwnm(x,y,0,31));
}

template<> inline word32 rotrMod<word32>(word32 x, unsigned int y)
{
        return (__rlwnm(x,32-y,0,31));
}

#endif // #ifdef PPC_INTRINSICS

// ************** endian reversal ***************

inline word16 byteReverse(word16 value)
{
        return rotlFixed(value, 8U);
}

inline word32 byteReverse(word32 value)
{
#ifdef PPC_INTRINSICS
        // PPC: load reverse indexed instruction
        return (word32)__lwbrx(&value,0);
#elif defined(FAST_ROTATE)
        // 5 instructions with rotate instruction, 9 without
        return (rotrFixed(value, 8U) & 0xff00ff00) | (rotlFixed(value, 8U) & 0x00ff00ff);
#else
        // 6 instructions with rotate instruction, 8 without
        value = ((value & 0xFF00FF00) >> 8) | ((value & 0x00FF00FF) << 8);
        return rotlFixed(value, 16U);
#endif
}

#ifdef WORD64_AVAILABLE
inline word64 byteReverse(word64 value)
{
#ifdef SLOW_WORD64
        return (word64(byteReverse(word32(value))) << 32) | byteReverse(word32(value>>32));
#else
        value = ((value & W64LIT(0xFF00FF00FF00FF00)) >> 8) | ((value & W64LIT(0x00FF00FF00FF00FF)) << 8);
        value = ((value & W64LIT(0xFFFF0000FFFF0000)) >> 16) | ((value & W64LIT(0x0000FFFF0000FFFF)) << 16);
        return rotlFixed(value, 32U);
#endif
}
#endif

inline byte bitReverse(byte value)
{
        value = ((value & 0xAA) >> 1) | ((value & 0x55) << 1);
        value = ((value & 0xCC) >> 2) | ((value & 0x33) << 2);
        return rotlFixed(value, 4);
}

inline word16 bitReverse(word16 value)
{
        value = ((value & 0xAAAA) >> 1) | ((value & 0x5555) << 1);
        value = ((value & 0xCCCC) >> 2) | ((value & 0x3333) << 2);
        value = ((value & 0xF0F0) >> 4) | ((value & 0x0F0F) << 4);
        return byteReverse(value);
}

inline word32 bitReverse(word32 value)
{
        value = ((value & 0xAAAAAAAA) >> 1) | ((value & 0x55555555) << 1);
        value = ((value & 0xCCCCCCCC) >> 2) | ((value & 0x33333333) << 2);
        value = ((value & 0xF0F0F0F0) >> 4) | ((value & 0x0F0F0F0F) << 4);
        return byteReverse(value);
}

#ifdef WORD64_AVAILABLE
inline word64 bitReverse(word64 value)
{
#ifdef SLOW_WORD64
        return (word64(bitReverse(word32(value))) << 32) | bitReverse(word32(value>>32));
#else
        value = ((value & W64LIT(0xAAAAAAAAAAAAAAAA)) >> 1) | ((value & W64LIT(0x5555555555555555)) << 1);
        value = ((value & W64LIT(0xCCCCCCCCCCCCCCCC)) >> 2) | ((value & W64LIT(0x3333333333333333)) << 2);
        value = ((value & W64LIT(0xF0F0F0F0F0F0F0F0)) >> 4) | ((value & W64LIT(0x0F0F0F0F0F0F0F0F)) << 4);
        return byteReverse(value);
#endif
}
#endif

template <class T>
inline T bitReverse(T value)
{
        if (sizeof(T) == 1)
                return bitReverse((byte)value);
        else if (sizeof(T) == 2)
                return bitReverse((word16)value);
        else if (sizeof(T) == 4)
                return bitReverse((word32)value);
        else
        {
#ifdef WORD64_AVAILABLE
                assert(sizeof(T) == 8);
                return bitReverse((word64)value);
#else
                assert(false);
                return 0;
#endif
        }
}

template <class T>
void byteReverse(T *out, const T *in, unsigned int byteCount)
{
        unsigned int count = (byteCount+sizeof(T)-1)/sizeof(T);
        for (unsigned int i=0; i<count; i++)
                out[i] = byteReverse(in[i]);
}

