@ -0,0 +1,425 @@ | |||
/* $OpenBSD: getentropy_osx.c,v 1.1 2014/07/08 10:45:35 beck Exp $ */ | |||
/* | |||
* Copyright (c) 2014 Theo de Raadt <deraadt@openbsd.org> | |||
* Copyright (c) 2014 Bob Beck <beck@obtuse.com> | |||
* | |||
* Permission to use, copy, modify, and distribute this software for any | |||
* purpose with or without fee is hereby granted, provided that the above | |||
* copyright notice and this permission notice appear in all copies. | |||
* | |||
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES | |||
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF | |||
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR | |||
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES | |||
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN | |||
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF | |||
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. | |||
*/ | |||
#include <sys/types.h> | |||
#include <sys/param.h> | |||
#include <sys/ioctl.h> | |||
#include <sys/resource.h> | |||
#include <sys/syscall.h> | |||
#include <sys/sysctl.h> | |||
#include <sys/statvfs.h> | |||
#include <sys/socket.h> | |||
#include <sys/mount.h> | |||
#include <sys/mman.h> | |||
#include <sys/stat.h> | |||
#include <sys/time.h> | |||
#include <stdlib.h> | |||
#include <stdint.h> | |||
#include <stdio.h> | |||
#include <termios.h> | |||
#include <fcntl.h> | |||
#include <signal.h> | |||
#include <string.h> | |||
#include <errno.h> | |||
#include <unistd.h> | |||
#include <time.h> | |||
#include <mach/mach_time.h> | |||
#include <mach/mach_host.h> | |||
#include <mach/host_info.h> | |||
#include <sys/socketvar.h> | |||
#include <sys/vmmeter.h> | |||
#include <netinet/in.h> | |||
#include <netinet/tcp.h> | |||
#include <netinet/udp.h> | |||
#include <netinet/ip_var.h> | |||
#include <netinet/tcp_var.h> | |||
#include <netinet/udp_var.h> | |||
#include <CommonCrypto/CommonDigest.h> | |||
#define SHA512_Update(a, b, c) (CC_SHA512_Update((a), (b), (c))) | |||
#define SHA512_Init(xxx) (CC_SHA512_Init((xxx))) | |||
#define SHA512_Final(xxx, yyy) (CC_SHA512_Final((xxx), (yyy))) | |||
#define SHA512_CTX CC_SHA512_CTX | |||
#define SHA512_DIGEST_LENGTH CC_SHA512_DIGEST_LENGTH | |||
#define REPEAT 5 | |||
#define min(a, b) (((a) < (b)) ? (a) : (b)) | |||
#define HX(a, b) \ | |||
do { \ | |||
if ((a)) \ | |||
HD(errno); \ | |||
else \ | |||
HD(b); \ | |||
} while (0) | |||
#define HR(x, l) (SHA512_Update(&ctx, (char *)(x), (l))) | |||
#define HD(x) (SHA512_Update(&ctx, (char *)&(x), sizeof (x))) | |||
int getentropy(void *buf, size_t len); | |||
extern int main(int, char *argv[]); | |||
static int gotdata(char *buf, size_t len); | |||
static int getentropy_urandom(void *buf, size_t len); | |||
static int getentropy_fallback(void *buf, size_t len); | |||
int | |||
getentropy(void *buf, size_t len) | |||
{ | |||
int ret = -1; | |||
if (len > 256) { | |||
errno = EIO; | |||
return -1; | |||
} | |||
/* | |||
* Try to get entropy with /dev/urandom | |||
* | |||
* This can fail if the process is inside a chroot or if file | |||
* descriptors are exhausted. | |||
*/ | |||
ret = getentropy_urandom(buf, len); | |||
if (ret != -1) | |||
return (ret); | |||
/* | |||
* Entropy collection via /dev/urandom and sysctl have failed. | |||
* | |||
* No other API exists for collecting entropy, and we have | |||
* no failsafe way to get it on OSX that is not sensitive | |||
* to resource exhaustion. | |||
* | |||
* We have very few options: | |||
* - Even syslog_r is unsafe to call at this low level, so | |||
* there is no way to alert the user or program. | |||
* - Cannot call abort() because some systems have unsafe | |||
* corefiles. | |||
* - Could raise(SIGKILL) resulting in silent program termination. | |||
* - Return EIO, to hint that arc4random's stir function | |||
* should raise(SIGKILL) | |||
* - Do the best under the circumstances.... | |||
* | |||
* This code path exists to bring light to the issue that OSX | |||
* does not provide a failsafe API for entropy collection. | |||
* | |||
* We hope this demonstrates that OSX should consider | |||
* providing a new failsafe API which works in a chroot or | |||
* when file descriptors are exhausted. | |||
*/ | |||
#undef FAIL_WHEN_SYSTEM_ENTROPY_FAILS | |||
#ifdef FAIL_WHEN_SYSTEM_ENTROPY_FAILS | |||
raise(SIGKILL); | |||
#endif | |||
ret = getentropy_fallback(buf, len); | |||
if (ret != -1) | |||
return (ret); | |||
errno = EIO; | |||
return (ret); | |||
} | |||
/* | |||
* Basic sanity checking; wish we could do better. | |||
*/ | |||
static int | |||
gotdata(char *buf, size_t len) | |||
{ | |||
char any_set = 0; | |||
size_t i; | |||
for (i = 0; i < len; ++i) | |||
any_set |= buf[i]; | |||
if (any_set == 0) | |||
return -1; | |||
return 0; | |||
} | |||
static int | |||
getentropy_urandom(void *buf, size_t len) | |||
{ | |||
struct stat st; | |||
size_t i; | |||
int fd, cnt, flags; | |||
int save_errno = errno; | |||
start: | |||
flags = O_RDONLY; | |||
#ifdef O_NOFOLLOW | |||
flags |= O_NOFOLLOW; | |||
#endif | |||
#ifdef O_CLOEXEC | |||
flags |= O_CLOEXEC; | |||
#endif | |||
fd = open("/dev/urandom", flags, 0); | |||
if (fd == -1) { | |||
if (errno == EINTR) | |||
goto start; | |||
goto nodevrandom; | |||
} | |||
#ifndef O_CLOEXEC | |||
fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC); | |||
#endif | |||
/* Lightly verify that the device node looks sane */ | |||
if (fstat(fd, &st) == -1 || !S_ISCHR(st.st_mode)) { | |||
close(fd); | |||
goto nodevrandom; | |||
} | |||
for (i = 0; i < len; ) { | |||
size_t wanted = len - i; | |||
ssize_t ret = read(fd, buf + i, wanted); | |||
if (ret == -1) { | |||
if (errno == EAGAIN || errno == EINTR) | |||
