Use upstream OpenBSD's arc4random.

The getentropy_linux.c is lightly modified to build on Android, but we're now
completely in sync with upstream OpenBSD's arc4random implementation.

Change-Id: If32229fc28aba908035fb38703190d41ddcabc95
This commit is contained in:
Elliott Hughes 2014-07-18 15:57:41 -07:00
parent 1fb90a8aa0
commit 2b67d7dee0
8 changed files with 915 additions and 291 deletions

View file

@ -37,7 +37,6 @@ endif
# Define the common source files for all the libc instances
# =========================================================
libc_common_src_files := \
bionic/arc4random.c \
bionic/bindresvport.c \
bionic/daemon.c \
bionic/err.c \
@ -125,6 +124,7 @@ libc_bionic_src_files := \
bionic/futimens.cpp \
bionic/getauxval.cpp \
bionic/getcwd.cpp \
bionic/getentropy_linux.c \
bionic/getpgrp.cpp \
bionic/getpid.cpp \
bionic/gettid.cpp \
@ -335,6 +335,8 @@ libc_upstream_openbsd_gdtoa_src_files_64 := \
upstream-openbsd/lib/libc/gdtoa/strtorQ.c \
libc_upstream_openbsd_src_files := \
upstream-openbsd/lib/libc/crypt/arc4random.c \
upstream-openbsd/lib/libc/crypt/arc4random_uniform.c \
upstream-openbsd/lib/libc/gen/alarm.c \
upstream-openbsd/lib/libc/gen/ctype_.c \
upstream-openbsd/lib/libc/gen/exec.c \

