xref: /freebsd/crypto/openssh/kex.h (revision f677a9e2672665f4eb3dd4111c07ee8f1f954262)
1 /* $OpenBSD: kex.h,v 1.56 2013/07/19 07:37:48 markus Exp $ */
2 /* $FreeBSD$ */
3 
4 /*
5  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 #ifndef KEX_H
28 #define KEX_H
29 
30 #include <signal.h>
31 #include <openssl/evp.h>
32 #include <openssl/hmac.h>
33 #ifdef OPENSSL_HAS_ECC
34 #include <openssl/ec.h>
35 #endif
36 
37 #define KEX_COOKIE_LEN	16
38 
39 #define	KEX_DH1			"diffie-hellman-group1-sha1"
40 #define	KEX_DH14		"diffie-hellman-group14-sha1"
41 #define	KEX_DHGEX_SHA1		"diffie-hellman-group-exchange-sha1"
42 #define	KEX_DHGEX_SHA256	"diffie-hellman-group-exchange-sha256"
43 #define	KEX_RESUME		"resume@appgate.com"
44 #define	KEX_ECDH_SHA2_NISTP256	"ecdh-sha2-nistp256"
45 #define	KEX_ECDH_SHA2_NISTP384	"ecdh-sha2-nistp384"
46 #define	KEX_ECDH_SHA2_NISTP521	"ecdh-sha2-nistp521"
47 
48 #define COMP_NONE	0
49 #define COMP_ZLIB	1
50 #define COMP_DELAYED	2
51 
52 enum kex_init_proposals {
53 	PROPOSAL_KEX_ALGS,
54 	PROPOSAL_SERVER_HOST_KEY_ALGS,
55 	PROPOSAL_ENC_ALGS_CTOS,
56 	PROPOSAL_ENC_ALGS_STOC,
57 	PROPOSAL_MAC_ALGS_CTOS,
58 	PROPOSAL_MAC_ALGS_STOC,
59 	PROPOSAL_COMP_ALGS_CTOS,
60 	PROPOSAL_COMP_ALGS_STOC,
61 	PROPOSAL_LANG_CTOS,
62 	PROPOSAL_LANG_STOC,
63 	PROPOSAL_MAX
64 };
65 
66 enum kex_modes {
67 	MODE_IN,
68 	MODE_OUT,
69 	MODE_MAX
70 };
71 
72 enum kex_exchange {
73 	KEX_DH_GRP1_SHA1,
74 	KEX_DH_GRP14_SHA1,
75 	KEX_DH_GEX_SHA1,
76 	KEX_DH_GEX_SHA256,
77 	KEX_ECDH_SHA2,
78 	KEX_MAX
79 };
80 
81 #define KEX_INIT_SENT	0x0001
82 
83 typedef struct Kex Kex;
84 typedef struct Mac Mac;
85 typedef struct Comp Comp;
86 typedef struct Enc Enc;
87 typedef struct Newkeys Newkeys;
88 
89 struct Enc {
90 	char	*name;
91 	const Cipher *cipher;
92 	int	enabled;
93 	u_int	key_len;
94 	u_int	iv_len;
95 	u_int	block_size;
96 	u_char	*key;
97 	u_char	*iv;
98 };
99 struct Mac {
100 	char	*name;
101 	int	enabled;
102 	u_int	mac_len;
103 	u_char	*key;
104 	u_int	key_len;
105 	int	type;
106 	int	etm;		/* Encrypt-then-MAC */
107 	const EVP_MD	*evp_md;
108 	HMAC_CTX	evp_ctx;
109 	struct umac_ctx *umac_ctx;
110 };
111 struct Comp {
112 	int	type;
113 	int	enabled;
114 	char	*name;
115 };
116 struct Newkeys {
117 	Enc	enc;
118 	Mac	mac;
119 	Comp	comp;
120 };
121 struct Kex {
122 	u_char	*session_id;
123 	u_int	session_id_len;
124 	Newkeys	*newkeys[MODE_MAX];
125 	u_int	we_need;
126 	int	server;
127 	char	*name;
128 	int	hostkey_type;
129 	int	kex_type;
130 	int	roaming;
131 	Buffer	my;
132 	Buffer	peer;
133 	sig_atomic_t done;
134 	int	flags;
135 	const EVP_MD *evp_md;
136 	int	ec_nid;
137 	char	*client_version_string;
138 	char	*server_version_string;
139 	int	(*verify_host_key)(Key *);
140 	Key	*(*load_host_public_key)(int);
141 	Key	*(*load_host_private_key)(int);
142 	int	(*host_key_index)(Key *);
143 	void    (*sign)(Key *, Key *, u_char **, u_int *, u_char *, u_int);
144 	void	(*kex[KEX_MAX])(Kex *);
145 };
146 
147 int	 kex_names_valid(const char *);
148 char	*kex_alg_list(void);
149 
150 #ifdef	NONE_CIPHER_ENABLED
151 void	 kex_prop2buf(Buffer *, char *[PROPOSAL_MAX]);
152 #endif
153 
154 Kex	*kex_setup(char *[PROPOSAL_MAX]);
155 void	 kex_finish(Kex *);
156 
157 void	 kex_send_kexinit(Kex *);
158 void	 kex_input_kexinit(int, u_int32_t, void *);
159 void	 kex_derive_keys(Kex *, u_char *, u_int, BIGNUM *);
160 
161 Newkeys *kex_get_newkeys(int);
162 
163 void	 kexdh_client(Kex *);
164 void	 kexdh_server(Kex *);
165 void	 kexgex_client(Kex *);
166 void	 kexgex_server(Kex *);
167 void	 kexecdh_client(Kex *);
168 void	 kexecdh_server(Kex *);
169 
170 void
171 kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int,
172     BIGNUM *, BIGNUM *, BIGNUM *, u_char **, u_int *);
173 void
174 kexgex_hash(const EVP_MD *, char *, char *, char *, int, char *,
175     int, u_char *, int, int, int, int, BIGNUM *, BIGNUM *, BIGNUM *,
176     BIGNUM *, BIGNUM *, u_char **, u_int *);
177 #ifdef OPENSSL_HAS_ECC
178 void
179 kex_ecdh_hash(const EVP_MD *, const EC_GROUP *, char *, char *, char *, int,
180     char *, int, u_char *, int, const EC_POINT *, const EC_POINT *,
181     const BIGNUM *, u_char **, u_int *);
182 #endif
183 
184 void
185 derive_ssh1_session_id(BIGNUM *, BIGNUM *, u_int8_t[8], u_int8_t[16]);
186 
187 #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) || defined(DEBUG_KEXECDH)
188 void	dump_digest(char *, u_char *, int);
189 #endif
190 
191 #endif
192