OSDN Git Service

Use upstream OpenBSD's arc4random.
authorElliott Hughes <enh@google.com>
Fri, 18 Jul 2014 22:57:41 +0000 (15:57 -0700)
committerElliott Hughes <enh@google.com>
Tue, 22 Jul 2014 02:17:15 +0000 (19:17 -0700)
The getentropy_linux.c is lightly modified to build on Android, but we're now
completely in sync with upstream OpenBSD's arc4random implementation.

(cherry picked from commit 2b67d7dee09852789d9ac7d8972ed6cdb2c18430)

Change-Id: Icc939b5fa2fcac3e15ff93735d2d34f67e9bb149

libc/Android.mk
libc/bionic/arc4random.c [deleted file]
libc/bionic/getentropy_linux.c [new file with mode: 0644]
libc/private/thread_private.h
libc/upstream-openbsd/android/include/arc4random.h [new file with mode: 0644]
libc/upstream-openbsd/android/include/openbsd-compat.h
libc/upstream-openbsd/lib/libc/crypt/arc4random.c [new file with mode: 0644]
libc/upstream-openbsd/lib/libc/crypt/arc4random_uniform.c [new file with mode: 0644]

index fd3da96..0bdf1a5 100644 (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 \
@@ -124,6 +123,7 @@ 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 \
diff --git a/libc/bionic/arc4random.c b/libc/bionic/arc4random.c
deleted file mode 100644 (file)
index 9bdf341..0000000
+++ /dev/null
@@ -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;
-}
diff --git a/libc/bionic/getentropy_linux.c b/libc/bionic/getentropy_linux.c
new file mode 100644 (file)
index 0000000..409bd7d
--- /dev/null
@@ -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 */
index b8b1a81..2e3ac3d 100644 (file)
@@ -46,8 +46,9 @@ __LIBC_HIDDEN__ void  _thread_atexit_unlock(void);
 __LIBC_HIDDEN__ void    _thread_arc4_lock(void);
 __LIBC_HIDDEN__ void    _thread_arc4_unlock(void);
 
-#define  _ARC4_LOCK() _thread_arc4_lock()
-#define  _ARC4_UNLOCK() _thread_arc4_unlock()
+#define _ARC4_LOCK() _thread_arc4_lock()
+#define _ARC4_UNLOCK() _thread_arc4_unlock()
+#define _ARC4_ATFORK(f) pthread_atfork(NULL, NULL, (f))
 
 __END_DECLS
 
diff --git a/libc/upstream-openbsd/android/include/arc4random.h b/libc/upstream-openbsd/android/include/arc4random.h
new file mode 100644 (file)
index 0000000..c07257d
--- /dev/null
@@ -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);
+}
index 5827a82..34ad2c5 100644 (file)
@@ -18,6 +18,7 @@
 #define _BIONIC_OPENBSD_COMPAT_H_included
 
 #include <sys/cdefs.h>
+#include <stddef.h> // For size_t.
 
 #define __USE_BSD
 
 /* 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_;
diff --git a/libc/upstream-openbsd/lib/libc/crypt/arc4random.c b/libc/upstream-openbsd/lib/libc/crypt/arc4random.c
new file mode 100644 (file)
index 0000000..64248b6
--- /dev/null
@@ -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();
+}
diff --git a/libc/upstream-openbsd/lib/libc/crypt/arc4random_uniform.c b/libc/upstream-openbsd/lib/libc/crypt/arc4random_uniform.c
new file mode 100644 (file)
index 0000000..1aa9a62
--- /dev/null
@@ -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;
+}