@ -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; | |||||
} |