Factor out getrnd() and rename to getentropy().

Factor out the arc4random seeding into its own file and change the
interface to match getentropy.  Use native getentropy if available.
This will make it easier to resync OpenBSD changes to arc4random.
Prompted by bz#3467, ok djm@.

diff --git a/configure.ac b/configure.ac
index e49e163b042e84e629207c095e2474ed537b595d..c36aee2c8e9d38e414e46b1a212dc894c1941e96 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -1879,6 +1879,7 @@ AC_CHECK_FUNCS([ \
        futimes \
        getaddrinfo \
        getcwd \
+       getentropy \
        getgrouplist \
        getline \
        getnameinfo \
@@ -2110,7 +2111,7 @@ AC_CHECK_DECLS([O_NONBLOCK], , ,
 #endif
        ])
 
-AC_CHECK_DECLS([ftruncate], , ,
+AC_CHECK_DECLS([ftruncate, getentropy], , ,
        [
 #include <sys/types.h>
 #include <unistd.h>

diff --git a/openbsd-compat/Makefile.in b/openbsd-compat/Makefile.in
index bca8c42a58db96086f800abce68d3d4d37348f97..cebe4fe458e8ec769081d54c1c6f050f1d33cf7d 100644 (file)
--- a/openbsd-compat/Makefile.in
+++ b/openbsd-compat/Makefile.in
@@ -70,6 +70,7 @@ COMPAT=       arc4random.o \
        bsd-cygwin_util.o \
        bsd-err.o \
        bsd-flock.o \
+       bsd-getentropy.o \
        bsd-getline.o \
        bsd-getpagesize.o \
        bsd-getpeereid.o \

diff --git a/openbsd-compat/arc4random.c b/openbsd-compat/arc4random.c
index ce5f054f1e2353239206972594943b4b6ba68039..f43b5c7cc2db6819d0e152e24fdbd99d67b421c0 100644 (file)
--- a/openbsd-compat/arc4random.c
+++ b/openbsd-compat/arc4random.c
@@ -33,19 +33,10 @@
 #include <string.h>
 #include <unistd.h>
 
-#ifdef HAVE_SYS_RANDOM_H
-# include <sys/random.h>
-#endif
-
 #ifndef HAVE_ARC4RANDOM
 
 #define MINIMUM(a, b)    (((a) < (b)) ? (a) : (b))
 
-#ifdef WITH_OPENSSL
-#include <openssl/rand.h>
-#include <openssl/err.h>
-#endif
-
 #include "log.h"
 
 #define KEYSTREAM_ONLY
@@ -83,56 +74,13 @@ _rs_init(u_char *buf, size_t n)
        chacha_ivsetup(&rs, buf + KEYSZ);
 }
 
-#ifndef WITH_OPENSSL
-# ifndef SSH_RANDOM_DEV
-#  define SSH_RANDOM_DEV "/dev/urandom"
-# endif /* SSH_RANDOM_DEV */
-static void
-getrnd(u_char *s, size_t len)
-{
-       int fd, save_errno;
-       ssize_t r;
-       size_t o = 0;
-
-#ifdef HAVE_GETRANDOM
-       if ((r = getrandom(s, len, 0)) > 0 && (size_t)r == len)
-               return;
-#endif /* HAVE_GETRANDOM */
-
-       if ((fd = open(SSH_RANDOM_DEV, O_RDONLY)) == -1) {
-               save_errno = errno;
-               /* Try egd/prngd before giving up. */
-               if (seed_from_prngd(s, len) == 0)
-                       return;
-               fatal("Couldn't open %s: %s", SSH_RANDOM_DEV,
-                   strerror(save_errno));
-       }
-       while (o < len) {
-               r = read(fd, s + o, len - o);
-               if (r < 0) {
-                       if (errno == EAGAIN || errno == EINTR ||
-                           errno == EWOULDBLOCK)
-                               continue;
-                       fatal("read %s: %s", SSH_RANDOM_DEV, strerror(errno));
-               }
-               o += r;
-       }
-       close(fd);
-}
-#endif /* WITH_OPENSSL */
-
 static void
 _rs_stir(void)
 {
        u_char rnd[KEYSZ + IVSZ];
 
