kex.h revision 181111 
1/* $OpenBSD: kex.h,v 1.46 2007/06/07 19:37:34 pvalchev 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_DH1			"diffie-hellman-group1-sha1"
34#define	KEX_DH14		"diffie-hellman-group14-sha1"
35#define	KEX_DHGEX_SHA1		"diffie-hellman-group-exchange-sha1"
36#define	KEX_DHGEX_SHA256	"diffie-hellman-group-exchange-sha256"
37
38#define COMP_NONE	0
39#define COMP_ZLIB	1
40#define COMP_DELAYED	2
41
42enum kex_init_proposals {
43	PROPOSAL_KEX_ALGS,
44	PROPOSAL_SERVER_HOST_KEY_ALGS,
45	PROPOSAL_ENC_ALGS_CTOS,
46	PROPOSAL_ENC_ALGS_STOC,
47	PROPOSAL_MAC_ALGS_CTOS,
48	PROPOSAL_MAC_ALGS_STOC,
49	PROPOSAL_COMP_ALGS_CTOS,
50	PROPOSAL_COMP_ALGS_STOC,
51	PROPOSAL_LANG_CTOS,
52	PROPOSAL_LANG_STOC,
53	PROPOSAL_MAX
54};
55
56enum kex_modes {
57	MODE_IN,
58	MODE_OUT,
59	MODE_MAX
60};
61
62enum kex_exchange {
63	KEX_DH_GRP1_SHA1,
64	KEX_DH_GRP14_SHA1,
65	KEX_DH_GEX_SHA1,
66	KEX_DH_GEX_SHA256,
67	KEX_MAX
68};
69
70#define KEX_INIT_SENT	0x0001
71
72typedef struct Kex Kex;
73typedef struct Mac Mac;
74typedef struct Comp Comp;
75typedef struct Enc Enc;
76typedef struct Newkeys Newkeys;
77
78struct Enc {
79	char	*name;
80	Cipher	*cipher;
81	int	enabled;
82	u_int	key_len;
83	u_int	block_size;
84	u_char	*key;
85	u_char	*iv;
86};
87struct Mac {
88	char	*name;
89	int	enabled;
90	u_int	mac_len;
91	u_char	*key;
92	u_int	key_len;
93	int	type;
94	const EVP_MD	*evp_md;
95	HMAC_CTX	evp_ctx;
96	struct umac_ctx *umac_ctx;
97};
98struct Comp {
99	int	type;
100	int	enabled;
101	char	*name;
102};
103struct Newkeys {
104	Enc	enc;
105	Mac	mac;
106	Comp	comp;
107};
108struct Kex {
109	u_char	*session_id;
110	u_int	session_id_len;
111	Newkeys	*newkeys[MODE_MAX];
112	u_int	we_need;
113	int	server;
114	char	*name;
115	int	hostkey_type;
116	int	kex_type;
117	Buffer	my;
118	Buffer	peer;
119	sig_atomic_t done;
120	int	flags;
121	const EVP_MD *evp_md;
122	char	*client_version_string;
123	char	*server_version_string;
124	int	(*verify_host_key)(Key *);
125	Key	*(*load_host_key)(int);
126	int	(*host_key_index)(Key *);
127	void	(*kex[KEX_MAX])(Kex *);
128};
129
130Kex	*kex_setup(char *[PROPOSAL_MAX]);
131void	 kex_finish(Kex *);
132
133void	 kex_send_kexinit(Kex *);
134void	 kex_input_kexinit(int, u_int32_t, void *);
135void	 kex_derive_keys(Kex *, u_char *, u_int, BIGNUM *);
136
137Newkeys *kex_get_newkeys(int);
138
139void	 kexdh_client(Kex *);
140void	 kexdh_server(Kex *);
141void	 kexgex_client(Kex *);
142void	 kexgex_server(Kex *);
143
144void
145kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int,
146    BIGNUM *, BIGNUM *, BIGNUM *, u_char **, u_int *);
147void
148kexgex_hash(const EVP_MD *, char *, char *, char *, int, char *,
149    int, u_char *, int, int, int, int, BIGNUM *, BIGNUM *, BIGNUM *,
150    BIGNUM *, BIGNUM *, u_char **, u_int *);
151
152void
153derive_ssh1_session_id(BIGNUM *, BIGNUM *, u_int8_t[8], u_int8_t[16]);
154
155#if defined(DEBUG_KEX) || defined(DEBUG_KEXDH)
156void	dump_digest(char *, u_char *, int);
157#endif
158
159#endif
160