- jmc@cvs.openbsd.org 2010/01/13 12:48:34

[openssh.git] / kexdhc.c

diff --git a/kexdhc.c b/kexdhc.c
index fe6dc53f85912ccf291340358f75454db5302600..d384c8052b605d5fe934de3d628cd82929db67c0 100644 (file)
--- a/kexdhc.c
+++ b/kexdhc.c
@@ -1,3 +1,4 @@
+/* $OpenBSD: kexdhc.c,v 1.11 2006/11/06 21:25:28 markus Exp $ */
 /*
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
  *
@@ -23,10 +24,18 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: kexdhc.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"
@@ -41,10 +50,20 @@ kexdh_client(Kex *kex)
        Key *server_host_key;
        u_char *server_host_key_blob = NULL, *signature = NULL;
        u_char *kbuf, *hash;
-       u_int klen, kout, slen, sbloblen;
+       u_int klen, slen, sbloblen, hashlen;
+       int kout;
 
        /* generate and send 'e', client DH public key */
-       dh = dh_new_group1();
+       switch (kex->kex_type) {
+       case KEX_DH_GRP1_SHA1:
+               dh = dh_new_group1();
+               break;
+       case KEX_DH_GRP14_SHA1:
+               dh = dh_new_group14();
+               break;
+       default:
+               fatal("%s: Unexpected KEX type %d", __func__, kex->kex_type);
+       }
        dh_gen_key(dh, kex->we_need * 8);
        packet_start(SSH2_MSG_KEXDH_INIT);
        packet_put_bignum2(dh->pub_key);
@@ -73,7 +92,7 @@ kexdh_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);
@@ -94,18 +113,20 @@ kexdh_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("kexdh_client: BN_new failed");
-       BN_bin2bn(kbuf, kout, shared_secret);
+       if (BN_bin2bn(kbuf, kout, shared_secret) == NULL)
+               fatal("kexdh_client: BN_bin2bn failed");
        memset(kbuf, 0, klen);
        xfree(kbuf);
 
        /* calc and verify H */
-       hash = kex_dh_hash(
+       kex_dh_hash(
            kex->client_version_string,
            kex->server_version_string,
            buffer_ptr(&kex->my), buffer_len(&kex->my),
@@ -113,25 +134,26 @@ kexdh_client(Kex *kex)
            server_host_key_blob, sbloblen,
            dh->pub_key,
            dh_server_pub,
-           shared_secret
+           shared_secret,
+           &hash, &hashlen
        );
        xfree(server_host_key_blob);
        BN_clear_free(dh_server_pub);
        DH_free(dh);
 
-       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);
 }