Attachment 230 Details for Bug 387 – fix

[patch] fix

U (text/plain), 43.84 KB, created by Markus Friedl on 2003-02-17 01:41:00 AEDT

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Creator: Markus Friedl

Created: 2003-02-17 01:41:00 AEDT

Size: 43.84 KB

patch

obsolete

>Index: kex.c
>===================================================================
>RCS file: /cvs/src/usr.bin/ssh/kex.c,v
>retrieving revision 1.53
>diff -u -r1.53 kex.c
>--- kex.c	2 Feb 2003 10:56:08 -0000	1.53
>+++ kex.c	16 Feb 2003 14:37:13 -0000
>@@ -44,11 +44,6 @@
> 
> #define KEX_COOKIE_LEN	16
> 
>-/* Use privilege separation for sshd */
>-int use_privsep;
>-struct monitor *pmonitor;
>-
>-
> /* prototype */
> static void kex_kexinit_finish(Kex *);
> static void kex_choose_conf(Kex *);
>@@ -237,14 +232,10 @@
> 
> 	kex_choose_conf(kex);
> 
>-	switch (kex->kex_type) {
>-	case DH_GRP1_SHA1:
>-		kexdh(kex);
>-		break;
>-	case DH_GEX_SHA1:
>-		kexgex(kex);
>-		break;
>-	default:
>+	if (kex->kex_type >= 0 && kex->kex_type < KEX_MAX &&
>+	    kex->kex[kex->kex_type] != NULL) {
>+		(kex->kex[kex->kex_type])(kex);
>+	} else {
> 		fatal("Unsupported key exchange %d", kex->kex_type);
> 	}
> }
>@@ -301,9 +292,9 @@
> 	if (k->name == NULL)
> 		fatal("no kex alg");
> 	if (strcmp(k->name, KEX_DH1) == 0) {
>-		k->kex_type = DH_GRP1_SHA1;
>+		k->kex_type = KEX_DH_GRP1_SHA1;
> 	} else if (strcmp(k->name, KEX_DHGEX) == 0) {
>-		k->kex_type = DH_GEX_SHA1;
>+		k->kex_type = KEX_DH_GEX_SHA1;
> 	} else
> 		fatal("bad kex alg %s", k->name);
> }
>Index: kex.h
>===================================================================
>RCS file: /cvs/src/usr.bin/ssh/kex.h,v
>retrieving revision 1.32
>diff -u -r1.32 kex.h
>--- kex.h	9 Sep 2002 14:54:14 -0000	1.32
>+++ kex.h	16 Feb 2003 14:37:13 -0000
>@@ -55,8 +55,9 @@
> };
> 
> enum kex_exchange {
>-	DH_GRP1_SHA1,
>-	DH_GEX_SHA1
>+	KEX_DH_GRP1_SHA1,
>+	KEX_DH_GEX_SHA1,
>+	KEX_MAX
> };
> 
> #define KEX_INIT_SENT	0x0001
>@@ -112,6 +113,7 @@
> 	int	(*verify_host_key)(Key *);
> 	Key	*(*load_host_key)(int);
> 	int	(*host_key_index)(Key *);
>+	void	(*kex[KEX_MAX])(Kex *);
> };
> 
> Kex	*kex_setup(char *[PROPOSAL_MAX]);
>@@ -121,10 +123,19 @@
> void	 kex_input_kexinit(int, u_int32_t, void *);
> void	 kex_derive_keys(Kex *, u_char *, BIGNUM *);
> 
>-void	 kexdh(Kex *);
>-void	 kexgex(Kex *);
>-
> Newkeys *kex_get_newkeys(int);
>+
>+void	 kexdh_client(Kex *);
>+void	 kexdh_server(Kex *);
>+void	 kexgex_client(Kex *);
>+void	 kexgex_server(Kex *);
>+
>+u_char *
>+kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int,
>+    BIGNUM *, BIGNUM *, BIGNUM *);
>+u_char *
>+kexgex_hash(char *, char *, char *, int, char *, int, u_char *, int,
>+    int, int, int, BIGNUM *, BIGNUM *, BIGNUM *, BIGNUM *, BIGNUM *);
> 
> #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH)
> void	dump_digest(char *, u_char *, int);
>Index: kexdh.c
>===================================================================
>RCS file: /cvs/src/usr.bin/ssh/kexdh.c,v
>retrieving revision 1.18
>diff -u -r1.18 kexdh.c
>--- kexdh.c	18 Mar 2002 17:50:31 -0000	1.18
>+++ kexdh.c	16 Feb 2003 14:37:13 -0000
>@@ -25,21 +25,13 @@
> #include "includes.h"
> RCSID("$OpenBSD: kexdh.c,v 1.18 2002/03/18 17:50:31 provos Exp $");
> 
>-#include <openssl/crypto.h>
>-#include <openssl/bn.h>
>+#include <openssl/evp.h>
> 
>-#include "xmalloc.h"
> #include "buffer.h"
> #include "bufaux.h"
>-#include "key.h"
>-#include "kex.h"
>-#include "log.h"
>-#include "packet.h"
>-#include "dh.h"
> #include "ssh2.h"
>-#include "monitor_wrap.h"
> 
>-static u_char *
>+u_char *
> kex_dh_hash(
>     char *client_version_string,
>     char *server_version_string,
>@@ -85,223 +77,4 @@
> 	dump_digest("hash", digest, EVP_MD_size(evp_md));
> #endif
> 	return digest;
>-}
>-
>-/* client */
>-
>-static void
>-kexdh_client(Kex *kex)
>-{
>-	BIGNUM *dh_server_pub = NULL, *shared_secret = NULL;
>-	DH *dh;
>-	Key *server_host_key;
>-	u_char *server_host_key_blob = NULL, *signature = NULL;
>-	u_char *kbuf, *hash;
>-	u_int klen, kout, slen, sbloblen;
>-
>-	/* generate and send 'e', client DH public key */
>-	dh = dh_new_group1();
>-	dh_gen_key(dh, kex->we_need * 8);
>-	packet_start(SSH2_MSG_KEXDH_INIT);
>-	packet_put_bignum2(dh->pub_key);
>-	packet_send();
>-
>-	debug("sending SSH2_MSG_KEXDH_INIT");
>-#ifdef DEBUG_KEXDH
>-	DHparams_print_fp(stderr, dh);
>-	fprintf(stderr, "pub= ");
>-	BN_print_fp(stderr, dh->pub_key);
>-	fprintf(stderr, "\n");
>-#endif
>-
>-	debug("expecting SSH2_MSG_KEXDH_REPLY");
>-	packet_read_expect(SSH2_MSG_KEXDH_REPLY);
>-
>-	/* key, cert */
>-	server_host_key_blob = packet_get_string(&sbloblen);
>-	server_host_key = key_from_blob(server_host_key_blob, sbloblen);
>-	if (server_host_key == NULL)
>-		fatal("cannot decode server_host_key_blob");
>-	if (server_host_key->type != kex->hostkey_type)
>-		fatal("type mismatch for decoded server_host_key_blob");
>-	if (kex->verify_host_key == NULL)
