/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* This file incorporates work covered by the following license notice:
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed
* with this work for additional information regarding copyright
* ownership. The ASF licenses this file to you under the Apache
* License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.apache.org/licenses/LICENSE-2.0 .
*/
#include <sal/config.h>
#include <cmath>
#include <sal/types.h>
#include <o3tl/temporary.hxx>
#include <osl/thread.h>
#include <osl/thread.hxx>
#include <osl/time.h>
#include <rtl/alloc.h>
#include <rtl/digest.h>
#include <rtl/random.h>
#include <oslrandom.h>
#define RTL_RANDOM_RNG_1(a) ((a) * 16807L)
#define RTL_RANDOM_RNG_2(a) ((a) * 65539L)
#define RTL_RANDOM_RNG(x, y, z) \
{ \
(x) = 170 * ((x) % 178) - 63 * ((x) / 178); \
if ((x) < 0) (x) += 30328; \
\
(y) = 171 * ((y) % 177) - 2 * ((y) / 177); \
if ((y) < 0) (y) += 30269; \
\
(z) = 172 * ((z) % 176) - 35 * ((z) / 176); \
if ((z) < 0) (z) += 30307; \
}
namespace {
struct RandomData_Impl
{
sal_Int16 m_nX;
sal_Int16 m_nY;
sal_Int16 m_nZ;
};
}
static double data (RandomData_Impl *pImpl);
#define RTL_RANDOM_DIGEST rtl_Digest_AlgorithmMD5
#define RTL_RANDOM_SIZE_DIGEST RTL_DIGEST_LENGTH_MD5
#define RTL_RANDOM_SIZE_POOL 1023
namespace {
struct RandomPool_Impl
{
rtlDigest m_hDigest;
sal_uInt8 m_pDigest[RTL_RANDOM_SIZE_DIGEST];
sal_uInt8 m_pData[RTL_RANDOM_SIZE_POOL + 1];
sal_uInt32 m_nData;
sal_uInt32 m_nIndex;
sal_uInt32 m_nCount;
};
}
static bool initPool(RandomPool_Impl *pImpl);
static void seedPool(
RandomPool_Impl *pImpl, const sal_uInt8 *pBuffer, sal_Size nBufLen);
static void readPool(
RandomPool_Impl *pImpl, sal_uInt8 *pBuffer, sal_Size nBufLen);
static double data(RandomData_Impl *pImpl)
{
double random;
RTL_RANDOM_RNG (pImpl->m_nX, pImpl->m_nY, pImpl->m_nZ);
random = ((static_cast<double>(pImpl->m_nX) / 30328.0) +
(static_cast<double>(pImpl->m_nY) / 30269.0) +
(static_cast<double>(pImpl->m_nZ) / 30307.0) );
return std::modf(random, &o3tl::temporary(double()));
}
static bool initPool(RandomPool_Impl *pImpl)
{
pImpl->m_hDigest = rtl_digest_create(RTL_RANDOM_DIGEST);
if (pImpl->m_hDigest)
{
oslThreadIdentifier tid;
TimeValue tv;
RandomData_Impl rd;
double seed;
/* The use of uninitialized stack variables as a way to
* enhance the entropy of the random pool triggers
* memory checkers like purify and valgrind.
*/
/*
seedPool (pImpl, (sal_uInt8*)&tid, sizeof(tid));
seedPool (pImpl, (sal_uInt8*)&tv, sizeof(tv));
seedPool (pImpl, (sal_uInt8*)&rd, sizeof(rd));
*/
tid = osl::Thread::getCurrentIdentifier();
tid = RTL_RANDOM_RNG_2(RTL_RANDOM_RNG_1(tid));
seedPool (pImpl, reinterpret_cast< sal_uInt8* >(&tid), sizeof(tid));
osl_getSystemTime (&tv);
tv.Seconds = RTL_RANDOM_RNG_2(tv.Seconds);
tv.Nanosec = RTL_RANDOM_RNG_2(tv.Nanosec);
seedPool (pImpl, reinterpret_cast< sal_uInt8* >(&tv), sizeof(tv));
rd.m_nX = static_cast<sal_Int16>(((tid >> 1) << 1) + 1);
rd.m_nY = static_cast<sal_Int16>(((tv.Seconds >> 1) << 1) + 1);
rd.m_nZ = static_cast<sal_Int16>(((tv.Nanosec >> 1) << 1) + 1);
seedPool (pImpl, reinterpret_cast< sal_uInt8* >(&rd), sizeof(rd));
while (pImpl->m_nData < RTL_RANDOM_SIZE_POOL)
{
seed = data (&rd);
seedPool (pImpl, reinterpret_cast< sal_uInt8* >(&seed), sizeof(seed));
}
return true;
}
return false;
}
static void seedPool(
RandomPool_Impl *pImpl, const sal_uInt8 *pBuffer, sal_Size nBufLen)
{
sal_Size i;
sal_sSize j, k;
for (i = 0; i < nBufLen; i += RTL_RANDOM_SIZE_DIGEST)
{
j = nBufLen - i;
if (j > RTL_RANDOM_SIZE_DIGEST)
j = RTL_RANDOM_SIZE_DIGEST;
rtl_digest_update(
