rdrand.cpp
// rdrand.cpp - written and placed in public domain by Jeffrey Walton and Uri Blumenthal.
// Copyright assigned to Crypto++ project.
#include "pch.h"
#include "config.h"
#include "cryptlib.h"
#include "secblock.h"
#include "rdrand.h"
#include "cpu.h"
#if CRYPTOPP_MSC_VERSION
# pragma warning(disable: 4100)
#endif
// This file (and friends) provides both RDRAND and RDSEED, but its somewhat
// experimental. They were added at Crypto++ 5.6.3. At compile time, it
// indirectly uses CRYPTOPP_BOOL_{X86|X32|X64} (via CRYPTOPP_CPUID_AVAILABLE)
// to select an implementation or "throw NotImplemented". At runtime, the
// class uses the result of CPUID to determine if RDRAND or RDSEED are
// available. If not available, a lazy throw strategy is used. I.e., the
// throw is deferred until GenerateBlock() is called.
// Here's the naming convention for the functions....
// MSC = Microsoft Compiler (and compatibles)
// GCC = GNU Compiler (and compatibles)
// ALL = MSC and GCC (and compatibles)
// RRA = RDRAND, Assembly
// RSA = RDSEED, Assembly
// RRI = RDRAND, Intrinsic
// RSA = RDSEED, Intrinsic
/////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////
// For Linux, install NASM, run rdrand-nasm.asm, add the apppropriate
// object file to the Makefile's LIBOBJS (rdrand-x{86|32|64}.o). After
// that, define these. They are not enabled by default because they
// are not easy to cut-in in the Makefile.
#if 0
#define NASM_RDRAND_ASM_AVAILABLE 1
#define NASM_RDSEED_ASM_AVAILABLE 1
#endif
/////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////
// In general, the library's ASM code is best on Windows, and Intrinsics is
// the best code under GCC. Clang is missing symbols, so it gets ASM.
// The NASM code is optimized well on Linux, but its not easy to cut-in.
#if (CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X32 || CRYPTOPP_BOOL_X64)
# ifndef CRYPTOPP_CPUID_AVAILABLE
# define CRYPTOPP_CPUID_AVAILABLE
# endif
#endif
#if defined(CRYPTOPP_CPUID_AVAILABLE)
# if defined(CRYPTOPP_MSC_VERSION)
# define MASM_RDRAND_ASM_AVAILABLE 1
# define MASM_RDSEED_ASM_AVAILABLE 1
# elif defined(CRYPTOPP_LLVM_CLANG_VERSION) || defined(CRYPTOPP_APPLE_CLANG_VERSION)
# define GCC_RDRAND_ASM_AVAILABLE 1
# define GCC_RDSEED_ASM_AVAILABLE 1
# elif defined(__SUNPRO_CC)
# if defined(__RDRND__) && (__SUNPRO_CC >= 0x5130)
# define ALL_RDRAND_INTRIN_AVAILABLE 1
# elif (__SUNPRO_CC >= 0x5100)
# define GCC_RDRAND_ASM_AVAILABLE 1
# endif
# if defined(__RDSEED__) && (__SUNPRO_CC >= 0x5140)
# define ALL_RDSEED_INTRIN_AVAILABLE 1
# elif (__SUNPRO_CC >= 0x5100)
# define GCC_RDSEED_ASM_AVAILABLE 1
# endif
# elif defined(CRYPTOPP_GCC_VERSION)
# if defined(__RDRND__) && (CRYPTOPP_GCC_VERSION >= 30200)
# define ALL_RDRAND_INTRIN_AVAILABLE 1
# else
# define GCC_RDRAND_ASM_AVAILABLE 1
# endif
# if defined(__RDSEED__) && (CRYPTOPP_GCC_VERSION >= 30200)
# define ALL_RDSEED_INTRIN_AVAILABLE 1
# else
# define GCC_RDSEED_ASM_AVAILABLE 1
# endif
# endif
#endif
