reduce risk of random number reuse after VM rollback

hrtimer.cpp

@@ -4,7 +4,6 @@
 #include "hrtimer.h"
 #include "misc.h"
 #include <stddef.h>		// for NULL
-#include <time.h>
 
 #if defined(CRYPTOPP_WIN32_AVAILABLE)
 #include <windows.h>
@@ -18,6 +17,8 @@
 
 NAMESPACE_BEGIN(CryptoPP)
 
+#ifndef CRYPTOPP_IMPORTS
+
 double TimerBase::ConvertTo(TimerWord t, Unit unit)
 {
 	static unsigned long unitsPerSecondTable[] = {1, 1000, 1000*1000, 1000*1000*1000};
@@ -56,6 +57,46 @@ unsigned long TimerBase::ElapsedTime()
 	return (unsigned long)elapsed;
 }
 
+TimerWord Timer::GetCurrentTimerValue()
+{
+#if defined(CRYPTOPP_WIN32_AVAILABLE)
+	LARGE_INTEGER now;
+	if (!QueryPerformanceCounter(&now))
+		throw Exception(Exception::OTHER_ERROR, "Timer: QueryPerformanceCounter failed with error " + IntToString(GetLastError()));
+	return now.QuadPart;
+#elif defined(CRYPTOPP_UNIX_AVAILABLE)
+	timeval now;
+	gettimeofday(&now, NULL);
+	return (TimerWord)now.tv_sec * 1000000 + now.tv_usec;
+#else
+	clock_t now;
+	return clock();
+#endif
+}
+
+TimerWord Timer::TicksPerSecond()
+{
+#if defined(CRYPTOPP_WIN32_AVAILABLE)
+	static LARGE_INTEGER freq = {0};
+	if (freq.QuadPart == 0)
+	{
+		if (!QueryPerformanceFrequency(&freq))
+			throw Exception(Exception::OTHER_ERROR, "Timer: QueryPerformanceFrequency failed with error " + IntToString(GetLastError()));
+	}
+	return freq.QuadPart;
+#elif defined(CRYPTOPP_UNIX_AVAILABLE)
+	return 1000000;
+#elif defined(CLOCKS_PER_SEC)
+	return CLOCKS_PER_SEC;
+#elif defined(CLK_TCK)
+	return CLK_TCK;
+#else
+	return 1000000;
+#endif
+}
+
+#endif	// #ifndef CRYPTOPP_IMPORTS
+
 TimerWord ThreadUserTimer::GetCurrentTimerValue()
 {
 #if defined(CRYPTOPP_WIN32_AVAILABLE)
@@ -98,37 +139,4 @@ TimerWord ThreadUserTimer::TicksPerSecond()
 #endif
 }
 
-#ifdef HIGHRES_TIMER_AVAILABLE
-
-TimerWord Timer::GetCurrentTimerValue()
-{
-#if defined(CRYPTOPP_WIN32_AVAILABLE)
-	LARGE_INTEGER now;
-	if (!QueryPerformanceCounter(&now))
-		throw Exception(Exception::OTHER_ERROR, "Timer: QueryPerformanceCounter failed with error " + IntToString(GetLastError()));
-	return now.QuadPart;
-#elif defined(CRYPTOPP_UNIX_AVAILABLE)
-	timeval now;
-	gettimeofday(&now, NULL);
-	return (TimerWord)now.tv_sec * 1000000 + now.tv_usec;
-#endif
-}
-
-TimerWord Timer::TicksPerSecond()
-{
-#if defined(CRYPTOPP_WIN32_AVAILABLE)
-	static LARGE_INTEGER freq = {0};
-	if (freq.QuadPart == 0)
-	{
-		if (!QueryPerformanceFrequency(&freq))
-			throw Exception(Exception::OTHER_ERROR, "Timer: QueryPerformanceFrequency failed with error " + IntToString(GetLastError()));
-	}
-	return freq.QuadPart;
-#elif defined(CRYPTOPP_UNIX_AVAILABLE)
-	return 1000000;
-#endif
-}
-
-#endif	// HIGHRES_TIMER_AVAILABLE
-
 NAMESPACE_END

hrtimer.h

@@ -5,14 +5,19 @@
 
 NAMESPACE_BEGIN(CryptoPP)
 
