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Damien Miller686c7d92014-05-15 14:37:03 +10001/* $OpenBSD: kex.h,v 1.64 2014/05/02 03:27:54 djm Exp $ */
Ben Lindstrom36579d32001-01-29 07:39:26 +00002
Damien Miller33b13562000-04-04 14:38:59 +10003/*
Ben Lindstrom44697232001-07-04 03:32:30 +00004 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
Damien Miller33b13562000-04-04 14:38:59 +10005 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
Damien Miller33b13562000-04-04 14:38:59 +100014 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26#ifndef KEX_H
27#define KEX_H
28
Damien Miller2bdd1c12006-04-23 12:28:53 +100029#include <signal.h>
Ben Lindstrom06b33aa2001-02-15 03:01:59 +000030#include <openssl/evp.h>
Darren Tucker5f3d5be2007-06-05 18:30:18 +100031#include <openssl/hmac.h>
Darren Tucker8ccb7392010-09-10 12:28:24 +100032#ifdef OPENSSL_HAS_ECC
Damien Millereb8b60e2010-08-31 22:41:14 +100033#include <openssl/ec.h>
Darren Tucker8ccb7392010-09-10 12:28:24 +100034#endif
Damien Millerd8337c52006-07-24 14:14:19 +100035
Darren Tucker5b48cdd2009-06-21 18:15:25 +100036#define KEX_COOKIE_LEN 16
37
Damien Miller19bb3a52005-11-05 15:19:35 +110038#define KEX_DH1 "diffie-hellman-group1-sha1"
39#define KEX_DH14 "diffie-hellman-group14-sha1"
40#define KEX_DHGEX_SHA1 "diffie-hellman-group-exchange-sha1"
Damien Millera63128d2006-03-15 12:08:28 +110041#define KEX_DHGEX_SHA256 "diffie-hellman-group-exchange-sha256"
Darren Tucker36331b52010-01-08 16:50:41 +110042#define KEX_RESUME "resume@appgate.com"
Damien Millerea111192013-04-23 19:24:32 +100043#define KEX_ECDH_SHA2_NISTP256 "ecdh-sha2-nistp256"
44#define KEX_ECDH_SHA2_NISTP384 "ecdh-sha2-nistp384"
45#define KEX_ECDH_SHA2_NISTP521 "ecdh-sha2-nistp521"
Damien Miller1e124262013-11-04 08:26:52 +110046#define KEX_CURVE25519_SHA256 "curve25519-sha256@libssh.org"
Damien Miller33b13562000-04-04 14:38:59 +100047
Damien Miller9786e6e2005-07-26 21:54:56 +100048#define COMP_NONE 0
49#define COMP_ZLIB 1
50#define COMP_DELAYED 2
51
Damien Miller33b13562000-04-04 14:38:59 +100052enum kex_init_proposals {
53 PROPOSAL_KEX_ALGS,
54 PROPOSAL_SERVER_HOST_KEY_ALGS,
55 PROPOSAL_ENC_ALGS_CTOS,
56 PROPOSAL_ENC_ALGS_STOC,
57 PROPOSAL_MAC_ALGS_CTOS,
58 PROPOSAL_MAC_ALGS_STOC,
59 PROPOSAL_COMP_ALGS_CTOS,
60 PROPOSAL_COMP_ALGS_STOC,
61 PROPOSAL_LANG_CTOS,
62 PROPOSAL_LANG_STOC,
63 PROPOSAL_MAX
64};
65
66enum kex_modes {
67 MODE_IN,
68 MODE_OUT,
69 MODE_MAX
70};
71
Damien Miller874d77b2000-10-14 16:23:11 +110072enum kex_exchange {
Damien Miller8e7fb332003-02-24 12:03:03 +110073 KEX_DH_GRP1_SHA1,
Damien Millerf675fc42004-06-15 10:30:09 +100074 KEX_DH_GRP14_SHA1,
Damien Miller8e7fb332003-02-24 12:03:03 +110075 KEX_DH_GEX_SHA1,
Damien Millera63128d2006-03-15 12:08:28 +110076 KEX_DH_GEX_SHA256,
Damien Millereb8b60e2010-08-31 22:41:14 +100077 KEX_ECDH_SHA2,
Damien Miller1e124262013-11-04 08:26:52 +110078 KEX_C25519_SHA256,
Damien Miller8e7fb332003-02-24 12:03:03 +110079 KEX_MAX
Damien Miller874d77b2000-10-14 16:23:11 +110080};
Kevin Stevesef4eea92001-02-05 12:42:17 +000081
Ben Lindstrom2d90e002001-04-04 02:00:54 +000082#define KEX_INIT_SENT 0x0001
83
Damien Miller33b13562000-04-04 14:38:59 +100084typedef struct Kex Kex;
85typedef struct Mac Mac;
86typedef struct Comp Comp;
87typedef struct Enc Enc;
Ben Lindstrom2d90e002001-04-04 02:00:54 +000088typedef struct Newkeys Newkeys;
Damien Miller33b13562000-04-04 14:38:59 +100089
90struct Enc {
