kex.h revision 197679 
1/* $OpenBSD: kex.h,v 1.47 2009/05/27 06:34:36 andreas 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
40#define COMP_NONE	0
41#define COMP_ZLIB	1
42#define COMP_DELAYED	2
43
44enum kex_init_proposals {
45	PROPOSAL_KEX_ALGS,
46	PROPOSAL_SERVER_HOST_KEY_ALGS,
47	PROPOSAL_ENC_ALGS_CTOS,
48	PROPOSAL_ENC_ALGS_STOC,
49	PROPOSAL_MAC_ALGS_CTOS,
50	PROPOSAL_MAC_ALGS_STOC,
51	PROPOSAL_COMP_ALGS_CTOS,
52	PROPOSAL_COMP_ALGS_STOC,
53	PROPOSAL_LANG_CTOS,
54	PROPOSAL_LANG_STOC,
55	PROPOSAL_MAX
56};
57
58enum kex_modes {
59	MODE_IN,
60	MODE_OUT,
61	MODE_MAX
62};
63
64enum kex_exchange {
65	KEX_DH_GRP1_SHA1,
66	KEX_DH_GRP14_SHA1,
67	KEX_DH_GEX_SHA1,
68	KEX_DH_GEX_SHA256,
69	KEX_MAX
70};
71
72#define KEX_INIT_SENT	0x0001
73
74typedef struct Kex Kex;
75typedef struct Mac Mac;
76typedef struct Comp Comp;
77typedef struct Enc Enc;
78typedef struct Newkeys Newkeys;
79
80struct Enc {
81	char	*name;
82	Cipher	*cipher;
83	int	enabled;
84	u_int	key_len;
85	u_int	block_size;
86	u_char	*key;
87	u_char	*iv;
88};
89struct Mac {
90	char	*name;
91	int	enabled;
92	u_int	mac_len;
93	u_char	*key;
94	u_int	key_len;
95	int	type;
96	const EVP_MD	*evp_md;
97	HMAC_CTX	evp_ctx;
98	struct umac_ctx *umac_ctx;
99};
100struct Comp {
101	int	type;
102	int	enabled;
103	char	*name;
104};
105struct Newkeys {
106	Enc	enc;
107	Mac	mac;
108	Comp	comp;
109};
110struct Kex {
111	u_char	*session_id;
112	u_int	session_id_len;
113	Newkeys	*newkeys[MODE_MAX];
114	u_int	we_need;
115	int	server;
116	char	*name;
117	int	hostkey_type;
118	int	kex_type;
119	Buffer	my;
120	Buffer	peer;
121	sig_atomic_t done;
122	int	flags;
123	const EVP_MD *evp_md;
124	char	*client_version_string;
125	char	*server_version_string;
126	int	(*verify_host_key)(Key *);
127	Key	*(*load_host_key)(int);
128	int	(*host_key_index)(Key *);
129	void	(*kex[KEX_MAX])(Kex *);
130};
131
132Kex	*kex_setup(char *[PROPOSAL_MAX]);
133void	 kex_finish(Kex *);
134
135void	 kex_send_kexinit(Kex *);
136void	 kex_input_kexinit(int, u_int32_t, void *);
137void	 kex_derive_keys(Kex *, u_char *, u_int, BIGNUM *);
138
139Newkeys *kex_get_newkeys(int);
140
141void	 kexdh_client(Kex *);
142void	 kexdh_server(Kex *);
143void	 kexgex_client(Kex *);
144void	 kexgex_server(Kex *);
145
146void
147kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int,
148    BIGNUM *, BIGNUM *, BIGNUM *, u_char **, u_int *);
149void
150kexgex_hash(const EVP_MD *, char *, char *, char *, int, char *,
151    int, u_char *, int, int, int, int, BIGNUM *, BIGNUM *, BIGNUM *,
152    BIGNUM *, BIGNUM *, u_char **, u_int *);
153
154void
155derive_ssh1_session_id(BIGNUM *, BIGNUM *, u_int8_t[8], u_int8_t[16]);
156
157#if defined(DEBUG_KEX) || defined(DEBUG_KEXDH)
158void	dump_digest(char *, u_char *, int);
159#endif
160
161#endif
162