// Debug diagnostics
#if 0
# if MASM_RDRAND_ASM_AVAILABLE
# pragma message ("MASM_RDRAND_ASM_AVAILABLE is 1")
# elif NASM_RDRAND_ASM_AVAILABLE
# pragma message ("NASM_RDRAND_ASM_AVAILABLE is 1")
# elif GCC_RDRAND_ASM_AVAILABLE
# pragma message ("GCC_RDRAND_ASM_AVAILABLE is 1")
# elif ALL_RDRAND_INTRIN_AVAILABLE
# pragma message ("ALL_RDRAND_INTRIN_AVAILABLE is 1")
# else
# pragma message ("RDRAND is not available")
# endif
# if MASM_RDSEED_ASM_AVAILABLE
# pragma message ("MASM_RDSEED_ASM_AVAILABLE is 1")
# elif NASM_RDSEED_ASM_AVAILABLE
# pragma message ("NASM_RDSEED_ASM_AVAILABLE is 1")
# elif GCC_RDSEED_ASM_AVAILABLE
# pragma message ("GCC_RDSEED_ASM_AVAILABLE is 1")
# elif ALL_RDSEED_INTRIN_AVAILABLE
# pragma message ("ALL_RDSEED_INTRIN_AVAILABLE is 1")
# else
# pragma message ("RDSEED is not available")
# endif
#endif
/////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////
#if (ALL_RDRAND_INTRIN_AVAILABLE || ALL_RDSEED_INTRIN_AVAILABLE)
# include <immintrin.h> // rdrand, MSC, ICC, GCC, and SunCC
# if defined(__GNUC__) && (CRYPTOPP_GCC_VERSION >= 40600)
# include <x86intrin.h> // rdseed for some compilers, like GCC
# endif
# if defined(__has_include)
# if __has_include(<x86intrin.h>)
# include <x86intrin.h> // rdrand for Clang (immintrin.h); rdseed for Clang (rdseedintrin.h)
# endif
# endif
#endif
#if MASM_RDRAND_ASM_AVAILABLE
# ifdef _M_X64
extern "C" int CRYPTOPP_FASTCALL MASM_RRA_GenerateBlock(byte*, size_t, unsigned int);
// # pragma comment(lib, "rdrand-x64.lib")
# else
extern "C" int MASM_RRA_GenerateBlock(byte*, size_t, unsigned int);
// # pragma comment(lib, "rdrand-x86.lib")
# endif
#endif
#if MASM_RDSEED_ASM_AVAILABLE
# ifdef _M_X64
extern "C" int CRYPTOPP_FASTCALL MASM_RSA_GenerateBlock(byte*, size_t, unsigned int);
// # pragma comment(lib, "rdrand-x64.lib")
# else
extern "C" int MASM_RSA_GenerateBlock(byte*, size_t, unsigned int);
// # pragma comment(lib, "rdrand-x86.lib")
# endif
#endif
#if NASM_RDRAND_ASM_AVAILABLE
extern "C" int NASM_RRA_GenerateBlock(byte*, size_t, unsigned int);
#endif
#if NASM_RDSEED_ASM_AVAILABLE
extern "C" int NASM_RSA_GenerateBlock(byte*, size_t, unsigned int);
#endif
/////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////
NAMESPACE_BEGIN(CryptoPP)
#if ALL_RDRAND_INTRIN_AVAILABLE
static int ALL_RRI_GenerateBlock(byte *output, size_t size, unsigned int safety)
{
assert((output && size) || !(output || size));
#if CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X32
word32 val;
#else
word64 val;
#endif
while (size >= sizeof(val))
{
#if CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X32
if (_rdrand32_step((word32*)output))
#else
// Cast due to GCC, http://github.com/weidai11/cryptopp/issues/236
if (_rdrand64_step(reinterpret_cast<unsigned long long*>(output)))
