Updated MersenneTwister tests

The tests now include the first 10 elements of the sequence to ensure a properly implemented algorithm and endianess correctness.

mersenne.h

@@ -26,7 +26,7 @@ NAMESPACE_BEGIN(CryptoPP)
 //!   required quickly. It should not be used for cryptographic purposes.
 //! \sa MT19937, MT19937ar
 //! \since Crypto++ 5.6.3
-template <unsigned int K, unsigned int M, unsigned int N, unsigned int F, unsigned long S>
+template <unsigned int K, unsigned int M, unsigned int N, unsigned int F, word32 S>
 class MersenneTwister : public RandomNumberGenerator
 {
 public:
@@ -38,11 +38,26 @@ public:
 	//! \param seed 32-bit seed
 	//! \details Defaults to template parameter S due to changing algorithm
 	//!   parameters over time
-	MersenneTwister(unsigned long seed = S) : m_seed(seed), m_idx(N)
+	MersenneTwister(word32 seed = S) : m_seed(seed), m_idx(N)
 	{
-		m_state[0] = seed;
+		Reset(seed);
-		for (unsigned int i = 1; i < N+1; i++)
+	}
-			m_state[i] = word32(F * (m_state[i-1] ^ (m_state[i-1] >> 30)) + i);
+
+	bool CanIncorporateEntropy() const {return true;}
+
+	//! \brief Update RNG state with additional unpredictable values
+	//! \param input the entropy to add to the generator
+	//! \param length the size of the input buffer
+	//! \details MersenneTwister uses the first 32-bits of <tt>input</tt> to reseed the
+    //!   generator. If fewer bytes are provided, then the seed is padded with 0's.
+	void IncorporateEntropy(const byte *input, size_t length)
+	{
+		word32 temp = 0;
+		::memcpy(&temp, input, STDMIN(sizeof(temp), length));
+		Reset(temp);
+
+		// Wipe temp
+		SecureWipeArray(&temp, 1);
 	}
 
 	//! \brief Generate random array of bytes
@@ -58,24 +73,15 @@ public:
 		word32 temp;
 		for (size_t i=0; i < size/4; i++, output += 4)
 		{
-#if defined(CRYPTOPP_ALLOW_UNALIGNED_DATA_ACCESS) && defined(IS_LITTLE_ENDIAN)
-			*((word32*)output) = ByteReverse(NextMersenneWord());
-#elif defined(CRYPTOPP_ALLOW_UNALIGNED_DATA_ACCESS)
-			*((word32*)output) = NextMersenneWord();
-#else
 			temp = NextMersenneWord();
-			output[3] = CRYPTOPP_GET_BYTE_AS_BYTE(temp, 0);
+			PutWord<word32>(false, LITTLE_ENDIAN_ORDER, output, temp);
-			output[2] = CRYPTOPP_GET_BYTE_AS_BYTE(temp, 1);
-			output[1] = CRYPTOPP_GET_BYTE_AS_BYTE(temp, 2);
-			output[0] = CRYPTOPP_GET_BYTE_AS_BYTE(temp, 3);
-#endif
 		}
 
 		// No tail bytes
 		if (size%4 == 0)
 		{
 			// Wipe temp
-			*((volatile word32*)&temp) = 0;
+			SecureWipeArray(&temp, 1);
 			return;
 		}
 
@@ -91,7 +97,7 @@ public:
 		}
 
 		// Wipe temp
-		*((volatile word32*)&temp) = 0;
+		SecureWipeArray(&temp, 1);
 	}
 
 	//! \brief Generate a random 32-bit word in the range min to max, inclusive
@@ -128,6 +134,16 @@ public:
 
 protected:
 
+	void Reset(word32 seed)
+	{
+		m_seed = seed;
+		m_idx = N;
+
+		m_state[0] = seed;
+		for (unsigned int i = 1; i < N+1; i++)
+			m_state[i] = word32(F * (m_state[i-1] ^ (m_state[i-1] >> 30)) + i);
+	}
+
 	//! \brief Returns the next 32-bit word from the state array
 	//! \returns the next 32-bit word from the state array
 	//! \details fetches the next word frm the state array, performs bit operations on
@@ -148,7 +164,7 @@ protected:
 	//! \brief Performs the twist operaton on the state array
 	void Twist()
 	{
-		static const unsigned long magic[2]={0x0UL, K};
+		static const word32 magic[2]={0x0UL, K};
 		word32 kk, temp;
 
