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

[openssh.git] / kexgexs.c

diff --git a/kexgexs.c b/kexgexs.c
index e3d0eacc55583442e08177620c65a8451228adb7..8515568b36edda5d4d8be638bb031d5f1039ddcb 100644 (file)
--- a/kexgexs.c
+++ b/kexgexs.c
@@ -1,3 +1,4 @@
+/* $OpenBSD: kexgexs.c,v 1.12 2009/06/21 07:37:15 dtucker Exp $ */
 /*
  * Copyright (c) 2000 Niels Provos.  All rights reserved.
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
@@ -25,14 +26,26 @@
 
 #include "includes.h"
 
+#include <sys/param.h>
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+#include <signal.h>
+
 #include "xmalloc.h"
+#include "buffer.h"
 #include "key.h"
+#include "cipher.h"
 #include "kex.h"
 #include "log.h"
 #include "packet.h"
 #include "dh.h"
 #include "ssh2.h"
 #include "compat.h"
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
 #include "monitor_wrap.h"
 
 void
@@ -42,8 +55,9 @@ kexgex_server(Kex *kex)
        Key *server_host_key;
        DH *dh;
        u_char *kbuf, *hash, *signature = NULL, *server_host_key_blob = NULL;
-       u_int sbloblen, klen, kout, slen, hashlen;
-       int min = -1, max = -1, nbits = -1, type;
+       u_int sbloblen, klen, slen, hashlen;
+       int omin = -1, min = -1, omax = -1, max = -1, onbits = -1, nbits = -1;
+       int type, kout;
 
        if (kex->load_host_key == NULL)
                fatal("Cannot load hostkey");
@@ -55,27 +69,29 @@ kexgex_server(Kex *kex)
        switch (type) {
        case SSH2_MSG_KEX_DH_GEX_REQUEST:
                debug("SSH2_MSG_KEX_DH_GEX_REQUEST received");
-               min = packet_get_int();
-               nbits = packet_get_int();
-               max = packet_get_int();
+               omin = min = packet_get_int();
+               onbits = nbits = packet_get_int();
+               omax = max = packet_get_int();
                min = MAX(DH_GRP_MIN, min);
                max = MIN(DH_GRP_MAX, max);
+               nbits = MAX(DH_GRP_MIN, nbits);
+               nbits = MIN(DH_GRP_MAX, nbits);
                break;
        case SSH2_MSG_KEX_DH_GEX_REQUEST_OLD:
                debug("SSH2_MSG_KEX_DH_GEX_REQUEST_OLD received");
-               nbits = packet_get_int();
-               min = DH_GRP_MIN;
-               max = DH_GRP_MAX;
+               onbits = nbits = packet_get_int();
                /* unused for old GEX */
+               omin = min = DH_GRP_MIN;
+               omax = max = DH_GRP_MAX;
                break;
        default:
                fatal("protocol error during kex, no DH_GEX_REQUEST: %d", type);
        }
        packet_check_eom();
 
-       if (max < min || nbits < min || max < nbits)
+       if (omax < omin || onbits < omin || omax < onbits)
                fatal("DH_GEX_REQUEST, bad parameters: %d !< %d !< %d",
-                   min, nbits, max);
+                   omin, onbits, omax);
 
        /* Contact privileged parent */
        dh = PRIVSEP(choose_dh(min, nbits, max));
@@ -121,20 +137,22 @@ kexgex_server(Kex *kex)
 
        klen = DH_size(dh);
        kbuf = xmalloc(klen);
-       kout = DH_compute_key(kbuf, dh_client_pub, dh);
+       if ((kout = DH_compute_key(kbuf, dh_client_pub, dh)) < 0)
+               fatal("DH_compute_key: failed");
 #ifdef DEBUG_KEXDH
        dump_digest("shared secret", kbuf, kout);
 #endif
        if ((shared_secret = BN_new()) == NULL)
                fatal("kexgex_server: BN_new failed");
-       BN_bin2bn(kbuf, kout, shared_secret);
+       if (BN_bin2bn(kbuf, kout, shared_secret) == NULL)
+               fatal("kexgex_server: BN_bin2bn failed");
        memset(kbuf, 0, klen);
        xfree(kbuf);
 
        key_to_blob(server_host_key, &server_host_key_blob, &sbloblen);
 
        if (type == SSH2_MSG_KEX_DH_GEX_REQUEST_OLD)
-               min = max = -1;
+               omin = min = omax = max = -1;
 
        /* calc H */
        kexgex_hash(
@@ -144,7 +162,7 @@ kexgex_server(Kex *kex)
            buffer_ptr(&kex->peer), buffer_len(&kex->peer),
            buffer_ptr(&kex->my), buffer_len(&kex->my),
            server_host_key_blob, sbloblen,
-           min, nbits, max,
+           omin, onbits, omax,
            dh->p, dh->g,
            dh_client_pub,
            dh->pub_key,
@@ -161,7 +179,9 @@ kexgex_server(Kex *kex)
        }
 
        /* sign H */
-       PRIVSEP(key_sign(server_host_key, &signature, &slen, hash, hashlen));
+       if (PRIVSEP(key_sign(server_host_key, &signature, &slen, hash,
+           hashlen)) < 0)
+               fatal("kexgex_server: key_sign failed");
 
        /* destroy_sensitive_data(); */