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Improve constant propagation of fix for Issue 146
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@noloader
noloader committed Apr 7, 2016
1 parent ab39385 commit 50e5c14
Showing 1 changed file with 8 additions and 4 deletions.
12 changes: 8 additions & 4 deletions rijndael.cpp
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Expand Up @@ -388,10 +388,12 @@ void Rijndael::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock
t3 = rk[7];
rk += 8;

// timing attack countermeasure. see comments at top for more details
// timing attack countermeasure. see comments at top for more details.
// also see http://github.com/weidai11/cryptopp/issues/146
const int cacheLineSize = GetCacheLineSize();
unsigned int i;
volatile word32 u = 0;
volatile word32 _u = 0;
word32 u = _u;
#if defined(CRYPTOPP_ALLOW_UNALIGNED_DATA_ACCESS) || defined(CRYPTOPP_ALLOW_RIJNDAEL_UNALIGNED_DATA_ACCESS)
for (i=0; i<2048; i+=cacheLineSize)
#else
Expand Down Expand Up @@ -464,10 +466,12 @@ void Rijndael::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock
t3 = rk[7];
rk += 8;

// timing attack countermeasure. see comments at top for more details
// timing attack countermeasure. see comments at top for more details.
// also see http://github.com/weidai11/cryptopp/issues/146
const int cacheLineSize = GetCacheLineSize();
unsigned int i;
volatile word32 u = 0;
volatile word32 _u = 0;
word32 u = _u;
#if defined(CRYPTOPP_ALLOW_UNALIGNED_DATA_ACCESS) || defined(CRYPTOPP_ALLOW_RIJNDAEL_UNALIGNED_DATA_ACCESS)
for (i=0; i<2048; i+=cacheLineSize)
#else
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1 comment on commit 50e5c14

@noloader
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Also see Issue 146 and the tail of the comments at Pull Request 154.

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