mirror of
git://anongit.mindrot.org/openssh.git
synced 2025-01-03 00:02:05 +00:00
- markus@cvs.openbsd.org 2003/02/16 17:09:57
[kex.c kexdh.c kexgex.c kex.h sshconnect2.c sshd.c ssh-keyscan.c]
split kex into client and server code, no need to link
server code into the client; ok provos@
This commit is contained in:
Damien Miller
parent
1587fb8a17
commit
8e7fb33523
@ -63,6 +63,10 @@
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- markus@cvs.openbsd.org 2003/02/12 21:39:50
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[crc32.c crc32.h]
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replace crc32.c with a BSD licensed version; noted by David Turner
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- markus@cvs.openbsd.org 2003/02/16 17:09:57
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[kex.c kexdh.c kexgex.c kex.h sshconnect2.c sshd.c ssh-keyscan.c]
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split kex into client and server code, no need to link
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server code into the client; ok provos@
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20030211
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- (djm) Cygwin needs libcrypt too. Patch from vinschen@redhat.com
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@ -1163,4 +1167,4 @@
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save auth method before monitor_reset_key_state(); bugzilla bug #284;
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ok provos@
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$Id: ChangeLog,v 1.2611 2003/02/24 01:02:12 djm Exp $
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$Id: ChangeLog,v 1.2612 2003/02/24 01:03:03 djm Exp $
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23
kex.c
23
kex.c
@ -23,7 +23,7 @@
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*/
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#include "includes.h"
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RCSID("$OpenBSD: kex.c,v 1.53 2003/02/02 10:56:08 markus Exp $");
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RCSID("$OpenBSD: kex.c,v 1.54 2003/02/16 17:09:57 markus Exp $");
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#include <openssl/crypto.h>
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@ -44,11 +44,6 @@ RCSID("$OpenBSD: kex.c,v 1.53 2003/02/02 10:56:08 markus Exp $");
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#define KEX_COOKIE_LEN 16
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/* Use privilege separation for sshd */
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int use_privsep;
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struct monitor *pmonitor;
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/* prototype */
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static void kex_kexinit_finish(Kex *);
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static void kex_choose_conf(Kex *);
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@ -237,14 +232,10 @@ kex_kexinit_finish(Kex *kex)
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kex_choose_conf(kex);
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switch (kex->kex_type) {
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case DH_GRP1_SHA1:
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kexdh(kex);
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break;
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case DH_GEX_SHA1:
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kexgex(kex);
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break;
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default:
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if (kex->kex_type >= 0 && kex->kex_type < KEX_MAX &&
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kex->kex[kex->kex_type] != NULL) {
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(kex->kex[kex->kex_type])(kex);
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} else {
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fatal("Unsupported key exchange %d", kex->kex_type);
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}
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}
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@ -301,9 +292,9 @@ choose_kex(Kex *k, char *client, char *server)
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if (k->name == NULL)
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fatal("no kex alg");
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if (strcmp(k->name, KEX_DH1) == 0) {
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k->kex_type = DH_GRP1_SHA1;
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k->kex_type = KEX_DH_GRP1_SHA1;
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} else if (strcmp(k->name, KEX_DHGEX) == 0) {
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k->kex_type = DH_GEX_SHA1;
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k->kex_type = KEX_DH_GEX_SHA1;
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} else
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fatal("bad kex alg %s", k->name);
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}
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23
kex.h
23
kex.h
@ -1,4 +1,4 @@
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/* $OpenBSD: kex.h,v 1.32 2002/09/09 14:54:14 markus Exp $ */
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/* $OpenBSD: kex.h,v 1.33 2003/02/16 17:09:57 markus Exp $ */
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/*
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* Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
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@ -55,8 +55,9 @@ enum kex_modes {
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};
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enum kex_exchange {
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DH_GRP1_SHA1,
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DH_GEX_SHA1
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KEX_DH_GRP1_SHA1,
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KEX_DH_GEX_SHA1,
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KEX_MAX
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};
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#define KEX_INIT_SENT 0x0001
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@ -112,6 +113,7 @@ struct Kex {
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int (*verify_host_key)(Key *);
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Key *(*load_host_key)(int);
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int (*host_key_index)(Key *);
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void (*kex[KEX_MAX])(Kex *);
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};
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Kex *kex_setup(char *[PROPOSAL_MAX]);
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@ -121,11 +123,20 @@ void kex_send_kexinit(Kex *);
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void kex_input_kexinit(int, u_int32_t, void *);
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void kex_derive_keys(Kex *, u_char *, BIGNUM *);
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void kexdh(Kex *);
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void kexgex(Kex *);
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Newkeys *kex_get_newkeys(int);
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void kexdh_client(Kex *);
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void kexdh_server(Kex *);
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void kexgex_client(Kex *);
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void kexgex_server(Kex *);
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u_char *
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kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int,
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BIGNUM *, BIGNUM *, BIGNUM *);
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u_char *
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kexgex_hash(char *, char *, char *, int, char *, int, u_char *, int,
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int, int, int, BIGNUM *, BIGNUM *, BIGNUM *, BIGNUM *, BIGNUM *);
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#if defined(DEBUG_KEX) || defined(DEBUG_KEXDH)
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void dump_digest(char *, u_char *, int);
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#endif
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234
kexdh.c
234
kexdh.c
@ -23,23 +23,16 @@
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*/