template <class T>
inline void GetUserKeyLittleEndian(T *out, unsigned int outlen, const byte *in, unsigned int inlen)
{
        const unsigned int U = sizeof(T);
        assert(inlen <= outlen*U);
        memcpy(out, in, inlen);
        memset((byte *)out+inlen, 0, outlen*U-inlen);
#ifndef IS_LITTLE_ENDIAN
        byteReverse(out, out, inlen);
#endif
}

template <class T>
inline void GetUserKeyBigEndian(T *out, unsigned int outlen, const byte *in, unsigned int inlen)
{
        const unsigned int U = sizeof(T);
        assert(inlen <= outlen*U);
        memcpy(out, in, inlen);
        memset((byte *)out+inlen, 0, outlen*U-inlen);
#ifdef IS_LITTLE_ENDIAN
        byteReverse(out, out, inlen);
#endif
}

// Fetch 2 words from user's buffer into "a", "b" in LITTLE-endian order
template <class T>
inline void GetBlockLittleEndian(const byte *block, T &a, T &b)
{
#ifdef IS_LITTLE_ENDIAN
        a = ((T *)block)[0];
        b = ((T *)block)[1];
#else
        a = byteReverse(((T *)block)[0]);
        b = byteReverse(((T *)block)[1]);
#endif
}

// Put 2 words back into user's buffer in LITTLE-endian order
template <class T>
inline void PutBlockLittleEndian(byte *block, T a, T b)
{
#ifdef IS_LITTLE_ENDIAN
        ((T *)block)[0] = a;
        ((T *)block)[1] = b;
#else
        ((T *)block)[0] = byteReverse(a);
        ((T *)block)[1] = byteReverse(b);
#endif
}

// Fetch 4 words from user's buffer into "a", "b", "c", "d" in LITTLE-endian order
template <class T>
inline void GetBlockLittleEndian(const byte *block, T &a, T &b, T &c, T &d)
{
#ifdef IS_LITTLE_ENDIAN
        a = ((T *)block)[0];
        b = ((T *)block)[1];
        c = ((T *)block)[2];
        d = ((T *)block)[3];
#else
        a = byteReverse(((T *)block)[0]);
        b = byteReverse(((T *)block)[1]);
        c = byteReverse(((T *)block)[2]);
        d = byteReverse(((T *)block)[3]);
#endif
}

// Put 4 words back into user's buffer in LITTLE-endian order
template <class T>
inline void PutBlockLittleEndian(byte *block, T a, T b, T c, T d)
{
#ifdef IS_LITTLE_ENDIAN
        ((T *)block)[0] = a;
        ((T *)block)[1] = b;
        ((T *)block)[2] = c;
        ((T *)block)[3] = d;
#else
        ((T *)block)[0] = byteReverse(a);
        ((T *)block)[1] = byteReverse(b);
        ((T *)block)[2] = byteReverse(c);
        ((T *)block)[3] = byteReverse(d);
#endif
}

// Fetch 2 words from user's buffer into "a", "b" in BIG-endian order
template <class T>
inline void GetBlockBigEndian(const byte *block, T &a, T &b)
{
#ifndef IS_LITTLE_ENDIAN
        a = ((T *)block)[0];
        b = ((T *)block)[1];
#else
        a = byteReverse(((T *)block)[0]);
        b = byteReverse(((T *)block)[1]);
#endif
}

// Put 2 words back into user's buffer in BIG-endian order
template <class T>
inline void PutBlockBigEndian(byte *block, T a, T b)
{
#ifndef IS_LITTLE_ENDIAN
        ((T *)block)[0] = a;
        ((T *)block)[1] = b;
#else
        ((T *)block)[0] = byteReverse(a);
        ((T *)block)[1] = byteReverse(b);
#endif
}