continue; | |||
close(fd); | |||
goto nodevrandom; | |||
} | |||
i += ret; | |||
} | |||
close(fd); | |||
if (gotdata(buf, len) == 0) { | |||
errno = save_errno; | |||
return 0; /* satisfied */ | |||
} | |||
nodevrandom: | |||
errno = EIO; | |||
return -1; | |||
} | |||
static int | |||
getentropy_fallback(void *buf, size_t len) | |||
{ | |||
int tcpmib[] = { CTL_NET, AF_INET, IPPROTO_TCP, TCPCTL_STATS }; | |||
int udpmib[] = { CTL_NET, AF_INET, IPPROTO_UDP, UDPCTL_STATS }; | |||
int ipmib[] = { CTL_NET, AF_INET, IPPROTO_IP, IPCTL_STATS }; | |||
int kmib[] = { CTL_KERN, KERN_USRSTACK }; | |||
int hwmib[] = { CTL_HW, HW_USERMEM }; | |||
int save_errno = errno, e, m, pgs = getpagesize(), faster = 0, repeat; | |||
uint8_t results[SHA512_DIGEST_LENGTH]; | |||
struct tcpstat tcpstat; | |||
struct udpstat udpstat; | |||
struct ipstat ipstat; | |||
u_int64_t mach_time; | |||
unsigned int idata; | |||
struct timespec ts; | |||
struct timeval tv; | |||
struct rusage ru; | |||
sigset_t sigset; | |||
struct stat st; | |||
static int cnt; | |||
SHA512_CTX ctx; | |||
static pid_t lastpid; | |||
void * addr; | |||
pid_t pid; | |||
size_t i, ii; | |||
char *p; | |||
pid = getpid(); | |||
if (lastpid == pid) { | |||
faster = 1; | |||
repeat = 2; | |||
} else { | |||
faster = 0; | |||
lastpid = pid; | |||
repeat = REPEAT; | |||
} | |||
for (i = 0; i < len; ) { | |||
int j; | |||
SHA512_Init(&ctx); | |||
for (j = 0; j < repeat; j++) { | |||
size_t len; | |||
HX((e = gettimeofday(&tv, NULL)) == -1, tv); | |||
if (e != -1) { | |||
cnt += (int)tv.tv_sec; | |||
cnt += (int)tv.tv_usec; | |||
} | |||
mach_time = mach_absolute_time(); | |||
HD(mach_time); | |||
len = sizeof(addr); | |||
HX(sysctl(kmib, sizeof(kmib) / sizeof(kmib[0]), | |||
&addr, &len, NULL, 0) == -1, addr); | |||
len = sizeof(idata); | |||
HX(sysctl(hwmib, sizeof(hwmib) / sizeof(hwmib[0]), | |||
&idata, &len, NULL, 0) == -1, idata); | |||
len = sizeof(tcpstat); | |||
HX(sysctl(tcpmib, sizeof(tcpmib) / sizeof(tcpmib[0]), | |||
&tcpstat, &len, NULL, 0) == -1, tcpstat); | |||
len = sizeof(udpstat); | |||
HX(sysctl(udpmib, sizeof(udpmib) / sizeof(udpmib[0]), | |||
&udpstat, &len, NULL, 0) == -1, udpstat); | |||
len = sizeof(ipstat); | |||
HX(sysctl(ipmib, sizeof(ipmib) / sizeof(ipmib[0]), | |||
&ipstat, &len, NULL, 0) == -1, ipstat); | |||
HX((pid = getpid()) == -1, pid); | |||
HX((pid = getsid(pid)) == -1, pid); | |||
HX((pid = getppid()) == -1, pid); | |||
HX((pid = getpgid(0)) == -1, pid); | |||
HX((m = getpriority(0, 0)) == -1, m); | |||
if (!faster) { | |||
ts.tv_sec = 0; | |||
ts.tv_nsec = 1; | |||
(void) nanosleep(&ts, NULL); | |||
} | |||
HX(sigpending(&sigset) == -1, sigset); | |||
HX(sigprocmask(SIG_BLOCK, NULL, &sigset) == -1, | |||
sigset); | |||
HD(main); /* an addr in program */ | |||
HD(getentropy); /* an addr in this library */ | |||
HD(printf); /* an addr in libc */ | |||
p = (char *)&p; | |||
HD(p); /* an addr on stack */ | |||
p = (char *)&errno; | |||
HD(p); /* the addr of errno */ | |||
if (i == 0) { | |||
struct sockaddr_storage ss; | |||
struct statvfs stvfs; | |||
struct termios tios; | |||
struct statfs stfs; | |||
socklen_t ssl; | |||
off_t off; | |||
/* | |||
* Prime-sized mappings encourage fragmentation; | |||
* thus exposing some address entropy. | |||
*/ | |||
struct mm { | |||
size_t npg; | |||
void *p; | |||
} mm[] = { | |||
{ 17, MAP_FAILED }, { 3, MAP_FAILED }, | |||
{ 11, MAP_FAILED }, { 2, MAP_FAILED }, | |||
{ 5, MAP_FAILED }, { 3, MAP_FAILED }, | |||
{ 7, MAP_FAILED }, { 1, MAP_FAILED }, | |||
{ 57, MAP_FAILED }, { 3, MAP_FAILED }, | |||
{ 131, MAP_FAILED }, { 1, MAP_FAILED }, | |||
}; | |||
for (m = 0; m < sizeof mm/sizeof(mm[0]); m++) { | |||
HX(mm[m].p = mmap(NULL, | |||
mm[m].npg * pgs, | |||
PROT_READ|PROT_WRITE, | |||
MAP_PRIVATE|MAP_ANON, -1, | |||
(off_t)0), mm[m].p); | |||
if (mm[m].p != MAP_FAILED) { | |||
size_t mo; | |||
/* Touch some memory... */ | |||
p = mm[m].p; | |||
mo = cnt % | |||
(mm[m].npg * pgs - 1); | |||
p[mo] = 1; | |||
cnt += (int)((long)(mm[m].p) | |||
/ pgs); | |||
} | |||
/* Check cnts and times... */ | |||
mach_time = mach_absolute_time(); | |||
HD(mach_time); | |||
cnt += (int)mach_time; | |||
HX((e = getrusage(RUSAGE_SELF, | |||
&ru)) == -1, ru); | |||
if (e != -1) { | |||
cnt += (int)ru.ru_utime.tv_sec; | |||
cnt += (int)ru.ru_utime.tv_usec; | |||
} | |||
} | |||
for (m = 0; m < sizeof mm/sizeof(mm[0]); m++) { | |||
if (mm[m].p != MAP_FAILED) | |||
munmap(mm[m].p, mm[m].npg * pgs); | |||
mm[m].p = MAP_FAILED; | |||
} | |||
HX(stat(".", &st) == -1, st); | |||
HX(statvfs(".", &stvfs) == -1, stvfs); | |||
HX(statfs(".", &stfs) == -1, stfs); | |||
HX(stat("/", &st) == -1, st); | |||
HX(statvfs("/", &stvfs) == -1, stvfs); | |||
HX(statfs("/", &stfs) == -1, stfs); | |||
HX((e = fstat(0, &st)) == -1, st); | |||
if (e == -1) { | |||
if (S_ISREG(st.st_mode) || | |||
S_ISFIFO(st.st_mode) || | |||
S_ISSOCK(st.st_mode)) { | |||
HX(fstatvfs(0, &stvfs) == -1, | |||
stvfs); | |||
HX(fstatfs(0, &stfs) == -1, | |||
stfs); | |||
HX((off = lseek(0, (off_t)0, | |||
SEEK_CUR)) < 0, off); | |||
} | |||
if (S_ISCHR(st.st_mode)) { | |||
HX(tcgetattr(0, &tios) == -1, | |||
tios); | |||
} else if (S_ISSOCK(st.st_mode)) { | |||
memset(&ss, 0, sizeof ss); | |||
ssl = sizeof(ss); | |||
HX(getpeername(0, | |||
(void *)&ss, &ssl) == -1, | |||
ss); | |||
} | |||
} | |||
HX((e = getrusage(RUSAGE_CHILDREN, | |||
&ru)) == -1, ru); | |||
if (e != -1) { | |||
cnt += (int)ru.ru_utime.tv_sec; | |||
cnt += (int)ru.ru_utime.tv_usec; | |||
} | |||
} else { | |||
/* Subsequent hashes absorb previous result */ | |||
HD(results); | |||
} | |||
HX((e = gettimeofday(&tv, NULL)) == -1, tv); | |||
if (e != -1) { | |||
