Adding upstream version 1.9.13p3.upstream/1.9.13p3upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 642 insertions, 0 deletions

diff --git a/lib/util/getentropy.c b/lib/util/getentropy.c
new file mode 100644
index 0000000..dc5c91c
--- /dev/null
+++ b/lib/util/getentropy.c
@@ -0,0 +1,642 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * 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://man.openbsd.org/getentropy.2
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <config.h>
+
+#ifndef HAVE_GETENTROPY
+
+#include <sys/param.h>
+#include <sys/mman.h>
+#include <sys/resource.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#ifdef HAVE_SYS_SYSCTL_H
+# include <sys/sysctl.h>
+#endif
+#ifdef HAVE_SYS_STATVFS_H
+# include <sys/statvfs.h>
+#endif
+#include <sys/stat.h>
+#include <sys/time.h>
+#ifdef HAVE_SYS_SYSCALL_H
+# include <sys/syscall.h>
+#endif
+#ifdef HAVE_LINUX_RANDOM_H
+# include <linux/types.h>
+# include <linux/random.h>
+#endif
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <termios.h>
+#include <time.h>
+#include <unistd.h>
+#if defined(HAVE_STDINT_H)
+# include <stdint.h>
+#elif defined(HAVE_INTTYPES_H)
+# include <inttypes.h>
+#endif
+#ifdef HAVE_GETAUXVAL
+# include <sys/auxv.h>
+#endif
+#ifdef HAVE_DL_ITERATE_PHDR
+# include <link.h>
+#endif
+#ifdef HAVE_OPENSSL
+# if defined(HAVE_WOLFSSL)
+#  include <wolfssl/options.h>
+# endif
+# include <openssl/rand.h>
+#endif
+
+#include "sudo_compat.h"
+#include "sudo_digest.h"
+#include "sudo_rand.h"
+
+#if !defined(MAP_ANON) && defined(MAP_ANONYMOUS)
+# define MAP_ANON MAP_ANONYMOUS
+#endif
+
+#ifndef MAP_FAILED
+# define MAP_FAILED ((void *) -1)
+#endif
+
+#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) (sudo_digest_update(ctx, (char *)(x), (l)))
+#define HD(x)    (sudo_digest_update(ctx, (char *)&(x), sizeof (x)))
+#define HF(x)    (sudo_digest_update(ctx, (char *)&(x), sizeof (void*)))
+
+int	sudo_getentropy(void *buf, size_t len);
+
+static int getentropy_getrandom(void *buf, size_t len);
+static int getentropy_sysctl(void *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);
+static int gotdata(char *buf, size_t len);
+#ifdef HAVE_DL_ITERATE_PHDR
+static int getentropy_phdr(struct dl_phdr_info *info, size_t size, void *data);
+#endif
+
+static void *
+mmap_anon(void *addr, size_t len, int prot, int flags, off_t offset)
+{
+#ifdef MAP_ANON
+	return mmap(addr, len, prot, flags | MAP_ANON, -1, offset);
+#else
+	int fd;
+
+	if ((fd = open("/dev/zero", O_RDWR)) == -1)
+		return MAP_FAILED;
+	addr = mmap(addr, len, prot, flags, fd, offset);
+	close(fd);
+	return addr;
+#endif
+}
+
+int
+sudo_getentropy(void *buf, size_t len)
+{
+	int ret = -1;
+
+	if (len > 256) {
+		errno = EIO;
+		return (-1);
+	}
+
+	ret = getentropy_getrandom(buf, len);
+	if (ret != -1)
+		return (ret);
+
+#ifdef HAVE_OPENSSL
+	if (RAND_bytes(buf, len) == 1)
+		return (0);
+#endif
+
+	ret = getentropy_sysctl(buf, len);
+	if (ret != -1)
+		return (ret);
+
+	/*
+	 * 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 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 the OS
+	 * does not provide a failsafe API for entropy collection.
