diff --git a/src/random.cpp b/src/random.cpp --- a/src/random.cpp +++ b/src/random.cpp @@ -79,7 +79,7 @@ static std::atomic hwrand_initialized{false}; static bool rdrand_supported = false; static constexpr uint32_t CPUID_F1_ECX_RDRAND = 0x40000000; -static void RDRandInit() { +static void InitHardwareRand() { uint32_t eax, ebx, ecx, edx; if (__get_cpuid(1, &eax, &ebx, &ecx, &edx) && (ecx & CPUID_F1_ECX_RDRAND)) { rdrand_supported = true; @@ -87,7 +87,7 @@ hwrand_initialized.store(true); } -static void RDRandReport() { +static void ReportHardwareRand() { assert(hwrand_initialized.load(std::memory_order_relaxed)); if (rdrand_supported) { // This must be done in a separate function, as HWRandInit() may be @@ -98,11 +98,17 @@ } #else -static void RDRandInit() {} -static void RDRandReport() {} +/** + * 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). + */ +static void InitHardwareRand() {} +static void ReportHardwareRand() {} #endif -static bool GetHWRand(uint8_t *ent32) { +static bool GetHardwareRand(uint8_t *ent32) { #if defined(__x86_64__) || defined(__amd64__) || defined(__i386__) assert(hwrand_initialized.load(std::memory_order_relaxed)); if (rdrand_supported) { @@ -306,7 +312,7 @@ uint8_t m_state[32] = {0}; uint64_t m_counter = 0; - explicit RNGState() { RDRandInit(); } + explicit RNGState() { InitHardwareRand(); } }; RNGState &GetRNGState() { @@ -368,7 +374,7 @@ hasher.Write(buf, 32); // Third source: HW RNG, if available. - if (GetHWRand(buf)) { + if (GetHardwareRand(buf)) { hasher.Write(buf, 32); } @@ -526,5 +532,5 @@ // Invoke RNG code to trigger initialization (if not already performed) GetRNGState(); - RDRandReport(); + ReportHardwareRand(); }