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#include "includes.h"
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RCSID("$OpenBSD: kexdh.c,v 1.18 2002/03/18 17:50:31 provos Exp $");
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RCSID("$OpenBSD: kexdh.c,v 1.19 2003/02/16 17:09:57 markus Exp $");
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#include <openssl/crypto.h>
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#include <openssl/bn.h>
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#include <openssl/evp.h>
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#include "xmalloc.h"
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#include "buffer.h"
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#include "bufaux.h"
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#include "key.h"
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#include "kex.h"
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#include "log.h"
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#include "packet.h"
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#include "dh.h"
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#include "ssh2.h"
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#include "monitor_wrap.h"
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#include "kex.h"
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static u_char *
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u_char *
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kex_dh_hash(
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char *client_version_string,
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char *server_version_string,
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@ -86,222 +79,3 @@ kex_dh_hash(
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#endif
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return digest;
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}
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/* client */
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static void
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kexdh_client(Kex *kex)
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{
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BIGNUM *dh_server_pub = NULL, *shared_secret = NULL;
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DH *dh;
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Key *server_host_key;
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u_char *server_host_key_blob = NULL, *signature = NULL;
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u_char *kbuf, *hash;
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u_int klen, kout, slen, sbloblen;
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/* generate and send 'e', client DH public key */
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dh = dh_new_group1();
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dh_gen_key(dh, kex->we_need * 8);
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packet_start(SSH2_MSG_KEXDH_INIT);
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packet_put_bignum2(dh->pub_key);
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packet_send();
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debug("sending SSH2_MSG_KEXDH_INIT");
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#ifdef DEBUG_KEXDH
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DHparams_print_fp(stderr, dh);
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fprintf(stderr, "pub= ");
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BN_print_fp(stderr, dh->pub_key);
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fprintf(stderr, "\n");
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#endif
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debug("expecting SSH2_MSG_KEXDH_REPLY");
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packet_read_expect(SSH2_MSG_KEXDH_REPLY);
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/* key, cert */
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server_host_key_blob = packet_get_string(&sbloblen);
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server_host_key = key_from_blob(server_host_key_blob, sbloblen);
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if (server_host_key == NULL)
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fatal("cannot decode server_host_key_blob");
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if (server_host_key->type != kex->hostkey_type)
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fatal("type mismatch for decoded server_host_key_blob");
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if (kex->verify_host_key == NULL)
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fatal("cannot verify server_host_key");
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if (kex->verify_host_key(server_host_key) == -1)
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fatal("server_host_key verification failed");
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/* DH paramter f, server public DH key */
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if ((dh_server_pub = BN_new()) == NULL)
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fatal("dh_server_pub == NULL");
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packet_get_bignum2(dh_server_pub);
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#ifdef DEBUG_KEXDH
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fprintf(stderr, "dh_server_pub= ");
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BN_print_fp(stderr, dh_server_pub);
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fprintf(stderr, "\n");
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debug("bits %d", BN_num_bits(dh_server_pub));
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#endif
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/* signed H */
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signature = packet_get_string(&slen);
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packet_check_eom();
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if (!dh_pub_is_valid(dh, dh_server_pub))
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packet_disconnect("bad server public DH value");
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klen = DH_size(dh);
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kbuf = xmalloc(klen);
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kout = DH_compute_key(kbuf, dh_server_pub, dh);
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#ifdef DEBUG_KEXDH
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dump_digest("shared secret", kbuf, kout);
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#endif
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if ((shared_secret = BN_new()) == NULL)
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fatal("kexdh_client: BN_new failed");
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BN_bin2bn(kbuf, kout, shared_secret);
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memset(kbuf, 0, klen);
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xfree(kbuf);
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/* calc and verify H */
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hash = kex_dh_hash(
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kex->client_version_string,
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kex->server_version_string,
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buffer_ptr(&kex->my), buffer_len(&kex->my),
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buffer_ptr(&kex->peer), buffer_len(&kex->peer),
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server_host_key_blob, sbloblen,
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dh->pub_key,
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dh_server_pub,
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shared_secret
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);
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xfree(server_host_key_blob);
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BN_clear_free(dh_server_pub);
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DH_free(dh);
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if (key_verify(server_host_key, signature, slen, hash, 20) != 1)
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fatal("key_verify failed for server_host_key");
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key_free(server_host_key);
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xfree(signature);
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/* save session id */
