+/* $OpenBSD: ssh-keysign.c,v 1.29 2006/08/03 03:34:42 deraadt Exp $ */
/*
* Copyright (c) 2002 Markus Friedl. All rights reserved.
*
* (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 1.4 2002/06/19 00:27:55 deraadt 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,
u_int datalen)
{
Buffer b;
- Key *key;
+ Key *key = NULL;
u_char *pkblob;
u_int blen, len;
char *pkalg, *p;
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);
/* end of message */
if (buffer_len(&b) != 0)
fail++;
+ buffer_free(&b);
debug3("valid_request: fail %d", fail);
main(int argc, char **argv)
{
Buffer b;
- Key *keys[2], *key;
+ Options options;
+ Key *keys[2], *key = NULL;
struct passwd *pw;
int key_fd[2], i, found, version = 2, fd;
u_char *signature, *data;
char *host;
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();
log_init("ssh-keysign", SYSLOG_LEVEL_DEBUG3, SYSLOG_FACILITY_AUTH, 0);
#endif
+ /* verify that ssh-keysign is enabled by the admin */
+ initialize_options(&options);
+ (void)read_config_file(_PATH_HOST_CONFIG_FILE, "", &options, 0);
+ fill_default_options(&options);
+ if (options.enable_ssh_keysign != 1)
+ fatal("ssh-keysign not enabled in %s",
+ _PATH_HOST_CONFIG_FILE);
+
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();
+ RAND_seed(rnd, sizeof(rnd));
found = 0;
for (i = 0; i < 2; i++) {
fatal("no hostkey found");
buffer_init(&b);
- if (msg_recv(STDIN_FILENO, &b) < 0)
- fatal("msg_recv failed");
+ if (ssh_msg_recv(STDIN_FILENO, &b) < 0)
+ fatal("ssh_msg_recv failed");
if (buffer_get_char(&b) != version)
fatal("bad version");
fd = buffer_get_int(&b);
data = buffer_get_string(&b, &dlen);
if (valid_request(pw, host, &key, data, dlen) < 0)
fatal("not a valid request");
- xfree(data);
xfree(host);
found = 0;
if (key_sign(keys[i], &signature, &slen, data, dlen) != 0)
fatal("key_sign failed");
+ xfree(data);
/* send reply */
buffer_clear(&b);
buffer_put_string(&b, signature, slen);
- msg_send(STDOUT_FILENO, version, &b);
+ if (ssh_msg_send(STDOUT_FILENO, version, &b) == -1)
+ fatal("ssh_msg_send failed");
return (0);
}