>-		fatal("cannot verify server_host_key");
>-	if (kex->verify_host_key(server_host_key) == -1)
>-		fatal("server_host_key verification failed");
>-
>-	/* DH paramter f, server public DH key */
>-	if ((dh_server_pub = BN_new()) == NULL)
>-		fatal("dh_server_pub == NULL");
>-	packet_get_bignum2(dh_server_pub);
>-
>-#ifdef DEBUG_KEXDH
>-	fprintf(stderr, "dh_server_pub= ");
>-	BN_print_fp(stderr, dh_server_pub);
>-	fprintf(stderr, "\n");
>-	debug("bits %d", BN_num_bits(dh_server_pub));
>-#endif
>-
>-	/* signed H */
>-	signature = packet_get_string(&slen);
>-	packet_check_eom();
>-
>-	if (!dh_pub_is_valid(dh, dh_server_pub))
>-		packet_disconnect("bad server public DH value");
>-
>-	klen = DH_size(dh);
>-	kbuf = xmalloc(klen);
>-	kout = DH_compute_key(kbuf, dh_server_pub, dh);
>-#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);
>-	memset(kbuf, 0, klen);
>-	xfree(kbuf);
>-
>-	/* calc and verify H */
>-	hash = kex_dh_hash(
>-	    kex->client_version_string,
>-	    kex->server_version_string,
>-	    buffer_ptr(&kex->my), buffer_len(&kex->my),
>-	    buffer_ptr(&kex->peer), buffer_len(&kex->peer),
>-	    server_host_key_blob, sbloblen,
>-	    dh->pub_key,
>-	    dh_server_pub,
>-	    shared_secret
>-	);
>-	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)
>-		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 = xmalloc(kex->session_id_len);
>-		memcpy(kex->session_id, hash, kex->session_id_len);
>-	}
>-
>-	kex_derive_keys(kex, hash, shared_secret);
>-	BN_clear_free(shared_secret);
>-	kex_finish(kex);
>-}
>-
>-/* server */
>-
>-static void
>-kexdh_server(Kex *kex)
>-{
>-	BIGNUM *shared_secret = NULL, *dh_client_pub = NULL;
>-	DH *dh;
>-	Key *server_host_key;
>-	u_char *kbuf, *hash, *signature = NULL, *server_host_key_blob = NULL;
>-	u_int sbloblen, klen, kout;
>-	u_int slen;
>-
>-	/* generate server DH public key */
>-	dh = dh_new_group1();
>-	dh_gen_key(dh, kex->we_need * 8);
>-
>-	debug("expecting SSH2_MSG_KEXDH_INIT");
>-	packet_read_expect(SSH2_MSG_KEXDH_INIT);
>-
>-	if (kex->load_host_key == NULL)
>-		fatal("Cannot load hostkey");
>-	server_host_key = kex->load_host_key(kex->hostkey_type);
>-	if (server_host_key == NULL)
>-		fatal("Unsupported hostkey type %d", kex->hostkey_type);
>-
>-	/* key, cert */
>-	if ((dh_client_pub = BN_new()) == NULL)
>-		fatal("dh_client_pub == NULL");
>-	packet_get_bignum2(dh_client_pub);
>-	packet_check_eom();
>-
>-#ifdef DEBUG_KEXDH
>-	fprintf(stderr, "dh_client_pub= ");
>-	BN_print_fp(stderr, dh_client_pub);
>-	fprintf(stderr, "\n");
>-	debug("bits %d", BN_num_bits(dh_client_pub));
>-#endif
>-
>-#ifdef DEBUG_KEXDH
>-	DHparams_print_fp(stderr, dh);
>-	fprintf(stderr, "pub= ");
>-	BN_print_fp(stderr, dh->pub_key);
>-	fprintf(stderr, "\n");
>-#endif
>-	if (!dh_pub_is_valid(dh, dh_client_pub))
>-		packet_disconnect("bad client public DH value");
>-
>-	klen = DH_size(dh);
>-	kbuf = xmalloc(klen);
>-	kout = DH_compute_key(kbuf, dh_client_pub, dh);
>-#ifdef DEBUG_KEXDH
>-	dump_digest("shared secret", kbuf, kout);
>-#endif
>-	if ((shared_secret = BN_new()) == NULL)
>-		fatal("kexdh_server: BN_new failed");
>-	BN_bin2bn(kbuf, kout, shared_secret);
>-	memset(kbuf, 0, klen);
>-	xfree(kbuf);
>-
>-	key_to_blob(server_host_key, &server_host_key_blob, &sbloblen);
>-
>-	/* calc H */
>-	hash = kex_dh_hash(
>-	    kex->client_version_string,
>-	    kex->server_version_string,
>-	    buffer_ptr(&kex->peer), buffer_len(&kex->peer),
>-	    buffer_ptr(&kex->my), buffer_len(&kex->my),
>-	    server_host_key_blob, sbloblen,
>-	    dh_client_pub,
>-	    dh->pub_key,
>-	    shared_secret
>-	);
>-	BN_clear_free(dh_client_pub);
>-
>-	/* save session id := H */
>-	/* XXX hashlen depends on KEX */
>-	if (kex->session_id == NULL) {
>-		kex->session_id_len = 20;
>-		kex->session_id = xmalloc(kex->session_id_len);
>-		memcpy(kex->session_id, hash, kex->session_id_len);
>-	}
>-
>-	/* sign H */
>-	/* XXX hashlen depends on KEX */
>-	PRIVSEP(key_sign(server_host_key, &signature, &slen, hash, 20));
>-
>-	/* destroy_sensitive_data(); */
>-
>-	/* send server hostkey, DH pubkey 'f' and singed H */
>-	packet_start(SSH2_MSG_KEXDH_REPLY);
>-	packet_put_string(server_host_key_blob, sbloblen);
>-	packet_put_bignum2(dh->pub_key);	/* f */
>-	packet_put_string(signature, slen);
>-	packet_send();
>-
>-	xfree(signature);
>-	xfree(server_host_key_blob);
>-	/* have keys, free DH */
>-	DH_free(dh);
>-
>-	kex_derive_keys(kex, hash, shared_secret);
>-	BN_clear_free(shared_secret);
>-	kex_finish(kex);
>-}
>-
>-void
>-kexdh(Kex *kex)
>-{
>-	if (kex->server)
>-		kexdh_server(kex);
>-	else
>-		kexdh_client(kex);
> }
>Index: kexdhc.c
>===================================================================
>RCS file: kexdhc.c
>diff -N kexdhc.c
>--- /dev/null	1 Jan 1970 00:00:00 -0000
>+++ kexdhc.c	16 Feb 2003 14:37:13 -0000
>@@ -0,0 +1,137 @@
>+/*
>+ * Copyright (c) 2001 Markus Friedl.  All rights reserved.