#endif
{
output += sizeof(val);
size -= sizeof(val);
}
else
{
if (!safety--)
{
assert(0);
return 0;
}
}
}
if (size)
{
#if CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X32
if (_rdrand32_step(&val))
#else
// Cast due to GCC, http://github.com/weidai11/cryptopp/issues/236
if (_rdrand64_step(reinterpret_cast<unsigned long long*>(&val)))
#endif
{
memcpy(output, &val, size);
size = 0;
}
else
{
if (!safety--)
{
assert(0);
return 0;
}
}
}
SecureWipeBuffer(&val, 1);
return int(size == 0);
}
#endif // ALL_RDRAND_INTRINSIC_AVAILABLE
#if GCC_RDRAND_ASM_AVAILABLE
static int GCC_RRA_GenerateBlock(byte *output, size_t size, unsigned int safety)
{
assert((output && size) || !(output || size));
#if CRYPTOPP_BOOL_X64 || CRYPTOPP_BOOL_X32
word64 val;
#else
word32 val;
#endif
char rc;
while (size)
{
__asm__ volatile(
#if CRYPTOPP_BOOL_X64 || CRYPTOPP_BOOL_X32
".byte 0x48, 0x0f, 0xc7, 0xf0;\n" // rdrand rax
#else
".byte 0x0f, 0xc7, 0xf0;\n" // rdrand eax
#endif
"setc %1; "
: "=a" (val), "=qm" (rc)
:
: "cc"
);
if (rc)
{
if (size >= sizeof(val))
{
#if defined(CRYPTOPP_ALLOW_UNALIGNED_DATA_ACCESS) && (CRYPTOPP_BOOL_X64 || CRYPTOPP_BOOL_X32)
*((word64*)(void *)output) = val;
#elif defined(CRYPTOPP_ALLOW_UNALIGNED_DATA_ACCESS) && (CRYPTOPP_BOOL_X86)
*((word32*)(void *)output) = val;
#else
memcpy(output, &val, sizeof(val));
#endif
output += sizeof(val);
size -= sizeof(val);
}
else
{
memcpy(output, &val, size);
size = 0;
}
}
else
{
if (!safety--)
{
assert(0);
return 0;
}
}
}
SecureWipeBuffer(&val, 1);
return int(size == 0);
}
#endif // GCC_RDRAND_ASM_AVAILABLE
#if (CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X32 || CRYPTOPP_BOOL_X64)
void RDRAND::GenerateBlock(byte *output, size_t size)
{
CRYPTOPP_UNUSED(output), CRYPTOPP_UNUSED(size);
assert((output && size) || !(output || size));
if(!HasRDRAND())
throw NotImplemented("RDRAND: rdrand is not available on this platform");
int rc; CRYPTOPP_UNUSED(rc);
#if MASM_RDRAND_ASM_AVAILABLE
rc = MASM_RRA_GenerateBlock(output, size, m_retries);
if (!rc) { throw RDRAND_Err("MASM_RRA_GenerateBlock"); }
#elif NASM_RDRAND_ASM_AVAILABLE
rc = NASM_RRA_GenerateBlock(output, size, m_retries);
if (!rc) { throw RDRAND_Err("NASM_RRA_GenerateBlock"); }
#elif ALL_RDRAND_INTRIN_AVAILABLE
rc = ALL_RRI_GenerateBlock(output, size, m_retries);
if (!rc) { throw RDRAND_Err("ALL_RRI_GenerateBlock"); }
#elif GCC_RDRAND_ASM_AVAILABLE
rc = GCC_RRA_GenerateBlock(output, size, m_retries);
if (!rc) { throw RDRAND_Err("GCC_RRA_GenerateBlock"); }
#else
// RDRAND not detected at compile time, and no suitable compiler found
throw NotImplemented("RDRAND: failed to find a suitable implementation???");
#endif // CRYPTOPP_CPUID_AVAILABLE
}
void RDRAND::DiscardBytes(size_t n)
{
// RoundUpToMultipleOf is used because a full word is read, and its cheaper
// to discard full words. There's no sense in dealing with tail bytes.
