dash/src/randomenv.cpp

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// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2019 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#if defined(HAVE_CONFIG_H)
#include <config/dash-config.h>
#endif
#include <randomenv.h>
#include <clientversion.h>
#include <compat/cpuid.h>
#include <crypto/sha512.h>
#include <support/cleanse.h>
#include <util/time.h> // for GetTime()
#ifdef WIN32
#include <compat.h> // for Windows API
#endif
#include <algorithm>
#include <atomic>
#include <chrono>
#include <climits>
#include <thread>
#include <vector>
#include <stdint.h>
#include <string.h>
#ifndef WIN32
#include <sys/types.h> // must go before a number of other headers
#include <fcntl.h>
#include <netinet/in.h>
#include <sys/resource.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/utsname.h>
#include <unistd.h>
#endif
#if HAVE_DECL_GETIFADDRS
#include <ifaddrs.h>
#endif
#if HAVE_SYSCTL
#include <sys/sysctl.h>
#if HAVE_VM_VM_PARAM_H
#include <vm/vm_param.h>
#endif
#if HAVE_SYS_RESOURCES_H
#include <sys/resources.h>
#endif
#if HAVE_SYS_VMMETER_H
#include <sys/vmmeter.h>
#endif
#endif
#ifdef __linux__
#include <sys/auxv.h>
#endif
//! Necessary on some platforms
extern char** environ;
namespace {
void RandAddSeedPerfmon(CSHA512& hasher)
{
#ifdef WIN32
// Seed with the entire set of perfmon data
Merge #20082: [bugfix] random: fixes read buffer to use min rather than max bd5215103eb3985c1622eddea45a040e6173829c random: fixes read buffer resizing in RandAddSeedPerfmon (Ethan Heilman) Pull request description: As shown below when resizing the read buffer `vData` `std::max((vData.size() * 3) / 2, nMaxSize)` is used. This means that the buffer size immediately jumps to `nMaxSize`. I believe the intend of this code is to grow the buffer size through several steps rather than immediately resize it to the max size. ```cpp std::vector<unsigned char> vData(250000, 0); long ret = 0; unsigned long nSize = 0; const size_t nMaxSize = 10000000; // Bail out at more than 10MB of performance data while (true) { nSize = vData.size(); ret = RegQueryValueExA(HKEY_PERFORMANCE_DATA, "Global", nullptr, nullptr, vData.data(), &nSize); if (ret != ERROR_MORE_DATA || vData.size() >= nMaxSize) break; vData.resize(std::max((vData.size() * 3) / 2, nMaxSize)); // Grow size of buffer exponentially } ``` vData always starts at size 250,000 and nMaxSize is always 10,000,000 so the first time this line is reached: ```cpp vData.resize(std::max((vData.size() * 3) / 2, nMaxSize)); ``` the effect will always be to resize vData to nMaxSize. Then because the loop terminates when vData.size >= 10,000,000 only one resize operation will take place. To fix this issue we replace `std::min` with `std::max` This PR also adds a comment clarifying the behavior of this function the first time it is called. ACKs for top commit: fanquake: ACK bd5215103eb3985c1622eddea45a040e6173829c - thanks for taking a look at this Ethan. Swapping from `std::max` to `std::min` here certainly seems correct. Tree-SHA512: 7c65f700e5bbe44bc2f1ffdcdc99ec19c542894c95b5ee9791facd09d02afae88d1f8f35af129719e4860db94bc790856e7adb1d218a395381e7c2913b95f1d0
2020-10-19 07:28:11 +02:00
// This can take up to 2 seconds, so only do it every 10 minutes.
// Initialize last_perfmon to 0 seconds, we don't skip the first call.