View file

@ -1,288 +0,0 @@
/* $OpenBSD: arc4random.c,v 1.33 2014/06/13 18:58:58 deraadt Exp $ */
/*
* Copyright (c) 1996, David Mazieres <dm@uun.org>
* Copyright (c) 2008, Damien Miller <djm@openbsd.org>
* Copyright (c) 2013, Markus Friedl <markus@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.
*/
/*
* ChaCha based random number generator for OpenBSD.
*/
#include <fcntl.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/mman.h>
#if defined(__ANDROID__)
#include <sys/stat.h>
#include <linux/random.h>
#include "private/libc_logging.h"
#include "private/thread_private.h"
#define explicit_bzero(p, s) memset(p, 0, s)
#undef MAP_ANON
#define MAP_ANON (MAP_PRIVATE | MAP_ANONYMOUS)
/*
* XXX Should be replaced with a proper entropy measure.
*/
static int
gotdata(u_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*/(u_char *buf, size_t len)
{
int save_errno = errno;
int fd = TEMP_FAILURE_RETRY(open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOFOLLOW, 0));
if (fd == -1) {
__libc_fatal("getentropy_urandom failed to open \"/dev/urandom\": %s",
strerror(errno));
}
/* Lightly verify that the device node looks sane */
struct stat st;
if (fstat(fd, &st) == -1 || !S_ISCHR(st.st_mode)) {
__libc_fatal("getentropy_urandom failed to fstat \"/dev/urandom\": %s",
strerror(errno));
}
int cnt;
if (ioctl(fd, RNDGETENTCNT, &cnt) == -1) {
__libc_fatal("getentropy_urandom failed to ioctl \"/dev/urandom\": %s",
strerror(errno));
}
for (size_t i = 0; i < len; ) {
size_t wanted = len - i;
ssize_t ret = TEMP_FAILURE_RETRY(read(fd, buf + i, wanted));
if (ret == -1) {
__libc_fatal("getentropy_urandom failed to read \"/dev/urandom\": %s",
strerror(errno));
}
i += ret;
}
close(fd);
if (gotdata(buf, len) == -1) {
__libc_fatal("getentropy_urandom failed to get enough entropy: %s",
strerror(errno));
}
errno = save_errno;
return 0;
}
#endif /* __ANDROID__ */
#define KEYSTREAM_ONLY
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-parameter"
#include "../upstream-openbsd/lib/libc/crypt/chacha_private.h"
#pragma GCC diagnostic pop
#ifdef __GNUC__
#define inline __inline
#else /* !__GNUC__ */
#define inline
#endif /* !__GNUC__ */
#define KEYSZ 32
#define IVSZ 8
#define BLOCKSZ 64
#define RSBUFSZ (16*BLOCKSZ)
static int rs_initialized;
static pid_t rs_stir_pid;
static chacha_ctx *rs; /* chacha context for random keystream */
static u_char *rs_buf; /* keystream blocks */
static size_t rs_have; /* valid bytes at end of rs_buf */
static size_t rs_count; /* bytes till reseed */
static inline void _rs_rekey(u_char *dat, size_t datlen);
static inline void
_rs_init(u_char *buf, size_t n)
{
if (n < KEYSZ + IVSZ)
return;
if (rs == NULL && (rs = mmap(NULL, sizeof(*rs), PROT_READ|PROT_WRITE,
MAP_ANON, -1, 0)) == MAP_FAILED)
abort();
if (rs_buf == NULL && (rs_buf = mmap(NULL, RSBUFSZ, PROT_READ|PROT_WRITE,