assert(HasRDRAND());
#if CRYPTOPP_BOOL_X64 || CRYPTOPP_BOOL_X32
FixedSizeSecBlock<word64, 16> discard;
n = RoundUpToMultipleOf(n, sizeof(word64));
#else
FixedSizeSecBlock<word32, 16> discard;
n = RoundUpToMultipleOf(n, sizeof(word32));
#endif
size_t count = STDMIN(n, discard.SizeInBytes());
while (count)
{
GenerateBlock(discard.BytePtr(), count);
n -= count;
count = STDMIN(n, discard.SizeInBytes());
}
}
#endif // CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X32 || CRYPTOPP_BOOL_X64
/////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////
#if ALL_RDSEED_INTRIN_AVAILABLE
static int ALL_RSI_GenerateBlock(byte *output, size_t size, unsigned int safety)
{
assert((output && size) || !(output || size));
#if CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X32
word32 val;
#else
word64 val;
#endif
while (size >= sizeof(val))
{
#if CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X32
if (_rdseed32_step((word32*)output))
#else
// Cast due to GCC, http://github.com/weidai11/cryptopp/issues/236
if (_rdseed64_step(reinterpret_cast<unsigned long long*>(output)))
#endif
{
output += sizeof(val);
size -= sizeof(val);
}
else
{
if (!safety--)
{
assert(0);
return 0;
}
}
}
if (size)
{
#if CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X32
if (_rdseed32_step(&val))
#else
// Cast due to GCC, http://github.com/weidai11/cryptopp/issues/236
if (_rdseed64_step(reinterpret_cast<unsigned long long*>(&val)))
#endif
{
memcpy(output, &val, size);
size = 0;
}
else
{
if (!safety--)
{
assert(0);
return 0;
}
}
}
SecureWipeBuffer(&val, 1);
return int(size == 0);
}
#endif // ALL_RDSEED_INTRIN_AVAILABLE
#if GCC_RDSEED_ASM_AVAILABLE
static int GCC_RSA_GenerateBlock(byte *output, size_t size, unsigned int safety)
{
assert((output && size) || !(output || size));
#if CRYPTOPP_BOOL_X64 || CRYPTOPP_BOOL_X32
word64 val;
#else
word32 val;
#endif
char rc;
while (size)
{
__asm__ volatile(
#if CRYPTOPP_BOOL_X64 || CRYPTOPP_BOOL_X32
".byte 0x48, 0x0f, 0xc7, 0xf8;\n" // rdseed rax
#else
".byte 0x0f, 0xc7, 0xf8;\n" // rdseed eax
#endif
"setc %1; "
: "=a" (val), "=qm" (rc)
:
: "cc"
);
if (rc)
{
if (size >= sizeof(val))
{
#if defined(CRYPTOPP_ALLOW_UNALIGNED_DATA_ACCESS) && (CRYPTOPP_BOOL_X64 || CRYPTOPP_BOOL_X32)
*((word64*)(void *)output) = val;
#elif defined(CRYPTOPP_ALLOW_UNALIGNED_DATA_ACCESS) && (CRYPTOPP_BOOL_X86)
*((word32*)(void *)output) = val;
#else
memcpy(output, &val, sizeof(val));
#endif
output += sizeof(val);
size -= sizeof(val);
}
else
{
memcpy(output, &val, size);
size = 0;
}
}
else
{
if (!safety--)
{
assert(0);
return 0;
}
}
}
SecureWipeBuffer(&val, 1);
return int(size == 0);
}
#endif // GCC_RDSEED_ASM_AVAILABLE
#if (CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X32 || CRYPTOPP_BOOL_X64)
void RDSEED::GenerateBlock(byte *output, size_t size)
{
CRYPTOPP_UNUSED(output), CRYPTOPP_UNUSED(size);
assert((output && size) || !(output || size));
if(!HasRDSEED())
throw NotImplemented("RDSEED: rdseed is not available on this platform");
int rc; CRYPTOPP_UNUSED(rc);
#if MASM_RDSEED_ASM_AVAILABLE
rc = MASM_RSA_GenerateBlock(output, size, m_retries);
if (!rc) { throw RDSEED_Err("MASM_RSA_GenerateBlock"); }
#elif NASM_RDSEED_ASM_AVAILABLE
rc = NASM_RSA_GenerateBlock(output, size, m_retries);
if (!rc) { throw RDRAND_Err("NASM_RSA_GenerateBlock"); }
#elif ALL_RDSEED_INTRIN_AVAILABLE
rc = ALL_RSI_GenerateBlock(output, size, m_retries);
if (!rc) { throw RDSEED_Err("ALL_RSI_GenerateBlock"); }
#elif GCC_RDSEED_ASM_AVAILABLE
rc = GCC_RSA_GenerateBlock(output, size, m_retries);
if (!rc) { throw RDSEED_Err("GCC_RSA_GenerateBlock"); }
#else
// RDSEED not detected at compile time, and no suitable compiler found
throw NotImplemented("RDSEED: failed to find a suitable implementation???");
#endif
}
void RDSEED::DiscardBytes(size_t n)
{
// RoundUpToMultipleOf is used because a full word is read, and its cheaper
// to discard full words. There's no sense in dealing with tail bytes.