cnt += (int)tv.tv_sec; | |||
cnt += (int)tv.tv_usec; | |||
} | |||
HD(cnt); | |||
} | |||
SHA512_Final(results, &ctx); | |||
memcpy(buf + i, results, min(sizeof(results), len - i)); | |||
i += min(sizeof(results), len - i); | |||
} | |||
memset(results, 0, sizeof results); | |||
if (gotdata(buf, len) == 0) { | |||
errno = save_errno; | |||
return 0; /* satisfied */ | |||
} | |||
errno = EIO; | |||
return -1; | |||
} |
@ -0,0 +1,413 @@ | |||
/* $OpenBSD: getentropy_solaris.c,v 1.1 2014/07/08 10:45:35 beck Exp $ */ | |||
/* | |||
* Copyright (c) 2014 Theo de Raadt <deraadt@openbsd.org> | |||
* Copyright (c) 2014 Bob Beck <beck@obtuse.com> | |||
* | |||
* Permission to use, copy, modify, and distribute this software for any | |||
* purpose with or without fee is hereby granted, provided that the above | |||
* copyright notice and this permission notice appear in all copies. | |||
* | |||
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES | |||
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF | |||
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR | |||
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES | |||
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN | |||
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF | |||
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. | |||
*/ | |||
#include <sys/types.h> | |||
#include <sys/param.h> | |||
#include <sys/ioctl.h> | |||
#include <sys/resource.h> | |||
#include <sys/syscall.h> | |||
#include <sys/statvfs.h> | |||
#include <sys/socket.h> | |||
#include <sys/mount.h> | |||
#include <sys/mman.h> | |||
#include <sys/stat.h> | |||
#include <sys/time.h> | |||
#include <stdlib.h> | |||
#include <stdint.h> | |||
#include <stdio.h> | |||
#include <termios.h> | |||
#include <fcntl.h> | |||
#include <signal.h> | |||
#include <string.h> | |||
#include <errno.h> | |||
#include <unistd.h> | |||
#include <time.h> | |||
#include <sys/sha2.h> | |||
#define SHA512_Init SHA512Init | |||
#define SHA512_Update SHA512Update | |||
#define SHA512_Final SHA512Final | |||
#include <sys/vfs.h> | |||
#include <sys/statfs.h> | |||
#include <sys/loadavg.h> | |||
#define REPEAT 5 | |||
#define min(a, b) (((a) < (b)) ? (a) : (b)) | |||
#define HX(a, b) \ | |||
do { \ | |||
if ((a)) \ | |||
HD(errno); \ | |||
else \ | |||
HD(b); \ | |||
} while (0) | |||
#define HR(x, l) (SHA512_Update(&ctx, (char *)(x), (l))) | |||
#define HD(x) (SHA512_Update(&ctx, (char *)&(x), sizeof (x))) | |||
int getentropy(void *buf, size_t len); | |||
extern int main(int, char *argv[]); | |||
static int gotdata(char *buf, size_t len); | |||
static int getentropy_urandom(void *buf, size_t len); | |||
static int getentropy_fallback(void *buf, size_t len); | |||
int | |||
getentropy(void *buf, size_t len) | |||
{ | |||
int ret = -1; | |||
if (len > 256) { | |||
errno = EIO; | |||
return -1; | |||
} | |||
/* | |||
* Try to get entropy with /dev/urandom | |||
* | |||
* This can fail if the process is inside a chroot or if file | |||
* descriptors are exhausted. | |||
*/ | |||
ret = getentropy_urandom(buf, len); | |||
if (ret != -1) | |||
return (ret); | |||
/* | |||
* Entropy collection via /dev/urandom and sysctl have failed. | |||
* | |||
* No other API exists for collecting entropy, and we have | |||
* no failsafe way to get it on Solaris that is not sensitive | |||
* to resource exhaustion. | |||
* | |||
* We have very few options: | |||
* - Even syslog_r is unsafe to call at this low level, so | |||
* there is no way to alert the user or program. | |||
* - Cannot call abort() because some systems have unsafe | |||
* corefiles. | |||
* - Could raise(SIGKILL) resulting in silent program termination. | |||
* - Return EIO, to hint that arc4random's stir function | |||
* should raise(SIGKILL) | |||
* - Do the best under the circumstances.... | |||
* | |||
* This code path exists to bring light to the issue that Solaris | |||
* does not provide a failsafe API for entropy collection. | |||
* | |||
* We hope this demonstrates that Solaris should consider | |||
* providing a new failsafe API which works in a chroot or | |||
* when file descriptors are exhausted. | |||
*/ | |||
#undef FAIL_WHEN_SYSTEM_ENTROPY_FAILS | |||
#ifdef FAIL_WHEN_SYSTEM_ENTROPY_FAILS | |||
raise(SIGKILL); | |||
#endif | |||
ret = getentropy_fallback(buf, len); | |||
if (ret != -1) | |||
return (ret); | |||
errno = EIO; | |||
return (ret); | |||
} | |||
/* | |||
* Basic sanity checking; wish we could do better. | |||
*/ | |||
static int | |||
gotdata(char *buf, size_t len) | |||
{ | |||
char any_set = 0; | |||
size_t i; | |||
for (i = 0; i < len; ++i) | |||
any_set |= buf[i]; | |||
if (any_set == 0) | |||
return -1; | |||
return 0; | |||
} | |||
static int | |||
getentropy_urandom(void *buf, size_t len) | |||
{ | |||
struct stat st; | |||
size_t i; | |||
int fd, flags; | |||
int save_errno = errno; | |||
start: | |||
flags = O_RDONLY; | |||
#ifdef O_NOFOLLOW | |||
flags |= O_NOFOLLOW; | |||
#endif | |||
#ifdef O_CLOEXEC | |||
flags |= O_CLOEXEC; | |||
#endif | |||
/* | |||
* Solaris provides /dev/urandom as a symbolic link. | |||
* /devices/pseudo/random@0:urandom should be the | |||
* real device path, and we do want O_NOFOLLOW. | |||
*/ | |||
fd = open("/devices/pseudo/random@0:urandom", flags, 0); | |||
if (fd == -1) { | |||
if (errno == EINTR) | |||
goto start; | |||
goto nodevrandom; | |||
} | |||
#ifndef O_CLOEXEC | |||
fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC); | |||
#endif | |||
/* Lightly verify that the device node looks sane */ | |||
if (fstat(fd, &st) == -1 || !S_ISCHR(st.st_mode)) { | |||
close(fd); | |||
goto nodevrandom; | |||
} | |||
for (i = 0; i < len; ) { | |||
