Commit 9a9a8b2d authored by Guillem Jover's avatar Guillem Jover

Add private getentropy module from OpenBSD and LibreSSL

Adapt the code to the local build system.
parent 5f9265f8
......@@ -128,8 +128,10 @@ AC_LINK_IFELSE(
AC_MSG_RESULT([yes])],
[AC_MSG_RESULT([no])])
AC_CHECK_FUNCS([clearenv dirfd fopencookie __fpurge getexecname getline \
AC_CHECK_FUNCS([clearenv dirfd fopencookie __fpurge \
getentropy getexecname getline \
pstat_getproc sysconf])
AM_CONDITIONAL(HAVE_GETENTROPY, [test "x$ac_cv_func_getentropy" = "xtrue"])
AC_CONFIG_FILES([
Makefile
......
......@@ -9,6 +9,12 @@ AM_CPPFLAGS = \
libbsd_la_included_sources = \
hash/helper.c \
getentropy_aix.c \
getentropy_bsd.c \
getentropy_hpux.c \
getentropy_linux.c \
getentropy_osx.c \
getentropy_solaris.c \
$(nil)
EXTRA_DIST = \
......@@ -97,6 +103,12 @@ libbsd_la_SOURCES = \
wcslcpy.c \
$(nil)
if !HAVE_GETENTROPY
libbsd_la_SOURCES += \
getentropy.c \
$(nil)
endif
libbsd_ctor_a_SOURCES = \
setproctitle_ctor.c \
$(nil)
......
/*
* Copyright © 2015 Guillem Jover <guillem@hadrons.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#if defined(__linux__)
#include "getentropy_linux.c"
#elif defined(__FreeBSD__)
#include "arc4random_bsd.c"
#elif defined(__NetBSD__)
#include "arc4random_bsd.c"
#elif defined(__sun)
#include "arc4random_solaris.c"
#elif defined(__APPLE__)
#include "arc4random_osx.c"
#elif defined(_AIX)
#include "arc4random_aix.c"
#elif defined(__hpux)
#include "arc4random_hpux.c"
#else
#error "No getentropy hooks defined for this platform."
#endif
/* $OpenBSD: getentropy_aix.c,v 1.3 2015/08/25 17:26:43 deraadt Exp $ */
/*
* Copyright (c) 2015 Michael Felt <aixtools@gmail.com>
* 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.
*
* Emulation of getentropy(2) as documented at:
* http://www.openbsd.org/cgi-bin/man.cgi/OpenBSD-current/man2/getentropy.2
*/
/*
* -lperfstat is needed for the psuedo entropy data
*/
#include <sys/mman.h>
#include <sys/procfs.h>
#include <sys/protosw.h>
#include <sys/resource.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/statvfs.h>
#include <sys/timers.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <termios.h>
#include <openssl/sha.h>
#include <libperfstat.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)))
#define HF(x) (SHA512_Update(&ctx, (char *)&(x), sizeof (void*)))
int getentropy(void *buf, size_t len);
static int gotdata(char *buf, size_t len);
static int getentropy_urandom(void *buf, size_t len, const char *path,
int devfscheck);
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
*/
ret = getentropy_urandom(buf, len, "/dev/urandom", 0);
if (ret != -1)
return (ret);
/*
* Entropy collection via /dev/urandom has failed.
*
* No other API exists for collecting entropy, and we have
* no failsafe way to get it on AIX 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 AIX
* does not provide a failsafe API for entropy collection.
*
* We hope this demonstrates that AIX should consider
* providing a new failsafe API which works in a chroot or
* when file descriptors are exhausted.