Ben Lindstrom2d90e002001-04-04 02:00:54 +000091 char *name;
Damien Millerea111192013-04-23 19:24:32 +100092 const Cipher *cipher;
Ben Lindstrom2d90e002001-04-04 02:00:54 +000093 int enabled;
Damien Miller963f6b22002-02-19 15:21:23 +110094 u_int key_len;
Damien Miller1d75abf2013-01-09 16:12:19 +110095 u_int iv_len;
Damien Miller963f6b22002-02-19 15:21:23 +110096 u_int block_size;
Ben Lindstrom46c16222000-12-22 01:43:59 +000097 u_char *key;
98 u_char *iv;
Damien Miller33b13562000-04-04 14:38:59 +100099};
100struct Mac {
Ben Lindstrom2d90e002001-04-04 02:00:54 +0000101 char *name;
102 int enabled;
Damien Millereccb9de2005-06-17 12:59:34 +1000103 u_int mac_len;
Ben Lindstrom46c16222000-12-22 01:43:59 +0000104 u_char *key;
Damien Millereccb9de2005-06-17 12:59:34 +1000105 u_int key_len;
Damien Millere45796f2007-06-11 14:01:42 +1000106 int type;
Damien Milleraf43a7a2012-12-12 10:46:31 +1100107 int etm; /* Encrypt-then-MAC */
Damien Miller4e8d9372014-02-04 11:02:42 +1100108 struct ssh_hmac_ctx *hmac_ctx;
109 struct umac_ctx *umac_ctx;
Damien Miller33b13562000-04-04 14:38:59 +1000110};
111struct Comp {
Ben Lindstrom2d90e002001-04-04 02:00:54 +0000112 int type;
113 int enabled;
114 char *name;
Damien Miller33b13562000-04-04 14:38:59 +1000115};
Ben Lindstrom2d90e002001-04-04 02:00:54 +0000116struct Newkeys {
117 Enc enc;
118 Mac mac;
119 Comp comp;
120};
Damien Miller33b13562000-04-04 14:38:59 +1000121struct Kex {
Ben Lindstrom2d90e002001-04-04 02:00:54 +0000122 u_char *session_id;
Damien Millera10f5612002-09-12 09:49:15 +1000123 u_int session_id_len;
Ben Lindstrombe2cc432001-04-04 23:46:07 +0000124 Newkeys *newkeys[MODE_MAX];
Damien Millereccb9de2005-06-17 12:59:34 +1000125 u_int we_need;
Damien Miller76eea4a2014-01-26 09:37:25 +1100126 u_int dh_need;
Ben Lindstrom2d90e002001-04-04 02:00:54 +0000127 int server;
128 char *name;
129 int hostkey_type;
130 int kex_type;
Darren Tucker36331b52010-01-08 16:50:41 +1100131 int roaming;
Ben Lindstrom2d90e002001-04-04 02:00:54 +0000132 Buffer my;
133 Buffer peer;
Damien Miller97c91f62006-04-23 12:08:37 +1000134 sig_atomic_t done;
Ben Lindstrom2d90e002001-04-04 02:00:54 +0000135 int flags;
Damien Millerb3051d02014-01-10 10:58:53 +1100136 int hash_alg;
Damien Millerea111192013-04-23 19:24:32 +1000137 int ec_nid;
Ben Lindstrom2d90e002001-04-04 02:00:54 +0000138 char *client_version_string;
139 char *server_version_string;
Ben Lindstrom16ae3d02001-07-04 04:02:36 +0000140 int (*verify_host_key)(Key *);
Damien Miller0a80ca12010-02-27 07:55:05 +1100141 Key *(*load_host_public_key)(int);
142 Key *(*load_host_private_key)(int);
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000143 int (*host_key_index)(Key *);
Damien Miller85b45e02013-07-20 13:21:52 +1000144 void (*sign)(Key *, Key *, u_char **, u_int *, u_char *, u_int);
Damien Miller8e7fb332003-02-24 12:03:03 +1100145 void (*kex[KEX_MAX])(Kex *);
Damien Miller33b13562000-04-04 14:38:59 +1000146};
147
Damien Millerd5f62bf2010-09-24 22:11:14 +1000148int kex_names_valid(const char *);
Damien Miller690d9892013-11-08 12:16:49 +1100149char *kex_alg_list(char);
Damien Millerd5f62bf2010-09-24 22:11:14 +1000150
Ben Lindstrom16ae3d02001-07-04 04:02:36 +0000151Kex *kex_setup(char *[PROPOSAL_MAX]);
Ben Lindstrom4cc240d2001-07-04 04:46:56 +0000152void kex_finish(Kex *);
Ben Lindstrom238abf62001-04-04 17:52:53 +0000153
Ben Lindstrom4cc240d2001-07-04 04:46:56 +0000154void kex_send_kexinit(Kex *);