size_t wanted = len - i; | |||
ssize_t ret = read(fd, buf + i, wanted); | |||
if (ret == -1) { | |||
if (errno == EAGAIN || errno == EINTR) | |||
continue; | |||
close(fd); | |||
goto nodevrandom; | |||
} | |||
i += ret; | |||
} | |||
close(fd); | |||
if (gotdata(buf, len) == 0) { | |||
errno = save_errno; | |||
return 0; /* satisfied */ | |||
} | |||
nodevrandom: | |||
errno = EIO; | |||
return -1; | |||
} | |||
static int cl[] = { | |||
CLOCK_REALTIME, | |||
#ifdef CLOCK_MONOTONIC | |||
CLOCK_MONOTONIC, | |||
#endif | |||
#ifdef CLOCK_MONOTONIC_RAW | |||
CLOCK_MONOTONIC_RAW, | |||
#endif | |||
#ifdef CLOCK_TAI | |||
CLOCK_TAI, | |||
#endif | |||
#ifdef CLOCK_VIRTUAL | |||
CLOCK_VIRTUAL, | |||
#endif | |||
#ifdef CLOCK_UPTIME | |||
CLOCK_UPTIME, | |||
#endif | |||
#ifdef CLOCK_PROCESS_CPUTIME_ID | |||
CLOCK_PROCESS_CPUTIME_ID, | |||
#endif | |||
#ifdef CLOCK_THREAD_CPUTIME_ID | |||
CLOCK_THREAD_CPUTIME_ID, | |||
#endif | |||
}; | |||
static int | |||
getentropy_fallback(void *buf, size_t len) | |||
{ | |||
uint8_t results[SHA512_DIGEST_LENGTH]; | |||
int save_errno = errno, e, m, pgs = getpagesize(), faster = 0, repeat; | |||
static int cnt; | |||
struct timespec ts; | |||
struct timeval tv; | |||
double loadavg[3]; | |||
struct rusage ru; | |||
sigset_t sigset; | |||
struct stat st; | |||
SHA512_CTX ctx; | |||
static pid_t lastpid; | |||
pid_t pid; | |||
size_t i, ii; | |||
char *p; | |||
pid = getpid(); | |||
if (lastpid == pid) { | |||
faster = 1; | |||
repeat = 2; | |||
} else { | |||
faster = 0; | |||
lastpid = pid; | |||
repeat = REPEAT; | |||
} | |||
for (i = 0; i < len; ) { | |||
int j; | |||
SHA512_Init(&ctx); | |||
for (j = 0; j < repeat; j++) { | |||
HX((e = gettimeofday(&tv, NULL)) == -1, tv); | |||
if (e != -1) { | |||
cnt += (int)tv.tv_sec; | |||
cnt += (int)tv.tv_usec; | |||
} | |||
for (ii = 0; ii < sizeof(cl)/sizeof(cl[0]); ii++) | |||
HX(clock_gettime(cl[ii], &ts) == -1, ts); | |||
HX((pid = getpid()) == -1, pid); | |||
HX((pid = getsid(pid)) == -1, pid); | |||
HX((pid = getppid()) == -1, pid); | |||
HX((pid = getpgid(0)) == -1, pid); | |||
HX((m = getpriority(0, 0)) == -1, m); | |||
HX((getloadavg(loadavg, 3) == -1), loadavg); | |||
if (!faster) { | |||
ts.tv_sec = 0; | |||
ts.tv_nsec = 1; | |||
(void) nanosleep(&ts, NULL); | |||
} | |||
HX(sigpending(&sigset) == -1, sigset); | |||
HX(sigprocmask(SIG_BLOCK, NULL, &sigset) == -1, | |||
sigset); | |||
HD(main); /* an addr in program */ | |||
HD(getentropy); /* an addr in this library */ | |||
HD(printf); /* an addr in libc */ | |||
p = (char *)&p; | |||
HD(p); /* an addr on stack */ | |||
p = (char *)&errno; | |||
HD(p); /* the addr of errno */ | |||
if (i == 0) { | |||
struct sockaddr_storage ss; | |||
struct statvfs stvfs; | |||
struct termios tios; | |||
socklen_t ssl; | |||
off_t off; | |||
/* | |||
* Prime-sized mappings encourage fragmentation; | |||
* thus exposing some address entropy. | |||
*/ | |||
struct mm { | |||
size_t npg; | |||
void *p; | |||
} mm[] = { | |||
{ 17, MAP_FAILED }, { 3, MAP_FAILED }, | |||
{ 11, MAP_FAILED }, { 2, MAP_FAILED }, | |||
{ 5, MAP_FAILED }, { 3, MAP_FAILED }, | |||
{ 7, MAP_FAILED }, { 1, MAP_FAILED }, | |||
{ 57, MAP_FAILED }, { 3, MAP_FAILED }, | |||
{ 131, MAP_FAILED }, { 1, MAP_FAILED }, | |||
}; | |||
for (m = 0; m < sizeof mm/sizeof(mm[0]); m++) { | |||
HX(mm[m].p = mmap(NULL, | |||
mm[m].npg * pgs, | |||
PROT_READ|PROT_WRITE, | |||
MAP_PRIVATE|MAP_ANON, -1, | |||
(off_t)0), mm[m].p); | |||
if (mm[m].p != MAP_FAILED) { | |||
size_t mo; | |||
/* Touch some memory... */ | |||
p = mm[m].p; | |||
mo = cnt % | |||
(mm[m].npg * pgs - 1); | |||
p[mo] = 1; | |||
cnt += (int)((long)(mm[m].p) | |||
/ pgs); | |||
} | |||
/* Check cnts and times... */ | |||
for (ii = 0; ii < sizeof(cl)/sizeof(cl[0]); | |||
ii++) { | |||
HX((e = clock_gettime(cl[ii], | |||
&ts)) == -1, ts); | |||
if (e != -1) | |||
cnt += (int)ts.tv_nsec; | |||
} | |||
HX((e = getrusage(RUSAGE_SELF, | |||
&ru)) == -1, ru); | |||
if (e != -1) { | |||
cnt += (int)ru.ru_utime.tv_sec; | |||
cnt += (int)ru.ru_utime.tv_usec; | |||
} | |||
} | |||
for (m = 0; m < sizeof mm/sizeof(mm[0]); m++) { | |||
if (mm[m].p != MAP_FAILED) | |||
munmap(mm[m].p, mm[m].npg * pgs); | |||
mm[m].p = MAP_FAILED; | |||
} | |||
HX(stat(".", &st) == -1, st); | |||
HX(statvfs(".", &stvfs) == -1, stvfs); | |||
HX(stat("/", &st) == -1, st); | |||
HX(statvfs("/", &stvfs) == -1, stvfs); | |||
HX((e = fstat(0, &st)) == -1, st); | |||
if (e == -1) { | |||
if (S_ISREG(st.st_mode) || | |||
S_ISFIFO(st.st_mode) || | |||
S_ISSOCK(st.st_mode)) { | |||
HX(fstatvfs(0, &stvfs) == -1, | |||
stvfs); | |||
HX((off = lseek(0, (off_t)0, | |||
SEEK_CUR)) < 0, off); | |||
} | |||
if (S_ISCHR(st.st_mode)) { | |||
HX(tcgetattr(0, &tios) == -1, | |||
tios); | |||
} else if (S_ISSOCK(st.st_mode)) { | |||
memset(&ss, 0, sizeof ss); | |||
ssl = sizeof(ss); | |||
HX(getpeername(0, | |||
(void *)&ss, &ssl) == -1, | |||
ss); | |||
} | |||
} | |||
HX((e = getrusage(RUSAGE_CHILDREN, | |||
&ru)) == -1, ru); | |||
if (e != -1) { | |||
cnt += (int)ru.ru_utime.tv_sec; | |||
cnt += (int)ru.ru_utime.tv_usec; | |||
} | |||
} else { | |||
/* Subsequent hashes absorb previous result */ | |||
HD(results); | |||
} | |||
HX((e = gettimeofday(&tv, NULL)) == -1, tv); | |||
if (e != -1) { | |||
cnt += (int)tv.tv_sec; | |||
cnt += (int)tv.tv_usec; | |||
} | |||
HD(cnt); | |||
} | |||
SHA512_Final(results, &ctx); | |||
memcpy(buf + i, results, min(sizeof(results), len - i)); | |||
i += min(sizeof(results), len - i); | |||
} | |||
memset(results, 0, sizeof results); | |||
if (gotdata(buf, len) == 0) { | |||
errno = save_errno; | |||
return 0; /* satisfied */ | |||
} | |||
errno = EIO; | |||
return -1; | |||
} |
