mirror of
https://github.com/shadps4-emu/ext-cryptopp.git
synced 2024-11-30 05:10:40 +00:00
96 lines
3.8 KiB
C++
96 lines
3.8 KiB
C++
// darn.h - written and placed in public domain by Jeffrey Walton
|
|
// DARN requires POWER9/ISA 3.0.
|
|
|
|
// At the moment only GCC 7.0 (and above) seems to support __builtin_darn()
|
|
// and __builtin_darn_32(). However, GCC generates incorrect code. Clang 7.0
|
|
// does not provide them, but it does support assembly instructions. XLC is
|
|
// unknown, but there are no hits when searching IBM's site. To cover more
|
|
// platforms we provide GCC inline assembly like we do with RDRAND and RDSEED.
|
|
// Platforms that don't support GCC inline assembly or the builtin will fail
|
|
// to compile. Also see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91481 and
|
|
// https://gcc.gnu.org/onlinedocs/gcc/Basic-PowerPC-Built-in-Functions-Available-on-ISA-3_002e0.html
|
|
|
|
/// \file darn.h
|
|
/// \brief Classes for DARN RNG
|
|
/// \sa <A HREF="https://openpowerfoundation.org/?resource_lib=power-isa-version-3-0">Power
|
|
/// ISA Version 3.0B</A>
|
|
/// \since Crypto++ 8.0
|
|
|
|
#ifndef CRYPTOPP_DARN_H
|
|
#define CRYPTOPP_DARN_H
|
|
|
|
#include "cryptlib.h"
|
|
|
|
NAMESPACE_BEGIN(CryptoPP)
|
|
|
|
/// \brief Exception thrown when a DARN generator encounters
|
|
/// a generator related error.
|
|
/// \since Crypto++ 8.0
|
|
class DARN_Err : public Exception
|
|
{
|
|
public:
|
|
DARN_Err(const std::string &operation)
|
|
: Exception(OTHER_ERROR, "DARN: " + operation + " operation failed") {}
|
|
};
|
|
|
|
/// \brief Hardware generated random numbers using DARN instruction
|
|
/// \details DARN() provides access to Power9's random number generator. The
|
|
/// Crypto++ implementation provides conditioned random numbers from the
|
|
/// generator as opposed to raw random numbers. According to Power ISA 3.0B
|
|
/// manual, a conditioned random number has been processed by hardware to
|
|
/// reduce bias. A raw random number is unconditioned noise source output.
|
|
/// \details According to Power ISA 3.0B manual, the random number generator
|
|
/// provided by the <tt>darn</tt> instruction is NIST SP800-90B and SP800-90C
|
|
/// compliant to the extent possible given the completeness of the standards
|
|
/// at the time the hardware is designed. The random number generator provides
|
|
/// a minimum of 0.5 bits of entropy per bit.
|
|
/// \par Wraps
|
|
/// darn instruction
|
|
/// \sa <A HREF="https://openpowerfoundation.org/?resource_lib=power-isa-version-3-0">Power
|
|
/// ISA Version 3.0B</A>, MaurerRandomnessTest() for random bit generators
|
|
/// \since Crypto++ 8.0
|
|
class DARN : public RandomNumberGenerator
|
|
{
|
|
public:
|
|
CRYPTOPP_STATIC_CONSTEXPR const char* StaticAlgorithmName() { return "DARN"; }
|
|
|
|
virtual ~DARN() {}
|
|
|
|
/// \brief Construct a DARN generator
|
|
/// \throw DARN_Err if the random number generator is not available
|
|
DARN();
|
|
|
|
/// \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 "Power9";
|
|
}
|
|
|
|
private:
|
|
SecBlock<byte, AllocatorWithCleanup<byte, true> > m_temp;
|
|
};
|
|
|
|
NAMESPACE_END
|
|
|
|
#endif // CRYPTOPP_DARN_H
|