ensure that stdio fds are attached; ok deraadt@

12 files changed, 68 insertions, 12 deletions

diff --git a/usr.bin/ssh/misc.c b/usr.bin/ssh/misc.c
index 6450198a0c3..b5721a0c4f8 100644
--- a/usr.bin/ssh/misc.c
+++ b/usr.bin/ssh/misc.c
@@ -24,7 +24,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: misc.c,v 1.34 2005/07/08 09:26:18 dtucker Exp $");
+RCSID("$OpenBSD: misc.c,v 1.35 2005/09/13 23:40:07 djm Exp $");
 
 #include "misc.h"
 #include "log.h"
@@ -501,6 +501,26 @@ read_keyfile_line(FILE *f, const char *filename, char *buf, size_t bufsz,
 	return -1;
 }
 
+void
+sanitise_stdfd(void)
+{
+	int nullfd;
+
+	if ((nullfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
+		fprintf(stderr, "Couldn't open /dev/null: %s", strerror(errno));
+		exit(1);
+	}
+	while (nullfd < 2) {
+		if (dup2(nullfd, nullfd + 1) == -1) {
+			fprintf(stderr, "dup2: %s", strerror(errno));
+			exit(1);
+		}
+		nullfd++;
+	}
+	if (nullfd > 2)
+		close(nullfd);
+}
+
 char *
 tohex(const u_char *d, u_int l)
 {
diff --git a/usr.bin/ssh/misc.h b/usr.bin/ssh/misc.h
index 2d630feb5f8..51541336cf3 100644
--- a/usr.bin/ssh/misc.h
+++ b/usr.bin/ssh/misc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: misc.h,v 1.25 2005/07/14 04:00:43 dtucker Exp $	*/
+/*	$OpenBSD: misc.h,v 1.26 2005/09/13 23:40:07 djm Exp $	*/
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -27,6 +27,7 @@ long	 convtime(const char *);
 char	*tilde_expand_filename(const char *, uid_t);
 char	*percent_expand(const char *, ...) __attribute__((__sentinel__));
 char	*tohex(const u_char *, u_int);
+void	 sanitise_stdfd(void);
 
 struct passwd *pwcopy(struct passwd *);
 
diff --git a/usr.bin/ssh/scp.c b/usr.bin/ssh/scp.c
index d02e69022a4..9a6c5288399 100644
--- a/usr.bin/ssh/scp.c
+++ b/usr.bin/ssh/scp.c
@@ -71,7 +71,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: scp.c,v 1.125 2005/07/27 10:39:03 dtucker Exp $");
+RCSID("$OpenBSD: scp.c,v 1.126 2005/09/13 23:40:07 djm Exp $");
 
 #include "xmalloc.h"
 #include "atomicio.h"
@@ -222,6 +222,9 @@ main(int argc, char **argv)
 	extern char *optarg;
 	extern int optind;
 
+	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
+	sanitise_stdfd();
+
 	args.list = NULL;
 	addargs(&args, "ssh");		/* overwritten with ssh_program */
 	addargs(&args, "-x");
diff --git a/usr.bin/ssh/sftp-server.c b/usr.bin/ssh/sftp-server.c
index 45a19f8fe77..8e78377f0b4 100644
--- a/usr.bin/ssh/sftp-server.c
+++ b/usr.bin/ssh/sftp-server.c
@@ -14,13 +14,14 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 #include "includes.h"
-RCSID("$OpenBSD: sftp-server.c,v 1.48 2005/06/17 02:44:33 djm Exp $");
+RCSID("$OpenBSD: sftp-server.c,v 1.49 2005/09/13 23:40:07 djm Exp $");
 
 #include "buffer.h"
 #include "bufaux.h"
 #include "getput.h"
 #include "log.h"
 #include "xmalloc.h"
+#include "misc.h"
 
