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author | Pieter Wuille <pieter.wuille@gmail.com> | 2019-10-26 18:05:10 -0700 |
---|---|---|
committer | Pieter Wuille <pieter.wuille@gmail.com> | 2019-11-12 15:24:02 -0800 |
commit | 2554c1b81bb8c40e1989025c6f18e7935720b156 (patch) | |
tree | 86dc2f698d86ed556c2fa0ac0f141dfde2f40b23 | |
parent | c2a262a78c3bcc4d5e13612ab0214874abe15de0 (diff) | |
download | bitcoin-2554c1b81bb8c40e1989025c6f18e7935720b156.tar.xz |
Gather additional entropy from the environment
This based on code by Gregory Maxwell.
-rw-r--r-- | src/randomenv.cpp | 194 |
1 files changed, 184 insertions, 10 deletions
diff --git a/src/randomenv.cpp b/src/randomenv.cpp index 3f970ec330..1faf2f4613 100644 --- a/src/randomenv.cpp +++ b/src/randomenv.cpp @@ -3,8 +3,13 @@ // 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/bitcoin-config.h> +#endif + #include <randomenv.h> +#include <clientversion.h> #include <crypto/sha512.h> #include <support/cleanse.h> #include <util/time.h> // for GetTime() @@ -14,14 +19,21 @@ #include <algorithm> #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/types.h> +#include <sys/utsname.h> #include <unistd.h> #endif #ifdef __MACH__ @@ -29,6 +41,12 @@ #include <mach/mach.h> #include <mach/mach_time.h> #endif +#if HAVE_DECL_GETIFADDRS +#include <ifaddrs.h> +#endif + +//! Necessary on some platforms +extern char** environ; namespace { @@ -85,6 +103,53 @@ CSHA512& operator<<(CSHA512& hasher, const T& 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 + + } // namespace void RandAddDynamicEnv(CSHA512& hasher) @@ -99,18 +164,18 @@ void RandAddDynamicEnv(CSHA512& hasher) #else # ifndef __MACH__ // On non-MacOS systems, use various clock_gettime() calls. - struct timespec ts; + struct timespec ts = {}; # ifdef CLOCK_MONOTONIC clock_gettime(CLOCK_MONOTONIC, &ts); - hasher << ts.tv_sec << ts.tv_nsec; + hasher << ts; # endif # ifdef CLOCK_REALTIME clock_gettime(CLOCK_REALTIME, &ts); - hasher << ts.tv_sec << ts.tv_nsec; + hasher << ts; # endif # ifdef CLOCK_BOOTTIME clock_gettime(CLOCK_BOOTTIME, &ts); - hasher << ts.tv_sec << ts.tv_nsec; + hasher << ts; # endif # else // On MacOS use mach_absolute_time (number of CPU ticks since boot) as a replacement for CLOCK_MONOTONIC, @@ -118,29 +183,138 @@ void RandAddDynamicEnv(CSHA512& hasher) hasher << mach_absolute_time(); // From https://gist.github.com/jbenet/1087739 clock_serv_t cclock; - mach_timespec_t mts; + mach_timespec_t mts = {}; if (host_get_clock_service(mach_host_self(), CALENDAR_CLOCK, &cclock) == KERN_SUCCESS && clock_get_time(cclock, &mts) == KERN_SUCCESS) { - hasher << mts.tv_sec << mts.tv_nsec; + hasher << mts; mach_port_deallocate(mach_task_self(), cclock); } # endif // gettimeofday is available on all UNIX systems, but only has microsecond precision. - struct timeval tv; + struct timeval tv = {}; gettimeofday(&tv, nullptr); - hasher << tv.tv_sec << tv.tv_usec; + 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 + + // 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; + + // 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"); + + /* TODO: sysctl's for OSX to fetch information not available from /proc */ +#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(); + hasher << getpid() << getppid() << getsid(0) << getpgid(0) << getuid() << geteuid() << getgid() << getegid(); #endif hasher << std::this_thread::get_id(); } |