// Fetch 4 words from user's buffer into "a", "b", "c", "d" in BIG-endian order
template <class T>
inline void GetBlockBigEndian(const byte *block, T &a, T &b, T &c, T &d)
{
#ifndef IS_LITTLE_ENDIAN
        a = ((T *)block)[0];
        b = ((T *)block)[1];
        c = ((T *)block)[2];
        d = ((T *)block)[3];
#else
        a = byteReverse(((T *)block)[0]);
        b = byteReverse(((T *)block)[1]);
        c = byteReverse(((T *)block)[2]);
        d = byteReverse(((T *)block)[3]);
#endif
}

// Put 4 words back into user's buffer in BIG-endian order
template <class T>
inline void PutBlockBigEndian(byte *block, T a, T b, T c, T d)
{
#ifndef IS_LITTLE_ENDIAN
        ((T *)block)[0] = a;
        ((T *)block)[1] = b;
        ((T *)block)[2] = c;
        ((T *)block)[3] = d;
#else
        ((T *)block)[0] = byteReverse(a);
        ((T *)block)[1] = byteReverse(b);
        ((T *)block)[2] = byteReverse(c);
        ((T *)block)[3] = byteReverse(d);
#endif
}

template <class T>
std::string WordToString(T value, bool highFirst = true)
{
        if (!CheckEndianess(highFirst))
                value = byteReverse(value);

        return std::string((char *)&value, sizeof(value));
}

template <class T>
T StringToWord(const std::string &str, bool highFirst = true)
{
        T value = 0;
        memcpy(&value, str.data(), STDMIN(sizeof(value), str.size()));
        return CheckEndianess(highFirst) ? value : byteReverse(value);
}

// ************** key length query ***************

template <unsigned int N>
class FixedKeyLength
{
public:
        enum {KEYLENGTH=N, MIN_KEYLENGTH=N, MAX_KEYLENGTH=N, DEFAULT_KEYLENGTH=N};
        static unsigned int KeyLength(unsigned int) {return KEYLENGTH;}
};

template <unsigned int D, unsigned int N, unsigned int M, unsigned int Q=1>
class VariableKeyLength
{
public:
        enum {MIN_KEYLENGTH=N, MAX_KEYLENGTH=M, DEFAULT_KEYLENGTH=D, KEYLENGTH_MULTIPLE=Q};
        static unsigned int KeyLength(unsigned int n)
        {
                assert(KEYLENGTH_MULTIPLE > 0 && MIN_KEYLENGTH % KEYLENGTH_MULTIPLE == 0 && MAX_KEYLENGTH % KEYLENGTH_MULTIPLE == 0);
                if (n < MIN_KEYLENGTH)
                        return MIN_KEYLENGTH;
                else if (n > MAX_KEYLENGTH)
                        return MAX_KEYLENGTH;
                else
                        return RoundUpToMultipleOf(n, KEYLENGTH_MULTIPLE);
        }
};

template <class T>
class SameKeyLengthAs
{
public:
        enum {MIN_KEYLENGTH=T::MIN_KEYLENGTH, MAX_KEYLENGTH=T::MAX_KEYLENGTH, DEFAULT_KEYLENGTH=T::DEFAULT_KEYLENGTH};
        static unsigned int KeyLength(unsigned int keylength)
                {return T::KeyLength(keylength);}
};

// ************** secure memory allocation ***************

#ifdef SECALLOC_DEFAULT
#define SecAlloc(type, number) (new type[(number)])
#define SecFree(ptr, number) (memset((ptr), 0, (number)*sizeof(*(ptr))), delete [] (ptr))
#else
#define SecAlloc(type, number) (new type[(number)])
#define SecFree(ptr, number) (delete [] (ptr))
#endif

template <class T> struct SecBlock
{
        explicit SecBlock(unsigned int size=0)
                : size(size) {ptr = SecAlloc(T, size);}
        SecBlock(const SecBlock<T> &t)
                : size(t.size) {ptr = SecAlloc(T, size); memcpy(ptr, t.ptr, size*sizeof(T));}
        SecBlock(const T *t, unsigned int len)
                : size(len) {ptr = SecAlloc(T, len); memcpy(ptr, t, len*sizeof(T));}
        ~SecBlock()
                {SecFree(ptr, size);}