static std::atomic<std::chrono::seconds> last_perfmon{std::chrono::seconds{0}};
auto last_time = last_perfmon.load();
auto current_time = GetTime<std::chrono::seconds>();
if (current_time < last_time + std::chrono::minutes{10}) return;
last_perfmon = current_time;
std::vector<unsigned char> vData(250000, 0);
long ret = 0;
unsigned long nSize = 0;
const size_t nMaxSize = 10000000; // Bail out at more than 10MB of performance data
while (true) {
nSize = vData.size();
ret = RegQueryValueExA(HKEY_PERFORMANCE_DATA, "Global", nullptr, nullptr, vData.data(), &nSize);
if (ret != ERROR_MORE_DATA || vData.size() >= nMaxSize)
break;
Merge #20082: [bugfix] random: fixes read buffer to use min rather than max bd5215103eb3985c1622eddea45a040e6173829c random: fixes read buffer resizing in RandAddSeedPerfmon (Ethan Heilman) Pull request description: As shown below when resizing the read buffer `vData` `std::max((vData.size() * 3) / 2, nMaxSize)` is used. This means that the buffer size immediately jumps to `nMaxSize`. I believe the intend of this code is to grow the buffer size through several steps rather than immediately resize it to the max size. ```cpp std::vector<unsigned char> vData(250000, 0); long ret = 0; unsigned long nSize = 0; const size_t nMaxSize = 10000000; // Bail out at more than 10MB of performance data while (true) { nSize = vData.size(); ret = RegQueryValueExA(HKEY_PERFORMANCE_DATA, "Global", nullptr, nullptr, vData.data(), &nSize); if (ret != ERROR_MORE_DATA || vData.size() >= nMaxSize) break; vData.resize(std::max((vData.size() * 3) / 2, nMaxSize)); // Grow size of buffer exponentially } ``` vData always starts at size 250,000 and nMaxSize is always 10,000,000 so the first time this line is reached: ```cpp vData.resize(std::max((vData.size() * 3) / 2, nMaxSize)); ``` the effect will always be to resize vData to nMaxSize. Then because the loop terminates when vData.size >= 10,000,000 only one resize operation will take place. To fix this issue we replace `std::min` with `std::max` This PR also adds a comment clarifying the behavior of this function the first time it is called. ACKs for top commit: fanquake: ACK bd5215103eb3985c1622eddea45a040e6173829c - thanks for taking a look at this Ethan. Swapping from `std::max` to `std::min` here certainly seems correct. Tree-SHA512: 7c65f700e5bbe44bc2f1ffdcdc99ec19c542894c95b5ee9791facd09d02afae88d1f8f35af129719e4860db94bc790856e7adb1d218a395381e7c2913b95f1d0
2020-10-19 07:28:11 +02:00
vData.resize(std::min((vData.size() * 3) / 2, nMaxSize)); // Grow size of buffer exponentially
}
RegCloseKey(HKEY_PERFORMANCE_DATA);
if (ret == ERROR_SUCCESS) {
hasher.Write(vData.data(), nSize);
memory_cleanse(vData.data(), nSize);
} else {
// Performance data is only a best-effort attempt at improving the
// situation when the OS randomness (and other sources) aren't
// adequate. As a result, failure to read it is isn't considered critical,
// so we don't call RandFailure().
// TODO: Add logging when the logger is made functional before global
// constructors have been invoked.
}
#endif
}
/** Helper to easily feed data into a CSHA512.
*
* Note that this does not serialize the passed object (like stream.h's << operators do).
* Its raw memory representation is used directly.
*/
template<typename T>
CSHA512& operator<<(CSHA512& hasher, const T& data) {
static_assert(!std::is_same<typename std::decay<T>::type, char*>::value, "Calling operator<<(CSHA512, char*) is probably not what you want");
static_assert(!std::is_same<typename std::decay<T>::type, unsigned char*>::value, "Calling operator<<(CSHA512, unsigned char*) is probably not what you want");
static_assert(!std::is_same<typename std::decay<T>::type, const char*>::value, "Calling operator<<(CSHA512, const char*) is probably not what you want");
