- djm@cvs.openbsd.org 2010/01/30 02:54:53

[openssh.git] / ssh-keysign.c

diff --git a/ssh-keysign.c b/ssh-keysign.c
index e642948a0f78c4ebc0e784b725cfe17367402c32..0fdcebbd22c79ea809d9d691e3e5cb05b8390eb9 100644 (file)
--- a/ssh-keysign.c
+++ b/ssh-keysign.c
@@ -1,3 +1,4 @@
+/* $OpenBSD: ssh-keysign.c,v 1.30 2010/01/13 01:20:20 dtucker Exp $ */
 /*
  * Copyright (c) 2002 Markus Friedl.  All rights reserved.
  *
@@ -21,35 +22,41 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
+
 #include "includes.h"
-RCSID("$OpenBSD: ssh-keysign.c,v 1.16 2004/04/18 23:10:26 djm Exp $");
+
+#include <fcntl.h>
+#ifdef HAVE_PATHS_H
+#include <paths.h>
+#endif
+#include <pwd.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
 
 #include <openssl/evp.h>
 #include <openssl/rand.h>
 #include <openssl/rsa.h>
 
+#include "xmalloc.h"
 #include "log.h"
 #include "key.h"
 #include "ssh.h"
 #include "ssh2.h"
 #include "misc.h"
-#include "xmalloc.h"
 #include "buffer.h"
-#include "bufaux.h"
 #include "authfile.h"
 #include "msg.h"
 #include "canohost.h"
 #include "pathnames.h"
 #include "readconf.h"
+#include "uidswap.h"
 
 /* XXX readconf.c needs these */
 uid_t original_real_uid;
 
-#ifdef HAVE___PROGNAME
 extern char *__progname;
-#else
-char *__progname;
-#endif
 
 static int
 valid_request(struct passwd *pw, char *host, Key **ret, u_char *data,
@@ -67,9 +74,9 @@ valid_request(struct passwd *pw, char *host, Key **ret, u_char *data,
        buffer_init(&b);
        buffer_append(&b, data, datalen);
 
-       /* session id, currently limited to SHA1 (20 bytes) */
+       /* session id, currently limited to SHA1 (20 bytes) or SHA256 (32) */
        p = buffer_get_string(&b, &len);
-       if (len != 20)
+       if (len != 20 && len != 32)
                fail++;
        xfree(p);
 
@@ -143,7 +150,7 @@ main(int argc, char **argv)
 {
        Buffer b;
        Options options;
-       Key *keys[2], *key;
+       Key *keys[2], *key = NULL;
        struct passwd *pw;
        int key_fd[2], i, found, version = 2, fd;
        u_char *signature, *data;
@@ -151,11 +158,22 @@ 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);
 
-       seteuid(getuid());
-       setuid(getuid());
+       original_real_uid = getuid();   /* XXX readconf.c needs this */
+       if ((pw = getpwuid(original_real_uid)) == NULL)
+               fatal("getpwuid failed");
+       pw = pwcopy(pw);
+
+       permanently_set_uid(pw);
 
        init_rng();
        seed_rng();
@@ -166,7 +184,6 @@ main(int argc, char **argv)
 #endif
 
        /* verify that ssh-keysign is enabled by the admin */
-       original_real_uid = getuid();   /* XXX readconf.c needs this */
        initialize_options(&options);
        (void)read_config_file(_PATH_HOST_CONFIG_FILE, "", &options, 0);
        fill_default_options(&options);
@@ -177,10 +194,6 @@ main(int argc, char **argv)
        if (key_fd[0] == -1 && key_fd[1] == -1)
                fatal("could not open any host key");
 
-       if ((pw = getpwuid(getuid())) == NULL)
-               fatal("getpwuid failed");
-       pw = pwcopy(pw);
-
        SSLeay_add_all_algorithms();
        for (i = 0; i < 256; i++)
                rnd[i] = arc4random();
@@ -209,7 +222,7 @@ main(int argc, char **argv)
        if ((fd == STDIN_FILENO) || (fd == STDOUT_FILENO))
                fatal("bad fd");
        if ((host = get_local_name(fd)) == NULL)
-               fatal("cannot get sockname for fd");
+               fatal("cannot get local name for fd");
 
        data = buffer_get_string(&b, &dlen);
        if (valid_request(pw, host, &key, data, dlen) < 0)