@ -0,0 +1,425 @@ | |||
/* $OpenBSD: getentropy_osx.c,v 1.1 2014/07/08 10:45:35 beck Exp $ */ | |||
/* | |||
* Copyright (c) 2014 Theo de Raadt <deraadt@openbsd.org> | |||
* Copyright (c) 2014 Bob Beck <beck@obtuse.com> | |||
* | |||
* Permission to use, copy, modify, and distribute this software for any | |||
* purpose with or without fee is hereby granted, provided that the above | |||
* copyright notice and this permission notice appear in all copies. | |||
* | |||
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES | |||
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF | |||
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR | |||
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES | |||
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN | |||
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF | |||
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. | |||
*/ | |||
#include <sys/types.h> | |||
#include <sys/param.h> | |||
#include <sys/ioctl.h> | |||
#include <sys/resource.h> | |||
#include <sys/syscall.h> | |||
#include <sys/sysctl.h> | |||
#include <sys/statvfs.h> | |||
#include <sys/socket.h> | |||
#include <sys/mount.h> | |||
#include <sys/mman.h> | |||
#include <sys/stat.h> | |||
#include <sys/time.h> | |||
#include <stdlib.h> | |||
#include <stdint.h> | |||
#include <stdio.h> | |||
#include <termios.h> | |||
#include <fcntl.h> | |||
#include <signal.h> | |||
#include <string.h> | |||
#include <errno.h> | |||
#include <unistd.h> | |||
#include <time.h> | |||
#include <mach/mach_time.h> | |||
#include <mach/mach_host.h> | |||
#include <mach/host_info.h> | |||
#include <sys/socketvar.h> | |||
#include <sys/vmmeter.h> | |||
#include <netinet/in.h> | |||
#include <netinet/tcp.h> | |||
#include <netinet/udp.h> | |||
#include <netinet/ip_var.h> | |||
#include <netinet/tcp_var.h> | |||
#include <netinet/udp_var.h> | |||
#include <CommonCrypto/CommonDigest.h> | |||
#define SHA512_Update(a, b, c) (CC_SHA512_Update((a), (b), (c))) | |||
#define SHA512_Init(xxx) (CC_SHA512_Init((xxx))) | |||
#define SHA512_Final(xxx, yyy) (CC_SHA512_Final((xxx), (yyy))) | |||
#define SHA512_CTX CC_SHA512_CTX | |||
#define SHA512_DIGEST_LENGTH CC_SHA512_DIGEST_LENGTH | |||
#define REPEAT 5 | |||
#define min(a, b) (((a) < (b)) ? (a) : (b)) | |||
#define HX(a, b) \ | |||
do { \ | |||
if ((a)) \ | |||
HD(errno); \ | |||
else \ | |||
HD(b); \ | |||
} while (0) | |||
#define HR(x, l) (SHA512_Update(&ctx, (char *)(x), (l))) | |||
#define HD(x) (SHA512_Update(&ctx, (char *)&(x), sizeof (x))) | |||
int getentropy(void *buf, size_t len); | |||
extern int main(int, char *argv[]); | |||
static int gotdata(char *buf, size_t len); | |||
static int getentropy_urandom(void *buf, size_t len); | |||
static int getentropy_fallback(void *buf, size_t len); | |||
int | |||
getentropy(void *buf, size_t len) | |||
{ | |||
int ret = -1; | |||
if (len > 256) { | |||
errno = EIO; | |||
return -1; | |||
} | |||
/* | |||
* Try to get entropy with /dev/urandom | |||
* | |||
* This can fail if the process is inside a chroot or if file | |||
* descriptors are exhausted. | |||
*/ | |||
ret = getentropy_urandom(buf, len); | |||
if (ret != -1) | |||
return (ret); | |||
/* | |||
* Entropy collection via /dev/urandom and sysctl have failed. | |||
* | |||
* No other API exists for collecting entropy, and we have | |||
* no failsafe way to get it on OSX that is not sensitive | |||
* to resource exhaustion. | |||
* | |||
* We have very few options: | |||
* - Even syslog_r is unsafe to call at this low level, so | |||
* there is no way to alert the user or program. | |||
* - Cannot call abort() because some systems have unsafe | |||
* corefiles. | |||
* - Could raise(SIGKILL) resulting in silent program termination. | |||
* - Return EIO, to hint that arc4random's stir function | |||
* should raise(SIGKILL) | |||
* - Do the best under the circumstances.... | |||
* | |||
* This code path exists to bring light to the issue that OSX | |||
* does not provide a failsafe API for entropy collection. | |||
* | |||
* We hope this demonstrates that OSX should consider | |||
* providing a new failsafe API which works in a chroot or | |||
* when file descriptors are exhausted. | |||
*/ | |||
#undef FAIL_WHEN_SYSTEM_ENTROPY_FAILS | |||
#ifdef FAIL_WHEN_SYSTEM_ENTROPY_FAILS | |||
raise(SIGKILL); | |||
#endif | |||
ret = getentropy_fallback(buf, len); | |||
if (ret != -1) | |||
return (ret); | |||
errno = EIO; | |||
return (ret); | |||
} | |||
/* | |||
* Basic sanity checking; wish we could do better. | |||
*/ | |||
static int | |||
gotdata(char *buf, size_t len) | |||
{ | |||
char any_set = 0; | |||
size_t i; | |||
for (i = 0; i < len; ++i) | |||
any_set |= buf[i]; | |||
if (any_set == 0) | |||
return -1; | |||
return 0; | |||
} | |||
static int | |||
getentropy_urandom(void *buf, size_t len) | |||
{ | |||
struct stat st; | |||
size_t i; | |||
int fd, cnt, flags; | |||
int save_errno = errno; | |||
start: | |||
flags = O_RDONLY; | |||
#ifdef O_NOFOLLOW | |||
flags |= O_NOFOLLOW; | |||
#endif | |||
#ifdef O_CLOEXEC | |||
flags |= O_CLOEXEC; | |||
#endif | |||
fd = open("/dev/urandom", flags, 0); | |||
if (fd == -1) { | |||
if (errno == EINTR) | |||
goto start; | |||
goto nodevrandom; | |||
} | |||
#ifndef O_CLOEXEC | |||
fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC); | |||
#endif | |||
/* Lightly verify that the device node looks sane */ | |||
if (fstat(fd, &st) == -1 || !S_ISCHR(st.st_mode)) { | |||
close(fd); | |||
goto nodevrandom; | |||
} | |||
for (i = 0; i < len; ) { | |||
size_t wanted = len - i; | |||
ssize_t ret = read(fd, buf + i, wanted); | |||
if (ret == -1) { | |||
if (errno == EAGAIN || errno == EINTR) | |||