 #include "sftp.h"
 #include "sftp-common.h"
@@ -1016,6 +1017,9 @@ main(int ac, char **av)
 	int in, out, max;
 	ssize_t len, olen, set_size;
 
+	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
+	sanitise_stdfd();
+
 	/* XXX should use getopt */
 
 	handle_init();
diff --git a/usr.bin/ssh/sftp.c b/usr.bin/ssh/sftp.c
index d0070a1d1af..f7c044b01be 100644
--- a/usr.bin/ssh/sftp.c
+++ b/usr.bin/ssh/sftp.c
@@ -16,7 +16,7 @@
 
 #include "includes.h"
 
-RCSID("$OpenBSD: sftp.c,v 1.66 2005/08/08 13:22:48 jaredy Exp $");
+RCSID("$OpenBSD: sftp.c,v 1.67 2005/09/13 23:40:07 djm Exp $");
 
 #include <glob.h>
 #include <histedit.h>
@@ -1428,6 +1428,9 @@ main(int argc, char **argv)
 	extern int optind;
 	extern char *optarg;
 
+	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
+	sanitise_stdfd();
+
 	args.list = NULL;
 	addargs(&args, "ssh");		/* overwritten with ssh_program */
 	addargs(&args, "-oForwardX11 no");
diff --git a/usr.bin/ssh/ssh-add.c b/usr.bin/ssh/ssh-add.c
index 0347b3a94bd..a836e32dfa5 100644
--- a/usr.bin/ssh/ssh-add.c
+++ b/usr.bin/ssh/ssh-add.c
@@ -35,7 +35,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: ssh-add.c,v 1.72 2005/07/17 07:17:55 djm Exp $");
+RCSID("$OpenBSD: ssh-add.c,v 1.73 2005/09/13 23:40:07 djm Exp $");
 
 #include <openssl/evp.h>
 
@@ -312,6 +312,9 @@ main(int argc, char **argv)
 	char *sc_reader_id = NULL;
 	int i, ch, deleting = 0, ret = 0;
 
+	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
+	sanitise_stdfd();
+
 	SSLeay_add_all_algorithms();
 
 	/* At first, get a connection to the authentication agent. */
diff --git a/usr.bin/ssh/ssh-agent.c b/usr.bin/ssh/ssh-agent.c
index 63b59a55d7b..912f3996bd9 100644
--- a/usr.bin/ssh/ssh-agent.c
+++ b/usr.bin/ssh/ssh-agent.c
@@ -35,7 +35,7 @@
 
 #include "includes.h"
 #include <sys/queue.h>
-RCSID("$OpenBSD: ssh-agent.c,v 1.122 2004/10/29 22:53:56 djm Exp $");
+RCSID("$OpenBSD: ssh-agent.c,v 1.123 2005/09/13 23:40:07 djm Exp $");
 
 #include <openssl/evp.h>
 #include <openssl/md5.h>
@@ -1001,6 +1001,9 @@ main(int ac, char **av)
 	pid_t pid;
 	char pidstrbuf[1 + 3 * sizeof pid];
 
+	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
+	sanitise_stdfd();
+
 	/* drop */
 	setegid(getgid());
 	setgid(getgid());
diff --git a/usr.bin/ssh/ssh-keygen.c b/usr.bin/ssh/ssh-keygen.c
index 07198ed2ec6..042f0983efd 100644
--- a/usr.bin/ssh/ssh-keygen.c
+++ b/usr.bin/ssh/ssh-keygen.c
@@ -12,7 +12,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: ssh-keygen.c,v 1.128 2005/07/17 07:17:55 djm Exp $");
+RCSID("$OpenBSD: ssh-keygen.c,v 1.129 2005/09/13 23:40:07 djm Exp $");
 
 #include <openssl/evp.h>
 #include <openssl/pem.h>
@@ -1018,6 +1018,9 @@ main(int ac, char **av)
 	extern int optind;
 	extern char *optarg;
 
