Initial revision

1 files changed, 170 insertions, 0 deletions

diff --git a/osrng.cpp b/osrng.cpp
new file mode 100644
index 00000000..9f45b86e
--- /dev/null
+++ b/osrng.cpp
@@ -0,0 +1,170 @@
+// osrng.cpp - written and placed in the public domain by Wei Dai
+
+// Thanks to Leonard Janke for the suggestion for AutoSeededRandomPool.
+
+#include "pch.h"
+#include "osrng.h"
+
+#ifdef OS_RNG_AVAILABLE
+
+#include "rng.h"
+
+#ifdef CRYPTOPP_WIN32_AVAILABLE
+#ifndef _WIN32_WINNT
+#define _WIN32_WINNT 0x0400
+#endif
+#include <windows.h>
+#include <wincrypt.h>
+#else
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#endif
+
+NAMESPACE_BEGIN(CryptoPP)
+
+#if defined(NONBLOCKING_RNG_AVAILABLE) || defined(BLOCKING_RNG_AVAILABLE)
+OS_RNG_Err::OS_RNG_Err(const std::string &operation)
+	: Exception(OTHER_ERROR, "OS_Rng: " + operation + " operation failed with error " + 
+#ifdef CRYPTOPP_WIN32_AVAILABLE
+		"0x" + IntToString(GetLastError(), 16)
+#else
+		IntToString(errno)
+#endif
+		)
+{
+}
+#endif
+
+#ifdef NONBLOCKING_RNG_AVAILABLE
+
+#ifdef CRYPTOPP_WIN32_AVAILABLE
+
+MicrosoftCryptoProvider::MicrosoftCryptoProvider()
+{
+	if(!CryptAcquireContext(&m_hProvider, 0, 0, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT))
+		throw OS_RNG_Err("CryptAcquireContext");
+}
+
+MicrosoftCryptoProvider::~MicrosoftCryptoProvider()
+{
+	CryptReleaseContext(m_hProvider, 0);
+}
+
+#endif
+
+NonblockingRng::NonblockingRng()
+{
+#ifndef CRYPTOPP_WIN32_AVAILABLE
+	m_fd = open("/dev/urandom",O_RDONLY);
+	if (m_fd == -1)
+		throw OS_RNG_Err("open /dev/urandom");
+#endif
+}
+
+NonblockingRng::~NonblockingRng()
+{
+#ifndef CRYPTOPP_WIN32_AVAILABLE
+	close(m_fd);
+#endif
+}
+
+byte NonblockingRng::GenerateByte()
+{
+	byte b;
+	GenerateBlock(&b, 1);
+	return b;
+}
+
+void NonblockingRng::GenerateBlock(byte *output, unsigned int size)
+{
+#ifdef CRYPTOPP_WIN32_AVAILABLE
+#	ifdef WORKAROUND_MS_BUG_Q258000
+		static MicrosoftCryptoProvider m_Provider;
+#	endif
+	if (!CryptGenRandom(m_Provider.GetProviderHandle(), size, output))
+		throw OS_RNG_Err("CryptGenRandom");
+#else
+	if (read(m_fd, output, size) != size)
+		throw OS_RNG_Err("read /dev/urandom");
+#endif
+}
+
+#endif
+
+// *************************************************************
+
+#ifdef BLOCKING_RNG_AVAILABLE
+
+BlockingRng::BlockingRng()
+{
+	m_fd = open("/dev/random",O_RDONLY);
+	if (m_fd == -1)
+		throw OS_RNG_Err("open /dev/random");
+}
+
+BlockingRng::~BlockingRng()
+{
+	close(m_fd);
+}
+
+byte BlockingRng::GenerateByte()
+{
+	byte b;
+	GenerateBlock(&b, 1);
+	return b;
+}
+
+void BlockingRng::GenerateBlock(byte *output, unsigned int size)
+{
+	while (size)
+	{
+		// on some systems /dev/random will block until all bytes
+		// are available, on others it will returns immediately
+		int len = read(m_fd, output, STDMIN(size, (unsigned int)INT_MAX));
+		if (len == -1)
+			throw OS_RNG_Err("read /dev/random");
+		size -= len;
+		output += len;
+		if (size)
+			sleep(1);
+	}
+}
+
+#endif
+
+// *************************************************************
+
+void OS_GenerateRandomBlock(bool blocking, byte *output, unsigned int size)
+{
+#ifdef NONBLOCKING_RNG_AVAILABLE
+	if (blocking)
+#endif
+	{
+#ifdef BLOCKING_RNG_AVAILABLE
+		BlockingRng rng;
+		rng.GenerateBlock(output, size);
+#endif
+	}
+
+#ifdef BLOCKING_RNG_AVAILABLE
+	if (!blocking)
+#endif
+	{
+#ifdef NONBLOCKING_RNG_AVAILABLE
+		NonblockingRng rng;
+		rng.GenerateBlock(output, size);
+#endif
+	}
+}
+
+void AutoSeededRandomPool::Reseed(bool blocking, unsigned int seedSize)
+{
+	SecByteBlock seed(seedSize);
+	OS_GenerateRandomBlock(blocking, seed, seedSize);
+	Put(seed, seedSize);
+}
+
+NAMESPACE_END
+
+#endif