misc.cpp

// misc.cpp - originally written and placed in the public domain by Wei Dai

#include "pch.h"
#include "config.h"

#if CRYPTOPP_MSC_VERSION
# pragma warning(disable: 4189)
# if (CRYPTOPP_MSC_VERSION >= 1400)
#  pragma warning(disable: 6237)
# endif
#endif

#ifndef CRYPTOPP_IMPORTS

#include "misc.h"
#include "trap.h"
#include "words.h"
#include "stdcpp.h"
#include "integer.h"
#include "secblock.h"

NAMESPACE_BEGIN(CryptoPP)

byte* BytePtr(SecByteBlock& str)
{
    // Caller wants a writeable pointer
    CRYPTOPP_ASSERT(str.empty() == false);

    if (str.empty())
        return NULLPTR;
    return reinterpret_cast<byte*>(str.data());
}

const byte* ConstBytePtr(const SecByteBlock& str)
{
    if (str.empty())
        return NULLPTR;
    return reinterpret_cast<const byte*>(str.data());
}

size_t BytePtrSize(const SecByteBlock& str)
{
    return str.size();
}

void xorbuf(byte *buf, const byte *mask, size_t count)
{
    CRYPTOPP_ASSERT(buf != NULLPTR);
    CRYPTOPP_ASSERT(mask != NULLPTR);
    CRYPTOPP_ASSERT(count > 0);

    size_t i=0;
    if (IsAligned<word32>(buf) && IsAligned<word32>(mask))
    {
        if (!CRYPTOPP_BOOL_SLOW_WORD64 && IsAligned<word64>(buf) && IsAligned<word64>(mask))
        {
            for (i=0; i<count/8; i++)
                ((word64*)(void*)buf)[i] ^= ((word64*)(void*)mask)[i];
            count -= 8*i;
            if (!count)
                return;
            buf += 8*i;
            mask += 8*i;
        }

        for (i=0; i<count/4; i++)
            ((word32*)(void*)buf)[i] ^= ((word32*)(void*)mask)[i];
        count -= 4*i;
        if (!count)
            return;
        buf += 4*i;
        mask += 4*i;
    }

    for (i=0; i<count; i++)
        buf[i] ^= mask[i];
}

void xorbuf(byte *output, const byte *input, const byte *mask, size_t count)
{
    CRYPTOPP_ASSERT(output != NULLPTR);
    CRYPTOPP_ASSERT(input != NULLPTR);
    CRYPTOPP_ASSERT(count > 0);

    size_t i=0;
    if (IsAligned<word32>(output) && IsAligned<word32>(input) && IsAligned<word32>(mask))
    {
        if (!CRYPTOPP_BOOL_SLOW_WORD64 && IsAligned<word64>(output) && IsAligned<word64>(input) && IsAligned<word64>(mask))
        {
            for (i=0; i<count/8; i++)
                ((word64*)(void*)output)[i] = ((word64*)(void*)input)[i] ^ ((word64*)(void*)mask)[i];
            count -= 8*i;
            if (!count)
                return;
            output += 8*i;
            input += 8*i;
            mask += 8*i;
        }

        for (i=0; i<count/4; i++)
            ((word32*)(void*)output)[i] = ((word32*)(void*)input)[i] ^ ((word32*)(void*)mask)[i];
        count -= 4*i;
        if (!count)
            return;
        output += 4*i;
        input += 4*i;
        mask += 4*i;
    }

    for (i=0; i<count; i++)
        output[i] = input[i] ^ mask[i];
}

bool VerifyBufsEqual(const byte *buf, const byte *mask, size_t count)
{
    CRYPTOPP_ASSERT(buf != NULLPTR);
    CRYPTOPP_ASSERT(mask != NULLPTR);
    // CRYPTOPP_ASSERT(count > 0);

    size_t i=0;
    byte acc8 = 0;

    if (IsAligned<word32>(buf) && IsAligned<word32>(mask) && count)
    {
        word32 acc32 = 0;
        if (!CRYPTOPP_BOOL_SLOW_WORD64 && IsAligned<word64>(buf) && IsAligned<word64>(mask))
        {
            word64 acc64 = 0;
            for (i=0; i<count/8; i++)
                acc64 |= ((word64*)(void*)buf)[i] ^ ((word64*)(void*)mask)[i];
            count -= 8*i;
            if (!count)
                return acc64 == 0;
            buf += 8*i;
            mask += 8*i;
            acc32 = word32(acc64) | word32(acc64>>32);
        }

