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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 (at) 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