Remove cryptoppwin submodule (#754)

third_party/cryptoppwin/include/cryptopp/rdrand.h

@@ -0,0 +1,145 @@
+// rdrand.h - written and placed in public domain by Jeffrey Walton and Uri Blumenthal.
+
+/// \file rdrand.h
+/// \brief Classes for RDRAND and RDSEED
+/// \since Crypto++ 5.6.3
+
+#ifndef CRYPTOPP_RDRAND_H
+#define CRYPTOPP_RDRAND_H
+
+#include "cryptlib.h"
+
+// This class file provides both RDRAND and RDSEED. They were added at
+//   Crypto++ 5.6.3. At compile time, it uses CRYPTOPP_BOOL_{X86|X32|X64}
+//   to select an implementation or "throw NotImplemented". At runtime the
+//   constructor will throw RDRAND_Err or RDSEED_Err if a generator is
+//   is not available.
+// The original classes accepted a retry count. Retries were superfluous for
+//   RDRAND, and RDSEED encountered a failure about 1 in 256 bytes depending
+//   on the processor. Retries were removed at Crypto++ 6.0 because
+//   GenerateBlock unconditionally retries and always fulfills the request.
+
+// Throughput varies wildly depending on processor and manufacturer. A Core i5 or
+//   Core i7 RDRAND can generate at over 200 MiB/s. It is below theroetical
+//   maximum, but it takes about 5 instructions to generate, retry and store a
+//   result. A low-end Celeron may perform RDRAND at about 7 MiB/s. RDSEED
+//   performs at about 1/4 to 1/2 the rate of RDRAND. AMD RDRAND performed poorly
+//   during testing with Athlon X4 845. The Bulldozer v4 only performed at 1 MiB/s.
+
+// Microsoft added RDRAND in August 2012, VS2012; RDSEED in October 2013, VS2013.
+// GCC added RDRAND in December 2010, GCC 4.6. LLVM added RDRAND in July 2012,
+// Clang 3.2. Intel added RDRAND in September 2011, ICC 12.1.
+
+NAMESPACE_BEGIN(CryptoPP)
+
+/// \brief Exception thrown when a RDRAND generator encounters
+///    a generator related error.
+/// \since Crypto++ 5.6.3
+class RDRAND_Err : public Exception
+{
+public:
+    RDRAND_Err(const std::string &operation)
+        : Exception(OTHER_ERROR, "RDRAND: " + operation + " operation failed") {}
+};
+
+/// \brief Hardware generated random numbers using RDRAND instruction
+/// \sa MaurerRandomnessTest() for random bit generators
+/// \since Crypto++ 5.6.3
+class RDRAND : public RandomNumberGenerator
+{
+public:
+    CRYPTOPP_STATIC_CONSTEXPR const char* StaticAlgorithmName() { return "RDRAND"; }
+
+    virtual ~RDRAND() {}
+
+    /// \brief Construct a RDRAND generator
+    /// \details According to DJ of Intel, the Intel RDRAND circuit does not underflow.
+    ///   If it did hypothetically underflow, then it would return 0 for the random value.
+    ///   AMD's RDRAND implementation appears to provide the same behavior.
+     /// \throw RDRAND_Err if the random number generator is not available
+    RDRAND();
+
+    /// \brief Generate random array of bytes
+    /// \param output the byte buffer
+    /// \param size the length of the buffer, in bytes
+    virtual void GenerateBlock(byte *output, size_t size);
+
+    /// \brief Generate and discard n bytes
+    /// \param n the number of bytes to generate and discard
+    /// \details the RDSEED generator discards words, not bytes. If n is
+    ///   not a multiple of a machine word, then it is rounded up to
+    ///   that size.
+    virtual void DiscardBytes(size_t n);
+
+    /// \brief Update RNG state with additional unpredictable values
+    /// \param input unused
+    /// \param length unused
+    /// \details The operation is a nop for this generator.
+    virtual void IncorporateEntropy(const byte *input, size_t length)
+    {
+        // Override to avoid the base class' throw.
+        CRYPTOPP_UNUSED(input); CRYPTOPP_UNUSED(length);
+    }
+
+    std::string AlgorithmProvider() const {
+        return "RDRAND";
+    }
+};
+
+/// \brief Exception thrown when a RDSEED generator encounters
+///    a generator related error.
+/// \since Crypto++ 5.6.3
+class RDSEED_Err : public Exception
+{
+public:
+    RDSEED_Err(const std::string &operation)
+        : Exception(OTHER_ERROR, "RDSEED: " + operation + " operation failed") {}
+};
+
+/// \brief Hardware generated random numbers using RDSEED instruction
+/// \sa MaurerRandomnessTest() for random bit generators
+/// \since Crypto++ 5.6.3
+class RDSEED : public RandomNumberGenerator
+{
+public:
+    CRYPTOPP_STATIC_CONSTEXPR const char* StaticAlgorithmName() { return "RDSEED"; }
+
+    virtual ~RDSEED() {}
+
+    /// \brief Construct a RDSEED generator
+    /// \details Empirical testing under a 6th generation i7 (6200U) shows RDSEED fails
+    ///   to fulfill requests at about once every for every 256 bytes requested.
+    ///   The generator runs about 4 times slower than RDRAND.
+     /// \throw RDSEED_Err if the random number generator is not available
+    RDSEED();
+
+    /// \brief Generate random array of bytes
+    /// \param output the byte buffer
+    /// \param size the length of the buffer, in bytes
+    virtual void GenerateBlock(byte *output, size_t size);
+
+    /// \brief Generate and discard n bytes
+    /// \param n the number of bytes to generate and discard
+    /// \details the RDSEED generator discards words, not bytes. If n is
+    ///   not a multiple of a machine word, then it is rounded up to
+    ///   that size.
+    virtual void DiscardBytes(size_t n);
+
+    /// \brief Update RNG state with additional unpredictable values
+    /// \param input unused
+    /// \param length unused
+    /// \details The operation is a nop for this generator.
+    virtual void IncorporateEntropy(const byte *input, size_t length)
+    {
+        // Override to avoid the base class' throw.
+        CRYPTOPP_UNUSED(input); CRYPTOPP_UNUSED(length);
+    }
+
+    std::string AlgorithmProvider() const {
+        return "RDSEED";
+    }
+};
+
+NAMESPACE_END
+
+#endif // CRYPTOPP_RDRAND_H