        for (i=0; i<count/4; i++)
            acc32 |= ((word32*)(void*)buf)[i] ^ ((word32*)(void*)mask)[i];
        count -= 4*i;
        if (!count)
            return acc32 == 0;
        buf += 4*i;
        mask += 4*i;
        acc8 = byte(acc32) | byte(acc32>>8) | byte(acc32>>16) | byte(acc32>>24);
    }

    for (i=0; i<count; i++)
        acc8 |= buf[i] ^ mask[i];
    return acc8 == 0;
}

std::string StringNarrow(const wchar_t *str, bool throwOnError)
{
    CRYPTOPP_ASSERT(str);
    std::string result;

    // Safer functions on Windows for C&A, https://github.com/weidai11/cryptopp/issues/55
#if (CRYPTOPP_MSC_VERSION >= 1400)
    size_t len=0, size=0;
    errno_t err = 0;

    //const wchar_t* ptr = str;
    //while (*ptr++) len++;
    len = wcslen(str)+1;

    err = wcstombs_s(&size, NULLPTR, 0, str, len*sizeof(wchar_t));
    CRYPTOPP_ASSERT(err == 0);
    if (err != 0)
    {
        if (throwOnError)
            throw InvalidArgument("StringNarrow: wcstombs_s() call failed with error " + IntToString(err));
        else
            return std::string();
    }

    result.resize(size);
    err = wcstombs_s(&size, &result[0], size, str, len*sizeof(wchar_t));
    CRYPTOPP_ASSERT(err == 0);
    if (err != 0)
    {
        if (throwOnError)
            throw InvalidArgument("StringNarrow: wcstombs_s() call failed with error " + IntToString(err));
        else
            return std::string();
    }

    // The safe routine's size includes the NULL.
    if (!result.empty() && result[size - 1] == '\0')
        result.erase(size - 1);
#else
    size_t size = wcstombs(NULLPTR, str, 0);
    CRYPTOPP_ASSERT(size != (size_t)-1);
    if (size == (size_t)-1)
    {
        if (throwOnError)
            throw InvalidArgument("StringNarrow: wcstombs() call failed");
        else
            return std::string();
    }

    result.resize(size);
    size = wcstombs(&result[0], str, size);
    CRYPTOPP_ASSERT(size != (size_t)-1);
    if (size == (size_t)-1)
    {
        if (throwOnError)
            throw InvalidArgument("StringNarrow: wcstombs() call failed");
        else
            return std::string();
    }
#endif

    return result;
}

std::wstring StringWiden(const char *str, bool throwOnError)
{
    CRYPTOPP_ASSERT(str);
    std::wstring result;

    // Safer functions on Windows for C&A, https://github.com/weidai11/cryptopp/issues/55
#if (CRYPTOPP_MSC_VERSION >= 1400)
    size_t len=0, size=0;
    errno_t err = 0;

    //const char* ptr = str;
    //while (*ptr++) len++;
    len = std::strlen(str)+1;

    err = mbstowcs_s(&size, NULLPTR, 0, str, len);
    CRYPTOPP_ASSERT(err == 0);
    if (err != 0)
    {
        if (throwOnError)
            throw InvalidArgument("StringWiden: wcstombs_s() call failed with error " + IntToString(err));
        else
            return std::wstring();
    }

    result.resize(size);
    err = mbstowcs_s(&size, &result[0], size, str, len);
    CRYPTOPP_ASSERT(err == 0);
    if (err != 0)
    {
        if (throwOnError)
            throw InvalidArgument("StringWiden: wcstombs_s() call failed with error " + IntToString(err));
        else
            return std::wstring();
    }

    // The safe routine's size includes the NULL.
    if (!result.empty() && result[size - 1] == '\0')
        result.erase(size - 1);
#else
    size_t size = mbstowcs(NULLPTR, str, 0);
    CRYPTOPP_ASSERT(size != (size_t)-1);
    if (size == (size_t)-1)
    {
        if (throwOnError)
            throw InvalidArgument("StringWiden: mbstowcs() call failed");
        else
            return std::wstring();
    }

    result.resize(size);
    size = mbstowcs(&result[0], str, size);
    CRYPTOPP_ASSERT(size != (size_t)-1);
    if (size == (size_t)-1)
    {
        if (throwOnError)
            throw InvalidArgument("StringWiden: mbstowcs() call failed");
        else
            return std::wstring();
    }
#endif

    return result;
}

NAMESPACE_END

#endif