 		CRYPTOPP_ASSERT(N >= M);
@@ -171,7 +187,7 @@ protected:
 		m_idx = 0;
 
 		// Wipe temp
-		*((volatile word32*)&temp) = 0;
+		SecureWipeArray(&temp, 1);
 	}
 
 private:
@@ -179,9 +195,9 @@ private:
 	//! \brief 32-bit word state array of size N
 	FixedSizeSecBlock<word32, N+1> m_state;
 	//! \brief the value used to seed the generator
-	unsigned int m_seed;
+	word32 m_seed;
 	//! \brief the current index into the state array
-	unsigned int m_idx;
+	word32 m_idx;
 };
 
 //! \class MT19937

validat0.cpp

@@ -98,11 +98,6 @@ bool TestZinflate()
     return !fail;
 }
 
-bool TestMersenne()
-{
-    return true;
-}
-
 bool TestDefaultEncryptor()
 {
     std::cout << "\nTesting DefaultEncryptor...\n\n";

validat1.cpp

@@ -45,6 +45,7 @@
 #include "osrng.h"
 #include "drbg.h"
 #include "rdrand.h"
+#include "mersenne.h"
 #include "zdeflate.h"
 #include "smartptr.h"
 #include "channels.h"
@@ -72,7 +73,9 @@ bool ValidateAll(bool thorough)
 	pass=TestAutoSeeded() && pass;
 	pass=TestAutoSeededX917() && pass;
 	// pass=TestSecRandom() && pass;
-
+#if (defined(CRYPTOPP_DEBUG) || defined(CRYPTOPP_COVERAGE)) && !defined(CRYPTOPP_IMPORTS)
+	pass=TestMersenne() && pass;
+#endif
 #if (CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X32 || CRYPTOPP_BOOL_X64)
 	pass=TestRDRAND() && pass;
 	pass=TestRDSEED() && pass;
@@ -96,7 +99,6 @@ bool ValidateAll(bool thorough)
     // Additional tests due to no coverage
 	pass=TestGzip() && pass;
 	pass=TestZinflate() && pass;
-	pass=TestMersenne() && pass;
 	pass=TestDefaultEncryptor() && pass;
 	pass=TestDefaultEncryptorWithMAC() && pass;
 	pass=TestLegacyEncryptor() && pass;
@@ -449,7 +451,7 @@ bool TestOS_RNG()
 		}
 		else
 			std::cout << "passed:";
-		std::cout << "  " << total << " generated bytes compressed to " << meter.GetTotalBytes() << " bytes by DEFLATE" << std::endl;
+		std::cout << "  " << total << " generated bytes compressed to " << meter.GetTotalBytes() << " bytes by DEFLATE\n";
 	}
 	else
 		std::cout << "\nNo operating system provided blocking random number generator, skipping test." << std::endl;
@@ -474,7 +476,7 @@ bool TestOS_RNG()
 		}
 		else
 			std::cout << "passed:";
-		std::cout << "  100000 generated bytes compressed to " << meter.GetTotalBytes() << " bytes by DEFLATE" << std::endl;
+		std::cout << "  100000 generated bytes compressed to " << meter.GetTotalBytes() << " bytes by DEFLATE\n";
 	}
 	else
 		std::cout << "\nNo operating system provided nonblocking random number generator, skipping test." << std::endl;
@@ -511,7 +513,7 @@ bool TestAutoSeeded()
 	}
 	else
 		std::cout << "passed:";
-	std::cout << "  100000 generated bytes compressed to " << meter.GetTotalBytes() << " bytes by DEFLATE" << std::endl;
+	std::cout << "  100000 generated bytes compressed to " << meter.GetTotalBytes() << " bytes by DEFLATE\n";
 
 	try
 	{
@@ -575,7 +577,7 @@ bool TestAutoSeededX917()
 	}
 	else
 		std::cout << "passed:";
-	std::cout << "  100000 generated bytes compressed to " << meter.GetTotalBytes() << " bytes by DEFLATE" << std::endl;
+	std::cout << "  100000 generated bytes compressed to " << meter.GetTotalBytes() << " bytes by DEFLATE\n";
 
 	try
 	{
@@ -621,6 +623,90 @@ bool TestAutoSeededX917()
 }
 #endif // NO_OS_DEPENDENCE
 