>+ *
>+ * Redistribution and use in source and binary forms, with or without
>+ * modification, are permitted provided that the following conditions
>+ * are met:
>+ * 1. Redistributions of source code must retain the above copyright
>+ *    notice, this list of conditions and the following disclaimer.
>+ * 2. Redistributions in binary form must reproduce the above copyright
>+ *    notice, this list of conditions and the following disclaimer in the
>+ *    documentation and/or other materials provided with the distribution.
>+ *
>+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
>+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
>+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
>+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
>+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
>+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
>+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
>+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
>+ * (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: kexdh.c,v 1.18 2002/03/18 17:50:31 provos Exp $");
>+
>+#include "xmalloc.h"
>+#include "key.h"
>+#include "kex.h"
>+#include "log.h"
>+#include "packet.h"
>+#include "dh.h"
>+#include "ssh2.h"
>+
>+void
>+kexdh_client(Kex *kex)
>+{
>+	BIGNUM *dh_server_pub = NULL, *shared_secret = NULL;
>+	DH *dh;
>+	Key *server_host_key;
>+	u_char *server_host_key_blob = NULL, *signature = NULL;
>+	u_char *kbuf, *hash;
>+	u_int klen, kout, slen, sbloblen;
>+
>+	/* generate and send 'e', client DH public key */
>+	dh = dh_new_group1();
>+	dh_gen_key(dh, kex->we_need * 8);
>+	packet_start(SSH2_MSG_KEXDH_INIT);
>+	packet_put_bignum2(dh->pub_key);
>+	packet_send();
>+
>+	debug("sending SSH2_MSG_KEXDH_INIT");
>+#ifdef DEBUG_KEXDH
>+	DHparams_print_fp(stderr, dh);
>+	fprintf(stderr, "pub= ");
>+	BN_print_fp(stderr, dh->pub_key);
>+	fprintf(stderr, "\n");
>+#endif
>+
>+	debug("expecting SSH2_MSG_KEXDH_REPLY");
>+	packet_read_expect(SSH2_MSG_KEXDH_REPLY);
>+
>+	/* key, cert */
>+	server_host_key_blob = packet_get_string(&sbloblen);
>+	server_host_key = key_from_blob(server_host_key_blob, sbloblen);
>+	if (server_host_key == NULL)
>+		fatal("cannot decode server_host_key_blob");
>+	if (server_host_key->type != kex->hostkey_type)
>+		fatal("type mismatch for decoded server_host_key_blob");
>+	if (kex->verify_host_key == NULL)
>+		fatal("cannot verify server_host_key");
>+	if (kex->verify_host_key(server_host_key) == -1)
>+		fatal("server_host_key verification failed");
>+
>+	/* DH paramter f, server public DH key */
>+	if ((dh_server_pub = BN_new()) == NULL)
>+		fatal("dh_server_pub == NULL");
>+	packet_get_bignum2(dh_server_pub);
>+
>+#ifdef DEBUG_KEXDH
>+	fprintf(stderr, "dh_server_pub= ");
>+	BN_print_fp(stderr, dh_server_pub);
>+	fprintf(stderr, "\n");
>+	debug("bits %d", BN_num_bits(dh_server_pub));
>+#endif
>+
>+	/* signed H */
>+	signature = packet_get_string(&slen);
>+	packet_check_eom();
>+
>+	if (!dh_pub_is_valid(dh, dh_server_pub))
>+		packet_disconnect("bad server public DH value");
>+
>+	klen = DH_size(dh);
>+	kbuf = xmalloc(klen);
>+	kout = DH_compute_key(kbuf, dh_server_pub, dh);
>+#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);
>+	memset(kbuf, 0, klen);
>+	xfree(kbuf);
>+
>+	/* calc and verify H */
>+	hash = kex_dh_hash(
>+	    kex->client_version_string,
>+	    kex->server_version_string,
>+	    buffer_ptr(&kex->my), buffer_len(&kex->my),
>+	    buffer_ptr(&kex->peer), buffer_len(&kex->peer),
>+	    server_host_key_blob, sbloblen,
>+	    dh->pub_key,
>+	    dh_server_pub,
>+	    shared_secret
>+	);
>+	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)
>+		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 = xmalloc(kex->session_id_len);
>+		memcpy(kex->session_id, hash, kex->session_id_len);
>+	}
>+
>+	kex_derive_keys(kex, hash, shared_secret);
>+	BN_clear_free(shared_secret);
>+	kex_finish(kex);
>+}
>Index: kexdhs.c
>===================================================================
>RCS file: kexdhs.c
>diff -N kexdhs.c
>--- /dev/null	1 Jan 1970 00:00:00 -0000
>+++ kexdhs.c	16 Feb 2003 14:37:13 -0000
>@@ -0,0 +1,138 @@
>+/*
>+ * Copyright (c) 2001 Markus Friedl.  All rights reserved.
>+ *
>+ * Redistribution and use in source and binary forms, with or without
>+ * modification, are permitted provided that the following conditions
>+ * are met:
>+ * 1. Redistributions of source code must retain the above copyright
>+ *    notice, this list of conditions and the following disclaimer.
>+ * 2. Redistributions in binary form must reproduce the above copyright
>+ *    notice, this list of conditions and the following disclaimer in the
>+ *    documentation and/or other materials provided with the distribution.
