kex.h revision 221420 
1/* $OpenBSD: kex.h,v 1.52 2010/09/22 05:01:29 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#ifdef OPENSSL_HAS_ECC
33#include <openssl/ec.h>
34#endif
35
36#define KEX_COOKIE_LEN	16
37
38#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"
41#define	KEX_DHGEX_SHA256	"diffie-hellman-group-exchange-sha256"
42#define	KEX_RESUME		"resume@appgate.com"
43/* The following represents the family of ECDH methods */
44#define	KEX_ECDH_SHA2_STEM	"ecdh-sha2-"
45
46#define COMP_NONE	0
47#define COMP_ZLIB	1
48#define COMP_DELAYED	2
49
50enum kex_init_proposals {
51	PROPOSAL_KEX_ALGS,
52	PROPOSAL_SERVER_HOST_KEY_ALGS,
53	PROPOSAL_ENC_ALGS_CTOS,
54	PROPOSAL_ENC_ALGS_STOC,
55	PROPOSAL_MAC_ALGS_CTOS,
56	PROPOSAL_MAC_ALGS_STOC,
57	PROPOSAL_COMP_ALGS_CTOS,
58	PROPOSAL_COMP_ALGS_STOC,
59	PROPOSAL_LANG_CTOS,
60	PROPOSAL_LANG_STOC,
61	PROPOSAL_MAX
62};
63
64enum kex_modes {
65	MODE_IN,
66	MODE_OUT,
67	MODE_MAX
68};
69
70enum kex_exchange {
71	KEX_DH_GRP1_SHA1,
72	KEX_DH_GRP14_SHA1,
73	KEX_DH_GEX_SHA1,
74	KEX_DH_GEX_SHA256,
75	KEX_ECDH_SHA2,
76	KEX_MAX
77};
78
79#define KEX_INIT_SENT	0x0001
80
81typedef struct Kex Kex;
82typedef struct Mac Mac;
83typedef struct Comp Comp;
84typedef struct Enc Enc;
85typedef struct Newkeys Newkeys;
86
87struct Enc {
88	char	*name;
89	Cipher	*cipher;
90	int	enabled;
91	u_int	key_len;
92	u_int	block_size;
93	u_char	*key;
94	u_char	*iv;
95};
96struct Mac {
97	char	*name;
98	int	enabled;
99	u_int	mac_len;
100	u_char	*key;
101	u_int	key_len;
102	int	type;
103	const EVP_MD	*evp_md;
104	HMAC_CTX	evp_ctx;
105	struct umac_ctx *umac_ctx;
106};
107struct Comp {
108	int	type;
109	int	enabled;
110	char	*name;
111};
112struct Newkeys {
113	Enc	enc;
114	Mac	mac;
115	Comp	comp;
116};
117struct Kex {
118	u_char	*session_id;
119	u_int	session_id_len;
120	Newkeys	*newkeys[MODE_MAX];
121	u_int	we_need;
122	int	server;
123	char	*name;
124	int	hostkey_type;
125	int	kex_type;
126	int	roaming;
127	Buffer	my;
128	Buffer	peer;
129	sig_atomic_t done;
130	int	flags;
131	const EVP_MD *evp_md;
132	char	*client_version_string;
133	char	*server_version_string;
134	int	(*verify_host_key)(Key *);
135	Key	*(*load_host_public_key)(int);
136	Key	*(*load_host_private_key)(int);
137	int	(*host_key_index)(Key *);
138	void	(*kex[KEX_MAX])(Kex *);
139};
140
141int	 kex_names_valid(const char *);
142
143Kex	*kex_setup(char *[PROPOSAL_MAX]);
144void	 kex_finish(Kex *);
145
146void	 kex_send_kexinit(Kex *);
147void	 kex_input_kexinit(int, u_int32_t, void *);
148void	 kex_derive_keys(Kex *, u_char *, u_int, BIGNUM *);
149
150Newkeys *kex_get_newkeys(int);
151
152void	 kexdh_client(Kex *);
153void	 kexdh_server(Kex *);
154void	 kexgex_client(Kex *);
155void	 kexgex_server(Kex *);
156void	 kexecdh_client(Kex *);
157void	 kexecdh_server(Kex *);
158
159void
160kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int,
161    BIGNUM *, BIGNUM *, BIGNUM *, u_char **, u_int *);
162void
163kexgex_hash(const EVP_MD *, char *, char *, char *, int, char *,
164    int, u_char *, int, int, int, int, BIGNUM *, BIGNUM *, BIGNUM *,
165    BIGNUM *, BIGNUM *, u_char **, u_int *);
166#ifdef OPENSSL_HAS_ECC
167void
168kex_ecdh_hash(const EVP_MD *, const EC_GROUP *, char *, char *, char *, int,
169    char *, int, u_char *, int, const EC_POINT *, const EC_POINT *,
170    const BIGNUM *, u_char **, u_int *);
171int	kex_ecdh_name_to_nid(const char *);
172const EVP_MD *kex_ecdh_name_to_evpmd(const char *);
173#else
174# define kex_ecdh_name_to_nid(x) (-1)
175# define kex_ecdh_name_to_evpmd(x) (NULL)
176#endif
177
178void
179derive_ssh1_session_id(BIGNUM *, BIGNUM *, u_int8_t[8], u_int8_t[16]);
180
181#if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) || defined(DEBUG_KEXECDH)
182void	dump_digest(char *, u_char *, int);
183#endif
184
185#endif
186