diff options
Diffstat (limited to 'comm/third_party/botan/src/lib/entropy/entropy_srcs.cpp')
| -rw-r--r-- | comm/third_party/botan/src/lib/entropy/entropy_srcs.cpp | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/entropy/entropy_srcs.cpp b/comm/third_party/botan/src/lib/entropy/entropy_srcs.cpp new file mode 100644 index 0000000000..e6573e2963 --- /dev/null +++ b/comm/third_party/botan/src/lib/entropy/entropy_srcs.cpp @@ -0,0 +1,235 @@ +/* +* Entropy Source Polling +* (C) 2008-2010,2015 Jack Lloyd +* +* Botan is released under the Simplified BSD License (see license.txt) +*/ + +#include <botan/entropy_src.h> +#include <botan/rng.h> + +#if defined(BOTAN_HAS_SYSTEM_RNG) + #include <botan/system_rng.h> +#endif + +#if defined(BOTAN_HAS_PROCESSOR_RNG) + #include <botan/processor_rng.h> +#endif + +#if defined(BOTAN_HAS_ENTROPY_SRC_RDRAND) + #include <botan/internal/rdrand.h> +#endif + +#if defined(BOTAN_HAS_ENTROPY_SRC_RDSEED) + #include <botan/internal/rdseed.h> +#endif + +#if defined(BOTAN_HAS_ENTROPY_SRC_DARN) + #include <botan/internal/p9_darn.h> +#endif + +#if defined(BOTAN_HAS_ENTROPY_SRC_DEV_RANDOM) + #include <botan/internal/dev_random.h> +#endif + +#if defined(BOTAN_HAS_ENTROPY_SRC_WIN32) + #include <botan/internal/es_win32.h> +#endif + +#if defined(BOTAN_HAS_ENTROPY_SRC_PROC_WALKER) + #include <botan/internal/proc_walk.h> + #include <botan/internal/os_utils.h> +#endif + +#if defined(BOTAN_HAS_ENTROPY_SRC_GETENTROPY) + #include <botan/internal/getentropy.h> +#endif + +namespace Botan { + +namespace { + +#if defined(BOTAN_HAS_SYSTEM_RNG) + +class System_RNG_EntropySource final : public Entropy_Source + { + public: + size_t poll(RandomNumberGenerator& rng) override + { + const size_t poll_bits = BOTAN_RNG_RESEED_POLL_BITS; + rng.reseed_from_rng(system_rng(), poll_bits); + return poll_bits; + } + + std::string name() const override { return "system_rng"; } + }; + +#endif + +#if defined(BOTAN_HAS_PROCESSOR_RNG) + +class Processor_RNG_EntropySource final : public Entropy_Source + { + public: + size_t poll(RandomNumberGenerator& rng) override + { + /* + * Intel's documentation for RDRAND at + * https://software.intel.com/en-us/articles/intel-digital-random-number-generator-drng-software-implementation-guide + * claims that software can guarantee a reseed event by polling enough data: + * "There is an upper bound of 511 samples per seed in the implementation + * where samples are 128 bits in size and can provide two 64-bit random + * numbers each." + * + * By requesting 65536 bits we are asking for 512 samples and thus are assured + * that at some point in producing the output, at least one reseed of the + * internal state will occur. + * + * The reseeding conditions of the POWER and ARM processor RNGs are not known + * but probably work in a somewhat similar manner. The exact amount requested + * may be tweaked if and when such conditions become publically known. + */ + const size_t poll_bits = 65536; + rng.reseed_from_rng(m_hwrng, poll_bits); + // Avoid trusting a black box, don't count this as contributing entropy: + return 0; + } + + std::string name() const override { return m_hwrng.name(); } + private: + Processor_RNG m_hwrng; + }; + +#endif + +} + +std::unique_ptr<Entropy_Source> Entropy_Source::create(const std::string& name) + { +#if defined(BOTAN_HAS_SYSTEM_RNG) + if(name == "system_rng" || name == "win32_cryptoapi") + { + return std::unique_ptr<Entropy_Source>(new System_RNG_EntropySource); + } +#endif + +#if defined(BOTAN_HAS_PROCESSOR_RNG) + if(name == "hwrng" || name == "rdrand" || name == "p9_darn") + { + if(Processor_RNG::available()) + { + return std::unique_ptr<Entropy_Source>(new Processor_RNG_EntropySource); + } + } +#endif + +#if defined(BOTAN_HAS_ENTROPY_SRC_RDSEED) + if(name == "rdseed") + { + return std::unique_ptr<Entropy_Source>(new Intel_Rdseed); + } +#endif + +#if defined(BOTAN_HAS_ENTROPY_SRC_GETENTROPY) + if(name == "getentropy") + { + return std::unique_ptr<Entropy_Source>(new Getentropy); + } +#endif + +#if defined(BOTAN_HAS_ENTROPY_SRC_DEV_RANDOM) + if(name == "dev_random") + { + return std::unique_ptr<Entropy_Source>(new Device_EntropySource(BOTAN_SYSTEM_RNG_POLL_DEVICES)); + } +#endif + +#if defined(BOTAN_HAS_ENTROPY_SRC_PROC_WALKER) + if(name == "proc_walk" && OS::running_in_privileged_state() == false) + { + const std::string root_dir = BOTAN_ENTROPY_PROC_FS_PATH; + if(!root_dir.empty()) + return std::unique_ptr<Entropy_Source>(new ProcWalking_EntropySource(root_dir)); + } +#endif + +#if defined(BOTAN_HAS_ENTROPY_SRC_WIN32) + if(name == "system_stats") + { + return std::unique_ptr<Entropy_Source>(new Win32_EntropySource); + } +#endif + + BOTAN_UNUSED(name); + return std::unique_ptr<Entropy_Source>(); + } + +void Entropy_Sources::add_source(std::unique_ptr<Entropy_Source> src) + { + if(src.get()) + { + m_srcs.push_back(std::move(src)); + } + } + +std::vector<std::string> Entropy_Sources::enabled_sources() const + { + std::vector<std::string> sources; + for(size_t i = 0; i != m_srcs.size(); ++i) + { + sources.push_back(m_srcs[i]->name()); + } + return sources; + } + +size_t Entropy_Sources::poll(RandomNumberGenerator& rng, + size_t poll_bits, + std::chrono::milliseconds timeout) + { + typedef std::chrono::system_clock clock; + + auto deadline = clock::now() + timeout; + + size_t bits_collected = 0; + + for(size_t i = 0; i != m_srcs.size(); ++i) + { + bits_collected += m_srcs[i]->poll(rng); + + if (bits_collected >= poll_bits || clock::now() > deadline) + break; + } + + return bits_collected; + } + +size_t Entropy_Sources::poll_just(RandomNumberGenerator& rng, const std::string& the_src) + { + for(size_t i = 0; i != m_srcs.size(); ++i) + { + if(m_srcs[i]->name() == the_src) + { + return m_srcs[i]->poll(rng); + } + } + + return 0; + } + +Entropy_Sources::Entropy_Sources(const std::vector<std::string>& sources) + { + for(auto&& src_name : sources) + { + add_source(Entropy_Source::create(src_name)); + } + } + +Entropy_Sources& Entropy_Sources::global_sources() + { + static Entropy_Sources global_entropy_sources(BOTAN_ENTROPY_DEFAULT_SOURCES); + + return global_entropy_sources; + } + +} + |