xref: /openbsd/usr.bin/ssh/kex.h (revision db3296cf)
1 /*	$OpenBSD: kex.h,v 1.33 2003/02/16 17:09:57 markus 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 <openssl/evp.h>
30 #include "buffer.h"
31 #include "cipher.h"
32 #include "key.h"
33 
34 #define	KEX_DH1		"diffie-hellman-group1-sha1"
35 #define	KEX_DHGEX	"diffie-hellman-group-exchange-sha1"
36 
37 enum kex_init_proposals {
38 	PROPOSAL_KEX_ALGS,
39 	PROPOSAL_SERVER_HOST_KEY_ALGS,
40 	PROPOSAL_ENC_ALGS_CTOS,
41 	PROPOSAL_ENC_ALGS_STOC,
42 	PROPOSAL_MAC_ALGS_CTOS,
43 	PROPOSAL_MAC_ALGS_STOC,
44 	PROPOSAL_COMP_ALGS_CTOS,
45 	PROPOSAL_COMP_ALGS_STOC,
46 	PROPOSAL_LANG_CTOS,
47 	PROPOSAL_LANG_STOC,
48 	PROPOSAL_MAX
49 };
50 
51 enum kex_modes {
52 	MODE_IN,
53 	MODE_OUT,
54 	MODE_MAX
55 };
56 
57 enum kex_exchange {
58 	KEX_DH_GRP1_SHA1,
59 	KEX_DH_GEX_SHA1,
60 	KEX_MAX
61 };
62 
63 #define KEX_INIT_SENT	0x0001
64 
65 typedef struct Kex Kex;
66 typedef struct Mac Mac;
67 typedef struct Comp Comp;
68 typedef struct Enc Enc;
69 typedef struct Newkeys Newkeys;
70 
71 struct Enc {
72 	char	*name;
73 	Cipher	*cipher;
74 	int	enabled;
75 	u_int	key_len;
76 	u_int	block_size;
77 	u_char	*key;
78 	u_char	*iv;
79 };
80 struct Mac {
81 	char	*name;
82 	int	enabled;
83 	const EVP_MD	*md;
84 	int	mac_len;
85 	u_char	*key;
86 	int	key_len;
87 };
88 struct Comp {
89 	int	type;
90 	int	enabled;
91 	char	*name;
92 };
93 struct Newkeys {
94 	Enc	enc;
95 	Mac	mac;
96 	Comp	comp;
97 };
98 struct Kex {
99 	u_char	*session_id;
100 	u_int	session_id_len;
101 	Newkeys	*newkeys[MODE_MAX];
102 	int	we_need;
103 	int	server;
104 	char	*name;
105 	int	hostkey_type;
106 	int	kex_type;
107 	Buffer	my;
108 	Buffer	peer;
109 	int	done;
110 	int	flags;
111 	char	*client_version_string;
112 	char	*server_version_string;
113 	int	(*verify_host_key)(Key *);
114 	Key	*(*load_host_key)(int);
115 	int	(*host_key_index)(Key *);
116 	void	(*kex[KEX_MAX])(Kex *);
117 };
118 
119 Kex	*kex_setup(char *[PROPOSAL_MAX]);
120 void	 kex_finish(Kex *);
121 
122 void	 kex_send_kexinit(Kex *);
123 void	 kex_input_kexinit(int, u_int32_t, void *);
124 void	 kex_derive_keys(Kex *, u_char *, BIGNUM *);
125 
126 Newkeys *kex_get_newkeys(int);
127 
128 void	 kexdh_client(Kex *);
129 void	 kexdh_server(Kex *);
130 void	 kexgex_client(Kex *);
131 void	 kexgex_server(Kex *);
132 
133 u_char *
134 kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int,
135     BIGNUM *, BIGNUM *, BIGNUM *);
136 u_char *
137 kexgex_hash(char *, char *, char *, int, char *, int, u_char *, int,
138     int, int, int, BIGNUM *, BIGNUM *, BIGNUM *, BIGNUM *, BIGNUM *);
139 
140 #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH)
141 void	dump_digest(char *, u_char *, int);
142 #endif
143 
144 #endif
145