+#ifdef HIGHRES_TIMER_AVAILABLE
 	#ifdef WORD64_AVAILABLE
 		typedef word64 TimerWord;
 	#else
 		typedef word32 TimerWord;
 	#endif
+#else
+	#include <time.h>
+	typedef clock_t TimerWord;
+#endif
 
 //! _
-class TimerBase
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE TimerBase
 {
 public:
 	enum Unit {SECONDS = 0, MILLISECONDS, MICROSECONDS, NANOSECONDS};
@@ -44,10 +49,8 @@ public:
 	TimerWord TicksPerSecond();
 };
 
-#ifdef HIGHRES_TIMER_AVAILABLE
-
 //! high resolution timer
-class Timer : public TimerBase
+class CRYPTOPP_DLL Timer : public TimerBase
 {
 public:
 	Timer(Unit unit = TimerBase::SECONDS, bool stuckAtZero = false)	: TimerBase(unit, stuckAtZero) {}
@@ -55,8 +58,6 @@ public:
 	TimerWord TicksPerSecond();
 };
 
-#endif	// HIGHRES_TIMER_AVAILABLE
-
 NAMESPACE_END
 
 #endif

osrng.cpp

@@ -74,13 +74,6 @@ NonblockingRng::~NonblockingRng()
 #endif
 }
 
-byte NonblockingRng::GenerateByte()
-{
-	byte b;
-	GenerateBlock(&b, 1);
-	return b;
-}
-
 void NonblockingRng::GenerateBlock(byte *output, size_t size)
 {
 #ifdef CRYPTOPP_WIN32_AVAILABLE
@@ -121,13 +114,6 @@ BlockingRng::~BlockingRng()
 	close(m_fd);
 }
 
-byte BlockingRng::GenerateByte()
-{
-	byte b;
-	GenerateBlock(&b, 1);
-	return b;
-}
-
 void BlockingRng::GenerateBlock(byte *output, size_t size)
 {
 	while (size)
@@ -175,7 +161,7 @@ void AutoSeededRandomPool::Reseed(bool blocking, unsigned int seedSize)
 {
 	SecByteBlock seed(seedSize);
 	OS_GenerateRandomBlock(blocking, seed, seedSize);
-	Put(seed, seedSize);
+	IncorporateEntropy(seed, seedSize);
 }
 
 NAMESPACE_END

osrng.h

@@ -7,7 +7,7 @@
 
 #include "randpool.h"
 #include "rng.h"
-#include "des.h"
+#include "aes.h"
 #include "fips140.h"
 
 NAMESPACE_BEGIN(CryptoPP)
@@ -46,7 +46,6 @@ class CRYPTOPP_DLL NonblockingRng : public RandomNumberGenerator
 public:
 	NonblockingRng();
 	~NonblockingRng();
-	byte GenerateByte();
 	void GenerateBlock(byte *output, size_t size);
 
 protected:
@@ -69,7 +68,6 @@ class CRYPTOPP_DLL BlockingRng : public RandomNumberGenerator
 public:
 	BlockingRng();
 	~BlockingRng();
-	byte GenerateByte();
 	void GenerateBlock(byte *output, size_t size);
 
 protected:
@@ -99,39 +97,39 @@ public:
 	//! use blocking to choose seeding with BlockingRng or NonblockingRng. the parameter is ignored if only one of these is available
 	explicit AutoSeededX917RNG(bool blocking = false)
 		{Reseed(blocking);}
-	void Reseed(bool blocking = false);
+	void Reseed(bool blocking = false, const byte *additionalEntropy = NULL, size_t length = 0);
 	// exposed for testing
 	void Reseed(const byte *key, size_t keylength, const byte *seed, const byte *timeVector);
 
-	byte GenerateByte();
+	bool CanIncorporateEntropy() const {return true;}
+	void IncorporateEntropy(const byte *input, size_t length) {Reseed(false, input, length);}
+	void GenerateIntoBufferedTransformation(BufferedTransformation &target, const std::string &channel, lword length) {m_rng->GenerateIntoBufferedTransformation(target, channel, length);}
 
 private:
 	member_ptr<RandomNumberGenerator> m_rng;
-	SecByteBlock m_lastBlock;
-	bool m_isDifferent;
-	unsigned int m_counter;
 };
 
