- markus@cvs.openbsd.org 2002/06/04 19:53:40
[monitor.c]
save the session id (hash) for ssh2 (it will be passed with the
initial sign request) and verify that this value is used during
authentication; ok provos@
diff --git a/monitor.c b/monitor.c
index 6fe0afd..a96ca04 100644
--- a/monitor.c
+++ b/monitor.c
@@ -25,7 +25,7 @@
*/
#include "includes.h"
-RCSID("$OpenBSD: monitor.c,v 1.12 2002/06/04 19:42:35 markus Exp $");
+RCSID("$OpenBSD: monitor.c,v 1.13 2002/06/04 19:53:40 markus Exp $");
#include <openssl/dh.h>
@@ -128,6 +128,8 @@
static u_char *hostbased_cuser = NULL;
static u_char *hostbased_chost = NULL;
static char *auth_method = "unknown";
+static int session_id2_len = 0;
+static u_char *session_id2 = NULL;
struct mon_table {
enum monitor_reqtype type;
@@ -454,6 +456,13 @@
if (datlen != 20)
fatal("%s: data length incorrect: %d", __FUNCTION__, datlen);
+ /* save session id, it will be passed on the first call */
+ if (session_id2_len == 0) {
+ session_id2_len = datlen;
+ session_id2 = xmalloc(session_id2_len);
+ memcpy(session_id2, p, session_id2_len);
+ }
+
if ((key = get_hostkey_by_index(keyid)) == NULL)
fatal("%s: no hostkey from index %d", __FUNCTION__, keyid);
if (key_sign(key, &signature, &siglen, p, datlen) < 0)
@@ -819,17 +828,25 @@
u_char *p;
u_int len;
int fail = 0;
- int session_id2_len = 20 /*XXX should get from [net] */;
buffer_init(&b);
buffer_append(&b, data, datalen);
if (datafellows & SSH_OLD_SESSIONID) {
+ p = buffer_ptr(&b);
+ len = buffer_len(&b);
+ if ((session_id2 == NULL) ||
+ (len < session_id2_len) ||
+ (memcmp(p, session_id2, session_id2_len) != 0))
+ fail++;
buffer_consume(&b, session_id2_len);
} else {
- xfree(buffer_get_string(&b, &len));
- if (len != session_id2_len)
+ p = buffer_get_string(&b, &len);
+ if ((session_id2 == NULL) ||
+ (len != session_id2_len) ||
+ (memcmp(p, session_id2, session_id2_len) != 0))
fail++;
+ xfree(p);
}
if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
fail++;
@@ -868,14 +885,17 @@
u_char *p;
u_int len;
int fail = 0;
- int session_id2_len = 20 /*XXX should get from [net] */;
buffer_init(&b);
buffer_append(&b, data, datalen);
- xfree(buffer_get_string(&b, &len));
- if (len != session_id2_len)
+ p = buffer_get_string(&b, &len);
+ if ((session_id2 == NULL) ||
+ (len != session_id2_len) ||
+ (memcmp(p, session_id2, session_id2_len) != 0))
fail++;
+ xfree(p);
+
if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
fail++;
p = buffer_get_string(&b, NULL);
@@ -1334,6 +1354,10 @@
kex = xmalloc(sizeof(*kex));
memset(kex, 0, sizeof(*kex));
kex->session_id = buffer_get_string(m, &kex->session_id_len);
+ if ((session_id2 == NULL) ||
+ (kex->session_id_len != session_id2_len) ||
+ (memcmp(kex->session_id, session_id2, session_id2_len) != 0))
+ fatal("mm_get_get: internal error: bad session id");
kex->we_need = buffer_get_int(m);
kex->server = 1;
kex->hostkey_type = buffer_get_int(m);