tripwire-open-source/src/cryptlib/misc.h

#ifndef MISC_H
#define MISC_H

#include "config.h"
#include <assert.h>
#ifdef HAVE_MEMORY_H
 #include <memory.h>
#else
 #include <string.h>
#endif

#if defined(__MINT__) || defined(__DJGPP__)
 // OS has memory.h, but memset defined in string.h anyway.
 #include <string.h>
#endif

#include <algorithm>

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

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

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

#if defined(_MSC_VER) || defined(__BCPLUSPLUS__)

#include <stdlib.h>
#define FAST_ROTATE

template<> inline unsigned short rotl<unsigned short>(unsigned short x, unsigned int y)
{
    return (unsigned short)((x<<y) | (x>>(16-y)));
}

template<> inline unsigned short rotr<unsigned short>(unsigned short x, unsigned int y)
{
    return (unsigned short)((x>>y) | (x<<(16-y)));
}

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

template<> inline unsigned long rotr<unsigned long>(unsigned long x, unsigned int y)
{
    return _lrotr(x, y);
}
#endif // defined(_MSC_VER) || defined(__BCPLUSPLUS__)

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

inline word32 byteReverse(word32 value)
{
#ifdef FAST_ROTATE
    // 5 instructions with rotate instruction, 9 without
    return (rotr(value, 8) & 0xff00ff00) | (rotl(value, 8) & 0x00ff00ff);
#elif defined(_KCC)
    // 6 instructions with rotate instruction, 8 without
    value = ((value & 0xFF00FF00) >> 8) | ((value & 0x00FF00FF) << 8);
    return ((value<<16U) | (value>>16U));
#else
    // 6 instructions with rotate instruction, 8 without
    value = ((value & 0xFF00FF00) >> 8) | ((value & 0x00FF00FF) << 8);
    return rotl(value, 16U);
#endif
}

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

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

#ifdef _MSC_VER
    #ifdef WORDS_BIGENDIAN
    #error MSVC big endian GETBYTE not implemented
    #else
    #define GETBYTE(x, y) (((ibyte *)&(x))[y])
    #endif
#else
    #define GETBYTE(x, y) (unsigned int)(((x)>>(8*(y)))&255)
#endif

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

// ********************************************************

#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
{
    SecBlock(unsigned int size=0)
        : size(size) {ptr = SecAlloc(T, size); memset(ptr, 0, size*sizeof(T));}
    SecBlock(const SecBlock<T> &t)
        : size(t.size) {ptr = SecAlloc(T, size); CopyFrom(t);}
    SecBlock(const T *t, unsigned int size)
        : size(size) {ptr = SecAlloc(T, size); memcpy(ptr, t, size*sizeof(T));}
    ~SecBlock()
        {SecFree(ptr, size);}

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

    operator const T *() const
        {return ptr;}
    operator T *()
        {return ptr;}

#if !defined(_MSC_VER) && !defined(_KCC)
    T *operator +(unsigned int offset)
        {return ptr+offset;}
    const T *operator +(unsigned int offset) const
        {return ptr+offset;}
    T *operator +(long offset)
        {return ptr+offset;}
    const T *operator +(long 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;}

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

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

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

    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 swap(SecBlock<T> &b);
    friend void swap(SecBlock<T> &a, SecBlock<T> &b) {a.swap(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<ibyte> SecByteBlock;
typedef SecBlock<word> SecWordBlock;

#endif // MISC_H