kex.h

   1 /* $OpenBSD: kex.h,v 1.47 2009/05/27 06:34:36 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
  40 #define COMP_NONE       0
  41 #define COMP_ZLIB       1
  42 #define COMP_DELAYED    2
  43
  44 enum kex_init_proposals {
  45         PROPOSAL_KEX_ALGS,
  46         PROPOSAL_SERVER_HOST_KEY_ALGS,
  47         PROPOSAL_ENC_ALGS_CTOS,
  48         PROPOSAL_ENC_ALGS_STOC,
  49         PROPOSAL_MAC_ALGS_CTOS,
  50         PROPOSAL_MAC_ALGS_STOC,
  51         PROPOSAL_COMP_ALGS_CTOS,
  52         PROPOSAL_COMP_ALGS_STOC,
  53         PROPOSAL_LANG_CTOS,
  54         PROPOSAL_LANG_STOC,
  55         PROPOSAL_MAX
  56 };
  57
  58 enum kex_modes {
  59         MODE_IN,
  60         MODE_OUT,
  61         MODE_MAX
  62 };
  63
  64 enum kex_exchange {
  65         KEX_DH_GRP1_SHA1,
  66         KEX_DH_GRP14_SHA1,
  67         KEX_DH_GEX_SHA1,
  68         KEX_DH_GEX_SHA256,
  69         KEX_MAX
  70 };
  71
  72 #define KEX_INIT_SENT   0x0001
  73
  74 typedef struct Kex Kex;
  75 typedef struct Mac Mac;
  76 typedef struct Comp Comp;
  77 typedef struct Enc Enc;
  78 typedef struct Newkeys Newkeys;
  79
  80 struct Enc {
  81         char    *name;
  82         Cipher  *cipher;
  83         int     enabled;
  84         u_int   key_len;
  85         u_int   block_size;
  86         u_char  *key;
  87         u_char  *iv;
  88 };
  89 struct Mac {
  90         char    *name;
  91         int     enabled;
  92         u_int   mac_len;
  93         u_char  *key;
  94         u_int   key_len;
  95         int     type;
  96         const EVP_MD    *evp_md;
  97         HMAC_CTX        evp_ctx;
  98         struct umac_ctx *umac_ctx;
  99 };
 100 struct Comp {
 101         int     type;
 102         int     enabled;
 103         char    *name;
 104 };
 105 struct Newkeys {
 106         Enc     enc;
 107         Mac     mac;
 108         Comp    comp;
 109 };
 110 struct Kex {
 111         u_char  *session_id;
 112         u_int   session_id_len;
 113         Newkeys *newkeys[MODE_MAX];
 114         u_int   we_need;
 115         int     server;
 116         char    *name;
 117         int     hostkey_type;
 118         int     kex_type;
 119         Buffer  my;
 120         Buffer  peer;
 121         sig_atomic_t done;
 122         int     flags;
 123         const EVP_MD *evp_md;
 124         char    *client_version_string;
 125         char    *server_version_string;
 126         int     (*verify_host_key)(Key *);
 127         Key     *(*load_host_key)(int);
 128         int     (*host_key_index)(Key *);
 129         void    (*kex[KEX_MAX])(Kex *);
 130 };
 131
 132 Kex     *kex_setup(char *[PROPOSAL_MAX]);
 133 void     kex_finish(Kex *);
 134
 135 void     kex_send_kexinit(Kex *);
 136 void     kex_input_kexinit(int, u_int32_t, void *);
 137 void     kex_derive_keys(Kex *, u_char *, u_int, BIGNUM *);
 138
 139 Newkeys *kex_get_newkeys(int);
 140
 141 void     kexdh_client(Kex *);
 142 void     kexdh_server(Kex *);
 143 void     kexgex_client(Kex *);
 144 void     kexgex_server(Kex *);
 145
 146 void
 147 kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int,
 148     BIGNUM *, BIGNUM *, BIGNUM *, u_char **, u_int *);
 149 void
 150 kexgex_hash(const EVP_MD *, char *, char *, char *, int, char *,
 151     int, u_char *, int, int, int, int, BIGNUM *, BIGNUM *, BIGNUM *,
 152     BIGNUM *, BIGNUM *, u_char **, u_int *);
 153
 154 void
 155 derive_ssh1_session_id(BIGNUM *, BIGNUM *, u_int8_t[8], u_int8_t[16]);
 156
 157 #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH)
 158 void    dump_digest(char *, u_char *, int);
 159 #endif
 160
 161 #endif