MAP_ANON, -1, 0)) == MAP_FAILED)
abort();
chacha_keysetup(rs, buf, KEYSZ * 8, 0);
chacha_ivsetup(rs, buf + KEYSZ);
}
static void
_rs_stir(void)
{
u_char rnd[KEYSZ + IVSZ];
/* XXX */
(void) getentropy(rnd, sizeof rnd);
if (!rs_initialized) {
rs_initialized = 1;
_rs_init(rnd, sizeof(rnd));
} else
_rs_rekey(rnd, sizeof(rnd));
explicit_bzero(rnd, sizeof(rnd));
/* invalidate rs_buf */
rs_have = 0;
memset(rs_buf, 0, RSBUFSZ);
rs_count = 1600000;
}
static inline void
_rs_stir_if_needed(size_t len)
{
pid_t pid = getpid();
if (rs_count <= len || !rs_initialized || rs_stir_pid != pid) {
rs_stir_pid = pid;
_rs_stir();
} else
rs_count -= len;
}
static inline void
_rs_rekey(u_char *dat, size_t datlen)
{
#ifndef KEYSTREAM_ONLY
memset(rs_buf, 0,RSBUFSZ);
#endif
/* fill rs_buf with the keystream */
chacha_encrypt_bytes(rs, rs_buf, rs_buf, RSBUFSZ);
/* mix in optional user provided data */
if (dat) {
size_t i, m;
m = MIN(datlen, KEYSZ + IVSZ);
for (i = 0; i < m; i++)
rs_buf[i] ^= dat[i];
}
/* immediately reinit for backtracking resistance */
_rs_init(rs_buf, KEYSZ + IVSZ);
memset(rs_buf, 0, KEYSZ + IVSZ);
rs_have = RSBUFSZ - KEYSZ - IVSZ;
}
static inline void
_rs_random_buf(void *_buf, size_t n)
{
u_char *buf = (u_char *)_buf;
size_t m;
_rs_stir_if_needed(n);
while (n > 0) {
if (rs_have > 0) {
m = MIN(n, rs_have);
memcpy(buf, rs_buf + RSBUFSZ - rs_have, m);
memset(rs_buf + RSBUFSZ - rs_have, 0, m);
buf += m;
n -= m;
rs_have -= m;
}
if (rs_have == 0)
_rs_rekey(NULL, 0);
}
}
static inline void
_rs_random_u32(u_int32_t *val)
{
_rs_stir_if_needed(sizeof(*val));
if (rs_have < sizeof(*val))
_rs_rekey(NULL, 0);
memcpy(val, rs_buf + RSBUFSZ - rs_have, sizeof(*val));
memset(rs_buf + RSBUFSZ - rs_have, 0, sizeof(*val));
rs_have -= sizeof(*val);
}
u_int32_t
arc4random(void)
{
u_int32_t val;
_ARC4_LOCK();
_rs_random_u32(&val);
_ARC4_UNLOCK();
return val;
}
void
arc4random_buf(void *buf, size_t n)
{
_ARC4_LOCK();
_rs_random_buf(buf, n);
_ARC4_UNLOCK();
}
/*
* Calculate a uniformly distributed random number less than upper_bound
* avoiding "modulo bias".
*
* Uniformity is achieved by generating new random numbers until the one
* returned is outside the range [0, 2**32 % upper_bound). This
* guarantees the selected random number will be inside
* [2**32 % upper_bound, 2**32) which maps back to [0, upper_bound)
* after reduction modulo upper_bound.
*/
u_int32_t
arc4random_uniform(u_int32_t upper_bound)
{
u_int32_t r, min;
if (upper_bound < 2)
return 0;
/* 2**32 % x == (2**32 - x) % x */
min = -upper_bound % upper_bound;
/*
* This could theoretically loop forever but each retry has
* p > 0.5 (worst case, usually far better) of selecting a
* number inside the range we need, so it should rarely need
* to re-roll.
*/
for (;;) {
r = arc4random();
if (r >= min)
break;
}
return r % upper_bound;
}

