From 16c25957a424e7a622ae20e751a9b6ff0fba61b5 Mon Sep 17 00:00:00 2001 From: Daniel Neus Date: Sun, 20 Dec 2015 23:08:14 +0100 Subject: RdRand and RdSeed logic changes * Make it configurable how often RdRand and RdSeed is polled * Make it configurable how many RdSeed retries are executed --- src/lib/entropy/rdrand/rdrand.cpp | 44 ++++++++++++++++++++++++--------------- src/lib/entropy/rdrand/rdrand.h | 4 +++- src/lib/entropy/rdseed/rdseed.cpp | 43 +++++++++++++++++++++++--------------- src/lib/entropy/rdseed/rdseed.h | 4 +++- 4 files changed, 59 insertions(+), 36 deletions(-) (limited to 'src/lib') diff --git a/src/lib/entropy/rdrand/rdrand.cpp b/src/lib/entropy/rdrand/rdrand.cpp index 24fe98cf8..36eaebee3 100644 --- a/src/lib/entropy/rdrand/rdrand.cpp +++ b/src/lib/entropy/rdrand/rdrand.cpp @@ -7,39 +7,49 @@ #include #include +#include +#include #if !defined(BOTAN_USE_GCC_INLINE_ASM) #include #endif -namespace Botan { - -/* -* Get the timestamp -*/ -void Intel_Rdrand::poll(Entropy_Accumulator& accum) - { - if(!CPUID::has_rdrand()) - return; +// RDRAND is guaranteed to generate a random number within 10 retries on a working CPU +#define INTEL_RDRAND_RETRIES 10 - const size_t RDRAND_POLLS = 32; +namespace Botan { - for(size_t i = 0; i != RDRAND_POLLS; ++i) +uint32_t Intel_Rdrand::get32BitRandom() { + for ( size_t i = 0; i != INTEL_RDRAND_RETRIES; ++i ) { - unsigned int r = 0; + uint32_t r = 0; #if defined(BOTAN_USE_GCC_INLINE_ASM) 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 ) + { + return r; + } + } + + throw Internal_Error( "RdRand failed after " + std::to_string( INTEL_RDRAND_RETRIES ) + " retries" ); + } - if(cf == 1) - accum.add(r, BOTAN_ENTROPY_ESTIMATE_HARDWARE_RNG); +void Intel_Rdrand::poll( Entropy_Accumulator& accum ) { + if ( !CPUID::has_rdrand() ) + return; + + for ( size_t i = 0; i != BOTAN_ENTROPY_INTEL_RNG_POLLS; ++i ) + { + uint32_t random = get32BitRandom(); + 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 1fa928641..5ace28382 100644 --- a/src/lib/entropy/rdrand/rdrand.h +++ b/src/lib/entropy/rdrand/rdrand.h @@ -20,7 +20,9 @@ class Intel_Rdrand : public Entropy_Source { public: std::string name() const override { return "rdrand"; } - void poll(Entropy_Accumulator& accum) override; + void poll( Entropy_Accumulator& accum ) override; + private: + static uint32_t get32BitRandom(); }; } diff --git a/src/lib/entropy/rdseed/rdseed.cpp b/src/lib/entropy/rdseed/rdseed.cpp index 91306769d..b995ab5d4 100644 --- a/src/lib/entropy/rdseed/rdseed.cpp +++ b/src/lib/entropy/rdseed/rdseed.cpp @@ -7,6 +7,7 @@ #include #include +#include #if !defined(BOTAN_USE_GCC_INLINE_ASM) #include @@ -14,32 +15,40 @@ namespace Botan { -/* -* Get the timestamp -*/ -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) +/// @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 ) { - unsigned int r = 0; + uint32_t 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"); + 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 ) + { + return r; + } + } + return 0; + } - if(cf == 1) - accum.add(r, BOTAN_ENTROPY_ESTIMATE_HARDWARE_RNG); +void Intel_Rdseed::poll( Entropy_Accumulator& accum ) { + if ( !CPUID::has_rdseed() ) + return; + + for ( size_t i = 0; i != BOTAN_ENTROPY_INTEL_RNG_POLLS; ++i ) + { + uint32_t random = get32BitRandom( BOTAN_ENTROPY_RDSEED_RETRIES ); + if ( random ) + { + 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 0f39250a1..a6f92709a 100644 --- a/src/lib/entropy/rdseed/rdseed.h +++ b/src/lib/entropy/rdseed/rdseed.h @@ -20,7 +20,9 @@ class Intel_Rdseed : public Entropy_Source { public: std::string name() const override { return "rdseed"; } - void poll(Entropy_Accumulator& accum) override; + void poll( Entropy_Accumulator& accum ) override; + private: + static uint32_t get32BitRandom( uint32_t