continue; | |||
close(fd); | |||
goto nodevrandom; | |||
} | |||
i += ret; | |||
} | |||
close(fd); | |||
if (gotdata(buf, len) == 0) { | |||
errno = save_errno; | |||
return 0; /* satisfied */ | |||
} | |||
nodevrandom: | |||
errno = EIO; | |||
return -1; | |||
} | |||
static int | |||
getentropy_fallback(void *buf, size_t len) | |||
{ | |||
int tcpmib[] = { CTL_NET, AF_INET, IPPROTO_TCP, TCPCTL_STATS }; | |||
int udpmib[] = { CTL_NET, AF_INET, IPPROTO_UDP, UDPCTL_STATS }; | |||
int ipmib[] = { CTL_NET, AF_INET, IPPROTO_IP, IPCTL_STATS }; | |||
int kmib[] = { CTL_KERN, KERN_USRSTACK }; | |||
int hwmib[] = { CTL_HW, HW_USERMEM }; | |||
int save_errno = errno, e, m, pgs = getpagesize(), faster = 0, repeat; | |||
uint8_t results[SHA512_DIGEST_LENGTH]; | |||
struct tcpstat tcpstat; | |||
struct udpstat udpstat; | |||
struct ipstat ipstat; | |||
u_int64_t mach_time; | |||
unsigned int idata; | |||
struct timespec ts; | |||
struct timeval tv; | |||
struct rusage ru; | |||
sigset_t sigset; | |||
struct stat st; | |||
static int cnt; | |||
SHA512_CTX ctx; | |||
static pid_t lastpid; | |||
void * addr; | |||
pid_t pid; | |||
size_t i, ii; | |||
char *p; | |||
pid = getpid(); | |||
if (lastpid == pid) { | |||
faster = 1; | |||
repeat = 2; | |||
} else { | |||
faster = 0; | |||
lastpid = pid; | |||
repeat = REPEAT; | |||
} | |||
for (i = 0; i < len; ) { | |||
int j; | |||
SHA512_Init(&ctx); | |||
for (j = 0; j < repeat; j++) { | |||
size_t len; | |||
HX((e = gettimeofday(&tv, NULL)) == -1, tv); | |||
if (e != -1) { | |||
cnt += (int)tv.tv_sec; | |||
cnt += (int)tv.tv_usec; | |||
} | |||
mach_time = mach_absolute_time(); | |||
HD(mach_time); | |||
len = sizeof(addr); | |||
HX(sysctl(kmib, sizeof(kmib) / sizeof(kmib[0]), | |||
&addr, &len, NULL, 0) == -1, addr); | |||
len = sizeof(idata); | |||
HX(sysctl(hwmib, sizeof(hwmib) / sizeof(hwmib[0]), | |||
&idata, &len, NULL, 0) == -1, idata); | |||
len = sizeof(tcpstat); | |||
HX(sysctl(tcpmib, sizeof(tcpmib) / sizeof(tcpmib[0]), | |||
&tcpstat, &len, NULL, 0) == -1, tcpstat); | |||
len = sizeof(udpstat); | |||
HX(sysctl(udpmib, sizeof(udpmib) / sizeof(udpmib[0]), | |||
&udpstat, &len, NULL, 0) == -1, udpstat); | |||
len = sizeof(ipstat); | |||
HX(sysctl(ipmib, sizeof(ipmib) / sizeof(ipmib[0]), | |||
&ipstat, &len, NULL, 0) == -1, ipstat); | |||
HX((pid = getpid()) == -1, pid); | |||
HX((pid = getsid(pid)) == -1, pid); | |||
HX((pid = getppid()) == -1, pid); | |||
HX((pid = getpgid(0)) == -1, pid); | |||
HX((m = getpriority(0, 0)) == -1, m); | |||
if (!faster) { | |||
ts.tv_sec = 0; | |||
ts.tv_nsec = 1; | |||
(void) nanosleep(&ts, NULL); | |||
} | |||
HX(sigpending(&sigset) == -1, sigset); | |||
HX(sigprocmask(SIG_BLOCK, NULL, &sigset) == -1, | |||
sigset); | |||
HD(main); /* an addr in program */ | |||
HD(getentropy); /* an addr in this library */ | |||
HD(printf); /* an addr in libc */ | |||
p = (char *)&p; | |||
HD(p); /* an addr on stack */ | |||
p = (char *)&errno; | |||
HD(p); /* the addr of errno */ | |||
if (i == 0) { | |||
struct sockaddr_storage ss; | |||
struct statvfs stvfs; | |||
struct termios tios; | |||
struct statfs stfs; | |||
socklen_t ssl; | |||
off_t off; | |||
/* | |||
* Prime-sized mappings encourage fragmentation; | |||
* thus exposing some address entropy. | |||
*/ | |||
struct mm { | |||
size_t npg; | |||
void *p; | |||
} mm[] = { | |||
{ 17, MAP_FAILED }, { 3, MAP_FAILED }, | |||
{ 11, MAP_FAILED }, { 2, MAP_FAILED }, | |||
{ 5, MAP_FAILED }, { 3, MAP_FAILED }, | |||
{ 7, MAP_FAILED }, { 1, MAP_FAILED }, | |||
{ 57, MAP_FAILED }, { 3, MAP_FAILED }, | |||
{ 131, MAP_FAILED }, { 1, MAP_FAILED }, | |||
}; | |||
for (m = 0; m < sizeof mm/sizeof(mm[0]); m++) { | |||
HX(mm[m].p = mmap(NULL, | |||
mm[m].npg * pgs, | |||
PROT_READ|PROT_WRITE, | |||
MAP_PRIVATE|MAP_ANON, -1, | |||
(off_t)0), mm[m].p); | |||
if (mm[m].p != MAP_FAILED) { | |||
size_t mo; | |||
/* Touch some memory... */ | |||
p = mm[m].p; | |||
mo = cnt % | |||
(mm[m].npg * pgs - 1); | |||
p[mo] = 1; | |||
cnt += (int)((long)(mm[m].p) | |||
/ pgs); | |||
} | |||
/* Check cnts and times... */ | |||
mach_time = mach_absolute_time(); | |||
HD(mach_time); | |||
cnt += (int)mach_time; | |||
HX((e = getrusage(RUSAGE_SELF, | |||
&ru)) == -1, ru); | |||
if (e != -1) { | |||
cnt += (int)ru.ru_utime.tv_sec; | |||
cnt += (int)ru.ru_utime.tv_usec; | |||
} | |||
} | |||
for (m = 0; m < sizeof mm/sizeof(mm[0]); m++) { | |||
if (mm[m].p != MAP_FAILED) | |||
munmap(mm[m].p, mm[m].npg * pgs); | |||
mm[m].p = MAP_FAILED; | |||
} | |||
HX(stat(".", &st) == -1, st); | |||
HX(statvfs(".", &stvfs) == -1, stvfs); | |||
HX(statfs(".", &stfs) == -1, stfs); | |||
HX(stat("/", &st) == -1, st); | |||
HX(statvfs("/", &stvfs) == -1, stvfs); | |||
HX(statfs("/", &stfs) == -1, stfs); | |||
HX((e = fstat(0, &st)) == -1, st); | |||
if (e == -1) { | |||
if (S_ISREG(st.st_mode) || | |||
S_ISFIFO(st.st_mode) || | |||
S_ISSOCK(st.st_mode)) { | |||
HX(fstatvfs(0, &stvfs) == -1, | |||
stvfs); | |||
HX(fstatfs(0, &stfs) == -1, | |||
stfs); | |||
HX((off = lseek(0, (off_t)0, | |||
SEEK_CUR)) < 0, off); | |||
} | |||
if (S_ISCHR(st.st_mode)) { | |||
HX(tcgetattr(0, &tios) == -1, | |||
tios); | |||
} else if (S_ISSOCK(st.st_mode)) { | |||
memset(&ss, 0, sizeof ss); | |||
ssl = sizeof(ss); | |||
HX(getpeername(0, | |||
(void *)&ss, &ssl) == -1, | |||
ss); | |||
} | |||
} | |||
HX((e = getrusage(RUSAGE_CHILDREN, | |||
&ru)) == -1, ru); | |||
if (e != -1) { | |||
cnt += (int)ru.ru_utime.tv_sec; | |||
cnt += (int)ru.ru_utime.tv_usec; | |||
} | |||
} else { | |||
/* Subsequent hashes absorb previous result */ | |||
HD(results); | |||
} | |||
HX((e = gettimeofday(&tv, NULL)) == -1, tv); | |||
if (e != -1) { | |||