>+ *
>+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
>+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
>+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
>+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
>+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
>+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
>+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
>+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
>+ * (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: kexdh.c,v 1.18 2002/03/18 17:50:31 provos Exp $");
>+
>+#include "xmalloc.h"
>+#include "key.h"
>+#include "kex.h"
>+#include "log.h"
>+#include "packet.h"
>+#include "dh.h"
>+#include "ssh2.h"
>+#include "monitor_wrap.h"
>+
>+void
>+kexdh_server(Kex *kex)
>+{
>+	BIGNUM *shared_secret = NULL, *dh_client_pub = NULL;
>+	DH *dh;
>+	Key *server_host_key;
>+	u_char *kbuf, *hash, *signature = NULL, *server_host_key_blob = NULL;
>+	u_int sbloblen, klen, kout;
>+	u_int slen;
>+
>+	/* generate server DH public key */
>+	dh = dh_new_group1();
>+	dh_gen_key(dh, kex->we_need * 8);
>+
>+	debug("expecting SSH2_MSG_KEXDH_INIT");
>+	packet_read_expect(SSH2_MSG_KEXDH_INIT);
>+
>+	if (kex->load_host_key == NULL)
>+		fatal("Cannot load hostkey");
>+	server_host_key = kex->load_host_key(kex->hostkey_type);
>+	if (server_host_key == NULL)
>+		fatal("Unsupported hostkey type %d", kex->hostkey_type);
>+
>+	/* key, cert */
>+	if ((dh_client_pub = BN_new()) == NULL)
>+		fatal("dh_client_pub == NULL");
>+	packet_get_bignum2(dh_client_pub);
>+	packet_check_eom();
>+
>+#ifdef DEBUG_KEXDH
>+	fprintf(stderr, "dh_client_pub= ");
>+	BN_print_fp(stderr, dh_client_pub);
>+	fprintf(stderr, "\n");
>+	debug("bits %d", BN_num_bits(dh_client_pub));
>+#endif
>+
>+#ifdef DEBUG_KEXDH
>+	DHparams_print_fp(stderr, dh);
>+	fprintf(stderr, "pub= ");
>+	BN_print_fp(stderr, dh->pub_key);
>+	fprintf(stderr, "\n");
>+#endif
>+	if (!dh_pub_is_valid(dh, dh_client_pub))
>+		packet_disconnect("bad client public DH value");
>+
>+	klen = DH_size(dh);
>+	kbuf = xmalloc(klen);
>+	kout = DH_compute_key(kbuf, dh_client_pub, dh);
>+#ifdef DEBUG_KEXDH
>+	dump_digest("shared secret", kbuf, kout);
>+#endif
>+	if ((shared_secret = BN_new()) == NULL)
>+		fatal("kexdh_server: BN_new failed");
>+	BN_bin2bn(kbuf, kout, shared_secret);
>+	memset(kbuf, 0, klen);
>+	xfree(kbuf);
>+
>+	key_to_blob(server_host_key, &server_host_key_blob, &sbloblen);
>+
>+	/* calc H */
>+	hash = kex_dh_hash(
>+	    kex->client_version_string,
>+	    kex->server_version_string,
>+	    buffer_ptr(&kex->peer), buffer_len(&kex->peer),
>+	    buffer_ptr(&kex->my), buffer_len(&kex->my),
>+	    server_host_key_blob, sbloblen,
>+	    dh_client_pub,
>+	    dh->pub_key,
>+	    shared_secret
>+	);
>+	BN_clear_free(dh_client_pub);
>+
>+	/* save session id := H */
>+	/* XXX hashlen depends on KEX */
>+	if (kex->session_id == NULL) {
>+		kex->session_id_len = 20;
>+		kex->session_id = xmalloc(kex->session_id_len);
>+		memcpy(kex->session_id, hash, kex->session_id_len);
>+	}
>+
>+	/* sign H */
>+	/* XXX hashlen depends on KEX */
>+	PRIVSEP(key_sign(server_host_key, &signature, &slen, hash, 20));
>+
>+	/* destroy_sensitive_data(); */
>+
>+	/* send server hostkey, DH pubkey 'f' and singed H */
>+	packet_start(SSH2_MSG_KEXDH_REPLY);
>+	packet_put_string(server_host_key_blob, sbloblen);
>+	packet_put_bignum2(dh->pub_key);	/* f */
>+	packet_put_string(signature, slen);
>+	packet_send();
>+
>+	xfree(signature);
>+	xfree(server_host_key_blob);
>+	/* have keys, free DH */
>+	DH_free(dh);
>+
>+	kex_derive_keys(kex, hash, shared_secret);
>+	BN_clear_free(shared_secret);
>+	kex_finish(kex);
>+}
>Index: kexgex.c
>===================================================================
>RCS file: /cvs/src/usr.bin/ssh/kexgex.c,v
>retrieving revision 1.22
>diff -u -r1.22 kexgex.c
>--- kexgex.c	24 Mar 2002 17:27:03 -0000	1.22
>+++ kexgex.c	16 Feb 2003 14:37:13 -0000
>@@ -26,21 +26,14 @@
> #include "includes.h"
> RCSID("$OpenBSD: kexgex.c,v 1.22 2002/03/24 17:27:03 stevesk Exp $");
> 
>-#include <openssl/bn.h>
>+#include <openssl/evp.h>
> 
>-#include "xmalloc.h"
> #include "buffer.h"
> #include "bufaux.h"
>-#include "key.h"
> #include "kex.h"
>-#include "log.h"
>-#include "packet.h"
>-#include "dh.h"
> #include "ssh2.h"
>-#include "compat.h"
>-#include "monitor_wrap.h"
> 
>-static u_char *
>+u_char *
> kexgex_hash(
>     char *client_version_string,
>     char *server_version_string,
>@@ -96,319 +89,4 @@
> 	dump_digest("hash", digest, EVP_MD_size(evp_md));
> #endif
> 	return digest;
>-}
>-
>-/* client */
>-
>-static void
>-kexgex_client(Kex *kex)
>-{
>-	BIGNUM *dh_server_pub = NULL, *shared_secret = NULL;
>-	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;
>-	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");
>-
>-		/* New GEX request */
>-		min = DH_GRP_MIN;
>-		max = DH_GRP_MAX;
>-		packet_start(SSH2_MSG_KEX_DH_GEX_REQUEST);
>-		packet_put_int(min);
>-		packet_put_int(nbits);
>-		packet_put_int(max);
>-	}
>-#ifdef DEBUG_KEXDH
>-	fprintf(stderr, "\nmin = %d, nbits = %d, max = %d\n",
>-	    min, nbits, max);
>-#endif
>-	packet_send();
>-
>-	debug("expecting SSH2_MSG_KEX_DH_GEX_GROUP");
>-	packet_read_expect(SSH2_MSG_KEX_DH_GEX_GROUP);
>-
>-	if ((p = BN_new()) == NULL)
>-		fatal("BN_new");
>-	packet_get_bignum2(p);
>-	if ((g = BN_new()) == NULL)
>-		fatal("BN_new");
>-	packet_get_bignum2(g);
>-	packet_check_eom();
>-
>-	if (BN_num_bits(p) < min || BN_num_bits(p) > max)
>-		fatal("DH_GEX group out of range: %d !< %d !< %d",
>-		    min, BN_num_bits(p), max);
>-
>-	dh = dh_new_group(g, p);
>-	dh_gen_key(dh, kex->we_need * 8);
>-
>-#ifdef DEBUG_KEXDH
>-	DHparams_print_fp(stderr, dh);
>-	fprintf(stderr, "pub= ");
>-	BN_print_fp(stderr, dh->pub_key);
>-	fprintf(stderr, "\n");
>-#endif
>-
>-	debug("SSH2_MSG_KEX_DH_GEX_INIT sent");
>-	/* generate and send 'e', client DH public key */
>-	packet_start(SSH2_MSG_KEX_DH_GEX_INIT);
>-	packet_put_bignum2(dh->pub_key);
>-	packet_send();
>-
>-	debug("expecting SSH2_MSG_KEX_DH_GEX_REPLY");
>-	packet_read_expect(SSH2_MSG_KEX_DH_GEX_REPLY);
>-
>-	/* key, cert */
>-	server_host_key_blob = packet_get_string(&sbloblen);
