diff options
author | Daniel Neus <d.neus@sirrix.com> | 2015-12-18 22:50:39 +0100 |
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committer | Daniel Neus <d.neus@sirrix.com> | 2015-12-18 22:50:39 +0100 |
commit | 3ebee37e0303d0a74c262153553d9905c847e5a9 (patch) | |
tree | a9e61c4b86ee7f7a6edf82a10f22b472d1584f98 /src/lib | |
parent | 56af160c9d4df53467ce742e2ba9b9f512fb7c83 (diff) |
add support for Intel RdSeed
Diffstat (limited to 'src/lib')
-rw-r--r-- | src/lib/entropy/entropy_srcs.cpp | 11 | ||||
-rw-r--r-- | src/lib/entropy/rdseed/info.txt | 23 | ||||
-rw-r--r-- | src/lib/entropy/rdseed/rdseed.cpp | 56 | ||||
-rw-r--r-- | src/lib/entropy/rdseed/rdseed.h | 28 |
4 files changed, 118 insertions, 0 deletions
diff --git a/src/lib/entropy/entropy_srcs.cpp b/src/lib/entropy/entropy_srcs.cpp index cbf13d488..a5dc0a819 100644 --- a/src/lib/entropy/entropy_srcs.cpp +++ b/src/lib/entropy/entropy_srcs.cpp @@ -15,6 +15,10 @@ #include <botan/internal/rdrand.h> #endif +#if defined(BOTAN_HAS_ENTROPY_SRC_RDSEED) + #include <botan/internal/rdseed.h> +#endif + #if defined(BOTAN_HAS_ENTROPY_SRC_DEV_RANDOM) #include <botan/internal/dev_random.h> #endif @@ -64,6 +68,13 @@ std::unique_ptr<Entropy_Source> Entropy_Source::create(const std::string& name) return std::unique_ptr<Entropy_Source>(new Intel_Rdrand); #endif } + + if(name == "rdseed") + { +#if defined(BOTAN_HAS_ENTROPY_SRC_RDSEED) + return std::unique_ptr<Entropy_Source>(new Intel_Rdseed); +#endif + } if(name == "proc_info") { diff --git a/src/lib/entropy/rdseed/info.txt b/src/lib/entropy/rdseed/info.txt new file mode 100644 index 000000000..53aa496b0 --- /dev/null +++ b/src/lib/entropy/rdseed/info.txt @@ -0,0 +1,23 @@ +define ENTROPY_SRC_RDSEED 20151218 + +need_isa rdseed + +<source> +rdseed.cpp +</source> + +<header:internal> +rdseed.h +</header:internal> + +<arch> +x86_32 +x86_64 +</arch> + +<cc> +gcc +clang +icc +msvc +</cc> diff --git a/src/lib/entropy/rdseed/rdseed.cpp b/src/lib/entropy/rdseed/rdseed.cpp new file mode 100644 index 000000000..8bdd79a1d --- /dev/null +++ b/src/lib/entropy/rdseed/rdseed.cpp @@ -0,0 +1,56 @@ +/* +* Entropy Source Using Intel's rdseed instruction +* (C) 2015 Jack Lloyd, Daniel Neus +* +* Botan is released under the Simplified BSD License (see license.txt) +*/ + +#include <botan/internal/rdseed.h> +#include <botan/cpuid.h> + +#if !defined(BOTAN_USE_GCC_INLINE_ASM) + #include <immintrin.h> +#endif + +namespace Botan { + +/* +* Get the timestamp +*/ +void Intel_Rdseed::poll(Entropy_Accumulator& accum) + { + if(!CPUID::has_rdseed()) + return; + + /* + Don't consider rdseed as contributing any entropy to the poll. It doesn't + make sense to trust uninspectible hardware. + + Even if backdoored, rdseed cannot harm us because the HMAC_RNG poll process + is designed to handle arbitrarily large amounts of attacker known/chosen + input (or even a reseed where every bit we reseeded with was attacker chosen), + as long as at least one seed occurred with enough unknown-to-attacker entropy. + */ + const double ENTROPY_ESTIMATE = 0.0; + const size_t RDSEED_POLLS = 32; + + for(size_t i = 0; i != RDSEED_POLLS; ++i) + { + unsigned int r = 0; + +#if defined(BOTAN_USE_GCC_INLINE_ASM) + int cf = 0; + + // Encoding of rdseed %eax + asm(".byte 0x0F, 0xC7, 0xF8; adcl $0,%1" : + "=a" (r), "=r" (cf) : "0" (r), "1" (cf) : "cc"); +#else + int cf = _rdseed32_step(&r); +#endif + + if(cf == 1) + accum.add(r, ENTROPY_ESTIMATE); + } + } + +} diff --git a/src/lib/entropy/rdseed/rdseed.h b/src/lib/entropy/rdseed/rdseed.h new file mode 100644 index 000000000..0f39250a1 --- /dev/null +++ b/src/lib/entropy/rdseed/rdseed.h @@ -0,0 +1,28 @@ +/* +* Entropy Source Using Intel's rdseed instruction +* (C) 2015 Jack Lloyd, Daniel Neus +* +* Botan is released under the Simplified BSD License (see license.txt) +*/ + +#ifndef BOTAN_ENTROPY_SRC_RDSEED_H__ +#define BOTAN_ENTROPY_SRC_RDSEED_H__ + +#include <botan/entropy_src.h> + +namespace Botan { + +/** +* Entropy source using the rdseed instruction first introduced on +* Intel's Broadwell architecture. +*/ +class Intel_Rdseed : public Entropy_Source + { + public: + std::string name() const override { return "rdseed"; } + void poll(Entropy_Accumulator& accum) override; + }; + +} + +#endif |