Use SetMark to avoid unneeded zeroization in Rijndael

1 files changed, 4 insertions, 0 deletions

diff --git a/rijndael.cpp b/rijndael.cpp
index 141ba646..90663535 100644
--- a/rijndael.cpp
+++ b/rijndael.cpp
@@ -316,6 +316,9 @@ void Rijndael::Base::UncheckedSetKey(const byte *userKey, unsigned int keyLen, c
 

 #if CRYPTOPP_BOOL_X64 || CRYPTOPP_BOOL_X32 || CRYPTOPP_BOOL_X86

 	m_aliasBlock.New(s_sizeToAllocate);

+	// The alias block is only used on IA-32 when unaligned data access is in effect.

+	// Setting the low water mark to 0 avoids zeroization when m_aliasBlock is unused.

+	m_aliasBlock.SetMark(0);

 #endif

 

 	m_rounds = keyLen/4 + 6;

@@ -1146,6 +1149,7 @@ size_t Rijndael::Enc::AdvancedProcessBlocks(const byte *inBlocks, const byte *xo
 			return length;

 

 		static const byte *zeros = (const byte*)(Te+256);

+		m_aliasBlock.SetMark(m_aliasBlock.size());

 		byte *space = NULLPTR, *originalSpace = const_cast<byte*>(m_aliasBlock.data());

 

 		// round up to nearest 256 byte boundary