compat.c

   1 /*
   2  * Copyright (c) 1999, 2000, 2001 Markus Friedl.  All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  14  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  15  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  16  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  17  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  18  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  19  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  20  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  21  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  22  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  23  */
  24
  25 #include "includes.h"
  26 RCSID("$OpenBSD: compat.c,v 1.59 2002/03/06 00:20:54 markus Exp $");
  27
  28 #include "buffer.h"
  29 #include "packet.h"
  30 #include "xmalloc.h"
  31 #include "compat.h"
  32 #include "log.h"
  33 #include "match.h"
  34
  35 int compat13 = 0;
  36 int compat20 = 0;
  37 int datafellows = 0;
  38
  39 void
  40 enable_compat20(void)
  41 {
  42         verbose("Enabling compatibility mode for protocol 2.0");
  43         compat20 = 1;
  44 }
  45 void
  46 enable_compat13(void)
  47 {
  48         verbose("Enabling compatibility mode for protocol 1.3");
  49         compat13 = 1;
  50 }
  51 /* datafellows bug compatibility */
  52 void
  53 compat_datafellows(const char *version)
  54 {
  55         int i;
  56         static struct {
  57                 char    *pat;
  58                 int     bugs;
  59         } check[] = {
  60                 { "OpenSSH-2.0*,"
  61                   "OpenSSH-2.1*,"
  62                   "OpenSSH_2.1*,"
  63                   "OpenSSH_2.2*",       SSH_OLD_SESSIONID|SSH_BUG_BANNER|
  64                                         SSH_OLD_DHGEX|SSH_BUG_NOREKEY },
  65                 { "OpenSSH_2.3.0*",     SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES|
  66                                         SSH_OLD_DHGEX|SSH_BUG_NOREKEY},
  67                 { "OpenSSH_2.3.*",      SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
  68                                         SSH_BUG_NOREKEY},
  69                 { "OpenSSH_2.5.0p1*,"
  70                   "OpenSSH_2.5.1p1*",
  71                                         SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
  72                                         SSH_BUG_NOREKEY },
  73                 { "OpenSSH_2.5.0*,"
  74                   "OpenSSH_2.5.1*,"
  75                   "OpenSSH_2.5.2*",     SSH_OLD_DHGEX|SSH_BUG_NOREKEY },
  76                 { "OpenSSH_2.5.3*",     SSH_BUG_NOREKEY },
  77                 { "Sun_SSH_1.0*",       SSH_BUG_NOREKEY },
  78                 { "OpenSSH*",           0 },
  79                 { "*MindTerm*",         0 },
  80                 { "2.1.0*",             SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
  81                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
  82                                         SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE },
  83                 { "2.1 *",              SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
  84                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
  85                                         SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE },
  86                 { "2.0.13*,"
  87                   "2.0.14*,"
  88                   "2.0.15*,"
  89                   "2.0.16*,"
  90                   "2.0.17*,"
  91                   "2.0.18*,"
  92                   "2.0.19*",            SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
  93                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
  94                                         SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
  95                                         SSH_BUG_PKOK|SSH_BUG_RSASIGMD5|
  96                                         SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE|
  97                                         SSH_BUG_DUMMYCHAN },
  98                 { "2.0.11*,"
  99                   "2.0.12*",            SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
 100                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
 101                                         SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
 102                                         SSH_BUG_PKAUTH|SSH_BUG_PKOK|
 103                                         SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
 104                                         SSH_BUG_DUMMYCHAN },