>-	server_host_key = key_from_blob(server_host_key_blob, sbloblen);
>-	if (server_host_key == NULL)
>-		fatal("cannot decode server_host_key_blob");
>-	if (server_host_key->type != kex->hostkey_type)
>-		fatal("type mismatch for decoded server_host_key_blob");
>-	if (kex->verify_host_key == NULL)
>-		fatal("cannot verify server_host_key");
>-	if (kex->verify_host_key(server_host_key) == -1)
>-		fatal("server_host_key verification failed");
>-
>-	/* DH paramter f, server public DH key */
>-	if ((dh_server_pub = BN_new()) == NULL)
>-		fatal("dh_server_pub == NULL");
>-	packet_get_bignum2(dh_server_pub);
>-
>-#ifdef DEBUG_KEXDH
>-	fprintf(stderr, "dh_server_pub= ");
>-	BN_print_fp(stderr, dh_server_pub);
>-	fprintf(stderr, "\n");
>-	debug("bits %d", BN_num_bits(dh_server_pub));
>-#endif
>-
>-	/* signed H */
>-	signature = packet_get_string(&slen);
>-	packet_check_eom();
>-
>-	if (!dh_pub_is_valid(dh, dh_server_pub))
>-		packet_disconnect("bad server public DH value");
>-
>-	klen = DH_size(dh);
>-	kbuf = xmalloc(klen);
>-	kout = DH_compute_key(kbuf, dh_server_pub, dh);
>-#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);
>-	memset(kbuf, 0, klen);
>-	xfree(kbuf);
>-
>-	if (datafellows & SSH_OLD_DHGEX)
>-		min = max = -1;
>-
>-	/* calc and verify H */
>-	hash = kexgex_hash(
>-	    kex->client_version_string,
>-	    kex->server_version_string,
>-	    buffer_ptr(&kex->my), buffer_len(&kex->my),
>-	    buffer_ptr(&kex->peer), buffer_len(&kex->peer),
>-	    server_host_key_blob, sbloblen,
>-	    min, nbits, max,
>-	    dh->p, dh->g,
>-	    dh->pub_key,
>-	    dh_server_pub,
>-	    shared_secret
>-	);
>-	/* 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)
>-		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 = xmalloc(kex->session_id_len);
>-		memcpy(kex->session_id, hash, kex->session_id_len);
>-	}
>-	kex_derive_keys(kex, hash, shared_secret);
>-	BN_clear_free(shared_secret);
>-
>-	kex_finish(kex);
>-}
>-
>-/* server */
>-
>-static void
>-kexgex_server(Kex *kex)
>-{
>-	BIGNUM *shared_secret = NULL, *dh_client_pub = NULL;
>-	Key *server_host_key;
>-	DH *dh;
>-	u_char *kbuf, *hash, *signature = NULL, *server_host_key_blob = NULL;
>-	u_int sbloblen, klen, kout, slen;
>-	int min = -1, max = -1, nbits = -1, type;
>-
>-	if (kex->load_host_key == NULL)
>-		fatal("Cannot load hostkey");
>-	server_host_key = kex->load_host_key(kex->hostkey_type);
>-	if (server_host_key == NULL)
>-		fatal("Unsupported hostkey type %d", kex->hostkey_type);
>-
>-	type = packet_read();
>-	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();
>-		min = MAX(DH_GRP_MIN, min);
>-		max = MIN(DH_GRP_MAX, max);
>-		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;
>-		/* unused for old GEX */
>-		break;
>-	default:
>-		fatal("protocol error during kex, no DH_GEX_REQUEST: %d", type);
>-	}
>-	packet_check_eom();
>-
>-	if (max < min || nbits < min || max < nbits)
>-		fatal("DH_GEX_REQUEST, bad parameters: %d !< %d !< %d",
>-		    min, nbits, max);
>-
>-	/* Contact privileged parent */
>-	dh = PRIVSEP(choose_dh(min, nbits, max));
>-	if (dh == NULL)
>-		packet_disconnect("Protocol error: no matching DH grp found");
>-
>-	debug("SSH2_MSG_KEX_DH_GEX_GROUP sent");
>-	packet_start(SSH2_MSG_KEX_DH_GEX_GROUP);
>-	packet_put_bignum2(dh->p);
>-	packet_put_bignum2(dh->g);
>-	packet_send();
>-
>-	/* flush */
>-	packet_write_wait();
>-
>-	/* Compute our exchange value in parallel with the client */
>-	dh_gen_key(dh, kex->we_need * 8);
>-
>-	debug("expecting SSH2_MSG_KEX_DH_GEX_INIT");
>-	packet_read_expect(SSH2_MSG_KEX_DH_GEX_INIT);
>-
>-	/* key, cert */
>-	if ((dh_client_pub = BN_new()) == NULL)
>-		fatal("dh_client_pub == NULL");
>-	packet_get_bignum2(dh_client_pub);
>-	packet_check_eom();
>-
>-#ifdef DEBUG_KEXDH
>-	fprintf(stderr, "dh_client_pub= ");
>-	BN_print_fp(stderr, dh_client_pub);
>-	fprintf(stderr, "\n");
>-	debug("bits %d", BN_num_bits(dh_client_pub));
>-#endif
>-
>-#ifdef DEBUG_KEXDH
>-	DHparams_print_fp(stderr, dh);
>-	fprintf(stderr, "pub= ");
>-	BN_print_fp(stderr, dh->pub_key);
>-	fprintf(stderr, "\n");
>-#endif
>-	if (!dh_pub_is_valid(dh, dh_client_pub))
>-		packet_disconnect("bad client public DH value");
>-
>-	klen = DH_size(dh);
>-	kbuf = xmalloc(klen);
>-	kout = DH_compute_key(kbuf, dh_client_pub, dh);
>-#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);
>-	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;
>-
>-	/* calc H */			/* XXX depends on 'kex' */
>-	hash = kexgex_hash(
>-	    kex->client_version_string,
>-	    kex->server_version_string,
>-	    buffer_ptr(&kex->peer), buffer_len(&kex->peer),
>-	    buffer_ptr(&kex->my), buffer_len(&kex->my),
>-	    server_host_key_blob, sbloblen,
>-	    min, nbits, max,
>-	    dh->p, dh->g,
>-	    dh_client_pub,
>-	    dh->pub_key,
>-	    shared_secret
>-	);
>-	BN_clear_free(dh_client_pub);
>-
>-	/* save session id := H */
>-	/* XXX hashlen depends on KEX */
>-	if (kex->session_id == NULL) {
>-		kex->session_id_len = 20;
>-		kex->session_id = xmalloc(kex->session_id_len);
>-		memcpy(kex->session_id, hash, kex->session_id_len);
>-	}
>-
>-	/* sign H */
>-	/* XXX hashlen depends on KEX */
>-	PRIVSEP(key_sign(server_host_key, &signature, &slen, hash, 20));
>-
>-	/* destroy_sensitive_data(); */
>-
>-	/* send server hostkey, DH pubkey 'f' and singed H */
>-	debug("SSH2_MSG_KEX_DH_GEX_REPLY sent");
>-	packet_start(SSH2_MSG_KEX_DH_GEX_REPLY);
>-	packet_put_string(server_host_key_blob, sbloblen);
>-	packet_put_bignum2(dh->pub_key);	/* f */
>-	packet_put_string(signature, slen);
>-	packet_send();
>-
>-	xfree(signature);
>-	xfree(server_host_key_blob);
>-	/* have keys, free DH */
>-	DH_free(dh);
>-
>-	kex_derive_keys(kex, hash, shared_secret);
>-	BN_clear_free(shared_secret);
>-
>-	kex_finish(kex);
>-}
>-
>-void
>-kexgex(Kex *kex)
>-{
>-	if (kex->server)
>-		kexgex_server(kex);
>-	else
>-		kexgex_client(kex);
> }
>Index: kexgexc.c
>===================================================================
>RCS file: kexgexc.c
>diff -N kexgexc.c
>--- /dev/null	1 Jan 1970 00:00:00 -0000
>+++ kexgexc.c	16 Feb 2003 14:37:13 -0000
>@@ -0,0 +1,189 @@
>+/*
>+ * Copyright (c) 2000 Niels Provos.  All rights reserved.