View file

@ -0,0 +1,565 @@
/* $OpenBSD: getentropy_linux.c,v 1.28 2014/07/20 03:24:10 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
*/
#define _POSIX_C_SOURCE 199309L
#define _GNU_SOURCE 1
#include <sys/types.h>
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/resource.h>
#include <sys/syscall.h>
#ifdef HAVE_SYS_SYSCTL_H
#include <sys/sysctl.h>
#endif
#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 <link.h>
#include <termios.h>
#include <fcntl.h>
#include <signal.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <time.h>
#ifdef HAVE_OPENSSL
#include <openssl/sha.h>
#endif
#include <linux/random.h>
#include <linux/sysctl.h>
#ifdef HAVE_GETAUXVAL
#include <sys/auxv.h>
#endif
#include <sys/vfs.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);
#ifdef SYS__getrandom
static int getentropy_getrandom(void *buf, size_t len);
#endif
static int getentropy_urandom(void *buf, size_t len);
#ifdef SYS__sysctl
static int getentropy_sysctl(void *buf, size_t len);
#endif
#ifdef HAVE_OPENSSL
static int getentropy_fallback(void *buf, size_t len);
static int getentropy_phdr(struct dl_phdr_info *info, size_t size, void *data);
#endif
int
getentropy(void *buf, size_t len)
{
int ret = -1;
if (len > 256) {
errno = EIO;
return -1;
}
#ifdef SYS__getrandom
/*
* Try descriptor-less getrandom()
*/
ret = getentropy_getrandom(buf, len);
if (ret != -1)
return (ret);
#endif
/*
* 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);
#ifdef SYS__sysctl
/*
* Try to use sysctl CTL_KERN, KERN_RANDOM, RANDOM_UUID.
* sysctl is a failsafe API, so it guarantees a result. This
* should work inside a chroot, or when file descriptors are
* exhuasted.
*
* However this can fail if the Linux kernel removes support
* for sysctl. Starting in 2007, there have been efforts to
* deprecate the sysctl API/ABI, and push callers towards use
* of the chroot-unavailable fd-using /proc mechanism --
* essentially the same problems as /dev/urandom.
*
* Numerous setbacks have been encountered in their deprecation
* schedule, so as of June 2014 the kernel ABI still exists on
* most Linux architectures. The sysctl() stub in libc is missing
* on some systems. There are also reports that some kernels
* spew messages to the console.
*/
ret = getentropy_sysctl(buf, len);
if (ret != -1)
return (ret);
#endif /* SYS__sysctl */
/*
* Entropy collection via /dev/urandom and sysctl have failed.
*
* No other API exists for collecting entropy. See the large
* comment block above.
*
* 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 Linux
* does not provide a failsafe API for entropy collection.
*
* We hope this demonstrates that Linux should either retain their
* sysctl ABI, or 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
#ifdef HAVE_OPENSSL
ret = getentropy_fallback(buf, len);
if (ret != -1)
return (ret);
#endif
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;
}
#ifdef SYS__getrandom
static int
getentropy_getrandom(void *buf, size_t len)
{
#if 0
/* Hand-definitions until the API becomes commonplace */
#ifndef SYS__getrandom
#ifdef __LP64__
#define SYS__getrandom 317
#else
#define SYS__getrandom 354
#endif
#endif
struct __getrandom_args args = {
.buf = buf;
.len = len;
.flags = 0;
};
if (len > 256)
return (-1);
ret = syscall(SYS__getrandom, &args);
if (ret == len)
return (0);
#endif
return -1;
}
#endif
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;
}
if (ioctl(fd, RNDGETENTCNT, &cnt) == -1) {
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;
}
#ifdef SYS__sysctl
static int
getentropy_sysctl(void *buf, size_t len)
{
static int mib[] = { CTL_KERN, KERN_RANDOM, RANDOM_UUID };
size_t i;
int save_errno = errno;
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;
}
#endif /* SYS__sysctl */
#ifdef HAVE_OPENSSL
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_phdr(struct dl_phdr_info *info, size_t size, void *data)
{
SHA512_CTX *ctx = data;
SHA512_Update(ctx, &info->dlpi_addr, sizeof (info->dlpi_addr));
return 0;
}
static int
getentropy_fallback(void *buf, size_t len)
{
uint8_t results[SHA512_DIGEST_LENGTH];
int save_errno = errno, e, pgs = getpagesize(), faster = 0, repeat;
static int cnt;
struct timespec ts;
struct timeval tv;
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;
}
dl_iterate_phdr(getentropy_phdr, &ctx);
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;
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... */
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(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);
}
#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
SHA512_Final(results, &ctx);
memcpy((char *)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;
}
#endif /* HAVE_OPENSSL */

