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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 
50 enum 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 
64 enum kex_modes {
65 	MODE_IN,
66 	MODE_OUT,
67 	MODE_MAX
68 };
69 
70 enum 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 
81 typedef struct Kex Kex;
82 typedef struct Mac Mac;
83 typedef struct Comp Comp;
84 typedef struct Enc Enc;
85 typedef struct Newkeys Newkeys;
86 
87 struct 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 };
96 struct 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 };
107 struct Comp {
108 	int	type;
109 	int	enabled;
110 	char	*name;
111 };
112 struct Newkeys {
113 	Enc	enc;
114 	Mac	mac;
115 	Comp	comp;
116 };
117 struct 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 
141 int	 kex_names_valid(const char *);
142 
143 Kex	*kex_setup(char *[PROPOSAL_MAX]);
144 void	 kex_finish(Kex *);
145 
146 void	 kex_send_kexinit(Kex *);
147 void	 kex_input_kexinit(int, u_int32_t, void *);
148 void	 kex_derive_keys(Kex *, u_char *, u_int, BIGNUM *);
149 
150 Newkeys *kex_get_newkeys(int);
151 
152 void	 kexdh_client(Kex *);
153 void	 kexdh_server(Kex *);
154 void	 kexgex_client(Kex *);
155 void	 kexgex_server(Kex *);
156 void	 kexecdh_client(Kex *);
157 void	 kexecdh_server(Kex *);
158 
159 void
160 kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int,
161     BIGNUM *, BIGNUM *, BIGNUM *, u_char **, u_int *);
162 void
163 kexgex_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
167 void
168 kex_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 *);
171 int	kex_ecdh_name_to_nid(const char *);
172 const 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 
178 void
179 derive_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)
182 void	dump_digest(char *, u_char *, int);
183 #endif
184 
185 #endif
186