 template <class BLOCK_CIPHER>
 void AutoSeededX917RNG<BLOCK_CIPHER>::Reseed(const byte *key, size_t keylength, const byte *seed, const byte *timeVector)
 {
 	m_rng.reset(new X917RNG(new typename BLOCK_CIPHER::Encryption(key, keylength), seed, timeVector));
-
-	// for FIPS 140-2
-	m_lastBlock.resize(16);
-	m_rng->GenerateBlock(m_lastBlock, m_lastBlock.size());
-	m_counter = 0;
-	m_isDifferent = false;
 }
 
 template <class BLOCK_CIPHER>
-void AutoSeededX917RNG<BLOCK_CIPHER>::Reseed(bool blocking)
+void AutoSeededX917RNG<BLOCK_CIPHER>::Reseed(bool blocking, const byte *input, size_t length)
 {
 	SecByteBlock seed(BLOCK_CIPHER::BLOCKSIZE + BLOCK_CIPHER::DEFAULT_KEYLENGTH);
 	const byte *key;
 	do
 	{
 		OS_GenerateRandomBlock(blocking, seed, seed.size());
+		if (length > 0)
+		{
+			SHA256 hash;
+			hash.Update(seed, seed.size());
+			hash.Update(input, length);
+			hash.TruncatedFinal(seed, UnsignedMin(hash.DigestSize(), seed.size()));
+		}
 		key = seed + BLOCK_CIPHER::BLOCKSIZE;
 	}	// check that seed and key don't have same value
 	while (memcmp(key, seed, STDMIN((unsigned int)BLOCK_CIPHER::BLOCKSIZE, (unsigned int)BLOCK_CIPHER::DEFAULT_KEYLENGTH)) == 0);
@@ -139,27 +137,13 @@ void AutoSeededX917RNG<BLOCK_CIPHER>::Reseed(bool blocking)
 	Reseed(key, BLOCK_CIPHER::DEFAULT_KEYLENGTH, seed, NULL);
 }
 
-template <class BLOCK_CIPHER>
+CRYPTOPP_DLL_TEMPLATE_CLASS AutoSeededX917RNG<AES>;
-byte AutoSeededX917RNG<BLOCK_CIPHER>::GenerateByte()
-{
-	byte b = m_rng->GenerateByte();
 
-	// for FIPS 140-2
+#if CRYPTOPP_ENABLE_COMPLIANCE_WITH_FIPS_140_2
-	m_isDifferent = m_isDifferent || b != m_lastBlock[m_counter];
+typedef AutoSeededX917RNG<AES> DefaultAutoSeededRNG;
-	m_lastBlock[m_counter] = b;
+#else
-	++m_counter;
+typedef AutoSeededRandomPool DefaultAutoSeededRNG;
-	if (m_counter == m_lastBlock.size())
+#endif
-	{
-		if (!m_isDifferent)
-			throw SelfTestFailure("AutoSeededX917RNG: Continuous random number generator test failed.");
-		m_counter = 0;
-		m_isDifferent = false;
-	}
-
-	return b;
-}
-
-CRYPTOPP_DLL_TEMPLATE_CLASS AutoSeededX917RNG<DES_EDE3>;
 
 NAMESPACE_END
 

rng.cpp

@@ -3,6 +3,7 @@
 #include "pch.h"
 
 #include "rng.h"
+#include "fips140.h"
 
 #include <time.h>
 #include <math.h>
@@ -35,7 +36,9 @@ const word16 LC_RNG::a=16807;
 const word16 LC_RNG::r=2836;
 #endif
 
-byte LC_RNG::GenerateByte()
+void LC_RNG::GenerateBlock(byte *output, size_t size)
+{
+	while (size--)
 	{
 		word32 hi = seed/q;
 		word32 lo = seed%q;
@@ -47,7 +50,8 @@ byte LC_RNG::GenerateByte()
 		else
 			seed = test+ m;
 
-	return (GETBYTE(seed, 0) ^ GETBYTE(seed, 1) ^ GETBYTE(seed, 2) ^ GETBYTE(seed, 3));
+		*output++ = (GETBYTE(seed, 0) ^ GETBYTE(seed, 1) ^ GETBYTE(seed, 2) ^ GETBYTE(seed, 3));
+	}
 }
 