+#if (defined(CRYPTOPP_DEBUG) || defined(CRYPTOPP_COVERAGE)) && !defined(CRYPTOPP_IMPORTS)
+bool TestMersenne()
+{
+	std::cout << "\nTesting Mersenne Twister...\n\n";
+
+	static const unsigned int ENTROPY_SIZE = 32;
+	bool equal = true, generate = true, discard = true, incorporate = false;
+
+    // First 10; http://create.stephan-brumme.com/mersenne-twister/
+	word32 result[10], expected[10] = {0xD091BB5C, 0x22AE9EF6,
+		0xE7E1FAEE, 0xD5C31F79, 0x2082352C, 0xF807B7DF, 0xE9D30005,
+		0x3895AFE1, 0xA1E24BBA, 0x4EE4092B};
+
+	MT19937ar prng;
+	prng.GenerateBlock(reinterpret_cast<byte*>(result), sizeof(result));
+    equal = (0 == ::memcmp(result, expected, sizeof(expected)));
+
+	if (equal)
+	{
+		std::cout << "passed:";
+	}
+	else
+	{
+		std::cout << "FAILED:";
+        equal = false;
+	}
+    std::cout << "  Expected sequence from MT19937ar (2002 version)\n";
+
+	MeterFilter meter(new Redirector(TheBitBucket()));
+	RandomNumberSource test(prng, 100000, true, new Deflator(new Redirector(meter)));
+
+	if (meter.GetTotalBytes() < 100000)
+	{
+		std::cout << "FAILED:";
+		generate = false;
+	}
+	else
+		std::cout << "passed:";
+	std::cout << "  100000 generated bytes compressed to " << meter.GetTotalBytes() << " bytes by DEFLATE\n";
+
+	try
+	{
+		prng.DiscardBytes(100000);
+	}
+	catch(const Exception&)
+	{
+		discard = false;
+	}
+
+	if (!discard)
+		std::cout << "FAILED:";
+	else
+		std::cout << "passed:";
+	std::cout << "  discarded 10000 bytes\n";
+
+	try
+	{
+		if(prng.CanIncorporateEntropy())
+		{
+			SecByteBlock entropy(ENTROPY_SIZE);
+			OS_GenerateRandomBlock(false, entropy, entropy.SizeInBytes());
+
+			prng.IncorporateEntropy(entropy, entropy.SizeInBytes());
+			prng.IncorporateEntropy(entropy, entropy.SizeInBytes());
+			prng.IncorporateEntropy(entropy, entropy.SizeInBytes());
+			prng.IncorporateEntropy(entropy, entropy.SizeInBytes());
+
+			incorporate = true;
+		}
+	}
+	catch(const Exception& /*ex*/)
+	{
+	}
+
+	if (!incorporate)
+		std::cout << "FAILED:";
+	else
+		std::cout << "passed:";
+	std::cout << "  IncorporateEntropy with " << 4*ENTROPY_SIZE << " bytes" << std::endl;
+
+	return equal && generate && discard && incorporate;
+}
+#endif
+
 #if (CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X32 || CRYPTOPP_BOOL_X64)
 bool TestRDRAND()
 {
@@ -657,7 +743,7 @@ bool TestRDRAND()
 		// Coverity finding, also see http://stackoverflow.com/a/34509163/608639.
 		StreamState ss(std::cout);
 		std::cout << std::setiosflags(std::ios::fixed) << std::setprecision(6);
-		std::cout << "  Maurer Randomness Test returned value " << mv << std::endl;
+		std::cout << "  Maurer Randomness Test returned value " << mv << "\n";
 
 		if (meter.GetTotalBytes() < SIZE)
 		{
@@ -691,9 +777,6 @@ bool TestRDRAND()
 	(void)rdrand.CanIncorporateEntropy();
 	rdrand.IncorporateEntropy(NULLPTR, 0);
 
-	if (!(entropy && compress && discard))
-		std::cout.flush();
-
 	return entropy && compress && discard;
 }
 #endif
@@ -769,9 +852,6 @@ bool TestRDSEED()
 	(void)rdseed.CanIncorporateEntropy();
 	rdseed.IncorporateEntropy(NULLPTR, 0);
 
-	if (!(entropy && compress && discard))
-		std::cout.flush();
-
 	return entropy && compress && discard;
 }
 #endif