xref: /freebsd/crypto/openssh/kex.h (revision cc16dea626cf2fc80cde667ac4798065108e596c)
1 /* $OpenBSD: kex.h,v 1.54 2013/01/08 18:49:04 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 /* The following represents the family of ECDH methods */
45 #define	KEX_ECDH_SHA2_STEM	"ecdh-sha2-"
46 
47 #define COMP_NONE	0
48 #define COMP_ZLIB	1
49 #define COMP_DELAYED	2
50 
51 enum kex_init_proposals {
52 	PROPOSAL_KEX_ALGS,
53 	PROPOSAL_SERVER_HOST_KEY_ALGS,
54 	PROPOSAL_ENC_ALGS_CTOS,
55 	PROPOSAL_ENC_ALGS_STOC,
56 	PROPOSAL_MAC_ALGS_CTOS,
57 	PROPOSAL_MAC_ALGS_STOC,
58 	PROPOSAL_COMP_ALGS_CTOS,
59 	PROPOSAL_COMP_ALGS_STOC,
60 	PROPOSAL_LANG_CTOS,
61 	PROPOSAL_LANG_STOC,
62 	PROPOSAL_MAX
63 };
64 
65 enum kex_modes {
66 	MODE_IN,
67 	MODE_OUT,
68 	MODE_MAX
69 };
70 
71 enum kex_exchange {
72 	KEX_DH_GRP1_SHA1,
73 	KEX_DH_GRP14_SHA1,
74 	KEX_DH_GEX_SHA1,
75 	KEX_DH_GEX_SHA256,
76 	KEX_ECDH_SHA2,
77 	KEX_MAX
78 };
79 
80 #define KEX_INIT_SENT	0x0001
81 
82 typedef struct Kex Kex;
83 typedef struct Mac Mac;
84 typedef struct Comp Comp;
85 typedef struct Enc Enc;
86 typedef struct Newkeys Newkeys;
87 
88 struct Enc {
89 	char	*name;
90 	Cipher	*cipher;
91 	int	enabled;
92 	u_int	key_len;
93 	u_int	iv_len;
94 	u_int	block_size;
95 	u_char	*key;
96 	u_char	*iv;
97 };
98 struct Mac {
99 	char	*name;
100 	int	enabled;
101 	u_int	mac_len;
102 	u_char	*key;
103 	u_int	key_len;
104 	int	type;
105 	int	etm;		/* Encrypt-then-MAC */
106 	const EVP_MD	*evp_md;
107 	HMAC_CTX	evp_ctx;
108 	struct umac_ctx *umac_ctx;
109 };
110 struct Comp {
111 	int	type;
112 	int	enabled;
113 	char	*name;
114 };
115 struct Newkeys {
116 	Enc	enc;
117 	Mac	mac;
118 	Comp	comp;
119 };
120 struct Kex {
121 	u_char	*session_id;
122 	u_int	session_id_len;
123 	Newkeys	*newkeys[MODE_MAX];
124 	u_int	we_need;
125 	int	server;
126 	char	*name;
127 	int	hostkey_type;
128 	int	kex_type;
129 	int	roaming;
130 	Buffer	my;
131 	Buffer	peer;
132 	sig_atomic_t done;
133 	int	flags;
134 	const EVP_MD *evp_md;
135 	char	*client_version_string;
136 	char	*server_version_string;
137 	int	(*verify_host_key)(Key *);
138 	Key	*(*load_host_public_key)(int);
139 	Key	*(*load_host_private_key)(int);
140 	int	(*host_key_index)(Key *);
141 	void	(*kex[KEX_MAX])(Kex *);
142 };
143 
144 int	 kex_names_valid(const char *);
145 
146 #ifdef	NONE_CIPHER_ENABLED
147 void	 kex_prop2buf(Buffer *, char *[PROPOSAL_MAX]);
148 #endif
149 
150 Kex	*kex_setup(char *[PROPOSAL_MAX]);
151 void	 kex_finish(Kex *);
152 
153 void	 kex_send_kexinit(Kex *);
154 void	 kex_input_kexinit(int, u_int32_t, void *);
155 void	 kex_derive_keys(Kex *, u_char *, u_int, BIGNUM *);
156 
157 Newkeys *kex_get_newkeys(int);
158 
159 void	 kexdh_client(Kex *);
160 void	 kexdh_server(Kex *);
161 void	 kexgex_client(Kex *);
162 void	 kexgex_server(Kex *);
163 void	 kexecdh_client(Kex *);
164 void	 kexecdh_server(Kex *);
165 
166 void
167 kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int,
168     BIGNUM *, BIGNUM *, BIGNUM *, u_char **, u_int *);
169 void
170 kexgex_hash(const EVP_MD *, char *, char *, char *, int, char *,
171     int, u_char *, int, int, int, int, BIGNUM *, BIGNUM *, BIGNUM *,
172     BIGNUM *, BIGNUM *, u_char **, u_int *);
173 #ifdef OPENSSL_HAS_ECC
174 void
175 kex_ecdh_hash(const EVP_MD *, const EC_GROUP *, char *, char *, char *, int,
176     char *, int, u_char *, int, const EC_POINT *, const EC_POINT *,
177     const BIGNUM *, u_char **, u_int *);
178 int	kex_ecdh_name_to_nid(const char *);
179 const EVP_MD *kex_ecdh_name_to_evpmd(const char *);
180 #else
181 # define kex_ecdh_name_to_nid(x) (-1)
182 # define kex_ecdh_name_to_evpmd(x) (NULL)
183 #endif
184 
185 void
186 derive_ssh1_session_id(BIGNUM *, BIGNUM *, u_int8_t[8], u_int8_t[16]);
187 
188 #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) || defined(DEBUG_KEXECDH)
189 void	dump_digest(char *, u_char *, int);
190 #endif
191 
192 #endif
193