Fix Clang 5.0 "runtime error: addition of unsigned offset to 0xXXXX overflowed to 0xYYYY" (GH #549)

1 files changed, 7 insertions, 6 deletions

diff --git a/cryptlib.cpp b/cryptlib.cpp
index 03f0f0ff..55df7134 100644
--- a/cryptlib.cpp
+++ b/cryptlib.cpp
@@ -26,6 +26,7 @@
 #include "osrng.h"

 #include "secblock.h"

 #include "smartptr.h"

+#include "stdcpp.h"

 

 // http://www.cygwin.com/faq.html#faq.api.winsock

 #if (defined(__CYGWIN__) || defined(__CYGWIN32__)) && defined(PREFER_WINDOWS_STYLE_SOCKETS)

@@ -147,14 +148,13 @@ size_t BlockTransformation::AdvancedProcessBlocks(const byte *inBlocks, const by
 	CRYPTOPP_ASSERT(outBlocks);

 	CRYPTOPP_ASSERT(length);

 

-	size_t blockSize = BlockSize();

-	size_t inIncrement = (flags & (BT_InBlockIsCounter|BT_DontIncrementInOutPointers)) ? 0 : blockSize;

-	size_t xorIncrement = xorBlocks ? blockSize : 0;

-	size_t outIncrement = (flags & BT_DontIncrementInOutPointers) ? 0 : blockSize;

+	ptrdiff_t blockSize = static_cast<ptrdiff_t>(BlockSize());

+	ptrdiff_t inIncrement = (flags & (BT_InBlockIsCounter|BT_DontIncrementInOutPointers)) ? 0 : blockSize;

+	ptrdiff_t xorIncrement = xorBlocks ? blockSize : 0;

+	ptrdiff_t outIncrement = (flags & BT_DontIncrementInOutPointers) ? 0 : blockSize;

 

 	if (flags & BT_ReverseDirection)

 	{

-		CRYPTOPP_ASSERT(length % blockSize == 0);

 		inBlocks += length - blockSize;

 		xorBlocks += length - blockSize;

 		outBlocks += length - blockSize;

@@ -164,7 +164,7 @@ size_t BlockTransformation::AdvancedProcessBlocks(const byte *inBlocks, const by
 	}

 

 	// Coverity finding.

-	bool xorFlag = xorBlocks && (flags & BT_XorInput);

+	const bool xorFlag = xorBlocks && (flags & BT_XorInput);

 	while (length >= blockSize)

 	{

 		if (xorFlag)

@@ -181,6 +181,7 @@ size_t BlockTransformation::AdvancedProcessBlocks(const byte *inBlocks, const by
 

 		if (flags & BT_InBlockIsCounter)

 			const_cast<byte *>(inBlocks)[blockSize-1]++;

+

 		inBlocks += inIncrement;

 		outBlocks += outIncrement;

 		xorBlocks += xorIncrement;