xref: /freebsd/crypto/openssh/kex.h (revision 4c8945a06b01a5c8122cdeb402af36bb46a06acc)
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 
45 enum 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 
59 enum kex_modes {
60 	MODE_IN,
61 	MODE_OUT,
62 	MODE_MAX
63 };
64 
65 enum 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 
75 typedef struct Kex Kex;
76 typedef struct Mac Mac;
77 typedef struct Comp Comp;
78 typedef struct Enc Enc;
79 typedef struct Newkeys Newkeys;
80 
81 struct 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 };
90 struct 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 };
101 struct Comp {
102 	int	type;
103 	int	enabled;
104 	char	*name;
105 };
106 struct Newkeys {
107 	Enc	enc;
108 	Mac	mac;
109 	Comp	comp;
110 };
111 struct 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 
135 Kex	*kex_setup(char *[PROPOSAL_MAX]);
136 void	 kex_finish(Kex *);
137 
138 void	 kex_send_kexinit(Kex *);
139 void	 kex_input_kexinit(int, u_int32_t, void *);
140 void	 kex_derive_keys(Kex *, u_char *, u_int, BIGNUM *);
141 
142 Newkeys *kex_get_newkeys(int);
143 
144 void	 kexdh_client(Kex *);
145 void	 kexdh_server(Kex *);
146 void	 kexgex_client(Kex *);
147 void	 kexgex_server(Kex *);
148 
149 void
150 kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int,
151     BIGNUM *, BIGNUM *, BIGNUM *, u_char **, u_int *);
152 void
153 kexgex_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 
157 void
158 derive_ssh1_session_id(BIGNUM *, BIGNUM *, u_int8_t[8], u_int8_t[16]);
159 
160 #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH)
161 void	dump_digest(char *, u_char *, int);
162 #endif
163 
164 #endif
165