>+ * Copyright (c) 2001 Markus Friedl.  All rights reserved.
>+ *
>+ * Redistribution and use in source and binary forms, with or without
>+ * modification, are permitted provided that the following conditions
>+ * are met:
>+ * 1. Redistributions of source code must retain the above copyright
>+ *    notice, this list of conditions and the following disclaimer.
>+ * 2. Redistributions in binary form must reproduce the above copyright
>+ *    notice, this list of conditions and the following disclaimer in the
>+ *    documentation and/or other materials provided with the distribution.
>+ *
>+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
>+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
>+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
>+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
>+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
>+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
>+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
>+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
>+ * (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: kexgex.c,v 1.22 2002/03/24 17:27:03 stevesk Exp $");
>+
>+#include "xmalloc.h"
>+#include "key.h"
>+#include "kex.h"
>+#include "log.h"
>+#include "packet.h"
>+#include "dh.h"
>+#include "ssh2.h"
>+#include "compat.h"
>+
>+void
>+kexgex_client(Kex *kex)
>+{
>+	BIGNUM *dh_server_pub = NULL, *shared_secret = NULL;
>+	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;
>+	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");
>+
>+		/* New GEX request */
>+		min = DH_GRP_MIN;
>+		max = DH_GRP_MAX;
>+		packet_start(SSH2_MSG_KEX_DH_GEX_REQUEST);
>+		packet_put_int(min);
>+		packet_put_int(nbits);
>+		packet_put_int(max);
>+	}
>+#ifdef DEBUG_KEXDH
>+	fprintf(stderr, "\nmin = %d, nbits = %d, max = %d\n",
>+	    min, nbits, max);
>+#endif
>+	packet_send();
>+
>+	debug("expecting SSH2_MSG_KEX_DH_GEX_GROUP");
>+	packet_read_expect(SSH2_MSG_KEX_DH_GEX_GROUP);
>+
>+	if ((p = BN_new()) == NULL)
>+		fatal("BN_new");
>+	packet_get_bignum2(p);
>+	if ((g = BN_new()) == NULL)
>+		fatal("BN_new");
>+	packet_get_bignum2(g);
>+	packet_check_eom();
>+
>+	if (BN_num_bits(p) < min || BN_num_bits(p) > max)
>+		fatal("DH_GEX group out of range: %d !< %d !< %d",
>+		    min, BN_num_bits(p), max);
>+
>+	dh = dh_new_group(g, p);
>+	dh_gen_key(dh, kex->we_need * 8);
>+
>+#ifdef DEBUG_KEXDH
>+	DHparams_print_fp(stderr, dh);
>+	fprintf(stderr, "pub= ");
>+	BN_print_fp(stderr, dh->pub_key);
>+	fprintf(stderr, "\n");
>+#endif
>+
>+	debug("SSH2_MSG_KEX_DH_GEX_INIT sent");
>+	/* generate and send 'e', client DH public key */
>+	packet_start(SSH2_MSG_KEX_DH_GEX_INIT);
>+	packet_put_bignum2(dh->pub_key);
>+	packet_send();
>+
>+	debug("expecting SSH2_MSG_KEX_DH_GEX_REPLY");
>+	packet_read_expect(SSH2_MSG_KEX_DH_GEX_REPLY);
>+
>+	/* key, cert */
>+	server_host_key_blob = packet_get_string(&sbloblen);
>+	server_host_key = key_from_blob(server_host_key_blob, sbloblen);
>+	if (server_host_key == NULL)
>+		fatal("cannot decode server_host_key_blob");
>+	if (server_host_key->type != kex->hostkey_type)
>+		fatal("type mismatch for decoded server_host_key_blob");
>+	if (kex->verify_host_key == NULL)
>+		fatal("cannot verify server_host_key");
>+	if (kex->verify_host_key(server_host_key) == -1)
>+		fatal("server_host_key verification failed");
>+
>+	/* DH paramter f, server public DH key */
>+	if ((dh_server_pub = BN_new()) == NULL)
>+		fatal("dh_server_pub == NULL");
>+	packet_get_bignum2(dh_server_pub);
>+
>+#ifdef DEBUG_KEXDH
>+	fprintf(stderr, "dh_server_pub= ");
>+	BN_print_fp(stderr, dh_server_pub);
>+	fprintf(stderr, "\n");
>+	debug("bits %d", BN_num_bits(dh_server_pub));
>+#endif
>+
>+	/* signed H */
>+	signature = packet_get_string(&slen);
>+	packet_check_eom();
>+
>+	if (!dh_pub_is_valid(dh, dh_server_pub))
>+		packet_disconnect("bad server public DH value");
>+
>+	klen = DH_size(dh);
>+	kbuf = xmalloc(klen);
>+	kout = DH_compute_key(kbuf, dh_server_pub, dh);
>+#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);
>+	memset(kbuf, 0, klen);
>+	xfree(kbuf);
>+
>+	if (datafellows & SSH_OLD_DHGEX)
>+		min = max = -1;
>+
>+	/* calc and verify H */
>+	hash = kexgex_hash(
>+	    kex->client_version_string,
>+	    kex->server_version_string,
>+	    buffer_ptr(&kex->my), buffer_len(&kex->my),
>+	    buffer_ptr(&kex->peer), buffer_len(&kex->peer),
>+	    server_host_key_blob, sbloblen,
>+	    min, nbits, max,
>+	    dh->p, dh->g,
>+	    dh->pub_key,
>+	    dh_server_pub,
>+	    shared_secret
>+	);
>+	/* 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)
>+		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 = xmalloc(kex->session_id_len);
>+		memcpy(kex->session_id, hash, kex->session_id_len);
>+	}
>+	kex_derive_keys(kex, hash, shared_secret);
>+	BN_clear_free(shared_secret);
>+
>+	kex_finish(kex);
>+}
>Index: kexgexs.c
>===================================================================
>RCS file: kexgexs.c
>diff -N kexgexs.c
>--- /dev/null	1 Jan 1970 00:00:00 -0000
>+++ kexgexs.c	16 Feb 2003 14:37:13 -0000
>@@ -0,0 +1,186 @@
>+/*
>+ * Copyright (c) 2000 Niels Provos.  All rights reserved.