pImpl->m_hDigest, pImpl->m_pDigest, RTL_RANDOM_SIZE_DIGEST);
k = (pImpl->m_nIndex + j) - RTL_RANDOM_SIZE_POOL;
if (k > 0)
{
rtl_digest_update(
pImpl->m_hDigest, &(pImpl->m_pData[pImpl->m_nIndex]), j - k);
rtl_digest_update(
pImpl->m_hDigest, &(pImpl->m_pData[0]), k);
}
else
{
rtl_digest_update(
pImpl->m_hDigest, &(pImpl->m_pData[pImpl->m_nIndex]), j);
}
rtl_digest_update(pImpl->m_hDigest, pBuffer, j);
pBuffer += j;
rtl_digest_get(
pImpl->m_hDigest, pImpl->m_pDigest, RTL_RANDOM_SIZE_DIGEST);
for (k = 0; k < j; k++)
{
pImpl->m_pData[pImpl->m_nIndex++] ^= pImpl->m_pDigest[k];
if (pImpl->m_nIndex >= RTL_RANDOM_SIZE_POOL)
{
pImpl->m_nData = RTL_RANDOM_SIZE_POOL;
pImpl->m_nIndex = 0;
}
}
}
if (pImpl->m_nIndex > pImpl->m_nData)
pImpl->m_nData = pImpl->m_nIndex;
}
static void readPool (
RandomPool_Impl *pImpl, sal_uInt8 *pBuffer, sal_Size nBufLen)
{
sal_Int32 j, k;
while (nBufLen > 0)
{
j = nBufLen;
if (j > RTL_RANDOM_SIZE_DIGEST/2)
j = RTL_RANDOM_SIZE_DIGEST/2;
nBufLen -= j;
rtl_digest_update(
pImpl->m_hDigest,
&(pImpl->m_pDigest[RTL_RANDOM_SIZE_DIGEST/2]),
RTL_RANDOM_SIZE_DIGEST/2);
k = (pImpl->m_nIndex + j) - pImpl->m_nData;
if (k > 0)
{
rtl_digest_update(
pImpl->m_hDigest, &(pImpl->m_pData[pImpl->m_nIndex]), j - k);
rtl_digest_update(
pImpl->m_hDigest, &(pImpl->m_pData[0]), k);
}
else
{
rtl_digest_update(
pImpl->m_hDigest, &(pImpl->m_pData[pImpl->m_nIndex]), j);
}
rtl_digest_get(
pImpl->m_hDigest, pImpl->m_pDigest, RTL_RANDOM_SIZE_DIGEST);
for (k = 0; k < j; k++)
{
if (pImpl->m_nIndex >= pImpl->m_nData)
pImpl->m_nIndex = 0;
pImpl->m_pData[pImpl->m_nIndex++] ^= pImpl->m_pDigest[k];
*pBuffer++ = pImpl->m_pDigest[k + RTL_RANDOM_SIZE_DIGEST/2];
}
}
pImpl->m_nCount++;
rtl_digest_update(
pImpl->m_hDigest, &(pImpl->m_nCount), sizeof(pImpl->m_nCount));
rtl_digest_update(
pImpl->m_hDigest, pImpl->m_pDigest, RTL_RANDOM_SIZE_DIGEST);
rtl_digest_get(
pImpl->m_hDigest, pImpl->m_pDigest, RTL_RANDOM_SIZE_DIGEST);
}
rtlRandomPool SAL_CALL rtl_random_createPool() SAL_THROW_EXTERN_C()
{
/* try to get system random number, if it fail fall back on own pool */
RandomPool_Impl *pImpl = static_cast< RandomPool_Impl* >(rtl_allocateZeroMemory(sizeof(RandomPool_Impl)));
if (pImpl)
{
char sanity[4];
if (!osl_get_system_random_data(sanity, 4))
{
if (!initPool(pImpl))
{
rtl_freeZeroMemory(pImpl, sizeof(RandomPool_Impl));
pImpl = nullptr;
}
}
}
return static_cast< rtlRandomPool >(pImpl);
}
void SAL_CALL rtl_random_destroyPool(rtlRandomPool Pool) SAL_THROW_EXTERN_C()
{
RandomPool_Impl *pImpl = static_cast< RandomPool_Impl* >(Pool);
if (pImpl)
{
if (pImpl->m_hDigest)
rtl_digest_destroy(pImpl->m_hDigest);
rtl_freeZeroMemory (pImpl, sizeof(RandomPool_Impl));
}
}
rtlRandomError SAL_CALL rtl_random_addBytes(
rtlRandomPool Pool, const void *Buffer, sal_Size Bytes) SAL_THROW_EXTERN_C()
{
RandomPool_Impl *pImpl = static_cast< RandomPool_Impl* >(Pool);
const sal_uInt8 *pBuffer = static_cast< const sal_uInt8* >(Buffer);
if (!pImpl || !pBuffer)
return rtl_Random_E_Argument;
if (pImpl->m_hDigest)
seedPool (pImpl, pBuffer, Bytes);
return rtl_Random_E_None;
}
rtlRandomError SAL_CALL rtl_random_getBytes (
rtlRandomPool Pool, void *Buffer, sal_Size Bytes) SAL_THROW_EXTERN_C()
{
RandomPool_Impl *pImpl = static_cast< RandomPool_Impl* >(Pool);
sal_uInt8 *pBuffer = static_cast< sal_uInt8* >(Buffer);
if (!pImpl || !pBuffer)
return rtl_Random_E_Argument;
if (pImpl->m_hDigest || !osl_get_system_random_data(static_cast< char* >(Buffer), Bytes))
{
if (!pImpl->m_hDigest && !initPool(pImpl))
return rtl_Random_E_Unknown;
readPool(pImpl, pBuffer, Bytes);
}
return rtl_Random_E_None;
}
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