diff options
Diffstat (limited to 'src/lib/entropy/rdseed/rdseed.cpp')
| -rw-r--r-- | src/lib/entropy/rdseed/rdseed.cpp | 29 |
1 files changed, 16 insertions, 13 deletions
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); } } } |