 // ********************************************************
@@ -59,24 +63,26 @@ X917RNG::X917RNG(BlockTransformation *c, const byte *seed, const byte *determini
 	  S(cipher->BlockSize()),
 	  dtbuf(S),
 	  randseed(seed, S),
-	  randbuf(S),
+	  m_lastBlock(S),
-	  randbuf_counter(0),
 	  m_deterministicTimeVector(deterministicTimeVector, deterministicTimeVector ? S : 0)
 {
 	if (!deterministicTimeVector)
 	{
 		time_t tstamp1 = time(0);
-		xorbuf(dtbuf, (byte *)&tstamp1, STDMIN((int)sizeof(tstamp1), S));
+		xorbuf(dtbuf, (byte *)&tstamp1, UnsignedMin(sizeof(tstamp1), S));
 		cipher->ProcessBlock(dtbuf);
 		clock_t tstamp2 = clock();
-		xorbuf(dtbuf, (byte *)&tstamp2, STDMIN((int)sizeof(tstamp2), S));
+		xorbuf(dtbuf, (byte *)&tstamp2, UnsignedMin(sizeof(tstamp2), S));
 		cipher->ProcessBlock(dtbuf);
 	}
+
+	// for FIPS 140-2
+	GenerateBlock(m_lastBlock, S);
 }
 
-byte X917RNG::GenerateByte()
+void X917RNG::GenerateIntoBufferedTransformation(BufferedTransformation &target, const std::string &channel, lword size)
 {
-	if (randbuf_counter==0)
+	while (size > 0)
 	{
 		// calculate new enciphered timestamp
 		if (m_deterministicTimeVector.size())
@@ -86,8 +92,10 @@ byte X917RNG::GenerateByte()
 		}
 		else
 		{
-			clock_t tstamp = clock();
+			clock_t c = clock();
-			xorbuf(dtbuf, (byte *)&tstamp, STDMIN((int)sizeof(tstamp), S));
+			xorbuf(dtbuf, (byte *)&c, UnsignedMin(sizeof(c), S));
+			time_t t = time(NULL);
+			xorbuf(dtbuf+S-UnsignedMin(sizeof(t), S), (byte *)&t, UnsignedMin(sizeof(t), S));
 			cipher->ProcessBlock(dtbuf);
 		}
 
@@ -95,16 +103,20 @@ byte X917RNG::GenerateByte()
 		xorbuf(randseed, dtbuf, S);
 
 		// generate a new block of random bytes
-		cipher->ProcessBlock(randseed, randbuf);
+		cipher->ProcessBlock(randseed);
+		if (memcmp(m_lastBlock, randseed, S) == 0)
+			throw SelfTestFailure("X917RNG: Continuous random number generator test failed.");
+
+		// output random bytes
+		size_t len = UnsignedMin(size, S);
+		target.ChannelPut(channel, randseed, len);
+		size -= len;
 
 		// compute new seed vector
-		for (int i=0; i<S; i++)
+		memcpy(m_lastBlock, randseed, S);
-			randseed[i] = randbuf[i] ^ dtbuf[i];
+		xorbuf(randseed, dtbuf, S);
 		cipher->ProcessBlock(randseed);
-
-		randbuf_counter=S;
 	}
-	return(randbuf[S-randbuf_counter--]);
 }
 
 #endif

rng.h

@@ -16,7 +16,7 @@ public:
 	LC_RNG(word32 init_seed)
 		: seed(init_seed) {}
 
-	byte GenerateByte();
+	void GenerateBlock(byte *output, size_t size);
 
 	word32 GetSeed() {return seed;}
 
@@ -37,14 +37,13 @@ public:
 	// cipher will be deleted by destructor, deterministicTimeVector = 0 means obtain time vector from system
 	X917RNG(BlockTransformation *cipher, const byte *seed, const byte *deterministicTimeVector = 0);
 
-	byte GenerateByte();
+	void GenerateIntoBufferedTransformation(BufferedTransformation &target, const std::string &channel, lword size);
 
 private:
 	member_ptr<BlockTransformation> cipher;
-	const int S;			// blocksize of cipher
+	unsigned int S;			// blocksize of cipher
 	SecByteBlock dtbuf; 	// buffer for enciphered timestamp
-	SecByteBlock randseed, randbuf, m_deterministicTimeVector;
+	SecByteBlock randseed, m_lastBlock, m_deterministicTimeVector;
-	int randbuf_counter;	// # of unused bytes left in randbuf
 };
 
 /** This class implements Maurer's Universal Statistical Test for Random Bit Generators