kex.h

   1 /* $OpenBSD: kex.h,v 1.48 2009/10/24 11:13:54 andreas 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
  33 #define KEX_COOKIE_LEN  16
  34
  35 #define KEX_DH1                 "diffie-hellman-group1-sha1"
  36 #define KEX_DH14                "diffie-hellman-group14-sha1"
  37 #define KEX_DHGEX_SHA1          "diffie-hellman-group-exchange-sha1"
  38 #define KEX_DHGEX_SHA256        "diffie-hellman-group-exchange-sha256"
  39 #define KEX_RESUME              "resume@appgate.com"
  40
  41 #define COMP_NONE       0
  42 #define COMP_ZLIB       1
  43 #define COMP_DELAYED    2
  44
  45 enum kex_init_proposals {
  46         PROPOSAL_KEX_ALGS,
  47         PROPOSAL_SERVER_HOST_KEY_ALGS,
  48         PROPOSAL_ENC_ALGS_CTOS,
  49         PROPOSAL_ENC_ALGS_STOC,
  50         PROPOSAL_MAC_ALGS_CTOS,
  51         PROPOSAL_MAC_ALGS_STOC,
  52         PROPOSAL_COMP_ALGS_CTOS,
  53         PROPOSAL_COMP_ALGS_STOC,
  54         PROPOSAL_LANG_CTOS,
  55         PROPOSAL_LANG_STOC,
  56         PROPOSAL_MAX
  57 };
  58
  59 enum kex_modes {
  60         MODE_IN,
  61         MODE_OUT,
  62         MODE_MAX
  63 };
  64
  65 enum kex_exchange {
  66         KEX_DH_GRP1_SHA1,
  67         KEX_DH_GRP14_SHA1,
  68         KEX_DH_GEX_SHA1,
  69         KEX_DH_GEX_SHA256,
  70         KEX_MAX
  71 };
  72
  73 #define KEX_INIT_SENT   0x0001
  74
  75 typedef struct Kex Kex;
  76 typedef struct Mac Mac;
  77 typedef struct Comp Comp;
  78 typedef struct Enc Enc;
  79 typedef struct Newkeys Newkeys;
  80
  81 struct Enc {
  82         char    *name;
  83         Cipher  *cipher;
  84         int     enabled;
  85         u_int   key_len;
  86         u_int   block_size;
  87         u_char  *key;
  88         u_char  *iv;
  89 };
  90 struct Mac {
  91         char    *name;
  92         int     enabled;
  93         u_int   mac_len;
  94         u_char  *key;
  95         u_int   key_len;
  96         int     type;
  97         const EVP_MD    *evp_md;
  98         HMAC_CTX        evp_ctx;
  99         struct umac_ctx *umac_ctx;
 100 };
 101 struct Comp {
 102         int     type;
 103         int     enabled;
 104         char    *name;
 105 };
 106 struct Newkeys {
 107         Enc     enc;
 108         Mac     mac;
 109         Comp    comp;
 110 };
 111 struct Kex {
 112         u_char  *session_id;
 113         u_int   session_id_len;
 114         Newkeys *newkeys[MODE_MAX];
 115         u_int   we_need;
 116         int     server;
 117         char    *name;
 118         int     hostkey_type;
 119         int     kex_type;
 120         int     roaming;
 121         Buffer  my;
 122         Buffer  peer;
 123         sig_atomic_t done;
 124         int     flags;
 125         const EVP_MD *evp_md;
 126         char    *client_version_string;
 127         char    *server_version_string;
 128         int     (*verify_host_key)(Key *);
 129         Key     *(*load_host_key)(int);
 130         int     (*host_key_index)(Key *);
 131         void    (*kex[KEX_MAX])(Kex *);
 132 };
 133
 134 Kex     *kex_setup(char *[PROPOSAL_MAX]);
 135 void     kex_finish(Kex *);
 136
 137 void     kex_send_kexinit(Kex *);
 138 void     kex_input_kexinit(int, u_int32_t, void *);
 139 void     kex_derive_keys(Kex *, u_char *, u_int, BIGNUM *);
 140
 141 Newkeys *kex_get_newkeys(int);
 142
 143 void     kexdh_client(Kex *);
 144 void     kexdh_server(Kex *);
 145 void     kexgex_client(Kex *);
 146 void     kexgex_server(Kex *);
 147
 148 void
 149 kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int,
 150     BIGNUM *, BIGNUM *, BIGNUM *, u_char **, u_int *);
 151 void
 152 kexgex_hash(const EVP_MD *, char *, char *, char *, int, char *,
 153     int, u_char *, int, int, int, int, BIGNUM *, BIGNUM *, BIGNUM *,
 154     BIGNUM *, BIGNUM *, u_char **, u_int *);
 155
 156 void
 157 derive_ssh1_session_id(BIGNUM *, BIGNUM *, u_int8_t[8], u_int8_t[16]);
 158
 159 #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH)
 160 void    dump_digest(char *, u_char *, int);
 161 #endif
 162
 163 #endif