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if (kex->session_id == NULL) {
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kex->session_id_len = 20;
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kex->session_id = xmalloc(kex->session_id_len);
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memcpy(kex->session_id, hash, kex->session_id_len);
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}
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kex_derive_keys(kex, hash, shared_secret);
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BN_clear_free(shared_secret);
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kex_finish(kex);
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}
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/* server */
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static void
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kexdh_server(Kex *kex)
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{
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BIGNUM *shared_secret = NULL, *dh_client_pub = NULL;
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DH *dh;
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Key *server_host_key;
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u_char *kbuf, *hash, *signature = NULL, *server_host_key_blob = NULL;
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u_int sbloblen, klen, kout;
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u_int slen;
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/* generate server DH public key */
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dh = dh_new_group1();
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dh_gen_key(dh, kex->we_need * 8);
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debug("expecting SSH2_MSG_KEXDH_INIT");
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packet_read_expect(SSH2_MSG_KEXDH_INIT);
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if (kex->load_host_key == NULL)
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fatal("Cannot load hostkey");
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server_host_key = kex->load_host_key(kex->hostkey_type);
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if (server_host_key == NULL)
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fatal("Unsupported hostkey type %d", kex->hostkey_type);
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/* key, cert */
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if ((dh_client_pub = BN_new()) == NULL)
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fatal("dh_client_pub == NULL");
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packet_get_bignum2(dh_client_pub);
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packet_check_eom();
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#ifdef DEBUG_KEXDH
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fprintf(stderr, "dh_client_pub= ");
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BN_print_fp(stderr, dh_client_pub);
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fprintf(stderr, "\n");
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debug("bits %d", BN_num_bits(dh_client_pub));
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#endif
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#ifdef DEBUG_KEXDH
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DHparams_print_fp(stderr, dh);
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fprintf(stderr, "pub= ");
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BN_print_fp(stderr, dh->pub_key);
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fprintf(stderr, "\n");
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#endif
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if (!dh_pub_is_valid(dh, dh_client_pub))
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packet_disconnect("bad client public DH value");
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klen = DH_size(dh);
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kbuf = xmalloc(klen);
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kout = DH_compute_key(kbuf, dh_client_pub, dh);
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#ifdef DEBUG_KEXDH
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dump_digest("shared secret", kbuf, kout);
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#endif
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if ((shared_secret = BN_new()) == NULL)
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fatal("kexdh_server: BN_new failed");
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BN_bin2bn(kbuf, kout, shared_secret);
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memset(kbuf, 0, klen);
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xfree(kbuf);
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key_to_blob(server_host_key, &server_host_key_blob, &sbloblen);
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/* calc H */
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hash = kex_dh_hash(
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kex->client_version_string,
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kex->server_version_string,
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buffer_ptr(&kex->peer), buffer_len(&kex->peer),
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buffer_ptr(&kex->my), buffer_len(&kex->my),
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server_host_key_blob, sbloblen,
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dh_client_pub,
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dh->pub_key,
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shared_secret
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);
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BN_clear_free(dh_client_pub);
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/* save session id := H */
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/* XXX hashlen depends on KEX */
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if (kex->session_id == NULL) {
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kex->session_id_len = 20;
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kex->session_id = xmalloc(kex->session_id_len);
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memcpy(kex->session_id, hash, kex->session_id_len);
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}
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/* sign H */
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/* XXX hashlen depends on KEX */
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PRIVSEP(key_sign(server_host_key, &signature, &slen, hash, 20));
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/* destroy_sensitive_data(); */
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/* send server hostkey, DH pubkey 'f' and singed H */
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packet_start(SSH2_MSG_KEXDH_REPLY);
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packet_put_string(server_host_key_blob, sbloblen);
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packet_put_bignum2(dh->pub_key); /* f */
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packet_put_string(signature, slen);
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packet_send();
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xfree(signature);
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xfree(server_host_key_blob);
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/* have keys, free DH */
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DH_free(dh);
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kex_derive_keys(kex, hash, shared_secret);
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BN_clear_free(shared_secret);
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kex_finish(kex);
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}
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void
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kexdh(Kex *kex)
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{
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if (kex->server)
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kexdh_server(kex);
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else
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kexdh_client(kex);
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}
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137
kexdhc.c
Normal file
137
kexdhc.c
Normal file
@ -0,0 +1,137 @@
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/*
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* Copyright (c) 2001 Markus Friedl. All rights reserved.
