Remove cryptoppwin submodule (#754)

third_party/cryptoppwin/include/cryptopp/mersenne.h

@@ -0,0 +1,231 @@
+// mersenne.h - written and placed in public domain by Jeffrey Walton.
+
+/// \file mersenne.h
+/// \brief Class file for Mersenne Twister
+/// \warning MersenneTwister is suitable for Monte-Carlo simulations, where uniformaly distributed
+///  numbers are required quickly. It should not be used for cryptographic purposes.
+/// \since Crypto++ 5.6.3
+#ifndef CRYPTOPP_MERSENNE_TWISTER_H
+#define CRYPTOPP_MERSENNE_TWISTER_H
+
+#include "cryptlib.h"
+#include "secblock.h"
+#include "misc.h"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+/// \brief Mersenne Twister class for Monte-Carlo simulations
+/// \tparam K Magic constant
+/// \tparam M Period parameter
+/// \tparam N Size of the state vector
+/// \tparam F Multiplier constant
+/// \tparam S Initial seed
+/// \details Provides the MersenneTwister implementation. The class is a header-only implementation.
+/// \details You should reseed the generator after a fork() to avoid multiple generators
+///  with the same internal state.
+/// \warning MersenneTwister is suitable for simulations, where uniformaly distributed numbers are
+///  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, word32 S>
+class MersenneTwister : public RandomNumberGenerator
+{
+public:
+	CRYPTOPP_STATIC_CONSTEXPR const char* StaticAlgorithmName() { return (S==5489 ? "MT19937ar" : (S==4537 ? "MT19937" : "MT19937x")); }
+
+	~MersenneTwister() {}
+
+	/// \brief Construct a Mersenne Twister
+	/// \param seed 32-bit seed
+	/// \details Defaults to template parameter S due to changing algorithm
+	///  parameters over time
+	MersenneTwister(word32 seed = S) : m_idx(N)
+	{
+		Reset(seed);
+	}
+
+	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)
+	{
+		// Handle word32 size blocks
+		FixedSizeSecBlock<word32, 1> temp;
+		temp[0] = 0;
+
+		if (length > 4)
+			length = 4;
+
+		for (size_t i=0; i<length; ++i)
+		{
+			temp[0] <<= 8;
+			temp[0] = temp[0] | input[i];
+		}
+
+		Reset(temp[0]);
+	}
+
+	/// \brief Generate random array of bytes
+	/// \param output byte buffer
+	/// \param size length of the buffer, in bytes
+	/// \details Bytes are written to output in big endian order. If output length
+	///  is not a multiple of word32, then unused bytes are not accumulated for subsequent
+	///  calls to GenerateBlock. Rather, the unused tail bytes are discarded, and the
+	///  stream is continued at the next word32 boundary from the state array.
+	void GenerateBlock(byte *output, size_t size)
+	{
+		// Handle word32 size blocks
+		FixedSizeSecBlock<word32, 1> temp;
+		for (size_t i=0; i < size/4; i++, output += 4)
+		{
+			temp[0] = NextMersenneWord();
+			std::memcpy(output, temp+0, 4);
+		}
+
+		// No tail bytes
+		if (size%4 == 0)
+			return;
+
+		// Handle tail bytes
+		temp[0] = NextMersenneWord();
+		switch (size%4)
+		{
+			case 3: output[2] = CRYPTOPP_GET_BYTE_AS_BYTE(temp[0], 1); /* fall through */
+			case 2: output[1] = CRYPTOPP_GET_BYTE_AS_BYTE(temp[0], 2); /* fall through */
+			case 1: output[0] = CRYPTOPP_GET_BYTE_AS_BYTE(temp[0], 3); break;
+
+			default: CRYPTOPP_ASSERT(0);;
+		}
+	}
+
+	/// \brief Generate a random 32-bit word in the range min to max, inclusive
+	/// \return random 32-bit word in the range min to max, inclusive
+	/// \details If the 32-bit candidate is not within the range, then it is discarded
+	///  and a new candidate is used.
+	word32 GenerateWord32(word32 min=0, word32 max=0xffffffffL)
+	{
+		const word32 range = max-min;
+		if (range == 0xffffffffL)
+			return NextMersenneWord();
+
+		const int maxBits = BitPrecision(range);
+		word32 value;
+
+		do{
+			value = Crop(NextMersenneWord(), maxBits);
+		} while (value > range);
+
+		return value+min;
+	}
+
+	/// \brief Generate and discard n bytes
+	/// \param n the number of bytes to discard, rounded up to a <tt>word32</tt> size
+	/// \details If n is not a multiple of <tt>word32</tt>, then unused bytes are
+	///  not accumulated for subsequent calls to GenerateBlock. Rather, the unused
+	///  tail bytes are discarded, and the stream is continued at the next
+	///  <tt>word32</tt> boundary from the state array.