>+ * Copyright (c) 2001 Markus Friedl.  All rights reserved.
>+ *
>+ * Redistribution and use in source and binary forms, with or without
>+ * modification, are permitted provided that the following conditions
>+ * are met:
>+ * 1. Redistributions of source code must retain the above copyright
>+ *    notice, this list of conditions and the following disclaimer.
>+ * 2. Redistributions in binary form must reproduce the above copyright
>+ *    notice, this list of conditions and the following disclaimer in the
>+ *    documentation and/or other materials provided with the distribution.
>+ *
>+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
>+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
>+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
>+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
>+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
>+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
>+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
>+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
>+ * (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: kexgex.c,v 1.22 2002/03/24 17:27:03 stevesk Exp $");
>+
>+#include "xmalloc.h"
>+#include "key.h"
>+#include "kex.h"
>+#include "log.h"
>+#include "packet.h"
>+#include "dh.h"
>+#include "ssh2.h"
>+#include "compat.h"
>+#include "monitor_wrap.h"
>+
>+void
>+kexgex_server(Kex *kex)
>+{
>+	BIGNUM *shared_secret = NULL, *dh_client_pub = NULL;
>+	Key *server_host_key;
>+	DH *dh;
>+	u_char *kbuf, *hash, *signature = NULL, *server_host_key_blob = NULL;
>+	u_int sbloblen, klen, kout, slen;
>+	int min = -1, max = -1, nbits = -1, type;
>+
>+	if (kex->load_host_key == NULL)
>+		fatal("Cannot load hostkey");
>+	server_host_key = kex->load_host_key(kex->hostkey_type);
>+	if (server_host_key == NULL)
>+		fatal("Unsupported hostkey type %d", kex->hostkey_type);
>+
>+	type = packet_read();
>+	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();
>+		min = MAX(DH_GRP_MIN, min);
>+		max = MIN(DH_GRP_MAX, max);
>+		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;
>+		/* unused for old GEX */
>+		break;
>+	default:
>+		fatal("protocol error during kex, no DH_GEX_REQUEST: %d", type);
>+	}
>+	packet_check_eom();
>+
>+	if (max < min || nbits < min || max < nbits)
>+		fatal("DH_GEX_REQUEST, bad parameters: %d !< %d !< %d",
>+		    min, nbits, max);
>+
>+	/* Contact privileged parent */
>+	dh = PRIVSEP(choose_dh(min, nbits, max));
>+	if (dh == NULL)
>+		packet_disconnect("Protocol error: no matching DH grp found");
>+
>+	debug("SSH2_MSG_KEX_DH_GEX_GROUP sent");
>+	packet_start(SSH2_MSG_KEX_DH_GEX_GROUP);
>+	packet_put_bignum2(dh->p);
>+	packet_put_bignum2(dh->g);
>+	packet_send();
>+
>+	/* flush */
>+	packet_write_wait();
>+
>+	/* Compute our exchange value in parallel with the client */
>+	dh_gen_key(dh, kex->we_need * 8);
>+
>+	debug("expecting SSH2_MSG_KEX_DH_GEX_INIT");
>+	packet_read_expect(SSH2_MSG_KEX_DH_GEX_INIT);
>+
>+	/* key, cert */
>+	if ((dh_client_pub = BN_new()) == NULL)
>+		fatal("dh_client_pub == NULL");
>+	packet_get_bignum2(dh_client_pub);
>+	packet_check_eom();
>+
>+#ifdef DEBUG_KEXDH
>+	fprintf(stderr, "dh_client_pub= ");
>+	BN_print_fp(stderr, dh_client_pub);
>+	fprintf(stderr, "\n");
>+	debug("bits %d", BN_num_bits(dh_client_pub));
>+#endif
>+
>+#ifdef DEBUG_KEXDH
>+	DHparams_print_fp(stderr, dh);
>+	fprintf(stderr, "pub= ");
>+	BN_print_fp(stderr, dh->pub_key);
>+	fprintf(stderr, "\n");
>+#endif
>+	if (!dh_pub_is_valid(dh, dh_client_pub))
>+		packet_disconnect("bad client public DH value");
>+
>+	klen = DH_size(dh);
>+	kbuf = xmalloc(klen);
>+	kout = DH_compute_key(kbuf, dh_client_pub, dh);
>+#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);
>+	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;
>+
>+	/* calc H */			/* XXX depends on 'kex' */
>+	hash = kexgex_hash(
>+	    kex->client_version_string,
>+	    kex->server_version_string,
>+	    buffer_ptr(&kex->peer), buffer_len(&kex->peer),
>+	    buffer_ptr(&kex->my), buffer_len(&kex->my),
>+	    server_host_key_blob, sbloblen,
>+	    min, nbits, max,
>+	    dh->p, dh->g,
>+	    dh_client_pub,
>+	    dh->pub_key,
>+	    shared_secret
>+	);
>+	BN_clear_free(dh_client_pub);
>+
>+	/* save session id := H */
>+	/* XXX hashlen depends on KEX */
>+	if (kex->session_id == NULL) {
>+		kex->session_id_len = 20;
>+		kex->session_id = xmalloc(kex->session_id_len);
>+		memcpy(kex->session_id, hash, kex->session_id_len);
>+	}
>+
>+	/* sign H */
>+	/* XXX hashlen depends on KEX */
>+	PRIVSEP(key_sign(server_host_key, &signature, &slen, hash, 20));
>+
>+	/* destroy_sensitive_data(); */
>+
>+	/* send server hostkey, DH pubkey 'f' and singed H */
>+	debug("SSH2_MSG_KEX_DH_GEX_REPLY sent");
>+	packet_start(SSH2_MSG_KEX_DH_GEX_REPLY);
>+	packet_put_string(server_host_key_blob, sbloblen);
>+	packet_put_bignum2(dh->pub_key);	/* f */
>+	packet_put_string(signature, slen);
>+	packet_send();
>+
>+	xfree(signature);
>+	xfree(server_host_key_blob);
>+	/* have keys, free DH */
>+	DH_free(dh);
>+
>+	kex_derive_keys(kex, hash, shared_secret);
>+	BN_clear_free(shared_secret);
