diff options
| -rw-r--r-- | src/random.cpp | 18 | ||||
| -rw-r--r-- | src/random.h | 16 |
2 files changed, 12 insertions, 22 deletions
diff --git a/src/random.cpp b/src/random.cpp index 09777237c2..fd1dfe506f 100644 --- a/src/random.cpp +++ b/src/random.cpp @@ -179,7 +179,7 @@ static uint64_t GetRdSeed() noexcept /* Access to other hardware random number generators could be added here later, * assuming it is sufficiently fast (in the order of a few hundred CPU cycles). * Slower sources should probably be invoked separately, and/or only from - * RandAddSeedSleep (which is called during idle background operation). + * RandAddPeriodic (which is called once a minute). */ static void InitHardwareRand() {} static void ReportHardwareRand() {} @@ -416,17 +416,7 @@ RNGState& GetRNGState() noexcept /* A note on the use of noexcept in the seeding functions below: * - * None of the RNG code should ever throw any exception, with the sole exception - * of MilliSleep in SeedSleep, which can (and does) support interruptions which - * cause a boost::thread_interrupted to be thrown. - * - * This means that SeedSleep, and all functions that invoke it are throwing. - * However, we know that GetRandBytes() and GetStrongRandBytes() never trigger - * this sleeping logic, so they are noexcept. The same is true for all the - * GetRand*() functions that use GetRandBytes() indirectly. - * - * TODO: After moving away from interruptible boost-based thread management, - * everything can become noexcept here. + * None of the RNG code should ever throw any exception. */ static void SeedTimestamp(CSHA512& hasher) noexcept @@ -498,7 +488,7 @@ static void SeedStrengthen(CSHA512& hasher, RNGState& rng, int microseconds) noe Strengthen(strengthen_seed, microseconds, hasher); } -static void SeedPeriodic(CSHA512& hasher, RNGState& rng) +static void SeedPeriodic(CSHA512& hasher, RNGState& rng) noexcept { // Everything that the 'fast' seeder includes SeedFast(hasher); @@ -575,7 +565,7 @@ static void ProcRand(unsigned char* out, int num, RNGLevel level) void GetRandBytes(unsigned char* buf, int num) noexcept { ProcRand(buf, num, RNGLevel::FAST); } void GetStrongRandBytes(unsigned char* buf, int num) noexcept { ProcRand(buf, num, RNGLevel::SLOW); } -void RandAddPeriodic() { ProcRand(nullptr, 0, RNGLevel::PERIODIC); } +void RandAddPeriodic() noexcept { ProcRand(nullptr, 0, RNGLevel::PERIODIC); } void RandAddEvent(const uint32_t event_info) { LOCK(events_mutex); diff --git a/src/random.h b/src/random.h index b6e70fcb1f..82dd6ecf9f 100644 --- a/src/random.h +++ b/src/random.h @@ -40,17 +40,17 @@ * These entropy sources are slower, but designed to make sure the RNG state contains * fresh data that is unpredictable to attackers. * - * - RandAddSeedSleep() seeds everything that fast seeding includes, but additionally: - * - A high-precision timestamp before and after sleeping 1ms. - * - (On Windows) Once every 10 minutes, performance monitoring data from the OS. - - - Once every minute, strengthen the entropy for 10 ms using repeated SHA512. - * These just exploit the fact the system is idle to improve the quality of the RNG - * slightly. + * - RandAddPeriodic() seeds everything that fast seeding includes, but additionally: + * - A high-precision timestamp + * - Dynamic environment data (performance monitoring, ...) + * - Strengthen the entropy for 10 ms using repeated SHA512. + * This is run once every minute. * * On first use of the RNG (regardless of what function is called first), all entropy * sources used in the 'slow' seeder are included, but also: * - 256 bits from the hardware RNG (rdseed or rdrand) when available. - * - (On Windows) Performance monitoring data from the OS. + * - Dynamic environment data (performance monitoring, ...) + * - Static environment data * - Strengthen the entropy for 100 ms using repeated SHA512. * * When mixing in new entropy, H = SHA512(entropy || old_rng_state) is computed, and @@ -87,7 +87,7 @@ void GetStrongRandBytes(unsigned char* buf, int num) noexcept; * * Thread-safe. */ -void RandAddPeriodic(); +void RandAddPeriodic() noexcept; /** * Gathers entropy from the low bits of the time at which events occur. Should |