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Fix AES and incorrect argument to _freea() under Microsoft compilers (PR 306, Issue 302)

pull/308/head
Jeffrey Walton 2016-09-24 18:38:41 -04:00
parent c892295487 3e94b27493
commit 31e776d4e7
1 changed files with 24 additions and 7 deletions
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31
rijndael.cpp
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@ -1035,6 +1035,9 @@ void Rijndael_Enc_AdvancedProcessBlocks(void *locals, const word32 *k);
#if CRYPTOPP_BOOL_X64 || CRYPTOPP_BOOL_X32 || CRYPTOPP_BOOL_X86
/* Determine whether the range between begin and end overlaps
* with the same 4k block offsets as the Te table.
*/
static inline bool AliasedWithTable(const byte *begin, const byte *end)
{
size_t s0 = size_t(begin)%4096, s1 = size_t(end)%4096;
@ -1250,15 +1253,25 @@ size_t Rijndael::Enc::AdvancedProcessBlocks(const byte *inBlocks, const byte *xo
};
const byte* zeros = (byte *)(Te+256);
byte *space = NULL;
byte *space = NULL, *originalSpace = NULL;
do {
// Microsoft C&A violation, http://msdn.microsoft.com/en-us/library/5471dc8s.aspx
// Also see http://github.com/weidai11/cryptopp/issues/302, CVE-2016-7544.
space = (byte *)alloca(255+sizeof(Locals));
space += (256-(size_t)space%256)%256;
const size_t aliasPageSize = 4096;
const size_t aliasBlockSize = 256;
const size_t sizeToAllocate = aliasPageSize + aliasBlockSize + sizeof(Locals);
#if (CRYPTOPP_MSC_VERSION >= 1400)
originalSpace = (byte *)_malloca(sizeToAllocate);
#else
originalSpace = (byte *)alloca(sizeToAllocate);
#endif
/* round up to nearest 256 byte boundary */
space = originalSpace +
(aliasBlockSize - (size_t)originalSpace % aliasBlockSize)
% aliasBlockSize;
while (AliasedWithTable(space, space + sizeof(Locals)))
{
space += 256;
CRYPTOPP_ASSERT(space < (originalSpace + aliasPageSize));
}
while (AliasedWithTable(space, space+sizeof(Locals)));
size_t increment = BLOCKSIZE;
if (flags & BT_ReverseDirection)
@ -1288,6 +1301,10 @@ size_t Rijndael::Enc::AdvancedProcessBlocks(const byte *inBlocks, const byte *xo
Rijndael_Enc_AdvancedProcessBlocks(&locals, m_key);
#if (CRYPTOPP_MSC_VERSION >= 1400)
_freea(originalSpace);
#endif
return length % BLOCKSIZE;
}
#endif