View file

@ -48,6 +48,7 @@ __LIBC_HIDDEN__ void _thread_arc4_unlock(void);
#define _ARC4_LOCK() _thread_arc4_lock()
#define _ARC4_UNLOCK() _thread_arc4_unlock()
#define _ARC4_ATFORK(f) pthread_atfork(NULL, NULL, (f))
__END_DECLS

View file

@ -0,0 +1,87 @@
/* $OpenBSD: arc4random_linux.h,v 1.7 2014/07/20 20:51:13 bcook Exp $ */
/*
* Copyright (c) 1996, David Mazieres <dm@uun.org>
* Copyright (c) 2008, Damien Miller <djm@openbsd.org>
* Copyright (c) 2013, Markus Friedl <markus@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.
*/
/*
* Stub functions for portability.
*/
#include <sys/mman.h>
#include <pthread.h>
#include <signal.h>
// Android gets these from "thread_private.h".
#include "thread_private.h"
//static pthread_mutex_t arc4random_mtx = PTHREAD_MUTEX_INITIALIZER;
//#define _ARC4_LOCK() pthread_mutex_lock(&arc4random_mtx)
//#define _ARC4_UNLOCK() pthread_mutex_unlock(&arc4random_mtx)
#ifdef __GLIBC__
extern void *__dso_handle;
extern int __register_atfork(void (*)(void), void(*)(void), void (*)(void), void *);
#define _ARC4_ATFORK(f) __register_atfork(NULL, NULL, (f), __dso_handle)
#else
#define _ARC4_ATFORK(f) pthread_atfork(NULL, NULL, (f))
#endif
static inline void
_getentropy_fail(void)
{
raise(SIGKILL);
}
static volatile sig_atomic_t _rs_forked;
static inline void
_rs_forkhandler(void)
{
_rs_forked = 1;
}
static inline void
_rs_forkdetect(void)
{
static pid_t _rs_pid = 0;
pid_t pid = getpid();
if (_rs_pid == 0 || _rs_pid != pid || _rs_forked) {
_rs_pid = pid;
_rs_forked = 0;
if (rs)
memset(rs, 0, sizeof(*rs));
}
}
static inline int
_rs_allocate(struct _rs **rsp, struct _rsx **rsxp)
{
if ((*rsp = mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE,
MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
return (-1);
if ((*rsxp = mmap(NULL, sizeof(**rsxp), PROT_READ|PROT_WRITE,
MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
munmap(*rsxp, sizeof(**rsxp));
return (-1);
}
_ARC4_ATFORK(_rs_forkhandler);
return (0);
}