-#ifdef WITH_OPENSSL
-       if (RAND_bytes(rnd, sizeof(rnd)) <= 0)
-               fatal("Couldn't obtain random bytes (error 0x%lx)",
-                   (unsigned long)ERR_get_error());
-#else
-       getrnd(rnd, sizeof(rnd));
-#endif
+       if (getentropy(rnd, sizeof rnd) == -1)
+               fatal("getentropy failed");
 
        if (!rs_initialized) {
                rs_initialized = 1;

diff --git a/openbsd-compat/bsd-getentropy.c b/openbsd-compat/bsd-getentropy.c
new file mode 100644 (file)
index 0000000..1733e28
--- /dev/null
+++ b/openbsd-compat/bsd-getentropy.c
@@ -0,0 +1,82 @@
+/*
+ * 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.
+ */
+
+#include "includes.h"
+
+#ifndef HAVE_GETENTROPY
+
+#ifndef SSH_RANDOM_DEV
+# define SSH_RANDOM_DEV "/dev/urandom"
+#endif /* SSH_RANDOM_DEV */
+
+#include <sys/types.h>
+#ifdef HAVE_SYS_RANDOM_H
+# include <sys/random.h>
+#endif
+
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#ifdef WITH_OPENSSL
+#include <openssl/rand.h>
+#include <openssl/err.h>
+#endif
+
+#include "log.h"
+
+int
+getentropy(void *s, size_t len)
+{
+#ifdef WITH_OPENSSL
+       if (RAND_bytes(s, len) <= 0)
+               fatal("Couldn't obtain random bytes (error 0x%lx)",
+                   (unsigned long)ERR_get_error());
+#else
+       int fd, save_errno;
+       ssize_t r;
+       size_t o = 0;
+
+#ifdef HAVE_GETRANDOM
+       if ((r = getrandom(s, len, 0)) > 0 && (size_t)r == len)
+               return 0;
+#endif /* HAVE_GETRANDOM */
+
+       if ((fd = open(SSH_RANDOM_DEV, O_RDONLY)) == -1) {
+               save_errno = errno;
+               /* Try egd/prngd before giving up. */
+               if (seed_from_prngd(s, len) == 0)
+                       return 0;
+               fatal("Couldn't open %s: %s", SSH_RANDOM_DEV,
+                   strerror(save_errno));
+       }
+       while (o < len) {
+               r = read(fd, (u_char *)s + o, len - o);
+               if (r < 0) {
+                       if (errno == EAGAIN || errno == EINTR ||
+                           errno == EWOULDBLOCK)
+                               continue;
+                       fatal("read %s: %s", SSH_RANDOM_DEV, strerror(errno));
+               }
+               o += r;
+       }
+       close(fd);
+#endif /* WITH_OPENSSL */
+       return 0;
+}
+#endif /* WITH_GETENTROPY */

diff --git a/openbsd-compat/openbsd-compat.h b/openbsd-compat/openbsd-compat.h
index 4316ab84bf8979e66c6548357bef058444765e76..93efff2f1f54d64564fec12582557a77f0de5509 100644 (file)
--- a/openbsd-compat/openbsd-compat.h
+++ b/openbsd-compat/openbsd-compat.h
@@ -69,6 +69,10 @@ void closefrom(int);
 int ftruncate(int filedes, off_t length);
 #endif
 
+#if defined(HAVE_DECL_GETENTROPY) && HAVE_DECL_GETENTROPY == 0
+int getentropy(void *, size_t);
+#endif
+
 #ifndef HAVE_GETLINE
 #include <stdio.h>
 ssize_t getline(char **, size_t *, FILE *);