+	 *
+	 * We hope this demonstrates that the OS 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);
+}
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+/*
+ * Basic validity 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:
+
+	/* We do not use O_NOFOLLOW since /dev/urandom is a link on Solaris. */
+	flags = O_RDONLY;
+#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 OK */
+	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);
+}
+
+#if defined(HAVE_SYSCTL) && defined(KERN_ARND)
+static int
+getentropy_sysctl(void *buf, size_t len)
+{
+	int save_errno = errno;
+	int mib[2];
+	size_t i;
+
+	mib[0] = CTL_KERN;
+	mib[1] = KERN_ARND;
+
+	for (i = 0; i < len; ) {
+		size_t chunk = len - i;
+
+		if (sysctl(mib, 2, (char *)buf + i, &chunk, NULL, 0) == -1)
+			goto sysctlfailed;
+		i += chunk;
+	}
+	if (gotdata(buf, len) == 0) {
+		errno = save_errno;
+		return (0);			/* satisfied */
+	}
+sysctlfailed:
+	errno = EIO;
+	return (-1);
+}
+#elif defined(SYS__sysctl) && defined(RANDOM_UUID)
+static int
+getentropy_sysctl(void *buf, size_t len)
+{
+	static int mib[3];
+	size_t i;
+	int save_errno = errno;
+
+	mib[0] = CTL_KERN;
+	mib[1] = KERN_RANDOM;
+	mib[2] = RANDOM_UUID;
+
+	for (i = 0; i < len; ) {
+		size_t chunk = min(len - i, 16);
+
+		/* SYS__sysctl because some systems already removed sysctl() */
+		struct __sysctl_args args = {
+			.name = mib,
+			.nlen = 3,
+			.oldval = (char *)buf + i,
+			.oldlenp = &chunk,
+		};
+		if (syscall(SYS__sysctl, &args) != 0)
+			goto sysctlfailed;
+		i += chunk;
+	}
+	if (gotdata(buf, len) == 0) {
+		errno = save_errno;
+		return (0);			/* satisfied */
+	}
+sysctlfailed:
+	errno = EIO;
+	return (-1);
+}
+#else
+static int
+getentropy_sysctl(void *buf, size_t len)
+{
+	errno = ENOTSUP;
+	return (-1);
+}
+#endif
+
+#if defined(SYS_getrandom) && defined(GRND_NONBLOCK)
+static int
+getentropy_getrandom(void *buf, size_t len)
+{
+	int pre_errno = errno;
+	int ret;
+
+        /*
+         * Try descriptor-less getrandom(), in non-blocking mode.
+         *
+         * The design of Linux getrandom is broken.  It has an
+         * uninitialized phase coupled with blocking behaviour, which
+         * is unacceptable from within a library at boot time without
+         * possible recovery. See http://bugs.python.org/issue26839#msg267745
+         */
+	do {
+		ret = syscall(SYS_getrandom, buf, len, GRND_NONBLOCK);
+	} while (ret == -1 && errno == EINTR);
+
+	if (ret < 0 || (size_t)ret != len)
+		return (-1);
+	errno = pre_errno;
+	return (0);
+}
+#else
+static int
+getentropy_getrandom(void *buf, size_t len)
+{
+	errno = ENOTSUP;
+	return (-1);
+}
+#endif
+
+#ifdef HAVE_CLOCK_GETTIME
+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
+};
+#endif /* HAVE_CLOCK_GETTIME */
+
+#ifdef HAVE_DL_ITERATE_PHDR
+static int
+getentropy_phdr(struct dl_phdr_info *info, size_t size, void *data)
+{
+	struct sudo_digest *ctx = data;
+
+	sudo_digest_update(ctx, &info->dlpi_addr, sizeof (info->dlpi_addr));
+	return (0);
+}
+#endif
+
+static int
+getentropy_fallback(void *buf, size_t len)
+{
+	unsigned char *results = NULL;
+	int save_errno = errno, e, pgs = sysconf(_SC_PAGESIZE), faster = 0, repeat;
+	int ret = -1;
+	static int cnt;
+	struct timespec ts;
+	struct timeval tv;
+	struct rusage ru;
+	sigset_t set;
+	struct stat st;