*/
#undef FAIL_INSTEAD_OF_TRYING_FALLBACK
#ifdef FAIL_INSTEAD_OF_TRYING_FALLBACK
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, const char *path, int devfscheck)
{
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
fd = open(path, 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, (char *)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 const 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, pgs = sysconf(_SC_PAGESIZE), faster = 0, repeat;
static int cnt;
struct timespec ts;
struct timeval tv;
perfstat_cpu_total_t cpustats;
#ifdef _AIX61
perfstat_cpu_total_wpar_t cpustats_wpar;
#endif
perfstat_partition_total_t lparstats;
perfstat_disk_total_t diskinfo;
perfstat_netinterface_total_t netinfo;
struct rusage ru;
sigset_t sigset;
struct stat st;
SHA512_CTX ctx;
static pid_t lastpid;
pid_t pid;
size_t i, ii, m;
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;
}
HX(perfstat_cpu_total(NULL, &cpustats,
sizeof(cpustats), 1) == -1, cpustats);
#ifdef _AIX61
HX(perfstat_cpu_total_wpar(NULL, &cpustats_wpar,
sizeof(cpustats_wpar), 1) == -1, cpustats_wpar);
#endif
HX(perfstat_partition_total(NULL, &lparstats,
sizeof(lparstats), 1) == -1, lparstats);
HX(perfstat_disk_total(NULL, &diskinfo,
sizeof(diskinfo), 1) == -1, diskinfo);
HX(perfstat_netinterface_total(NULL, &netinfo,
sizeof(netinfo), 1) == -1, netinfo);
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((e = getpriority(0, 0)) == -1, e);
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);
HF(getentropy); /* an addr in this library */
HF(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((char *)buf + i, results, min(sizeof(results), len - i));
i += min(sizeof(results), len - i);
}
explicit_bzero(&ctx, sizeof ctx);
explicit_bzero(results, sizeof results);
if (gotdata(buf, len) == 0) {
errno = save_errno;
return (0); /* satisfied */
}
errno = EIO;
return (-1);
}
/* $OpenBSD: getentropy_freebsd.c,v 1.1 2014/11/03 06:23:30 bcook Exp $ */
/*
* Copyright (c) 2014 Pawel Jakub Dawidek <pjd@FreeBSD.org>
* Copyright (c) 2014 Brent Cook <bcook@openbsd.org>
*
* 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.
*
* Emulation of getentropy(2) as documented at:
* http://www.openbsd.org/cgi-bin/man.cgi/OpenBSD-current/man2/getentropy.2
*/
#include <sys/types.h>
#include <sys/sysctl.h>
#include <errno.h>
#include <stddef.h>
/*
* Derived from lib/libc/gen/arc4random.c from FreeBSD.
*/
static size_t
getentropy_sysctl(u_char *buf, size_t size)
{
int mib[2];
size_t len, done;
mib[0] = CTL_KERN;
mib[1] = KERN_ARND;
done = 0;
do {
len = size;
if (sysctl(mib, 2, buf, &len, NULL, 0) == -1)
return (done);
done += len;
buf += len;
size -= len;
} while (size > 0);
return (done);
}
int
getentropy(void *buf, size_t len)
{
if (len <= 256 && getentropy_sysctl(buf, len) == len)
return (0);
errno = EIO;
return (-1);
}
/* $OpenBSD: getentropy_hpux.c,v 1.3 2015/08/25 17:26:43 deraadt 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.
*
* Emulation of getentropy(2) as documented at:
* http://www.openbsd.org/cgi-bin/man.cgi/OpenBSD-current/man2/getentropy.2
*/
#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 <openssl/sha.h>
#include <sys/vfs.h>
#include <sys/pstat.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)))
#define HF(x) (SHA512_Update(&ctx, (char *)&(x), sizeof (void*)))
int getentropy(void *buf, size_t len);
static int gotdata(char *buf, size_t len);
static int getentropy_urandom(void *buf, size_t len, const char *path,
int devfscheck);
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
*/
ret = getentropy_urandom(buf, len, "/dev/urandom", 0);
if (ret != -1)
return (ret);
/*
* Entropy collection via /dev/urandom has failed.
*
* No other API exists for collecting entropy, and we have
* no failsafe way to get it on hpux 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 hpux
* does not provide a failsafe API for entropy collection.
*
* We hope this demonstrates that hpux should consider
* providing a new failsafe API which works in a chroot or
* when file descriptors are exhausted.
*/
#undef FAIL_INSTEAD_OF_TRYING_FALLBACK
#ifdef FAIL_INSTEAD_OF_TRYING_FALLBACK
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, const char *path, int devfscheck)
{
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
fd = open(path, 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, (char *)buf + i, wanted);
if (ret == -1) {
if (errno == EAGAIN || errno == EINTR)
continue;
close(fd);