kex.h revision 204917 
1/* $OpenBSD: kex.h,v 1.49 2010/02/26 20:29:54 djm Exp $ */
2
3/*
4 * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
5 *
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.
14 *
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
29#include <signal.h>
30#include <openssl/evp.h>
31#include <openssl/hmac.h>
32
33#define KEX_COOKIE_LEN	16
34
35#define	KEX_DH1			"diffie-hellman-group1-sha1"
36#define	KEX_DH14		"diffie-hellman-group14-sha1"
37#define	KEX_DHGEX_SHA1		"diffie-hellman-group-exchange-sha1"
38#define	KEX_DHGEX_SHA256	"diffie-hellman-group-exchange-sha256"
39#define	KEX_RESUME		"resume@appgate.com"
40
41#define COMP_NONE	0
42#define COMP_ZLIB	1
43#define COMP_DELAYED	2
44
45enum kex_init_proposals {
46	PROPOSAL_KEX_ALGS,
47	PROPOSAL_SERVER_HOST_KEY_ALGS,
48	PROPOSAL_ENC_ALGS_CTOS,
49	PROPOSAL_ENC_ALGS_STOC,
50	PROPOSAL_MAC_ALGS_CTOS,
51	PROPOSAL_MAC_ALGS_STOC,
52	PROPOSAL_COMP_ALGS_CTOS,
53	PROPOSAL_COMP_ALGS_STOC,
54	PROPOSAL_LANG_CTOS,
55	PROPOSAL_LANG_STOC,
56	PROPOSAL_MAX
57};
58
59enum kex_modes {
60	MODE_IN,
61	MODE_OUT,
62	MODE_MAX
63};
64
65enum kex_exchange {
66	KEX_DH_GRP1_SHA1,
67	KEX_DH_GRP14_SHA1,
68	KEX_DH_GEX_SHA1,
69	KEX_DH_GEX_SHA256,
70	KEX_MAX
71};
72
73#define KEX_INIT_SENT	0x0001
74
75typedef struct Kex Kex;
76typedef struct Mac Mac;
77typedef struct Comp Comp;
78typedef struct Enc Enc;
79typedef struct Newkeys Newkeys;
80
81struct Enc {
82	char	*name;
83	Cipher	*cipher;
84	int	enabled;
85	u_int	key_len;
86	u_int	block_size;
87	u_char	*key;
88	u_char	*iv;
89};
90struct Mac {
91	char	*name;
92	int	enabled;
93	u_int	mac_len;
94	u_char	*key;
95	u_int	key_len;
96	int	type;
97	const EVP_MD	*evp_md;
98	HMAC_CTX	evp_ctx;
99	struct umac_ctx *umac_ctx;
100};
101struct Comp {
102	int	type;
103	int	enabled;
104	char	*name;
105};
106struct Newkeys {
107	Enc	enc;
108	Mac	mac;
109	Comp	comp;
110};
111struct Kex {
112	u_char	*session_id;
113	u_int	session_id_len;
114	Newkeys	*newkeys[MODE_MAX];
115	u_int	we_need;
116	int	server;
117	char	*name;
118	int	hostkey_type;
119	int	kex_type;
120	int	roaming;
121	Buffer	my;
122	Buffer	peer;
123	sig_atomic_t done;
124	int	flags;
125	const EVP_MD *evp_md;
126	char	*client_version_string;
127	char	*server_version_string;
128	int	(*verify_host_key)(Key *);
129	Key	*(*load_host_public_key)(int);
130	Key	*(*load_host_private_key)(int);
131	int	(*host_key_index)(Key *);
132	void	(*kex[KEX_MAX])(Kex *);
133};
134
135Kex	*kex_setup(char *[PROPOSAL_MAX]);
136void	 kex_finish(Kex *);
137
138void	 kex_send_kexinit(Kex *);
139void	 kex_input_kexinit(int, u_int32_t, void *);
140void	 kex_derive_keys(Kex *, u_char *, u_int, BIGNUM *);
141
142Newkeys *kex_get_newkeys(int);
143
144void	 kexdh_client(Kex *);
145void	 kexdh_server(Kex *);
146void	 kexgex_client(Kex *);
147void	 kexgex_server(Kex *);
148
149void
150kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int,
151    BIGNUM *, BIGNUM *, BIGNUM *, u_char **, u_int *);
152void
153kexgex_hash(const EVP_MD *, char *, char *, char *, int, char *,
154    int, u_char *, int, int, int, int, BIGNUM *, BIGNUM *, BIGNUM *,
155    BIGNUM *, BIGNUM *, u_char **, u_int *);
156
157void
158derive_ssh1_session_id(BIGNUM *, BIGNUM *, u_int8_t[8], u_int8_t[16]);
159
160#if defined(DEBUG_KEX) || defined(DEBUG_KEXDH)
161void	dump_digest(char *, u_char *, int);
162#endif
163
164#endif
165