Guard use of volatile cast in TEA and XTEA

1 files changed, 11 insertions, 4 deletions

diff --git a/tea.cpp b/tea.cpp
index 30e75832..32708c93 100644
--- a/tea.cpp
+++ b/tea.cpp
@@ -4,6 +4,13 @@
 #include "tea.h"

 #include "misc.h"

 

+// http://github.com/weidai11/cryptopp/issues/503

+#if defined(__xlC__) || defined(__SUNPRO_CC)

+# define MAYBE_VOLATILE(x) (*const_cast<volatile word32*>(&x))

+#else

+# define MAYBE_VOLATILE(x) (x)

+#endif

+

 NAMESPACE_BEGIN(CryptoPP)

 

 static const word32 DELTA = 0x9e3779b9;

@@ -26,7 +33,7 @@ void TEA::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byt
 	Block::Get(inBlock)(y)(z);

 

 	// http://github.com/weidai11/cryptopp/issues/503

-	while (*const_cast<volatile word32*>(&sum) != m_limit)

+	while (MAYBE_VOLATILE(sum) != m_limit)

 	{

 		sum += DELTA;

 		y += ((z << 4) + m_k[0]) ^ (z + sum) ^ ((z >> 5) + m_k[1]);

@@ -42,7 +49,7 @@ void TEA::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byt
 	Block::Get(inBlock)(y)(z);

 

 	// http://github.com/weidai11/cryptopp/issues/503

-	while (*const_cast<volatile word32*>(&sum) != 0)

+	while (MAYBE_VOLATILE(sum) != 0)

 	{

 		z -= ((y << 4) + m_k[2]) ^ (y + sum) ^ ((y >> 5) + m_k[3]);

 		y -= ((z << 4) + m_k[0]) ^ (z + sum) ^ ((z >> 5) + m_k[1]);

@@ -66,7 +73,7 @@ void XTEA::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, by
 	Block::Get(inBlock)(y)(z);

 

 	// http://github.com/weidai11/cryptopp/issues/503

-	while (*const_cast<volatile word32*>(&sum) != m_limit)

+	while (MAYBE_VOLATILE(sum) != m_limit)

 	{

 		y += ((z<<4 ^ z>>5) + z) ^ (sum + m_k[sum&3]);

 		sum += DELTA;

@@ -82,7 +89,7 @@ void XTEA::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, by
 	Block::Get(inBlock)(y)(z);

 

 	// http://github.com/weidai11/cryptopp/issues/503

-	while (*const_cast<volatile word32*>(&sum) != 0)

+	while (MAYBE_VOLATILE(sum) != 0)

 	{

 		z -= ((y<<4 ^ y>>5) + y) ^ (sum + m_k[sum>>11 & 3]);

 		sum -= DELTA;