cnt += (int)tv.tv_sec; | |||
cnt += (int)tv.tv_usec; | |||
} | |||
HD(cnt); | |||
} | |||
SHA512_Final(results, &ctx); | |||
memcpy(buf + i, results, min(sizeof(results), len - i)); | |||
i += min(sizeof(results), len - i); | |||
} | |||
memset(results, 0, sizeof results); | |||
if (gotdata(buf, len) == 0) { | |||
errno = save_errno; | |||
return 0; /* satisfied */ | |||
} | |||
errno = EIO; | |||
return -1; | |||
} |
@ -0,0 +1,413 @@ | |||
/* $OpenBSD: getentropy_solaris.c,v 1.1 2014/07/08 10:45:35 beck Exp $ */ | |||
/* | |||
* Copyright (c) 2014 Theo de Raadt <deraadt@openbsd.org> | |||
* Copyright (c) 2014 Bob Beck <beck@obtuse.com> | |||
* | |||
* Permission to use, copy, modify, and distribute this software for any | |||
* purpose with or without fee is hereby granted, provided that the above | |||
* copyright notice and this permission notice appear in all copies. | |||
* | |||
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES | |||
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF | |||
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR | |||
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES | |||
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN | |||
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF | |||
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. | |||
*/ | |||
#include <sys/types.h> | |||
#include <sys/param.h> | |||
#include <sys/ioctl.h> | |||
#include <sys/resource.h> | |||
#include <sys/syscall.h> | |||
#include <sys/statvfs.h> | |||
#include <sys/socket.h> | |||
#include <sys/mount.h> | |||
#include <sys/mman.h> | |||
#include <sys/stat.h> | |||
#include <sys/time.h> | |||
#include <stdlib.h> | |||
#include <stdint.h> | |||
#include <stdio.h> | |||
#include <termios.h> | |||
#include <fcntl.h> | |||
#include <signal.h> | |||
#include <string.h> | |||
#include <errno.h> | |||
#include <unistd.h> | |||
#include <time.h> | |||
#include <sys/sha2.h> | |||
#define SHA512_Init SHA512Init | |||
#define SHA512_Update SHA512Update | |||
#define SHA512_Final SHA512Final | |||
#include <sys/vfs.h> | |||
#include <sys/statfs.h> | |||
#include <sys/loadavg.h> | |||
#define REPEAT 5 | |||
#define min(a, b) (((a) < (b)) ? (a) : (b)) | |||
#define HX(a, b) \ | |||
do { \ | |||
if ((a)) \ | |||
HD(errno); \ | |||
else \ | |||
HD(b); \ | |||
} while (0) | |||
#define HR(x, l) (SHA512_Update(&ctx, (char *)(x), (l))) | |||
#define HD(x) (SHA512_Update(&ctx, (char *)&(x), sizeof (x))) | |||
int getentropy(void *buf, size_t len); | |||
extern int main(int, char *argv[]); | |||
static int gotdata(char *buf, size_t len); | |||
static int getentropy_urandom(void *buf, size_t len); | |||
static int getentropy_fallback(void *buf, size_t len); | |||
int | |||
getentropy(void *buf, size_t len) | |||
{ | |||
int ret = -1; | |||
if (len > 256) { | |||
errno = EIO; | |||
return -1; | |||
} | |||
/* | |||
* Try to get entropy with /dev/urandom | |||
* | |||
* This can fail if the process is inside a chroot or if file | |||
* descriptors are exhausted. | |||
*/ | |||
ret = getentropy_urandom(buf, len); | |||
if (ret != -1) | |||
return (ret); | |||
/* | |||
* Entropy collection via /dev/urandom and sysctl have failed. | |||
* | |||
* No other API exists for collecting entropy, and we have | |||
* no failsafe way to get it on Solaris that is not sensitive | |||
* to resource exhaustion. | |||
* | |||
* We have very few options: | |||
* - Even syslog_r is unsafe to call at this low level, so | |||
* there is no way to alert the user or program. | |||
* - Cannot call abort() because some systems have unsafe | |||
* corefiles. | |||
* - Could raise(SIGKILL) resulting in silent program termination. | |||
* - Return EIO, to hint that arc4random's stir function | |||
* should raise(SIGKILL) | |||
* - Do the best under the circumstances.... | |||
* | |||
* This code path exists to bring light to the issue that Solaris | |||
* does not provide a failsafe API for entropy collection. | |||
* | |||
* We hope this demonstrates that Solaris should consider | |||
* providing a new failsafe API which works in a chroot or | |||
* when file descriptors are exhausted. | |||
*/ | |||
#undef FAIL_WHEN_SYSTEM_ENTROPY_FAILS | |||
#ifdef FAIL_WHEN_SYSTEM_ENTROPY_FAILS | |||
raise(SIGKILL); | |||
#endif | |||
ret = getentropy_fallback(buf, len); | |||
if (ret != -1) | |||
return (ret); | |||
errno = EIO; | |||
return (ret); | |||
} | |||
/* | |||
* Basic sanity checking; wish we could do better. | |||
*/ | |||
static int | |||
gotdata(char *buf, size_t len) | |||
{ | |||
char any_set = 0; | |||
size_t i; | |||
for (i = 0; i < len; ++i) | |||
any_set |= buf[i]; | |||
if (any_set == 0) | |||
return -1; | |||
return 0; | |||
} | |||
static int | |||
getentropy_urandom(void *buf, size_t len) | |||
{ | |||
struct stat st; | |||
size_t i; | |||
int fd, flags; | |||
int save_errno = errno; | |||
start: | |||
flags = O_RDONLY; | |||
#ifdef O_NOFOLLOW | |||
flags |= O_NOFOLLOW; | |||
#endif | |||
#ifdef O_CLOEXEC | |||
flags |= O_CLOEXEC; | |||
#endif | |||
/* | |||
* Solaris provides /dev/urandom as a symbolic link. | |||
* /devices/pseudo/random@0:urandom should be the | |||
* real device path, and we do want O_NOFOLLOW. | |||
*/ | |||
fd = open("/devices/pseudo/random@0:urandom", flags, 0); | |||
if (fd == -1) { | |||
if (errno == EINTR) | |||
goto start; | |||
goto nodevrandom; | |||
} | |||
#ifndef O_CLOEXEC | |||
fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC); | |||
#endif | |||
/* Lightly verify that the device node looks sane */ | |||
if (fstat(fd, &st) == -1 || !S_ISCHR(st.st_mode)) { | |||
close(fd); | |||
goto nodevrandom; | |||
} | |||
for (i = 0; i < len; ) { | |||
