kex.h

   1 /* $OpenBSD: kex.h,v 1.44 2006/08/03 03:34:42 deraadt 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
  32 #define KEX_DH1                 "diffie-hellman-group1-sha1"
  33 #define KEX_DH14                "diffie-hellman-group14-sha1"
  34 #define KEX_DHGEX_SHA1          "diffie-hellman-group-exchange-sha1"
  35 #define KEX_DHGEX_SHA256        "diffie-hellman-group-exchange-sha256"
  36
  37 #define COMP_NONE       0
  38 #define COMP_ZLIB       1
  39 #define COMP_DELAYED    2
  40
  41 enum kex_init_proposals {
  42         PROPOSAL_KEX_ALGS,
  43         PROPOSAL_SERVER_HOST_KEY_ALGS,
  44         PROPOSAL_ENC_ALGS_CTOS,
  45         PROPOSAL_ENC_ALGS_STOC,
  46         PROPOSAL_MAC_ALGS_CTOS,
  47         PROPOSAL_MAC_ALGS_STOC,
  48         PROPOSAL_COMP_ALGS_CTOS,
  49         PROPOSAL_COMP_ALGS_STOC,
  50         PROPOSAL_LANG_CTOS,
  51         PROPOSAL_LANG_STOC,
  52         PROPOSAL_MAX
  53 };
  54
  55 enum kex_modes {
  56         MODE_IN,
  57         MODE_OUT,
  58         MODE_MAX
  59 };
  60
  61 enum kex_exchange {
  62         KEX_DH_GRP1_SHA1,
  63         KEX_DH_GRP14_SHA1,
  64         KEX_DH_GEX_SHA1,
  65         KEX_DH_GEX_SHA256,
  66         KEX_MAX
  67 };
  68
  69 #define KEX_INIT_SENT   0x0001
  70
  71 typedef struct Kex Kex;
  72 typedef struct Mac Mac;
  73 typedef struct Comp Comp;
  74 typedef struct Enc Enc;
  75 typedef struct Newkeys Newkeys;
  76
  77 struct Enc {
  78         char    *name;
  79         Cipher  *cipher;
  80         int     enabled;
  81         u_int   key_len;
  82         u_int   block_size;
  83         u_char  *key;
  84         u_char  *iv;
  85 };
  86 struct Mac {
  87         char    *name;
  88         int     enabled;
  89         const EVP_MD    *md;
  90         u_int   mac_len;
  91         u_char  *key;
  92         u_int   key_len;
  93 };
  94 struct Comp {
  95         int     type;
  96         int     enabled;
  97         char    *name;
  98 };
  99 struct Newkeys {
 100         Enc     enc;
 101         Mac     mac;
 102         Comp    comp;
 103 };
 104 struct Kex {
 105         u_char  *session_id;
 106         u_int   session_id_len;
 107         Newkeys *newkeys[MODE_MAX];
 108         u_int   we_need;
 109         int     server;
 110         char    *name;
 111         int     hostkey_type;
 112         int     kex_type;
 113         Buffer  my;
 114         Buffer  peer;
 115         sig_atomic_t done;
 116         int     flags;
 117         const EVP_MD *evp_md;
 118         char    *client_version_string;
 119         char    *server_version_string;
 120         int     (*verify_host_key)(Key *);
 121         Key     *(*load_host_key)(int);
 122         int     (*host_key_index)(Key *);
 123         void    (*kex[KEX_MAX])(Kex *);
 124 };
 125
 126 Kex     *kex_setup(char *[PROPOSAL_MAX]);
 127 void     kex_finish(Kex *);
 128
 129 void     kex_send_kexinit(Kex *);
 130 void     kex_input_kexinit(int, u_int32_t, void *);
 131 void     kex_derive_keys(Kex *, u_char *, u_int, BIGNUM *);
 132
 133 Newkeys *kex_get_newkeys(int);
 134
 135 void     kexdh_client(Kex *);
 136 void     kexdh_server(Kex *);
 137 void     kexgex_client(Kex *);
 138 void     kexgex_server(Kex *);
 139
 140 void
 141 kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int,
 142     BIGNUM *, BIGNUM *, BIGNUM *, u_char **, u_int *);
 143 void
 144 kexgex_hash(const EVP_MD *, char *, char *, char *, int, char *,
 145     int, u_char *, int, int, int, int, BIGNUM *, BIGNUM *, BIGNUM *,
 146     BIGNUM *, BIGNUM *, u_char **, u_int *);
 147
 148 void
 149 derive_ssh1_session_id(BIGNUM *, BIGNUM *, u_int8_t[8], u_int8_t[16]);
 150
 151 #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH)
 152 void    dump_digest(char *, u_char *, int);
 153 #endif
 154
 155 #endif