Cleared Valgrind warnings on uninitialized reads (Issue 105)

1 files changed, 32 insertions, 24 deletions

diff --git a/rng.cpp b/rng.cpp
index 354856c4..22141cb7 100644
--- a/rng.cpp
+++ b/rng.cpp
@@ -59,25 +59,33 @@ void LC_RNG::GenerateBlock(byte *output, size_t size)
 #ifndef CRYPTOPP_IMPORTS

 

 X917RNG::X917RNG(BlockTransformation *c, const byte *seed, const byte *deterministicTimeVector)

-	: cipher(c),

-	  S(cipher->BlockSize()),

-	  dtbuf(S),

-	  randseed(seed, S),

-	  m_lastBlock(S),

-	  m_deterministicTimeVector(deterministicTimeVector, deterministicTimeVector ? S : 0)

+	: m_cipher(c),

+	  m_size(m_cipher->BlockSize()),

+	  m_datetime(m_size),

+	  m_randseed(seed, m_size),

+	  m_lastBlock(m_size),

+	  m_deterministicTimeVector(deterministicTimeVector, deterministicTimeVector ? m_size : 0)

 {

+	// Valgrind finding, http://github.com/weidai11/cryptopp/issues/105

+	// Garbage in the tail creates a non-conforming X9.17 or X9.31 generator.

+	if (m_size > 8)

+	{

+		memset(m_datetime, 0x00, m_size);

+		memset(m_lastBlock, 0x00, m_size);

+	}

+

 	if (!deterministicTimeVector)

 	{

 		time_t tstamp1 = time(0);

-		xorbuf(dtbuf, (byte *)&tstamp1, UnsignedMin(sizeof(tstamp1), S));

-		cipher->ProcessBlock(dtbuf);

+		xorbuf(m_datetime, (byte *)&tstamp1, UnsignedMin(sizeof(tstamp1), m_size));

+		m_cipher->ProcessBlock(m_datetime);

 		clock_t tstamp2 = clock();

-		xorbuf(dtbuf, (byte *)&tstamp2, UnsignedMin(sizeof(tstamp2), S));

-		cipher->ProcessBlock(dtbuf);

+		xorbuf(m_datetime, (byte *)&tstamp2, UnsignedMin(sizeof(tstamp2), m_size));

+		m_cipher->ProcessBlock(m_datetime);

 	}

 

 	// for FIPS 140-2

-	GenerateBlock(m_lastBlock, S);

+	GenerateBlock(m_lastBlock, m_size);

 }

 

 void X917RNG::GenerateIntoBufferedTransformation(BufferedTransformation &target, const std::string &channel, lword size)

@@ -87,35 +95,35 @@ void X917RNG::GenerateIntoBufferedTransformation(BufferedTransformation &target,
 		// calculate new enciphered timestamp

 		if (m_deterministicTimeVector.size())

 		{

-			cipher->ProcessBlock(m_deterministicTimeVector, dtbuf);

-			IncrementCounterByOne(m_deterministicTimeVector, S);

+			m_cipher->ProcessBlock(m_deterministicTimeVector, m_datetime);

+			IncrementCounterByOne(m_deterministicTimeVector, m_size);

 		}

 		else

 		{

 			clock_t c = clock();

-			xorbuf(dtbuf, (byte *)&c, UnsignedMin(sizeof(c), S));

+			xorbuf(m_datetime, (byte *)&c, UnsignedMin(sizeof(c), m_size));

 			time_t t = time(NULL);

-			xorbuf(dtbuf+S-UnsignedMin(sizeof(t), S), (byte *)&t, UnsignedMin(sizeof(t), S));

-			cipher->ProcessBlock(dtbuf);

+			xorbuf(m_datetime+m_size-UnsignedMin(sizeof(t), m_size), (byte *)&t, UnsignedMin(sizeof(t), m_size));

+			m_cipher->ProcessBlock(m_datetime);

 		}

 

 		// combine enciphered timestamp with seed

-		xorbuf(randseed, dtbuf, S);

+		xorbuf(m_randseed, m_datetime, m_size);

 

 		// generate a new block of random bytes

-		cipher->ProcessBlock(randseed);

-		if (memcmp(m_lastBlock, randseed, S) == 0)

+		m_cipher->ProcessBlock(m_randseed);

+		if (memcmp(m_lastBlock, m_randseed, m_size) == 0)

 			throw SelfTestFailure("X917RNG: Continuous random number generator test failed.");

 

 		// output random bytes

-		size_t len = UnsignedMin(S, size);

-		target.ChannelPut(channel, randseed, len);

+		size_t len = UnsignedMin(m_size, size);

+		target.ChannelPut(channel, m_randseed, len);

 		size -= len;

 

 		// compute new seed vector

-		memcpy(m_lastBlock, randseed, S);

-		xorbuf(randseed, dtbuf, S);

-		cipher->ProcessBlock(randseed);

+		memcpy(m_lastBlock, m_randseed, m_size);

+		xorbuf(m_randseed, m_datetime, m_size);

+		m_cipher->ProcessBlock(m_randseed);

 	}

 }