#if defined(__GNUC__) || defined(__BCPLUSPLUS__)
        operator const void *() const
                {return ptr;}
        operator void *()
                {return ptr;}
#endif
#if defined(__GNUC__)   // reduce warnings
        operator const void *()
                {return ptr;}
#endif

        operator const T *() const
                {return ptr;}
        operator T *()
                {return ptr;}
#if defined(__GNUC__)   // reduce warnings
        operator const T *()
                {return ptr;}
#endif

// CodeWarrior defines _MSC_VER
#if !defined(_MSC_VER) || defined(__MWERKS__)
        T *operator +(unsigned int offset)
                {return ptr+offset;}
        const T *operator +(unsigned int offset) const
                {return ptr+offset;}
        T& operator[](unsigned int index)
                {assert(index<size); return ptr[index];}
        const T& operator[](unsigned int index) const
                {assert(index<size); return ptr[index];}
#endif

        const T* Begin() const
                {return ptr;}
        T* Begin()
                {return ptr;}
        const T* End() const
                {return ptr+size;}
        T* End()
                {return ptr+size;}

        unsigned int Size() const {return size;}

        void Assign(const T *t, unsigned int len)
        {
                New(len);
                memcpy(ptr, t, len*sizeof(T));
        }

        void Assign(const SecBlock<T> &t)
        {
                New(t.size);
                memcpy(ptr, t.ptr, size*sizeof(T));
        }

        SecBlock& operator=(const SecBlock<T> &t)
        {
                Assign(t);
                return *this;
        }

        bool operator==(const SecBlock<T> &t) const
        {
                return size == t.size && memcmp(ptr, t.ptr, size*sizeof(T)) == 0;
        }

        bool operator!=(const SecBlock<T> &t) const
        {
                return !operator==(t);
        }

        void New(unsigned int newSize)
        {
                if (newSize != size)
                {
                        T *newPtr = SecAlloc(T, newSize);
                        SecFree(ptr, size);
                        ptr = newPtr;
                        size = newSize;
                }
        }

        void CleanNew(unsigned int newSize)
        {
                if (newSize != size)
                {
                        T *newPtr = SecAlloc(T, newSize);
                        SecFree(ptr, size);
                        ptr = newPtr;
                        size = newSize;
                }
                memset(ptr, 0, size*sizeof(T));
        }

        void Grow(unsigned int newSize)
        {
                if (newSize > size)
                {
                        T *newPtr = SecAlloc(T, newSize);
                        memcpy(newPtr, ptr, size*sizeof(T));
                        SecFree(ptr, size);
                        ptr = newPtr;
                        size = newSize;
                }
        }

        void CleanGrow(unsigned int newSize)
        {
                if (newSize > size)
                {
                        T *newPtr = SecAlloc(T, newSize);
                        memcpy(newPtr, ptr, size*sizeof(T));
                        memset(newPtr+size, 0, (newSize-size)*sizeof(T));
                        SecFree(ptr, size);
                        ptr = newPtr;
                        size = newSize;
                }
        }

        void Resize(unsigned int newSize)
        {
                if (newSize != size)
                {
                        T *newPtr = SecAlloc(T, newSize);
                        memcpy(newPtr, ptr, STDMIN(newSize, size)*sizeof(T));
                        SecFree(ptr, size);
                        ptr = newPtr;
                        size = newSize;
                }
        }

        void swap(SecBlock<T> &b);

        unsigned int size;
        T *ptr;
};

template <class T> void SecBlock<T>::swap(SecBlock<T> &b)
{
        std::swap(size, b.size);
        std::swap(ptr, b.ptr);
}

typedef SecBlock<byte> SecByteBlock;
typedef SecBlock<word> SecWordBlock;

NAMESPACE_END

NAMESPACE_BEGIN(std)
template <class T>
inline void swap(CryptoPP::SecBlock<T> &a, CryptoPP::SecBlock<T> &b)
{
        a.swap(b);
}

NAMESPACE_END

#endif // MISC_H

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