+	struct sudo_digest *ctx;
+	static pid_t lastpid;
+	pid_t pid;
+	size_t i, ii, m, digest_len;
+	char *p;
+
+	if ((ctx = sudo_digest_alloc(SUDO_DIGEST_SHA512)) == NULL)
+		goto done;
+	digest_len = sudo_digest_getlen(SUDO_DIGEST_SHA512);
+	if (digest_len == (size_t)-1 || (results = malloc(digest_len)) == NULL)
+		goto done;
+
+	pid = getpid();
+	if (lastpid == pid) {
+		faster = 1;
+		repeat = 2;
+	} else {
+		faster = 0;
+		lastpid = pid;
+		repeat = REPEAT;
+	}
+	for (i = 0; i < len; ) {
+		int j;
+		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;
+			}
+#ifdef HAVE_DL_ITERATE_PHDR
+			dl_iterate_phdr(getentropy_phdr, ctx);
+#endif
+
+#ifdef HAVE_CLOCK_GETTIME
+			for (ii = 0; ii < sizeof(cl)/sizeof(cl[0]); ii++)
+				HX(clock_gettime(cl[ii], &ts) == -1, ts);
+#endif /* HAVE_CLOCK_GETTIME */
+
+			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(&set) == -1, set);
+			HX(sigprocmask(SIG_BLOCK, NULL, &set) == -1, set);
+
+			HF(sudo_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) {
+#ifdef HAVE_SYS_STATVFS_H
+				struct statvfs stvfs;
+#endif
+				struct termios tios;
+				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_anon(NULL,
+					    mm[m].npg * pgs,
+					    PROT_READ|PROT_WRITE,
+					    MAP_PRIVATE,
+					    (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);
+					}
+
+#ifdef HAVE_CLOCK_GETTIME
+					/* 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;
+					}
+#endif /* HAVE_CLOCK_GETTIME */
+
+					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(stat("/", &st) == -1, st);
+
+#ifdef HAVE_SYS_STATVFS_H
+				HX(statvfs(".", &stvfs) == -1, stvfs);
+				HX(statvfs("/", &stvfs) == -1, stvfs);
+#endif
+				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)) {
+#ifdef HAVE_SYS_STATVFS_H
+						HX(fstatvfs(0, &stvfs) == -1,
+						    stvfs);
+#endif
+						HX((off = lseek(0, (off_t)0,
+						    SEEK_CUR)) < 0, off);
+					}
+					if (S_ISCHR(st.st_mode)) {
+						HX(tcgetattr(0, &tios) == -1,
+						    tios);
+#if 0
+					} else if (S_ISSOCK(st.st_mode)) {
+						struct sockaddr_storage ss;
+						socklen_t ssl;
+						memset(&ss, 0, sizeof ss);
+						ssl = sizeof(ss);
+						HX(getpeername(0,
+						    (void *)&ss, &ssl) == -1,
+						    ss);
+#endif
+					}
+				}
+
+				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 */
+				HR(results, digest_len);
+			}
+
+			HX((e = gettimeofday(&tv, NULL)) == -1, tv);
+			if (e != -1) {
+				cnt += (int)tv.tv_sec;
+				cnt += (int)tv.tv_usec;
+			}
+
+			HD(cnt);
+		}
+
+#ifdef HAVE_GETAUXVAL
+#ifdef AT_RANDOM
+		/* Not as random as you think but we take what we are given */
+		p = (char *) getauxval(AT_RANDOM);
+		if (p)
+			HR(p, 16);
+#endif
+#ifdef AT_SYSINFO_EHDR
+		p = (char *) getauxval(AT_SYSINFO_EHDR);
+		if (p)
+			HR(p, pgs);
+#endif
+#ifdef AT_BASE
+		p = (char *) getauxval(AT_BASE);
+		if (p)
+			HD(p);
+#endif
+#endif /* HAVE_GETAUXVAL  */
+
+		sudo_digest_final(ctx, results);
+		sudo_digest_reset(ctx);
+		memcpy((char *)buf + i, results, min(digest_len, len - i));
+		i += min(digest_len, len - i);
+	}
+	if (gotdata(buf, len) == 0) {
+		errno = save_errno;
+		ret = 0;		/* satisfied */
+	} else {
+		errno = EIO;
+	}
+done:
+	sudo_digest_free(ctx);
+	if (results != NULL)
+		freezero(results, digest_len);
+	return (ret);
+}
+
+#endif /* HAVE_GETENTROPY */