 105                 { "2.0.*",              SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
 106                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
 107                                         SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
 108                                         SSH_BUG_PKAUTH|SSH_BUG_PKOK|
 109                                         SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
 110                                         SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN },
 111                 { "2.2.0*,"
 112                   "2.3.0*",             SSH_BUG_HMAC|SSH_BUG_DEBUG|
 113                                         SSH_BUG_RSASIGMD5 },
 114                 { "2.3.*",              SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5 },
 115                 { "2.4",                SSH_OLD_SESSIONID },    /* Van Dyke */
 116                 { "2.*",                SSH_BUG_DEBUG },
 117                 { "3.0.*",              SSH_BUG_DEBUG },
 118                 { "3.0 SecureCRT*",     SSH_OLD_SESSIONID },
 119                 { "1.7 SecureFX*",      SSH_OLD_SESSIONID },
 120                 { "1.2.18*,"
 121                   "1.2.19*,"
 122                   "1.2.20*,"
 123                   "1.2.21*,"
 124                   "1.2.22*",            SSH_BUG_IGNOREMSG },
 125                 { "1.3.2*",             SSH_BUG_IGNOREMSG },    /* f-secure */
 126                 { "*SSH Compatible Server*",                    /* Netscreen */
 127                                         SSH_BUG_PASSWORDPAD },
 128                 { "*OSU_0*,"
 129                   "OSU_1.0*,"
 130                   "OSU_1.1*,"
 131                   "OSU_1.2*,"
 132                   "OSU_1.3*,"
 133                   "OSU_1.4*,"
 134                   "OSU_1.5alpha1*,"
 135                   "OSU_1.5alpha2*,"
 136                   "OSU_1.5alpha3*",     SSH_BUG_PASSWORDPAD },
 137                 { "*SSH_Version_Mapper*",
 138                                         SSH_BUG_SCANNER },
 139                 { NULL,                 0 }
 140         };
 141
 142         /* process table, return first match */
 143         for (i = 0; check[i].pat; i++) {
 144                 if (match_pattern_list(version, check[i].pat,
 145                     strlen(check[i].pat), 0) == 1) {
 146                         debug("match: %s pat %s", version, check[i].pat);
 147                         datafellows = check[i].bugs;
 148                         return;
 149                 }
 150         }
 151         debug("no match: %s", version);
 152 }
 153
 154 #define SEP     ","
 155 int
 156 proto_spec(const char *spec)
 157 {
 158         char *s, *p, *q;
 159         int ret = SSH_PROTO_UNKNOWN;
 160
 161         if (spec == NULL)
 162                 return ret;
 163         q = s = xstrdup(spec);
 164         for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) {
 165                 switch (atoi(p)) {
 166                 case 1:
 167                         if (ret == SSH_PROTO_UNKNOWN)
 168                                 ret |= SSH_PROTO_1_PREFERRED;
 169                         ret |= SSH_PROTO_1;
 170                         break;
 171                 case 2:
 172                         ret |= SSH_PROTO_2;
 173                         break;
 174                 default:
 175                         log("ignoring bad proto spec: '%s'.", p);
 176                         break;
 177                 }
 178         }
 179         xfree(s);
 180         return ret;
 181 }
 182
 183 char *
 184 compat_cipher_proposal(char *cipher_prop)
 185 {
 186         Buffer b;
 187         char *orig_prop, *fix_ciphers;
 188         char *cp, *tmp;
 189
 190         if (!(datafellows & SSH_BUG_BIGENDIANAES))
 191                 return(cipher_prop);
 192
 193         buffer_init(&b);
 194         tmp = orig_prop = xstrdup(cipher_prop);
 195         while ((cp = strsep(&tmp, ",")) != NULL) {
 196                 if (strncmp(cp, "aes", 3) != 0) {
 197                         if (buffer_len(&b) > 0)
 198                                 buffer_append(&b, ",", 1);
 199                         buffer_append(&b, cp, strlen(cp));
 200                 }
 201         }
 202         buffer_append(&b, "\0", 1);
 203         fix_ciphers = xstrdup(buffer_ptr(&b));
 204         buffer_free(&b);
 205         xfree(orig_prop);
 206         debug2("Original cipher proposal: %s", cipher_prop);
 207         debug2("Compat cipher proposal: %s", fix_ciphers);
 208         if (!*fix_ciphers)
 209                 fatal("No available ciphers found.");
 210
 211         return(fix_ciphers);
 212 }