max_retries ); }; } -- cgit v1.2.3 From 0b021ef91f204fa6326a00c5a1550f5cabc5e3c9 Mon Sep 17 00:00:00 2001 From: Daniel Neus Date: Mon, 21 Dec 2015 18:10:25 +0100 Subject: 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 --- src/build-data/buildh.in | 3 +++ src/lib/entropy/rdrand/rdrand.cpp | 39 +++++++++++++++++++++------------------ src/lib/entropy/rdrand/rdrand.h | 4 +--- src/lib/entropy/rdseed/rdseed.cpp | 29 ++++++++++++++++------------- src/lib/entropy/rdseed/rdseed.h | 4 +--- 5 files changed, 42 insertions(+), 37 deletions(-) (limited to 'src/lib') diff --git a/src/build-data/buildh.in b/src/build-data/buildh.in index 84756536d..d709c27af 100644 --- a/src/build-data/buildh.in +++ b/src/build-data/buildh.in @@ -180,6 +180,9 @@ 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 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 #include -#include #include #if !defined(BOTAN_USE_GCC_INLINE_ASM) - #include +#include #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 #if !defined(BOTAN_USE_GCC_INLINE_ASM) - #include +#include #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; }; } -- cgit v1.2.3 From b642fa9bc637b3a7fe39f5640b9a2f6f9ea5f581 Mon Sep 17 00:00:00 2001 From: Daniel Neus Date: Tue, 26 Jan 2016 22:08:55 +0100 Subject: move logic back into poll() prevents filtering out any 0x00000000 outputs from RDRAND/RDSEED --- src/lib/entropy/rdrand/rdrand.cpp | 48 +++++++++++++++------------------------ src/lib/entropy/rdseed/rdseed.cpp | 48 +++++++++++++++------------------------ 2 files changed, 36 insertions(+), 60 deletions(-) (limited to 'src/lib') diff --git a/src/lib/entropy/rdrand/rdrand.cpp b/src/lib/entropy/rdrand/rdrand.cpp index ef8c5882d..13263bb63 100644 --- a/src/lib/entropy/rdrand/rdrand.cpp +++ b/src/lib/entropy/rdrand/rdrand.cpp @@ -11,47 +11,35 @@ #include #if !defined(BOTAN_USE_GCC_INLINE_ASM) -#include + #include #endif namespace Botan { -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; - -#if defined(BOTAN_USE_GCC_INLINE_ASM) - int cf = 0; - - // 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); -#endif - if(1 == cf) - { - return r; - } - } - return 0; - } -} - void Intel_Rdrand::poll(Entropy_Accumulator& accum) { if(!CPUID::has_rdrand()) return; for(size_t i = 0; i != BOTAN_ENTROPY_INTEL_RNG_POLLS; ++i) { - uint32_t random = get_32bit_random(BOTAN_ENTROPY_RDRAND_RETRIES); - if(random) + for(size_t i = 0; i != BOTAN_ENTROPY_RDRAND_RETRIES; ++i) { - accum.add(random, BOTAN_ENTROPY_ESTIMATE_HARDWARE_RNG); + uint32_t r = 0; + +#if defined(BOTAN_USE_GCC_INLINE_ASM) + int cf = 0; + + // 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); +#endif + 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 adca605f6..bcef9ad83 100644 --- a/src/lib/entropy/rdseed/rdseed.cpp +++ b/src/lib/entropy/rdseed/rdseed.cpp @@ -10,47 +10,35 @@ #include #if !defined(BOTAN_USE_GCC_INLINE_ASM) -#include + #include #endif namespace Botan { -namespace { - -/// @returns 0 if RdSeed failed after @param max_retries otherwise the 32 bit random number generated by RdSeed -uint32_t get_32bit_random(const uint32_t max_retries) { - for(size_t i = 0; i != max_retries; ++i) - { - uint32_t 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(1 == cf) - { - return r; - } - } - return 0; - } -} - void Intel_Rdseed::poll(Entropy_Accumulator& accum) { if(!CPUID::has_rdseed()) return; for(size_t i = 0; i != BOTAN_ENTROPY_INTEL_RNG_POLLS; ++i) { - uint32_t random = get_32bit_random(BOTAN_ENTROPY_RDSEED_RETRIES); - if(random) + for(size_t i = 0; i != BOTAN_ENTROPY_RDSEED_RETRIES; ++i) { - accum.add(random, BOTAN_ENTROPY_ESTIMATE_HARDWARE_RNG); + uint32_t 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(1 == cf) + { + accum.add(r, BOTAN_ENTROPY_ESTIMATE_HARDWARE_RNG); + break; + } } } } -- cgit v1.2.3