View file

@ -18,6 +18,7 @@
#define _BIONIC_OPENBSD_COMPAT_H_included
#include <sys/cdefs.h>
#include <stddef.h> // For size_t.
#define __USE_BSD
@ -36,6 +37,11 @@
/* OpenBSD has this, but we can't really implement it correctly on Linux. */
#define issetugid() 0
#define explicit_bzero(p, s) memset(p, 0, s)
/* We have OpenBSD's getentropy_linux.c, but we don't mention getentropy in any header. */
__LIBC_HIDDEN__ extern int getentropy(void*, size_t);
/* LP32 NDK ctype.h contained references to these. */
__LIBC64_HIDDEN__ extern const short* _tolower_tab_;
__LIBC64_HIDDEN__ extern const short* _toupper_tab_;

View file

@ -0,0 +1,195 @@
/* $OpenBSD: arc4random.c,v 1.50 2014/07/21 18:13:12 deraadt Exp $ */
/*
* Copyright (c) 1996, David Mazieres <dm@uun.org>
* Copyright (c) 2008, Damien Miller <djm@openbsd.org>
* Copyright (c) 2013, Markus Friedl <markus@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.
*/
/*
* ChaCha based random number generator for OpenBSD.
*/
#include <fcntl.h>
#include <limits.h>
#include <signal.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/time.h>
#define KEYSTREAM_ONLY
#include "chacha_private.h"
#define min(a, b) ((a) < (b) ? (a) : (b))
#ifdef __GNUC__
#define inline __inline
#else /* !__GNUC__ */
#define inline
#endif /* !__GNUC__ */
#define KEYSZ 32
#define IVSZ 8
#define BLOCKSZ 64
#define RSBUFSZ (16*BLOCKSZ)
/* Marked MAP_INHERIT_ZERO, so zero'd out in fork children. */
static struct _rs {
size_t rs_have; /* valid bytes at end of rs_buf */
size_t rs_count; /* bytes till reseed */
} *rs;
/* Maybe be preserved in fork children, if _rs_allocate() decides. */
static struct _rsx {
chacha_ctx rs_chacha; /* chacha context for random keystream */
u_char rs_buf[RSBUFSZ]; /* keystream blocks */
} *rsx;
static inline int _rs_allocate(struct _rs **, struct _rsx **);
static inline void _rs_forkdetect(void);
#include "arc4random.h"
static inline void _rs_rekey(u_char *dat, size_t datlen);
static inline void
_rs_init(u_char *buf, size_t n)
{
if (n < KEYSZ + IVSZ)
return;
if (rs == NULL) {
if (_rs_allocate(&rs, &rsx) == -1)
abort();
}
chacha_keysetup(&rsx->rs_chacha, buf, KEYSZ * 8, 0);
chacha_ivsetup(&rsx->rs_chacha, buf + KEYSZ);
}
static void
_rs_stir(void)
{
u_char rnd[KEYSZ + IVSZ];
if (getentropy(rnd, sizeof rnd) == -1)
_getentropy_fail();
if (!rs)
_rs_init(rnd, sizeof(rnd));
else
_rs_rekey(rnd, sizeof(rnd));
explicit_bzero(rnd, sizeof(rnd)); /* discard source seed */
/* invalidate rs_buf */
rs->rs_have = 0;
memset(rsx->rs_buf, 0, sizeof(rsx->rs_buf));
rs->rs_count = 1600000;
}
static inline void
_rs_stir_if_needed(size_t len)
{
_rs_forkdetect();
if (!rs || rs->rs_count <= len)
_rs_stir();
if (rs->rs_count <= len)
rs->rs_count = 0;
else
rs->rs_count -= len;
}
static inline void
_rs_rekey(u_char *dat, size_t datlen)
{
#ifndef KEYSTREAM_ONLY
memset(rsx->rs_buf, 0, sizeof(rsx->rs_buf));
#endif
/* fill rs_buf with the keystream */
chacha_encrypt_bytes(&rsx->rs_chacha, rsx->rs_buf,
rsx->rs_buf, sizeof(rsx->rs_buf));
/* mix in optional user provided data */
if (dat) {
size_t i, m;
m = min(datlen, KEYSZ + IVSZ);
for (i = 0; i < m; i++)
rsx->rs_buf[i] ^= dat[i];
}
/* immediately reinit for backtracking resistance */
_rs_init(rsx->rs_buf, KEYSZ + IVSZ);
memset(rsx->rs_buf, 0, KEYSZ + IVSZ);
rs->rs_have = sizeof(rsx->rs_buf) - KEYSZ - IVSZ;
}
static inline void
_rs_random_buf(void *_buf, size_t n)
{
u_char *buf = (u_char *)_buf;
u_char *keystream;
size_t m;
_rs_stir_if_needed(n);
while (n > 0) {
if (rs->rs_have > 0) {
m = min(n, rs->rs_have);
keystream = rsx->rs_buf + sizeof(rsx->rs_buf)
- rs->rs_have;
memcpy(buf, keystream, m);
memset(keystream, 0, m);
buf += m;
n -= m;
rs->rs_have -= m;
}
if (rs->rs_have == 0)
_rs_rekey(NULL, 0);
}
}
static inline void
_rs_random_u32(uint32_t *val)
{
u_char *keystream;
_rs_stir_if_needed(sizeof(*val));
if (rs->rs_have < sizeof(*val))
_rs_rekey(NULL, 0);
keystream = rsx->rs_buf + sizeof(rsx->rs_buf) - rs->rs_have;
memcpy(val, keystream, sizeof(*val));
memset(keystream, 0, sizeof(*val));
rs->rs_have -= sizeof(*val);
}
uint32_t
arc4random(void)
{
uint32_t val;
_ARC4_LOCK();
_rs_random_u32(&val);
_ARC4_UNLOCK();
return val;
}
void
arc4random_buf(void *buf, size_t n)
{
_ARC4_LOCK();
_rs_random_buf(buf, n);
_ARC4_UNLOCK();
}

View file

@ -0,0 +1,56 @@
/* $OpenBSD: arc4random_uniform.c,v 1.1 2014/07/12 13:24:54 deraadt Exp $ */
/*
* Copyright (c) 2008, Damien Miller <djm@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.
*/
#include <sys/types.h>
#include <stdlib.h>
/*
* Calculate a uniformly distributed random number less than upper_bound
* avoiding "modulo bias".
*
* Uniformity is achieved by generating new random numbers until the one
* returned is outside the range [0, 2**32 % upper_bound). This
* guarantees the selected random number will be inside
* [2**32 % upper_bound, 2**32) which maps back to [0, upper_bound)
* after reduction modulo upper_bound.
*/
uint32_t
arc4random_uniform(uint32_t upper_bound)
{
uint32_t r, min;
if (upper_bound < 2)
return 0;
/* 2**32 % x == (2**32 - x) % x */
min = -upper_bound % upper_bound;
/*
* This could theoretically loop forever but each retry has
* p > 0.5 (worst case, usually far better) of selecting a
* number inside the range we need, so it should rarely need
* to re-roll.
*/
for (;;) {
r = arc4random();
if (r >= min)
break;
}
return r % upper_bound;
}