diff options
| -rw-r--r-- | src/build-data/buildh.in | 16 | ||||
| -rw-r--r-- | src/lib/entropy/rdrand/rdrand.cpp | 35 | ||||
| -rw-r--r-- | src/lib/entropy/rdseed/rdseed.cpp | 34 |
3 files changed, 51 insertions, 34 deletions
diff --git a/src/build-data/buildh.in b/src/build-data/buildh.in index a1d8890db..6412fdcdf 100644 --- a/src/build-data/buildh.in +++ b/src/build-data/buildh.in @@ -167,6 +167,22 @@ softare-based entropy polling is still used. */ #define BOTAN_ENTROPY_ESTIMATE_HARDWARE_RNG 0.0 +/* +How often should the RdRand/RdSeed RNGs be polled + +Each poll generates 32 bit entropy +*/ +#define BOTAN_ENTROPY_INTEL_RNG_POLLS 32 + +// According to Intel RdRand is guaranteed to generate a random number within 10 retries on a working CPU +#define BOTAN_ENTROPY_RDRAND_RETRIES 10 + +/* +* RdSeed is not guaranteed to generate a random number within a specific number of retries +* Define the number of retries here +*/ +#define BOTAN_ENTROPY_RDSEED_RETRIES 20 + // The output of a PRNG we are trusting to be strong #define BOTAN_ENTROPY_ESTIMATE_STRONG_RNG 7.0 diff --git a/src/lib/entropy/rdrand/rdrand.cpp b/src/lib/entropy/rdrand/rdrand.cpp index 24fe98cf8..13263bb63 100644 --- a/src/lib/entropy/rdrand/rdrand.cpp +++ b/src/lib/entropy/rdrand/rdrand.cpp @@ -1,12 +1,14 @@ /* * 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/build.h> #if !defined(BOTAN_USE_GCC_INLINE_ASM) #include <immintrin.h> @@ -14,32 +16,31 @@ namespace Botan { -/* -* Get the timestamp -*/ -void Intel_Rdrand::poll(Entropy_Accumulator& accum) - { +void Intel_Rdrand::poll(Entropy_Accumulator& accum) { if(!CPUID::has_rdrand()) return; - const size_t RDRAND_POLLS = 32; - - for(size_t i = 0; i != RDRAND_POLLS; ++i) + for(size_t i = 0; i != BOTAN_ENTROPY_INTEL_RNG_POLLS; ++i) { - unsigned int r = 0; + for(size_t i = 0; i != BOTAN_ENTROPY_RDRAND_RETRIES; ++i) + { + uint32_t r = 0; #if defined(BOTAN_USE_GCC_INLINE_ASM) - int cf = 0; + int cf = 0; - // Encoding of rdrand %eax - asm(".byte 0x0F, 0xC7, 0xF0; adcl $0,%1" : - "=a" (r), "=r" (cf) : "0" (r), "1" (cf) : "cc"); + // Encoding of rdrand %eax + 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(cf == 1) - accum.add(r, BOTAN_ENTROPY_ESTIMATE_HARDWARE_RNG); + if(1 == cf) + { + accum.add(r, BOTAN_ENTROPY_ESTIMATE_HARDWARE_RNG); + break; + } + } } } diff --git a/src/lib/entropy/rdseed/rdseed.cpp b/src/lib/entropy/rdseed/rdseed.cpp index 91306769d..bcef9ad83 100644 --- a/src/lib/entropy/rdseed/rdseed.cpp +++ b/src/lib/entropy/rdseed/rdseed.cpp @@ -7,6 +7,7 @@ #include <botan/internal/rdseed.h> #include <botan/cpuid.h> +#include <botan/build.h> #if !defined(BOTAN_USE_GCC_INLINE_ASM) #include <immintrin.h> @@ -14,32 +15,31 @@ namespace Botan { -/* -* Get the timestamp -*/ -void Intel_Rdseed::poll(Entropy_Accumulator& accum) - { +void Intel_Rdseed::poll(Entropy_Accumulator& accum) { if(!CPUID::has_rdseed()) return; - const size_t RDSEED_POLLS = 32; - - for(size_t i = 0; i != RDSEED_POLLS; ++i) + for(size_t i = 0; i != BOTAN_ENTROPY_INTEL_RNG_POLLS; ++i) { - unsigned int r = 0; + for(size_t i = 0; i != BOTAN_ENTROPY_RDSEED_RETRIES; ++i) + { + uint32_t r = 0; #if defined(BOTAN_USE_GCC_INLINE_ASM) - int cf = 0; + int cf = 0; - // Encoding of rdseed %eax - asm(".byte 0x0F, 0xC7, 0xF8; adcl $0,%1" : - "=a" (r), "=r" (cf) : "0" (r), "1" (cf) : "cc"); + // 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); + int cf = _rdseed32_step(&r); #endif - - if(cf == 1) - accum.add(r, BOTAN_ENTROPY_ESTIMATE_HARDWARE_RNG); + if(1 == cf) + { + accum.add(r, BOTAN_ENTROPY_ESTIMATE_HARDWARE_RNG); + break; + } + } } } |