size_t wanted = len - i; | |||
ssize_t ret = read(fd, buf + i, wanted); | |||
if (ret == -1) { | |||
if (errno == EAGAIN || errno == EINTR) | |||
continue; | |||
close(fd); | |||
goto nodevrandom; | |||
} | |||
i += ret; | |||
} | |||
close(fd); | |||
if (gotdata(buf, len) == 0) { | |||
errno = save_errno; | |||
return 0; /* satisfied */ | |||
} | |||
nodevrandom: | |||
errno = EIO; | |||
return -1; | |||
} | |||
static int cl[] = { | |||
CLOCK_REALTIME, | |||
#ifdef CLOCK_MONOTONIC | |||
CLOCK_MONOTONIC, | |||
#endif | |||
#ifdef CLOCK_MONOTONIC_RAW | |||
CLOCK_MONOTONIC_RAW, | |||
#endif | |||
#ifdef CLOCK_TAI | |||
CLOCK_TAI, | |||
#endif | |||
#ifdef CLOCK_VIRTUAL | |||
CLOCK_VIRTUAL, | |||
#endif | |||
#ifdef CLOCK_UPTIME | |||
CLOCK_UPTIME, | |||
#endif | |||
#ifdef CLOCK_PROCESS_CPUTIME_ID | |||
CLOCK_PROCESS_CPUTIME_ID, | |||
#endif | |||
#ifdef CLOCK_THREAD_CPUTIME_ID | |||
CLOCK_THREAD_CPUTIME_ID, | |||
#endif | |||
}; | |||
static int | |||
getentropy_fallback(void *buf, size_t len) | |||
{ | |||
uint8_t results[SHA512_DIGEST_LENGTH]; | |||
int save_errno = errno, e, m, pgs = getpagesize(), faster = 0, repeat; | |||
static int cnt; | |||
struct timespec ts; | |||
struct timeval tv; | |||
double loadavg[3]; | |||
struct rusage ru; | |||
sigset_t sigset; | |||
struct stat st; | |||
SHA512_CTX ctx; | |||
static pid_t lastpid; | |||
pid_t pid; | |||
size_t i, ii; | |||
char *p; | |||
pid = getpid(); | |||
if (lastpid == pid) { | |||
faster = 1; | |||
repeat = 2; | |||
} else { | |||
faster = 0; | |||
lastpid = pid; | |||
repeat = REPEAT; | |||
} | |||
for (i = 0; i < len; ) { | |||
int j; | |||
SHA512_Init(&ctx); | |||
for (j = 0; j < repeat; j++) { | |||
HX((e = gettimeofday(&tv, NULL)) == -1, tv); | |||
if (e != -1) { | |||
cnt += (int)tv.tv_sec; | |||
cnt += (int)tv.tv_usec; | |||
} | |||
for (ii = 0; ii < sizeof(cl)/sizeof(cl[0]); ii++) | |||
HX(clock_gettime(cl[ii], &ts) == -1, ts); | |||
HX((pid = getpid()) == -1, pid); | |||
HX((pid = getsid(pid)) == -1, pid); | |||
HX((pid = getppid()) == -1, pid); | |||
HX((pid = getpgid(0)) == -1, pid); | |||
HX((m = getpriority(0, 0)) == -1, m); | |||
HX((getloadavg(loadavg, 3) == -1), loadavg); | |||
if (!faster) { | |||
ts.tv_sec = 0; | |||
ts.tv_nsec = 1; | |||
(void) nanosleep(&ts, NULL); | |||
} | |||
HX(sigpending(&sigset) == -1, sigset); | |||
HX(sigprocmask(SIG_BLOCK, NULL, &sigset) == -1, | |||
sigset); | |||
HD(main); /* an addr in program */ | |||
HD(getentropy); /* an addr in this library */ | |||
HD(printf); /* an addr in libc */ | |||
p = (char *)&p; | |||
HD(p); /* an addr on stack */ | |||
p = (char *)&errno; | |||
HD(p); /* the addr of errno */ | |||
if (i == 0) { | |||
struct sockaddr_storage ss; | |||
struct statvfs stvfs; | |||
struct termios tios; | |||
socklen_t ssl; | |||
off_t off; | |||
/* | |||
* Prime-sized mappings encourage fragmentation; | |||
* thus exposing some address entropy. | |||
*/ | |||
struct mm { | |||
size_t npg; | |||
void *p; | |||
} mm[] = { | |||
{ 17, MAP_FAILED }, { 3, MAP_FAILED }, | |||
{ 11, MAP_FAILED }, { 2, MAP_FAILED }, | |||
{ 5, MAP_FAILED }, { 3, MAP_FAILED }, | |||
{ 7, MAP_FAILED }, { 1, MAP_FAILED }, | |||
{ 57, MAP_FAILED }, { 3, MAP_FAILED }, | |||
{ 131, MAP_FAILED }, { 1, MAP_FAILED }, | |||
}; | |||
for (m = 0; m < sizeof mm/sizeof(mm[0]); m++) { | |||
HX(mm[m].p = mmap(NULL, | |||
mm[m].npg * pgs, | |||
PROT_READ|PROT_WRITE, | |||
MAP_PRIVATE|MAP_ANON, -1, | |||
(off_t)0), mm[m].p); | |||
if (mm[m].p != MAP_FAILED) { | |||
size_t mo; | |||
/* Touch some memory... */ | |||
p = mm[m].p; | |||
mo = cnt % | |||
(mm[m].npg * pgs - 1); | |||
p[mo] = 1; | |||
cnt += (int)((long)(mm[m].p) | |||
/ pgs); | |||
} | |||
/* Check cnts and times... */ | |||
for (ii = 0; ii < sizeof(cl)/sizeof(cl[0]); | |||
ii++) { | |||
HX((e = clock_gettime(cl[ii], | |||
&ts)) == -1, ts); | |||
if (e != -1) | |||
cnt += (int)ts.tv_nsec; | |||
} | |||
HX((e = getrusage(RUSAGE_SELF, | |||
&ru)) == -1, ru); | |||
if (e != -1) { | |||
cnt += (int)ru.ru_utime.tv_sec; | |||
cnt += (int)ru.ru_utime.tv_usec; | |||
} | |||
} | |||
for (m = 0; m < sizeof mm/sizeof(mm[0]); m++) { | |||
if (mm[m].p != MAP_FAILED) | |||
munmap(mm[m].p, mm[m].npg * pgs); | |||
mm[m].p = MAP_FAILED; | |||
} | |||
HX(stat(".", &st) == -1, st); | |||
HX(statvfs(".", &stvfs) == -1, stvfs); | |||
HX(stat("/", &st) == -1, st); | |||
HX(statvfs("/", &stvfs) == -1, stvfs); | |||
HX((e = fstat(0, &st)) == -1, st); | |||
if (e == -1) { | |||
if (S_ISREG(st.st_mode) || | |||
S_ISFIFO(st.st_mode) || | |||
S_ISSOCK(st.st_mode)) { | |||
HX(fstatvfs(0, &stvfs) == -1, | |||
stvfs); | |||
HX((off = lseek(0, (off_t)0, | |||
SEEK_CUR)) < 0, off); | |||
} | |||
if (S_ISCHR(st.st_mode)) { | |||
HX(tcgetattr(0, &tios) == -1, | |||
tios); | |||
} else if (S_ISSOCK(st.st_mode)) { | |||
memset(&ss, 0, sizeof ss); | |||
ssl = sizeof(ss); | |||
HX(getpeername(0, | |||
(void *)&ss, &ssl) == -1, | |||
ss); | |||
} | |||
} | |||
HX((e = getrusage(RUSAGE_CHILDREN, | |||
&ru)) == -1, ru); | |||
if (e != -1) { | |||
cnt += (int)ru.ru_utime.tv_sec; | |||
cnt += (int)ru.ru_utime.tv_usec; | |||
} | |||
} else { | |||
/* Subsequent hashes absorb previous result */ | |||
HD(results); | |||
} | |||
HX((e = gettimeofday(&tv, NULL)) == -1, tv); | |||
if (e != -1) { | |||
cnt += (int)tv.tv_sec; | |||
cnt += (int)tv.tv_usec; | |||
} | |||
HD(cnt); | |||
} | |||
SHA512_Final(results, &ctx); | |||
memcpy(buf + i, results, min(sizeof(results), len - i)); | |||
i += min(sizeof(results), len - i); | |||
} | |||
memset(results, 0, sizeof results); | |||
if (gotdata(buf, len) == 0) { | |||
errno = save_errno; | |||
return 0; /* satisfied */ | |||
} | |||
errno = EIO; | |||
return -1; | |||
} |