|
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*
|
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* 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.
|
||||
*/
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#include "includes.h"
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RCSID("$OpenBSD: kexdhc.c,v 1.1 2003/02/16 17:09:57 markus Exp $");
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#include "xmalloc.h"
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#include "key.h"
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#include "kex.h"
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#include "log.h"
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#include "packet.h"
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#include "dh.h"
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#include "ssh2.h"
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|
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void
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kexdh_client(Kex *kex)
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{
|
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BIGNUM *dh_server_pub = NULL, *shared_secret = NULL;
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DH *dh;
|
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Key *server_host_key;
|
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u_char *server_host_key_blob = NULL, *signature = NULL;
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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);
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packet_put_bignum2(dh->pub_key);
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packet_send();
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|
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debug("sending SSH2_MSG_KEXDH_INIT");
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#ifdef DEBUG_KEXDH
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DHparams_print_fp(stderr, dh);
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fprintf(stderr, "pub= ");
|
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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);
|
||||
}
|
||||
138
kexdhs.c
Normal file
138
kexdhs.c
Normal file
@ -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: kexdhs.c,v 1.1 2003/02/16 17:09:57 markus 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);
|
||||
}
|
||||
328
kexgex.c
328
kexgex.c
@ -24,23 +24,16 @@
|
||||
*/
|
||||
|
||||
#include "includes.h"
|
||||
RCSID("$OpenBSD: kexgex.c,v 1.22 2002/03/24 17:27:03 stevesk Exp $");
|
||||
RCSID("$OpenBSD: kexgex.c,v 1.23 2003/02/16 17:09:57 markus 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,
|
||||
@ -97,318 +90,3 @@ kexgex_hash(
|
||||
#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);
|
||||
}
|
||||
|
||||
189
kexgexc.c
Normal file
189
kexgexc.c
Normal file
@ -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: kexgexc.c,v 1.1 2003/02/16 17:09:57 markus 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);
|
||||
}
|
||||
186
kexgexs.c
Normal file
186
kexgexs.c
Normal file
@ -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: kexgexs.c,v 1.1 2003/02/16 17:09:57 markus 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);
|
||||
}
|
||||
@ -7,7 +7,7 @@
|
||||
*/
|
||||
|
||||
#include "includes.h"
|
||||
RCSID("$OpenBSD: ssh-keyscan.c,v 1.40 2002/07/06 17:47:58 stevesk Exp $");
|
||||
RCSID("$OpenBSD: ssh-keyscan.c,v 1.41 2003/02/16 17:09:57 markus Exp $");
|
||||
|
||||
#include "openbsd-compat/sys-queue.h"
|
||||
|
||||
@ -354,6 +354,8 @@ keygrab_ssh2(con *c)
|
||||
myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
|
||||
"ssh-dss": "ssh-rsa";
|
||||
c->c_kex = kex_setup(myproposal);
|
||||
c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
|
||||
c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
|
||||
c->c_kex->verify_host_key = hostjump;
|
||||
|
||||
if (!(j = setjmp(kexjmp))) {
|
||||
|
||||
@ -23,7 +23,7 @@
|
||||
*/
|
||||
|
||||
#include "includes.h"
|
||||
RCSID("$OpenBSD: sshconnect2.c,v 1.110 2002/12/19 00:07:02 djm Exp $");
|
||||
RCSID("$OpenBSD: sshconnect2.c,v 1.111 2003/02/16 17:09:57 markus Exp $");
|
||||
|
||||
#include "ssh.h"
|
||||
#include "ssh2.h"
|
||||
@ -110,6 +110,8 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
|
||||
|
||||
/* start key exchange */
|
||||
kex = kex_setup(myproposal);
|
||||
kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
|
||||
kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
|
||||
kex->client_version_string=client_version_string;
|
||||
kex->server_version_string=server_version_string;
|
||||
kex->verify_host_key=&verify_host_key_callback;
|
||||
|
||||
8
sshd.c
8
sshd.c
@ -42,7 +42,7 @@
|
||||
*/
|
||||
|
||||
#include "includes.h"
|
||||
RCSID("$OpenBSD: sshd.c,v 1.262 2003/01/27 17:06:31 markus Exp $");
|
||||
RCSID("$OpenBSD: sshd.c,v 1.263 2003/02/16 17:09:57 markus Exp $");
|
||||
|
||||
#include <openssl/dh.h>
|
||||
#include <openssl/bn.h>
|
||||
@ -202,8 +202,8 @@ int *startup_pipes = NULL;
|
||||
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);
|
||||
@ -1814,6 +1814,8 @@ do_ssh2_kex(void)
|
||||
|
||||
/* 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;
|
||||
|
||||
Loading…
Reference in New Issue
Block a user