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

[openssh.git] / kexgexc.c

diff --git a/kexgexc.c b/kexgexc.c
index f14ac44ca04321eb4eb85efdcdb9c11833e92392..adb973d5b40cb9656d2a7a3877f74ed066e1f7a1 100644 (file)
--- a/kexgexc.c
+++ b/kexgexc.c
@@ -1,3 +1,4 @@
+/* $OpenBSD: kexgexc.c,v 1.11 2006/11/06 21:25:28 markus Exp $ */
 /*
  * Copyright (c) 2000 Niels Provos.  All rights reserved.
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
@@ -24,10 +25,18 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: kexgexc.c,v 1.1 2003/02/16 17:09:57 markus Exp $");
+
+#include <sys/types.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"
@@ -42,23 +51,22 @@ kexgex_client(Kex *kex)
        BIGNUM *p = NULL, *g = NULL;
        Key *server_host_key;
        u_char *kbuf, *hash, *signature = NULL, *server_host_key_blob = NULL;
-       u_int klen, kout, slen, sbloblen;
+       u_int klen, slen, sbloblen, hashlen;
+       int kout;
        int min, max, nbits;
        DH *dh;
 
        nbits = dh_estimate(kex->we_need * 8);
 
        if (datafellows & SSH_OLD_DHGEX) {
-               debug("SSH2_MSG_KEX_DH_GEX_REQUEST_OLD sent");
-
                /* Old GEX request */
                packet_start(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD);
                packet_put_int(nbits);
                min = DH_GRP_MIN;
                max = DH_GRP_MAX;
-       } else {
-               debug("SSH2_MSG_KEX_DH_GEX_REQUEST sent");
 
+               debug("SSH2_MSG_KEX_DH_GEX_REQUEST_OLD(%u) sent", nbits);
+       } else {
                /* New GEX request */
                min = DH_GRP_MIN;
                max = DH_GRP_MAX;
@@ -66,6 +74,9 @@ kexgex_client(Kex *kex)
                packet_put_int(min);
                packet_put_int(nbits);
                packet_put_int(max);
+
+               debug("SSH2_MSG_KEX_DH_GEX_REQUEST(%u<%u<%u) sent",
+                   min, nbits, max);
        }
 #ifdef DEBUG_KEXDH
        fprintf(stderr, "\nmin = %d, nbits = %d, max = %d\n",
@@ -119,7 +130,7 @@ kexgex_client(Kex *kex)
        if (kex->verify_host_key(server_host_key) == -1)
                fatal("server_host_key verification failed");
 
-       /* DH paramter f, server public DH key */
+       /* DH parameter f, server public DH key */
        if ((dh_server_pub = BN_new()) == NULL)
                fatal("dh_server_pub == NULL");
        packet_get_bignum2(dh_server_pub);
@@ -140,13 +151,15 @@ kexgex_client(Kex *kex)
 
        klen = DH_size(dh);
        kbuf = xmalloc(klen);
-       kout = DH_compute_key(kbuf, dh_server_pub, dh);
+       if ((kout = DH_compute_key(kbuf, dh_server_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_client: BN_new failed");
-       BN_bin2bn(kbuf, kout, shared_secret);
+       if (BN_bin2bn(kbuf, kout, shared_secret) == NULL)
+               fatal("kexgex_client: BN_bin2bn failed");
        memset(kbuf, 0, klen);
        xfree(kbuf);
 
@@ -154,7 +167,8 @@ kexgex_client(Kex *kex)
                min = max = -1;
 
        /* calc and verify H */
-       hash = kexgex_hash(
+       kexgex_hash(
+           kex->evp_md,
            kex->client_version_string,
            kex->server_version_string,
            buffer_ptr(&kex->my), buffer_len(&kex->my),
@@ -164,25 +178,27 @@ kexgex_client(Kex *kex)
            dh->p, dh->g,
            dh->pub_key,
            dh_server_pub,
-           shared_secret
+           shared_secret,
+           &hash, &hashlen
        );
+
        /* have keys, free DH */
        DH_free(dh);
        xfree(server_host_key_blob);
        BN_clear_free(dh_server_pub);
 
-       if (key_verify(server_host_key, signature, slen, hash, 20) != 1)
+       if (key_verify(server_host_key, signature, slen, hash, hashlen) != 1)
                fatal("key_verify failed for server_host_key");
        key_free(server_host_key);
        xfree(signature);
 
        /* save session id */
        if (kex->session_id == NULL) {
-               kex->session_id_len = 20;
+               kex->session_id_len = hashlen;
                kex->session_id = xmalloc(kex->session_id_len);
                memcpy(kex->session_id, hash, kex->session_id_len);
        }
-       kex_derive_keys(kex, hash, shared_secret);
+       kex_derive_keys(kex, hash, hashlen, shared_secret);
        BN_clear_free(shared_secret);
 
        kex_finish(kex);