From b21162cf8e06f40baa1f58be6a8c17435cebc34d Mon Sep 17 00:00:00 2001
From: weidai <weidai@57ff6487-cd31-0410-9ec3-f628ee90f5f0>
Date: Fri, 4 Oct 2002 17:31:41 +0000
Subject: Initial revision

git-svn-id: svn://svn.code.sf.net/p/cryptopp/code/trunk/c5@2 57ff6487-cd31-0410-9ec3-f628ee90f5f0
---
 osrng.h | 157 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 157 insertions(+)
 create mode 100644 osrng.h

(limited to 'osrng.h')

diff --git a/osrng.h b/osrng.h
new file mode 100644
index 0000000..3a40560
--- /dev/null
+++ b/osrng.h
@@ -0,0 +1,157 @@
+#ifndef CRYPTOPP_OSRNG_H
+#define CRYPTOPP_OSRNG_H
+
+#include "config.h"
+
+#ifdef OS_RNG_AVAILABLE
+
+#include "randpool.h"
+#include "rng.h"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+//! Exception class for Operating-System Random Number Generator.
+class OS_RNG_Err : public Exception
+{
+public:
+	OS_RNG_Err(const std::string &operation);
+};
+
+#ifdef NONBLOCKING_RNG_AVAILABLE
+
+#ifdef CRYPTOPP_WIN32_AVAILABLE
+class MicrosoftCryptoProvider
+{
+public:
+	MicrosoftCryptoProvider();
+	~MicrosoftCryptoProvider();
+#if defined(_WIN64)
+	typedef unsigned __int64 ProviderHandle;	// type HCRYPTPROV, avoid #include <windows.h>
+#else
+	typedef unsigned long ProviderHandle;
+#endif
+	ProviderHandle GetProviderHandle() const {return m_hProvider;}
+private:
+	ProviderHandle m_hProvider;
+};
+#endif
+
+//! encapsulate CryptoAPI's CryptGenRandom or /dev/urandom
+class NonblockingRng : public RandomNumberGenerator
+{
+public:
+	NonblockingRng();
+	~NonblockingRng();
+	byte GenerateByte();
+	void GenerateBlock(byte *output, unsigned int size);
+
+protected:
+#ifdef CRYPTOPP_WIN32_AVAILABLE
+#	ifndef WORKAROUND_MS_BUG_Q258000
+		MicrosoftCryptoProvider m_Provider;
+#	endif
+#else
+	int m_fd;
+#endif
+};
+
+#endif
+
+#ifdef BLOCKING_RNG_AVAILABLE
+
+//! encapsulate /dev/random
+class BlockingRng : public RandomNumberGenerator
+{
+public:
+	BlockingRng();
+	~BlockingRng();
+	byte GenerateByte();
+	void GenerateBlock(byte *output, unsigned int size);
+
+protected:
+	int m_fd;
+};
+
+#endif
+
+void OS_GenerateRandomBlock(bool blocking, byte *output, unsigned int size);
+
+//! Automaticly Seeded Randomness Pool
+/*! This class seeds itself using an operating system provided RNG. */
+class AutoSeededRandomPool : public RandomPool
+{
+public:
+	//! blocking will be ignored if the prefered RNG isn't available
+	explicit AutoSeededRandomPool(bool blocking = false, unsigned int seedSize = 32)
+		{Reseed(blocking, seedSize);}
+	void Reseed(bool blocking = false, unsigned int seedSize = 32);
+};
+
+//! RNG from ANSI X9.17 Appendix C, seeded using an OS provided RNG
+template <class BLOCK_CIPHER>
+class AutoSeededX917RNG : public RandomNumberGenerator
+{
+public:
+	//! blocking will be ignored if the prefered RNG isn't available
+	explicit AutoSeededX917RNG(bool blocking = false)
+		{Reseed(blocking);}
+	void Reseed(bool blocking = false);
+
+	byte GenerateByte();
+
+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(bool blocking)
+{
+	SecByteBlock seed(BLOCK_CIPHER::BLOCKSIZE + BLOCK_CIPHER::DEFAULT_KEYLENGTH);
+	const byte *key;
+	do
+	{
+		OS_GenerateRandomBlock(blocking, seed, 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);
+	m_rng.reset(new X917RNG(new typename BLOCK_CIPHER::Encryption(key, BLOCK_CIPHER::DEFAULT_KEYLENGTH), seed));
+
+	if (FIPS_140_2_ComplianceEnabled())
+	{
+		m_lastBlock.resize(16);
+		m_rng->GenerateBlock(m_lastBlock, m_lastBlock.size());
+		m_counter = 0;
+		m_isDifferent = false;
+	}
+}
+
+template <class BLOCK_CIPHER>
+byte AutoSeededX917RNG<BLOCK_CIPHER>::GenerateByte()
+{
+	byte b = m_rng->GenerateByte();
+
+	if (FIPS_140_2_ComplianceEnabled())
+	{
+		m_isDifferent = m_isDifferent || b != m_lastBlock[m_counter];
+		m_lastBlock[m_counter] = b;
+		++m_counter;
+		if (m_counter == m_lastBlock.size())
+		{
+			if (!m_isDifferent)
+				throw SelfTestFailure("AutoSeededX917RNG: Continuous random number generator test failed.");
+			m_counter = 0;
+			m_isDifferent = false;
+		}
+	}
+
+	return b;
+}
+
+NAMESPACE_END
+
+#endif
+
+#endif
-- 
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