diff options
author | Daniel Neus <[email protected]> | 2015-12-21 18:10:25 +0100 |
---|---|---|
committer | Daniel Neus <[email protected]> | 2015-12-21 18:21:59 +0100 |
commit | 0b021ef91f204fa6326a00c5a1550f5cabc5e3c9 (patch) | |
tree | 9b179c8b043fd4bcc137cdeede5a063634a9e09c /src/lib | |
parent | 16c25957a424e7a622ae20e751a9b6ff0fba61b5 (diff) |
review changes
* no spaces around if(), for() etc
* snake_case for plain functions
* anonymous namespace function instead private and static
* don't propagate failed poll to the calling application
* RdRand retires configurable in build.h
Diffstat (limited to 'src/lib')
-rw-r--r-- | src/lib/entropy/rdrand/rdrand.cpp | 39 | ||||
-rw-r--r-- | src/lib/entropy/rdrand/rdrand.h | 4 | ||||
-rw-r--r-- | src/lib/entropy/rdseed/rdseed.cpp | 29 | ||||
-rw-r--r-- | src/lib/entropy/rdseed/rdseed.h | 4 |
4 files changed, 39 insertions, 37 deletions
diff --git a/src/lib/entropy/rdrand/rdrand.cpp b/src/lib/entropy/rdrand/rdrand.cpp index 36eaebee3..ef8c5882d 100644 --- a/src/lib/entropy/rdrand/rdrand.cpp +++ b/src/lib/entropy/rdrand/rdrand.cpp @@ -1,26 +1,26 @@ /* * Entropy Source Using Intel's rdrand instruction * (C) 2012,2015 Jack Lloyd +* (C) 2015 Daniel Neus * * Botan is released under the Simplified BSD License (see license.txt) */ #include <botan/internal/rdrand.h> #include <botan/cpuid.h> -#include <botan/exceptn.h> #include <botan/build.h> #if !defined(BOTAN_USE_GCC_INLINE_ASM) - #include <immintrin.h> +#include <immintrin.h> #endif -// RDRAND is guaranteed to generate a random number within 10 retries on a working CPU -#define INTEL_RDRAND_RETRIES 10 - namespace Botan { -uint32_t Intel_Rdrand::get32BitRandom() { - for ( size_t i = 0; i != INTEL_RDRAND_RETRIES; ++i ) +namespace { + +/// @returns 0 if RdRand failed after @param max_retries otherwise the 32 bit random number generated by RdRand +uint32_t get_32bit_random(const uint32_t max_retries) { + for(size_t i = 0; i != max_retries; ++i) { uint32_t r = 0; @@ -28,28 +28,31 @@ uint32_t Intel_Rdrand::get32BitRandom() { int cf = 0; // Encoding of rdrand %eax - asm( ".byte 0x0F, 0xC7, 0xF0; adcl $0,%1" : - "=a" ( r ), "=r" ( cf ) : "0" ( r ), "1" ( cf ) : "cc" ); + asm(".byte 0x0F, 0xC7, 0xF0; adcl $0,%1" : + "=a" (r), "=r" (cf) : "0" (r), "1" (cf) : "cc"); #else - int cf = _rdrand32_step( &r ); + int cf = _rdrand32_step(&r); #endif - if ( 1 == cf ) + if(1 == cf) { return r; } } - - throw Internal_Error( "RdRand failed after " + std::to_string( INTEL_RDRAND_RETRIES ) + " retries" ); + return 0; } +} -void Intel_Rdrand::poll( Entropy_Accumulator& accum ) { - if ( !CPUID::has_rdrand() ) +void Intel_Rdrand::poll(Entropy_Accumulator& accum) { + if(!CPUID::has_rdrand()) return; - for ( size_t i = 0; i != BOTAN_ENTROPY_INTEL_RNG_POLLS; ++i ) + for(size_t i = 0; i != BOTAN_ENTROPY_INTEL_RNG_POLLS; ++i) { - uint32_t random = get32BitRandom(); - accum.add( random, BOTAN_ENTROPY_ESTIMATE_HARDWARE_RNG ); + uint32_t random = get_32bit_random(BOTAN_ENTROPY_RDRAND_RETRIES); + if(random) + { + accum.add(random, BOTAN_ENTROPY_ESTIMATE_HARDWARE_RNG); + } } } diff --git a/src/lib/entropy/rdrand/rdrand.h b/src/lib/entropy/rdrand/rdrand.h index 5ace28382..1fa928641 100644 --- a/src/lib/entropy/rdrand/rdrand.h +++ b/src/lib/entropy/rdrand/rdrand.h @@ -20,9 +20,7 @@ class Intel_Rdrand : public Entropy_Source { public: std::string name() const override { return "rdrand"; } - void poll( Entropy_Accumulator& accum ) override; - private: - static uint32_t get32BitRandom(); + void poll(Entropy_Accumulator& accum) override; }; } diff --git a/src/lib/entropy/rdseed/rdseed.cpp b/src/lib/entropy/rdseed/rdseed.cpp index b995ab5d4..adca605f6 100644 --- a/src/lib/entropy/rdseed/rdseed.cpp +++ b/src/lib/entropy/rdseed/rdseed.cpp @@ -10,14 +10,16 @@ #include <botan/build.h> #if !defined(BOTAN_USE_GCC_INLINE_ASM) - #include <immintrin.h> +#include <immintrin.h> #endif namespace Botan { +namespace { + /// @returns 0 if RdSeed failed after @param max_retries otherwise the 32 bit random number generated by RdSeed -uint32_t Intel_Rdseed::get32BitRandom( const uint32_t max_retries ) { - for ( size_t i = 0; i != max_retries; ++i ) +uint32_t get_32bit_random(const uint32_t max_retries) { + for(size_t i = 0; i != max_retries; ++i) { uint32_t r = 0; @@ -25,29 +27,30 @@ uint32_t Intel_Rdseed::get32BitRandom( const uint32_t max_retries ) { int cf = 0; // Encoding of rdseed %eax - asm( ".byte 0x0F, 0xC7, 0xF8; adcl $0,%1" : - "=a" ( r ), "=r" ( cf ) : "0" ( r ), "1" ( cf ) : "cc" ); + asm(".byte 0x0F, 0xC7, 0xF8; adcl $0,%1" : + "=a" (r), "=r" (cf) : "0" (r), "1" (cf) : "cc"); #else - int cf = _rdseed32_step( &r ); + int cf = _rdseed32_step(&r); #endif - if ( 1 == cf ) + if(1 == cf) { return r; } } return 0; } +} -void Intel_Rdseed::poll( Entropy_Accumulator& accum ) { - if ( !CPUID::has_rdseed() ) +void Intel_Rdseed::poll(Entropy_Accumulator& accum) { + if(!CPUID::has_rdseed()) return; - for ( size_t i = 0; i != BOTAN_ENTROPY_INTEL_RNG_POLLS; ++i ) + for(size_t i = 0; i != BOTAN_ENTROPY_INTEL_RNG_POLLS; ++i) { - uint32_t random = get32BitRandom( BOTAN_ENTROPY_RDSEED_RETRIES ); - if ( random ) + uint32_t random = get_32bit_random(BOTAN_ENTROPY_RDSEED_RETRIES); + if(random) { - accum.add( random, BOTAN_ENTROPY_ESTIMATE_HARDWARE_RNG ); + accum.add(random, BOTAN_ENTROPY_ESTIMATE_HARDWARE_RNG); } } } diff --git a/src/lib/entropy/rdseed/rdseed.h b/src/lib/entropy/rdseed/rdseed.h index a6f92709a..0f39250a1 100644 --- a/src/lib/entropy/rdseed/rdseed.h +++ b/src/lib/entropy/rdseed/rdseed.h @@ -20,9 +20,7 @@ class Intel_Rdseed : public Entropy_Source { public: std::string name() const override { return "rdseed"; } - void poll( Entropy_Accumulator& accum ) override; - private: - static uint32_t get32BitRandom( uint32_t max_retries ); + void poll(Entropy_Accumulator& accum) override; }; } |