static_assert(!std::is_same<typename std::decay<T>::type, const unsigned char*>::value, "Calling operator<<(CSHA512, const unsigned char*) is probably not what you want");
hasher.Write((const unsigned char*)&data, sizeof(data));
return hasher;
}
#ifndef WIN32
void AddSockaddr(CSHA512& hasher, const struct sockaddr *addr)
{
if (addr == nullptr) return;
switch (addr->sa_family) {
case AF_INET:
hasher.Write((const unsigned char*)addr, sizeof(sockaddr_in));
break;
case AF_INET6:
hasher.Write((const unsigned char*)addr, sizeof(sockaddr_in6));
break;
default:
hasher.Write((const unsigned char*)&addr->sa_family, sizeof(addr->sa_family));
}
}
void AddFile(CSHA512& hasher, const char *path)
{
struct stat sb = {};
int f = open(path, O_RDONLY);
size_t total = 0;
if (f != -1) {
unsigned char fbuf[4096];
int n;
hasher.Write((const unsigned char*)&f, sizeof(f));
if (fstat(f, &sb) == 0) hasher << sb;
do {
n = read(f, fbuf, sizeof(fbuf));
if (n > 0) hasher.Write(fbuf, n);
total += n;
/* not bothering with EINTR handling. */
} while (n == sizeof(fbuf) && total < 1048576); // Read only the first 1 Mbyte
close(f);
}
}
void AddPath(CSHA512& hasher, const char *path)
{
struct stat sb = {};
if (stat(path, &sb) == 0) {
hasher.Write((const unsigned char*)path, strlen(path) + 1);
hasher << sb;
}
}
#endif
#if HAVE_SYSCTL
template<int... S>
void AddSysctl(CSHA512& hasher)
{
int CTL[sizeof...(S)] = {S...};
unsigned char buffer[65536];
size_t siz = 65536;
int ret = sysctl(CTL, sizeof...(S), buffer, &siz, nullptr, 0);
if (ret == 0 || (ret == -1 && errno == ENOMEM)) {
hasher << sizeof(CTL);
hasher.Write((const unsigned char*)CTL, sizeof(CTL));
if (siz > sizeof(buffer)) siz = sizeof(buffer);
hasher << siz;
hasher.Write(buffer, siz);
}
}
#endif
#ifdef HAVE_GETCPUID
void inline AddCPUID(CSHA512& hasher, uint32_t leaf, uint32_t subleaf, uint32_t& ax, uint32_t& bx, uint32_t& cx, uint32_t& dx)
{
GetCPUID(leaf, subleaf, ax, bx, cx, dx);
hasher << leaf << subleaf << ax << bx << cx << dx;
}
void AddAllCPUID(CSHA512& hasher)
{
uint32_t ax, bx, cx, dx;
// Iterate over all standard leaves
AddCPUID(hasher, 0, 0, ax, bx, cx, dx); // Returns max leaf in ax
uint32_t max = ax;
for (uint32_t leaf = 1; leaf <= max && leaf <= 0xFF; ++leaf) {
uint32_t maxsub = 0;
for (uint32_t subleaf = 0; subleaf <= 0xFF; ++subleaf) {
AddCPUID(hasher, leaf, subleaf, ax, bx, cx, dx);
// Iterate subleafs for leaf values 4, 7, 11, 13
if (leaf == 4) {
if ((ax & 0x1f) == 0) break;
} else if (leaf == 7) {
if (subleaf == 0) maxsub = ax;
if (subleaf == maxsub) break;
} else if (leaf == 11) {
if ((cx & 0xff00) == 0) break;
} else if (leaf == 13) {
if (ax == 0 && bx == 0 && cx == 0 && dx == 0) break;
} else {
// For any other leaf, stop after subleaf 0.
break;
}
}
}
// Iterate over all extended leaves
AddCPUID(hasher, 0x80000000, 0, ax, bx, cx, dx); // Returns max extended leaf in ax
uint32_t ext_max = ax;
for (uint32_t leaf = 0x80000001; leaf <= ext_max && leaf <= 0x800000FF; ++leaf) {
AddCPUID(hasher, leaf, 0, ax, bx, cx, dx);
}
}
#endif
} // namespace
void RandAddDynamicEnv(CSHA512& hasher)
{
RandAddSeedPerfmon(hasher);
// Various clocks
#ifdef WIN32
FILETIME ftime;
GetSystemTimeAsFileTime(&ftime);
hasher << ftime;
#else
struct timespec ts = {};
# ifdef CLOCK_MONOTONIC
clock_gettime(CLOCK_MONOTONIC, &ts);
hasher << ts;
# endif
# ifdef CLOCK_REALTIME
clock_gettime(CLOCK_REALTIME, &ts);
hasher << ts;
# endif
# ifdef CLOCK_BOOTTIME
clock_gettime(CLOCK_BOOTTIME, &ts);
hasher << ts;
# endif
// gettimeofday is available on all UNIX systems, but only has microsecond precision.
struct timeval tv = {};
gettimeofday(&tv, nullptr);
hasher << tv;
#endif
// Probably redundant, but also use all the clocks C++11 provides:
hasher << std::chrono::system_clock::now().time_since_epoch().count();
hasher << std::chrono::steady_clock::now().time_since_epoch().count();
hasher << std::chrono::high_resolution_clock::now().time_since_epoch().count();
#ifndef WIN32
// Current resource usage.
