kex.h revision 262566
1/* $OpenBSD: kex.h,v 1.61 2014/01/25 10:12:50 dtucker Exp $ */
2/* $FreeBSD: stable/10/crypto/openssh/kex.h 262566 2014-02-27 17:29:02Z des $ */
3
4/*
5 * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27#ifndef KEX_H
28#define KEX_H
29
30#include <signal.h>
31#include <openssl/evp.h>
32#include <openssl/hmac.h>
33#ifdef OPENSSL_HAS_ECC
34#include <openssl/ec.h>
35#endif
36
37#define KEX_COOKIE_LEN	16
38
39#define	KEX_DH1			"diffie-hellman-group1-sha1"
40#define	KEX_DH14		"diffie-hellman-group14-sha1"
41#define	KEX_DHGEX_SHA1		"diffie-hellman-group-exchange-sha1"
42#define	KEX_DHGEX_SHA256	"diffie-hellman-group-exchange-sha256"
43#define	KEX_RESUME		"resume@appgate.com"
44#define	KEX_ECDH_SHA2_NISTP256	"ecdh-sha2-nistp256"
45#define	KEX_ECDH_SHA2_NISTP384	"ecdh-sha2-nistp384"
46#define	KEX_ECDH_SHA2_NISTP521	"ecdh-sha2-nistp521"
47#define	KEX_CURVE25519_SHA256	"curve25519-sha256@libssh.org"
48
49#define COMP_NONE	0
50#define COMP_ZLIB	1
51#define COMP_DELAYED	2
52
53enum kex_init_proposals {
54	PROPOSAL_KEX_ALGS,
55	PROPOSAL_SERVER_HOST_KEY_ALGS,
56	PROPOSAL_ENC_ALGS_CTOS,
57	PROPOSAL_ENC_ALGS_STOC,
58	PROPOSAL_MAC_ALGS_CTOS,
59	PROPOSAL_MAC_ALGS_STOC,
60	PROPOSAL_COMP_ALGS_CTOS,
61	PROPOSAL_COMP_ALGS_STOC,
62	PROPOSAL_LANG_CTOS,
63	PROPOSAL_LANG_STOC,
64	PROPOSAL_MAX
65};
66
67enum kex_modes {
68	MODE_IN,
69	MODE_OUT,
70	MODE_MAX
71};
72
73enum kex_exchange {
74	KEX_DH_GRP1_SHA1,
75	KEX_DH_GRP14_SHA1,
76	KEX_DH_GEX_SHA1,
77	KEX_DH_GEX_SHA256,
78	KEX_ECDH_SHA2,
79	KEX_C25519_SHA256,
80	KEX_MAX
81};
82
83#define KEX_INIT_SENT	0x0001
84
85typedef struct Kex Kex;
86typedef struct Mac Mac;
87typedef struct Comp Comp;
88typedef struct Enc Enc;
89typedef struct Newkeys Newkeys;
90
91struct Enc {
92	char	*name;
93	const Cipher *cipher;
94	int	enabled;
95	u_int	key_len;
96	u_int	iv_len;
97	u_int	block_size;
98	u_char	*key;
99	u_char	*iv;
100};
101struct Mac {
102	char	*name;
103	int	enabled;
104	u_int	mac_len;
105	u_char	*key;
106	u_int	key_len;
107	int	type;
108	int	etm;		/* Encrypt-then-MAC */
109	const EVP_MD	*evp_md;
110	HMAC_CTX	evp_ctx;
111	struct umac_ctx *umac_ctx;
112};
113struct Comp {
114	int	type;
115	int	enabled;
116	char	*name;
117};
118struct Newkeys {
119	Enc	enc;
120	Mac	mac;
121	Comp	comp;
122};
123struct Kex {
124	u_char	*session_id;
125	u_int	session_id_len;
126	Newkeys	*newkeys[MODE_MAX];
127	u_int	we_need;
128	u_int	dh_need;
129	int	server;
130	char	*name;
131	int	hostkey_type;
132	int	kex_type;
133	int	roaming;
134	Buffer	my;
135	Buffer	peer;
136	sig_atomic_t done;
137	int	flags;
138	int	hash_alg;
139	int	ec_nid;
140	char	*client_version_string;
141	char	*server_version_string;
142	int	(*verify_host_key)(Key *);
143	Key	*(*load_host_public_key)(int);
144	Key	*(*load_host_private_key)(int);
145	int	(*host_key_index)(Key *);
146	void    (*sign)(Key *, Key *, u_char **, u_int *, u_char *, u_int);
147	void	(*kex[KEX_MAX])(Kex *);
148};
149
150int	 kex_names_valid(const char *);
151char	*kex_alg_list(char);
152
153#ifdef	NONE_CIPHER_ENABLED
154void	 kex_prop2buf(Buffer *, char *[PROPOSAL_MAX]);
155#endif
156
157Kex	*kex_setup(char *[PROPOSAL_MAX]);
158void	 kex_finish(Kex *);
159
160void	 kex_send_kexinit(Kex *);
161void	 kex_input_kexinit(int, u_int32_t, void *);
162void	 kex_derive_keys(Kex *, u_char *, u_int, const u_char *, u_int);
163void	 kex_derive_keys_bn(Kex *, u_char *, u_int, const BIGNUM *);
164
165Newkeys *kex_get_newkeys(int);
166
167void	 kexdh_client(Kex *);
168void	 kexdh_server(Kex *);
169void	 kexgex_client(Kex *);
170void	 kexgex_server(Kex *);
171void	 kexecdh_client(Kex *);
172void	 kexecdh_server(Kex *);
173void	 kexc25519_client(Kex *);
174void	 kexc25519_server(Kex *);
175
176void
177kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int,
178    BIGNUM *, BIGNUM *, BIGNUM *, u_char **, u_int *);
179void
180kexgex_hash(int, char *, char *, char *, int, char *,
181    int, u_char *, int, int, int, int, BIGNUM *, BIGNUM *, BIGNUM *,
182    BIGNUM *, BIGNUM *, u_char **, u_int *);
183#ifdef OPENSSL_HAS_ECC
184void
185kex_ecdh_hash(int, const EC_GROUP *, char *, char *, char *, int,
186    char *, int, u_char *, int, const EC_POINT *, const EC_POINT *,
187    const BIGNUM *, u_char **, u_int *);
188#endif
189void
190kex_c25519_hash(int, char *, char *, char *, int,
191    char *, int, u_char *, int, const u_char *, const u_char *,
192    const u_char *, u_int, u_char **, u_int *);
193
194#define CURVE25519_SIZE 32
195void	kexc25519_keygen(u_char[CURVE25519_SIZE], u_char[CURVE25519_SIZE])
196	__attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
197	__attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)));
198void kexc25519_shared_key(const u_char key[CURVE25519_SIZE],
199    const u_char pub[CURVE25519_SIZE], Buffer *out)
200	__attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
201	__attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)));
202
203void
204derive_ssh1_session_id(BIGNUM *, BIGNUM *, u_int8_t[8], u_int8_t[16]);
205
206#if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) || defined(DEBUG_KEXECDH)
207void	dump_digest(char *, u_char *, int);
208#endif
209
210#endif
211