assert(HasRDSEED());
#if CRYPTOPP_BOOL_X64 || CRYPTOPP_BOOL_X32
FixedSizeSecBlock<word64, 16> discard;
n = RoundUpToMultipleOf(n, sizeof(word64));
#else
FixedSizeSecBlock<word32, 16> discard;
n = RoundUpToMultipleOf(n, sizeof(word32));
#endif
size_t count = STDMIN(n, discard.SizeInBytes());
while (count)
{
GenerateBlock(discard.BytePtr(), count);
n -= count;
count = STDMIN(n, discard.SizeInBytes());
}
}
#endif // CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X32 || CRYPTOPP_BOOL_X64
NAMESPACE_END
NotImplemented
A method was called which was not implemented.
Definition: cryptlib.h:203
RoundUpToMultipleOf
T1 RoundUpToMultipleOf(const T1 &n, const T2 &m)
Rounds a value up to a multiple of a second value.
Definition: misc.h:865
rdrand.h
Classes for RDRAND and RDSEED.
secblock.h
Classes and functions for secure memory allocations.
RDSEED::GenerateBlock
virtual void GenerateBlock(byte *output, size_t size)
Generate random array of bytes.
Definition: rdrand.h:162
RDRAND::DiscardBytes
virtual void DiscardBytes(size_t n)
Generate and discard n bytes.
Definition: rdrand.h:92
SecBlock< T, FixedSizeAllocatorWithCleanup< T, S > >::BytePtr
byte * BytePtr()
Provides a byte pointer to the first element in the memory block.
Definition: secblock.h:531
RDSEED::DiscardBytes
virtual void DiscardBytes(size_t n)
Generate and discard n bytes.
Definition: rdrand.h:176
SecBlock< T, FixedSizeAllocatorWithCleanup< T, S > >::SizeInBytes
size_type SizeInBytes() const
Provides the number of bytes in the SecBlock.
Definition: secblock.h:538
HasRDSEED
bool HasRDSEED()
Determines RDSEED availability.
Definition: cpu.h:311
RDRAND_Err
Exception thrown when a RDRAND generator encounters a generator related error.
Definition: rdrand.h:29
STDMIN
const T & STDMIN(const T &a, const T &b)
Replacement function for std::min.
Definition: misc.h:467
cpu.h
Functions for CPU features and intrinsics.
HasRDRAND
bool HasRDRAND()
Determines RDRAND availability.
Definition: cpu.h:301
RDSEED_Err
Exception thrown when a RDSEED generator encounters a generator related error.
Definition: rdrand.h:116
FixedSizeSecBlock
Fixed size stack-based SecBlock.
Definition: secblock.h:753
RDRAND::GenerateBlock
virtual void GenerateBlock(byte *output, size_t size)
Generate random array of bytes.
Definition: rdrand.h:78
CryptoPP
Crypto++ library namespace.
config.h
Library configuration file.
SecureWipeBuffer
void SecureWipeBuffer(T *buf, size_t n)
Sets each element of an array to 0.
Definition: misc.h:1069
cryptlib.h
Abstract base classes that provide a uniform interface to this library.