+	void DiscardBytes(size_t n)
+	{
+		for(size_t i=0; i < RoundUpToMultipleOf(n, 4U); i++)
+			NextMersenneWord();
+	}
+
+protected:
+
+	void Reset(word32 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
+	/// \return the next 32-bit word from the state array
+	/// \details fetches the next word frm the state array, performs bit operations on
+	///  it, and then returns the value to the caller.
+	word32 NextMersenneWord()
+	{
+		if (m_idx >= N) { Twist(); }
+
+		word32 temp = m_state[m_idx++];
+
+		temp ^= (temp >> 11);
+		temp ^= (temp << 7)  & 0x9D2C5680; // 0x9D2C5680 (2636928640)
+		temp ^= (temp << 15) & 0xEFC60000; // 0xEFC60000 (4022730752)
+
+		return temp ^ (temp >> 18);
+	}
+
+	/// \brief Performs the twist operation on the state array
+	void Twist()
+	{
+		static const word32 magic[2]={0x0UL, K};
+		word32 kk, temp;
+
+		CRYPTOPP_ASSERT(N >= M);
+		for (kk=0;kk<N-M;kk++)
+		{
+			temp = (m_state[kk] & 0x80000000)|(m_state[kk+1] & 0x7FFFFFFF);
+			m_state[kk] = m_state[kk+M] ^ (temp >> 1) ^ magic[temp & 0x1UL];
+		}
+
+		for (;kk<N-1;kk++)
+		{
+			temp = (m_state[kk] & 0x80000000)|(m_state[kk+1] & 0x7FFFFFFF);
+			m_state[kk] = m_state[kk+(M-N)] ^ (temp >> 1) ^ magic[temp & 0x1UL];
+		}
+
+		temp = (m_state[N-1] & 0x80000000)|(m_state[0] & 0x7FFFFFFF);
+		m_state[N-1] = m_state[M-1] ^ (temp >> 1) ^ magic[temp & 0x1UL];
+
+		// Reset index
+		m_idx = 0;
+
+		// Wipe temp
+		SecureWipeArray(&temp, 1);
+	}
+
+private:
+
+	/// \brief 32-bit word state array of size N
+	FixedSizeSecBlock<word32, N+1> m_state;
+	/// \brief the current index into the state array
+	word32 m_idx;
+};
+
+/// \brief Original MT19937 generator provided in the ACM paper.
+/// \details MT19937 uses 4537 as default initial seed.
+/// \details You should reseed the generator after a fork() to avoid multiple generators
+///  with the same internal state.
+/// \sa MT19937ar, <A HREF="http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/ARTICLES/mt.pdf">Mersenne twister:
+///  a 623-dimensionally equidistributed uniform pseudo-random number generator</A>
+/// \since Crypto++ 5.6.3
+#if CRYPTOPP_DOXYGEN_PROCESSING
+class MT19937 : public MersenneTwister<0x9908B0DF /*2567483615*/, 397, 624, 0x10DCD /*69069*/, 4537> {};
+#else
+typedef MersenneTwister<0x9908B0DF /*2567483615*/, 397, 624, 0x10DCD /*69069*/, 4537> MT19937;
+#endif
+
+/// \brief Updated MT19937 generator adapted to provide an array for initialization.
+/// \details MT19937 uses 5489 as default initial seed. Use this generator when interoperating with C++11's
+///  mt19937 class.
+/// \details You should reseed the generator after a fork() to avoid multiple generators
+///  with the same internal state.
+/// \sa MT19937, <A HREF="http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/MT2002/emt19937ar.html">Mersenne Twister
+///  with improved initialization</A>
+/// \since Crypto++ 5.6.3
+#if CRYPTOPP_DOXYGEN_PROCESSING
+class MT19937ar : public MersenneTwister<0x9908B0DF /*2567483615*/, 397, 624, 0x6C078965 /*1812433253*/, 5489> {};
+#else
+typedef MersenneTwister<0x9908B0DF /*2567483615*/, 397, 624, 0x6C078965 /*1812433253*/, 5489> MT19937ar;
+#endif
+
+NAMESPACE_END
+
+#endif // CRYPTOPP_MERSENNE_TWISTER_H