kex.h

   1 /* $OpenBSD: kex.h,v 1.51 2010/09/09 10:45:45 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@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 Kex     *kex_setup(char *[PROPOSAL_MAX]);
 142 void     kex_finish(Kex *);
 143
 144 void     kex_send_kexinit(Kex *);
 145 void     kex_input_kexinit(int, u_int32_t, void *);
 146 void     kex_derive_keys(Kex *, u_char *, u_int, BIGNUM *);
 147
 148 Newkeys *kex_get_newkeys(int);
 149
 150 void     kexdh_client(Kex *);
 151 void     kexdh_server(Kex *);
 152 void     kexgex_client(Kex *);
 153 void     kexgex_server(Kex *);
 154 void     kexecdh_client(Kex *);
 155 void     kexecdh_server(Kex *);
 156
 157 void
 158 kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int,
 159     BIGNUM *, BIGNUM *, BIGNUM *, u_char **, u_int *);
 160 void
 161 kexgex_hash(const EVP_MD *, char *, char *, char *, int, char *,
 162     int, u_char *, int, int, int, int, BIGNUM *, BIGNUM *, BIGNUM *,
 163     BIGNUM *, BIGNUM *, u_char **, u_int *);
 164 #ifdef OPENSSL_HAS_ECC
 165 void
 166 kex_ecdh_hash(const EVP_MD *, const EC_GROUP *, char *, char *, char *, int,
 167     char *, int, u_char *, int, const EC_POINT *, const EC_POINT *,
 168     const BIGNUM *, u_char **, u_int *);
 169 int     kex_ecdh_name_to_nid(const char *);
 170 const EVP_MD *kex_ecdh_name_to_evpmd(const char *);
 171 #else
 172 # define kex_ecdh_name_to_evpmd(x) NULL
 173 #endif
 174
 175 void
 176 derive_ssh1_session_id(BIGNUM *, BIGNUM *, u_int8_t[8], u_int8_t[16]);
 177
 178 #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) || defined(DEBUG_KEXECDH)
 179 void    dump_digest(char *, u_char *, int);
 180 #endif
 181
 182 #endif