struct rusage usage = {};
if (getrusage(RUSAGE_SELF, &usage) == 0) hasher << usage;
#endif
#ifdef __linux__
AddFile(hasher, "/proc/diskstats");
AddFile(hasher, "/proc/vmstat");
AddFile(hasher, "/proc/schedstat");
AddFile(hasher, "/proc/zoneinfo");
AddFile(hasher, "/proc/meminfo");
AddFile(hasher, "/proc/softirqs");
AddFile(hasher, "/proc/stat");
AddFile(hasher, "/proc/self/schedstat");
AddFile(hasher, "/proc/self/status");
#endif
#if HAVE_SYSCTL
# ifdef CTL_KERN
# if defined(KERN_PROC) && defined(KERN_PROC_ALL)
AddSysctl<CTL_KERN, KERN_PROC, KERN_PROC_ALL>(hasher);
# endif
# endif
# ifdef CTL_HW
# ifdef HW_DISKSTATS
AddSysctl<CTL_HW, HW_DISKSTATS>(hasher);
# endif
# endif
# ifdef CTL_VM
# ifdef VM_LOADAVG
AddSysctl<CTL_VM, VM_LOADAVG>(hasher);
# endif
# ifdef VM_TOTAL
AddSysctl<CTL_VM, VM_TOTAL>(hasher);
# endif
# ifdef VM_METER
AddSysctl<CTL_VM, VM_METER>(hasher);
# endif
# endif
#endif
// Stack and heap location
void* addr = malloc(4097);
hasher << &addr << addr;
free(addr);
}
void RandAddStaticEnv(CSHA512& hasher)
{
// Some compile-time static properties
hasher << (CHAR_MIN < 0) << sizeof(void*) << sizeof(long) << sizeof(int);
#if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__)
hasher << __GNUC__ << __GNUC_MINOR__ << __GNUC_PATCHLEVEL__;
#endif
#ifdef _MSC_VER
hasher << _MSC_VER;
#endif
hasher << __cplusplus;
#ifdef _XOPEN_VERSION
hasher << _XOPEN_VERSION;
#endif
#ifdef __VERSION__
const char* COMPILER_VERSION = __VERSION__;
hasher.Write((const unsigned char*)COMPILER_VERSION, strlen(COMPILER_VERSION) + 1);
#endif
// Bitcoin client version
hasher << CLIENT_VERSION;
#ifdef __linux__
// Information available through getauxval()
# ifdef AT_HWCAP
hasher << getauxval(AT_HWCAP);
# endif
# ifdef AT_HWCAP2
hasher << getauxval(AT_HWCAP2);
# endif
# ifdef AT_RANDOM
const unsigned char* random_aux = (const unsigned char*)getauxval(AT_RANDOM);
if (random_aux) hasher.Write(random_aux, 16);
# endif
# ifdef AT_PLATFORM
const char* platform_str = (const char*)getauxval(AT_PLATFORM);
if (platform_str) hasher.Write((const unsigned char*)platform_str, strlen(platform_str) + 1);
# endif
# ifdef AT_EXECFN
const char* exec_str = (const char*)getauxval(AT_EXECFN);
if (exec_str) hasher.Write((const unsigned char*)exec_str, strlen(exec_str) + 1);
# endif
#endif // __linux__
#ifdef HAVE_GETCPUID
AddAllCPUID(hasher);
#endif
// Memory locations
hasher << &hasher << &RandAddStaticEnv << &malloc << &errno << &environ;
// Hostname
char hname[256];
if (gethostname(hname, 256) == 0) {
hasher.Write((const unsigned char*)hname, strnlen(hname, 256));
}
#if HAVE_DECL_GETIFADDRS
// Network interfaces
struct ifaddrs *ifad = NULL;
getifaddrs(&ifad);
struct ifaddrs *ifit = ifad;
while (ifit != NULL) {
hasher.Write((const unsigned char*)&ifit, sizeof(ifit));
hasher.Write((const unsigned char*)ifit->ifa_name, strlen(ifit->ifa_name) + 1);
hasher.Write((const unsigned char*)&ifit->ifa_flags, sizeof(ifit->ifa_flags));
AddSockaddr(hasher, ifit->ifa_addr);
AddSockaddr(hasher, ifit->ifa_netmask);
AddSockaddr(hasher, ifit->ifa_dstaddr);
ifit = ifit->ifa_next;
}
freeifaddrs(ifad);
#endif
#ifndef WIN32
// UNIX kernel information
struct utsname name;
if (uname(&name) != -1) {
hasher.Write((const unsigned char*)&name.sysname, strlen(name.sysname) + 1);
hasher.Write((const unsigned char*)&name.nodename, strlen(name.nodename) + 1);
hasher.Write((const unsigned char*)&name.release, strlen(name.release) + 1);
hasher.Write((const unsigned char*)&name.version, strlen(name.version) + 1);
hasher.Write((const unsigned char*)&name.machine, strlen(name.machine) + 1);
}
/* Path and filesystem provided data */
AddPath(hasher, "/");
AddPath(hasher, ".");
AddPath(hasher, "/tmp");
AddPath(hasher, "/home");
AddPath(hasher, "/proc");
#ifdef __linux__
AddFile(hasher, "/proc/cmdline");
AddFile(hasher, "/proc/cpuinfo");
AddFile(hasher, "/proc/version");
#endif
AddFile(hasher, "/etc/passwd");
AddFile(hasher, "/etc/group");
AddFile(hasher, "/etc/hosts");
AddFile(hasher, "/etc/resolv.conf");
AddFile(hasher, "/etc/timezone");
AddFile(hasher, "/etc/localtime");
#endif
// For MacOS/BSDs, gather data through sysctl instead of /proc. Not all of these
// will exist on every system.