Damien Miller630d6f42002-01-22 23:17:30 +1100155void kex_input_kexinit(int, u_int32_t, void *);
Damien Miller91b580e2014-01-12 19:21:22 +1100156void kex_derive_keys(Kex *, u_char *, u_int, const u_char *, u_int);
157void kex_derive_keys_bn(Kex *, u_char *, u_int, const BIGNUM *);
Damien Miller33b13562000-04-04 14:38:59 +1000158
Ben Lindstrom16ae3d02001-07-04 04:02:36 +0000159Newkeys *kex_get_newkeys(int);
Ben Lindstrom2d90e002001-04-04 02:00:54 +0000160
Damien Miller8e7fb332003-02-24 12:03:03 +1100161void kexdh_client(Kex *);
162void kexdh_server(Kex *);
163void kexgex_client(Kex *);
164void kexgex_server(Kex *);
Damien Millereb8b60e2010-08-31 22:41:14 +1000165void kexecdh_client(Kex *);
166void kexecdh_server(Kex *);
Damien Miller1e124262013-11-04 08:26:52 +1100167void kexc25519_client(Kex *);
168void kexc25519_server(Kex *);
Damien Miller8e7fb332003-02-24 12:03:03 +1100169
Damien Miller19bb3a52005-11-05 15:19:35 +1100170void
Damien Miller8e7fb332003-02-24 12:03:03 +1100171kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int,
Damien Miller19bb3a52005-11-05 15:19:35 +1100172 BIGNUM *, BIGNUM *, BIGNUM *, u_char **, u_int *);
173void
Damien Millerb3051d02014-01-10 10:58:53 +1100174kexgex_hash(int, char *, char *, char *, int, char *,
Damien Miller51b4f822006-03-26 00:04:32 +1100175 int, u_char *, int, int, int, int, BIGNUM *, BIGNUM *, BIGNUM *,
Damien Miller19bb3a52005-11-05 15:19:35 +1100176 BIGNUM *, BIGNUM *, u_char **, u_int *);
Damien Miller6af914a2010-09-10 11:39:26 +1000177#ifdef OPENSSL_HAS_ECC
Damien Millereb8b60e2010-08-31 22:41:14 +1000178void
Damien Millerb3051d02014-01-10 10:58:53 +1100179kex_ecdh_hash(int, const EC_GROUP *, char *, char *, char *, int,
Damien Millereb8b60e2010-08-31 22:41:14 +1000180 char *, int, u_char *, int, const EC_POINT *, const EC_POINT *,
181 const BIGNUM *, u_char **, u_int *);
Damien Miller6af914a2010-09-10 11:39:26 +1000182#endif
Damien Miller1e124262013-11-04 08:26:52 +1100183void
Damien Millerb3051d02014-01-10 10:58:53 +1100184kex_c25519_hash(int, char *, char *, char *, int,
Damien Miller1e124262013-11-04 08:26:52 +1100185 char *, int, u_char *, int, const u_char *, const u_char *,
Damien Miller91b580e2014-01-12 19:21:22 +1100186 const u_char *, u_int, u_char **, u_int *);
Damien Miller1e124262013-11-04 08:26:52 +1100187
188#define CURVE25519_SIZE 32
189void kexc25519_keygen(u_char[CURVE25519_SIZE], u_char[CURVE25519_SIZE])
Damien Miller686c7d92014-05-15 14:37:03 +1000190 __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
191 __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)));
Damien Miller91b580e2014-01-12 19:21:22 +1100192void kexc25519_shared_key(const u_char key[CURVE25519_SIZE],
193 const u_char pub[CURVE25519_SIZE], Buffer *out)
Damien Miller686c7d92014-05-15 14:37:03 +1000194 __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
195 __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)));
Damien Miller8e7fb332003-02-24 12:03:03 +1100196
Darren Tuckere4ab1152004-05-24 10:14:24 +1000197void
198derive_ssh1_session_id(BIGNUM *, BIGNUM *, u_int8_t[8], u_int8_t[16]);
199
Damien Millereb8b60e2010-08-31 22:41:14 +1000200#if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) || defined(DEBUG_KEXECDH)
Ben Lindstrom16ae3d02001-07-04 04:02:36 +0000201void dump_digest(char *, u_char *, int);
Ben Lindstrom20d7c7b2001-04-04 01:56:17 +0000202#endif
203
Damien Miller33b13562000-04-04 14:38:59 +1000204#endif