>+
>+	kex_finish(kex);
>+}
>Index: monitor.c
>===================================================================
>RCS file: /cvs/src/usr.bin/ssh/monitor.c,v
>retrieving revision 1.31
>diff -u -r1.31 monitor.c
>--- monitor.c	4 Feb 2003 09:33:22 -0000	1.31
>+++ monitor.c	16 Feb 2003 14:37:13 -0000
>@@ -791,6 +791,7 @@
> 
> 	buffer_clear(m);
> 	buffer_put_int(m, allowed);
>+	buffer_put_int(m, forced_command != NULL);
> 
> 	mm_append_debug(m);
> 
>@@ -1153,6 +1154,7 @@
> 	}
> 	buffer_clear(m);
> 	buffer_put_int(m, allowed);
>+	buffer_put_int(m, forced_command != NULL);
> 
> 	/* clear temporarily storage (used by generate challenge) */
> 	monitor_reset_key_state();
>Index: monitor_wrap.c
>===================================================================
>RCS file: /cvs/src/usr.bin/ssh/monitor_wrap.c,v
>retrieving revision 1.21
>diff -u -r1.21 monitor_wrap.c
>--- monitor_wrap.c	4 Feb 2003 09:33:22 -0000	1.21
>+++ monitor_wrap.c	16 Feb 2003 14:37:13 -0000
>@@ -34,6 +34,7 @@
> #include "dh.h"
> #include "kex.h"
> #include "auth.h"
>+#include "auth-options.h"
> #include "buffer.h"
> #include "bufaux.h"
> #include "packet.h"
>@@ -310,7 +311,7 @@
> 	Buffer m;
> 	u_char *blob;
> 	u_int len;
>-	int allowed = 0;
>+	int allowed = 0, have_forced = 0;
> 
> 	debug3("%s entering", __func__);
> 
>@@ -332,6 +333,14 @@
> 
> 	allowed = buffer_get_int(&m);
> 
>+	/* fake forced command */
>+	if (forced_command) {
>+		xfree(forced_command);
>+		forced_command = NULL;
>+	}
>+	have_forced = buffer_get_int(&m);
>+	forced_command = have_forced ? xstrdup("true") : NULL;
>+
> 	/* Send potential debug messages */
> 	mm_send_debug(&m);
> 
>@@ -834,7 +843,7 @@
> 	Key *key;
> 	u_char *blob;
> 	u_int blen;
>-	int allowed = 0;
>+	int allowed = 0, have_forced = 0;
> 
> 	debug3("%s entering", __func__);
> 
>@@ -845,6 +854,14 @@
> 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_RSAKEYALLOWED, &m);
> 
> 	allowed = buffer_get_int(&m);
>+
>+	/* fake forced command */
>+	if (forced_command) {
>+		xfree(forced_command);
>+		forced_command = NULL;
>+	}
>+	have_forced = buffer_get_int(&m);
>+	forced_command = have_forced ? xstrdup("true") : NULL;
> 
> 	if (allowed && rkey != NULL) {
> 		blob = buffer_get_string(&m, &blen);
>Index: ssh-keyscan.c
>===================================================================
>RCS file: /cvs/src/usr.bin/ssh/ssh-keyscan.c,v
>retrieving revision 1.40
>diff -u -r1.40 ssh-keyscan.c
>--- ssh-keyscan.c	6 Jul 2002 17:47:58 -0000	1.40
>+++ ssh-keyscan.c	16 Feb 2003 14:37:13 -0000
>@@ -335,6 +335,8 @@
> 	myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
> 	    "ssh-dss": "ssh-rsa";
> 	c->c_kex = kex_setup(myproposal);
>+	c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
>+	c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
> 	c->c_kex->verify_host_key = hostjump;
> 
> 	if (!(j = setjmp(kexjmp))) {
>Index: sshconnect2.c
>===================================================================
>RCS file: /cvs/src/usr.bin/ssh/sshconnect2.c,v
>retrieving revision 1.110
>diff -u -r1.110 sshconnect2.c
>--- sshconnect2.c	19 Dec 2002 00:07:02 -0000	1.110
>+++ sshconnect2.c	16 Feb 2003 14:37:13 -0000
>@@ -110,6 +110,8 @@
> 
> 	/* start key exchange */
> 	kex = kex_setup(myproposal);
>+	kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
>+	kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
> 	kex->client_version_string=client_version_string;
> 	kex->server_version_string=server_version_string;
> 	kex->verify_host_key=&verify_host_key_callback;
>Index: sshd.c
>===================================================================
>RCS file: /cvs/src/usr.bin/ssh/sshd.c,v
>retrieving revision 1.262
>diff -u -r1.262 sshd.c
>--- sshd.c	27 Jan 2003 17:06:31 -0000	1.262
>+++ sshd.c	16 Feb 2003 14:37:13 -0000
>@@ -189,8 +189,8 @@
> int startup_pipe;		/* in child */
> 
> /* variables used for privilege separation */
>-extern struct monitor *pmonitor;
>-extern int use_privsep;
>+int use_privsep;
>+struct monitor *pmonitor;
> 
> /* Prototypes for various functions defined later in this file. */
> void destroy_sensitive_data(void);
>@@ -1746,6 +1746,8 @@
> 
> 	/* start key exchange */
> 	kex = kex_setup(myproposal);
>+	kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
>+	kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
> 	kex->server = 1;
> 	kex->client_version_string=client_version_string;
> 	kex->server_version_string=server_version_string;
>Index: lib/Makefile
>===================================================================
>RCS file: /cvs/src/usr.bin/ssh/lib/Makefile,v
>retrieving revision 1.37
>diff -u -r1.37 Makefile
>--- lib/Makefile	12 Jan 2003 16:59:14 -0000	1.37
>+++ lib/Makefile	16 Feb 2003 14:37:13 -0000
>@@ -9,6 +9,7 @@
> 	rsa.c tildexpand.c ttymodes.c xmalloc.c atomicio.c \
> 	key.c dispatch.c kex.c mac.c uuencode.c misc.c \
> 	rijndael.c ssh-dss.c ssh-rsa.c dh.c kexdh.c kexgex.c \
>+	kexdhs.c kexdhc.c kexgexs.c kexgexc.c \
> 	scard.c monitor_wrap.c monitor_fdpass.c msg.c progressmeter.c
> 
> DEBUGLIBS= no

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