#if HAVE_SYSCTL
# ifdef CTL_HW
# ifdef HW_MACHINE
AddSysctl<CTL_HW, HW_MACHINE>(hasher);
# endif
# ifdef HW_MODEL
AddSysctl<CTL_HW, HW_MODEL>(hasher);
# endif
# ifdef HW_NCPU
AddSysctl<CTL_HW, HW_NCPU>(hasher);
# endif
# ifdef HW_PHYSMEM
AddSysctl<CTL_HW, HW_PHYSMEM>(hasher);
# endif
# ifdef HW_USERMEM
AddSysctl<CTL_HW, HW_USERMEM>(hasher);
# endif
# ifdef HW_MACHINE_ARCH
AddSysctl<CTL_HW, HW_MACHINE_ARCH>(hasher);
# endif
# ifdef HW_REALMEM
AddSysctl<CTL_HW, HW_REALMEM>(hasher);
# endif
# ifdef HW_CPU_FREQ
AddSysctl<CTL_HW, HW_CPU_FREQ>(hasher);
# endif
# ifdef HW_BUS_FREQ
AddSysctl<CTL_HW, HW_BUS_FREQ>(hasher);
# endif
# ifdef HW_CACHELINE
AddSysctl<CTL_HW, HW_CACHELINE>(hasher);
# endif
# endif
# ifdef CTL_KERN
# ifdef KERN_BOOTFILE
AddSysctl<CTL_KERN, KERN_BOOTFILE>(hasher);
# endif
# ifdef KERN_BOOTTIME
AddSysctl<CTL_KERN, KERN_BOOTTIME>(hasher);
# endif
# ifdef KERN_CLOCKRATE
AddSysctl<CTL_KERN, KERN_CLOCKRATE>(hasher);
# endif
# ifdef KERN_HOSTID
AddSysctl<CTL_KERN, KERN_HOSTID>(hasher);
# endif
# ifdef KERN_HOSTUUID
AddSysctl<CTL_KERN, KERN_HOSTUUID>(hasher);
# endif
# ifdef KERN_HOSTNAME
AddSysctl<CTL_KERN, KERN_HOSTNAME>(hasher);
# endif
# ifdef KERN_OSRELDATE
AddSysctl<CTL_KERN, KERN_OSRELDATE>(hasher);
# endif
# ifdef KERN_OSRELEASE
AddSysctl<CTL_KERN, KERN_OSRELEASE>(hasher);
# endif
# ifdef KERN_OSREV
AddSysctl<CTL_KERN, KERN_OSREV>(hasher);
# endif
# ifdef KERN_OSTYPE
AddSysctl<CTL_KERN, KERN_OSTYPE>(hasher);
# endif
# ifdef KERN_POSIX1
AddSysctl<CTL_KERN, KERN_OSREV>(hasher);
# endif
# ifdef KERN_VERSION
AddSysctl<CTL_KERN, KERN_VERSION>(hasher);
# endif
# endif
#endif
// Env variables
if (environ) {
for (size_t i = 0; environ[i]; ++i) {
hasher.Write((const unsigned char*)environ[i], strlen(environ[i]));
}
}
// Process, thread, user, session, group, ... ids.
#ifdef WIN32
hasher << GetCurrentProcessId() << GetCurrentThreadId();
#else
hasher << getpid() << getppid() << getsid(0) << getpgid(0) << getuid() << geteuid() << getgid() << getegid();
#endif
hasher << std::this_thread::get_id();
}