+	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
+	sanitise_stdfd();
+
 	SSLeay_add_all_algorithms();
 	log_init(av[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
 
diff --git a/usr.bin/ssh/ssh-keyscan.c b/usr.bin/ssh/ssh-keyscan.c
index 5e2377c0a69..634184723e2 100644
--- a/usr.bin/ssh/ssh-keyscan.c
+++ b/usr.bin/ssh/ssh-keyscan.c
@@ -7,7 +7,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: ssh-keyscan.c,v 1.55 2005/06/17 02:44:33 djm Exp $");
+RCSID("$OpenBSD: ssh-keyscan.c,v 1.56 2005/09/13 23:40:07 djm Exp $");
 
 #include <sys/queue.h>
 #include <errno.h>
@@ -700,6 +700,9 @@ main(int argc, char **argv)
 
 	TAILQ_INIT(&tq);
 
+	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
+	sanitise_stdfd();
+
 	if (argc <= 1)
 		usage();
 
diff --git a/usr.bin/ssh/ssh-keysign.c b/usr.bin/ssh/ssh-keysign.c
index e3e4c33ada7..d26ec1e4fb6 100644
--- a/usr.bin/ssh/ssh-keysign.c
+++ b/usr.bin/ssh/ssh-keysign.c
@@ -22,7 +22,7 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 #include "includes.h"
-RCSID("$OpenBSD: ssh-keysign.c,v 1.18 2004/08/23 14:29:23 dtucker Exp $");
+RCSID("$OpenBSD: ssh-keysign.c,v 1.19 2005/09/13 23:40:07 djm Exp $");
 
 #include <openssl/evp.h>
 #include <openssl/rand.h>
@@ -146,6 +146,13 @@ main(int argc, char **argv)
 	u_int slen, dlen;
 	u_int32_t rnd[256];
 
+	/* Ensure that stdin and stdout are connected */
+	if ((fd = open(_PATH_DEVNULL, O_RDWR)) < 2)
+		exit(1);
+	/* Leave /dev/null fd iff it is attached to stderr */
+	if (fd > 2)
+		close(fd);
+
 	key_fd[0] = open(_PATH_HOST_RSA_KEY_FILE, O_RDONLY);
 	key_fd[1] = open(_PATH_HOST_DSA_KEY_FILE, O_RDONLY);
 
diff --git a/usr.bin/ssh/ssh.c b/usr.bin/ssh/ssh.c
index 328bfda3eac..6e160bfda25 100644
--- a/usr.bin/ssh/ssh.c
+++ b/usr.bin/ssh/ssh.c
@@ -40,7 +40,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: ssh.c,v 1.249 2005/07/30 01:26:16 djm Exp $");
+RCSID("$OpenBSD: ssh.c,v 1.250 2005/09/13 23:40:07 djm Exp $");
 
 #include <openssl/evp.h>
 #include <openssl/err.h>
@@ -188,6 +188,9 @@ main(int ac, char **av)
 	struct servent *sp;
 	Forward fwd;
 
+	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
+	sanitise_stdfd();
+
 	/*
 	 * Save the original real uid.  It will be needed later (uid-swapping
 	 * may clobber the real uid).
diff --git a/usr.bin/ssh/sshd.c b/usr.bin/ssh/sshd.c
index e0753035bc2..0d790609ce6 100644
--- a/usr.bin/ssh/sshd.c
+++ b/usr.bin/ssh/sshd.c
@@ -42,7 +42,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: sshd.c,v 1.312 2005/07/25 11:59:40 markus Exp $");
+RCSID("$OpenBSD: sshd.c,v 1.313 2005/09/13 23:40:07 djm Exp $");
 
 #include <openssl/dh.h>
 #include <openssl/bn.h>
@@ -886,6 +886,9 @@ main(int ac, char **av)
 	saved_argv = av;
 	rexec_argc = ac;
 
+	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
+	sanitise_stdfd();
+
 	/* Initialize configuration options to their default values. */
 	initialize_server_options(&options);