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 1.56 2001/12/19 07:18:56 deraadt Exp $");
  27
  28 #include "packet.h"
  29 #include "xmalloc.h"
  30 #include "compat.h"
  31 #include "log.h"
  32 #include "match.h"
  33
  34 int compat13 = 0;
  35 int compat20 = 0;
  36 int datafellows = 0;
  37
  38 void
  39 enable_compat20(void)
  40 {
  41         verbose("Enabling compatibility mode for protocol 2.0");
  42         compat20 = 1;
  43 }
  44 void
  45 enable_compat13(void)
  46 {
  47         verbose("Enabling compatibility mode for protocol 1.3");
  48         compat13 = 1;
  49 }
  50 /* datafellows bug compatibility */
  51 void
  52 compat_datafellows(const char *version)
  53 {
  54         int i;
  55         static struct {
  56                 char    *pat;
  57                 int     bugs;
  58         } check[] = {
  59                 { "OpenSSH-2.0*,"
  60                   "OpenSSH-2.1*,"
  61                   "OpenSSH_2.1*,"
  62                   "OpenSSH_2.2*",       SSH_OLD_SESSIONID|SSH_BUG_BANNER|
  63                                         SSH_OLD_DHGEX|SSH_BUG_NOREKEY },
  64                 { "OpenSSH_2.3.0*",     SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES|
  65                                         SSH_OLD_DHGEX|SSH_BUG_NOREKEY},
  66                 { "OpenSSH_2.3.*",      SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
  67                                         SSH_BUG_NOREKEY},
  68                 { "OpenSSH_2.5.0p1*,"
  69                   "OpenSSH_2.5.1p1*",
  70                                         SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
  71                                         SSH_BUG_NOREKEY },
  72                 { "OpenSSH_2.5.0*,"
  73                   "OpenSSH_2.5.1*,"
  74                   "OpenSSH_2.5.2*",     SSH_OLD_DHGEX|SSH_BUG_NOREKEY },
  75                 { "OpenSSH_2.5.3*",
  76                                         SSH_BUG_NOREKEY },
  77                 { "OpenSSH*",           0 },
  78                 { "*MindTerm*",         0 },
  79                 { "2.1.0*",             SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
  80                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
  81                                         SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE },
  82                 { "2.1 *",              SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
  83                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
  84                                         SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE },
  85                 { "2.0.13*,"
  86                   "2.0.14*,"
  87                   "2.0.15*,"
  88                   "2.0.16*,"
  89                   "2.0.17*,"
  90                   "2.0.18*,"
  91                   "2.0.19*",            SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
  92                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
  93                                         SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
  94                                         SSH_BUG_PKOK|SSH_BUG_RSASIGMD5|
  95                                         SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE|
  96                                         SSH_BUG_DUMMYCHAN },
  97                 { "2.0.11*,"
  98                   "2.0.12*",            SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
  99                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
 100                                         SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
 101                                         SSH_BUG_PKAUTH|SSH_BUG_PKOK|
 102                                         SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
 103                                         SSH_BUG_DUMMYCHAN },
 104                 { "2.0.*",              SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
 105                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
 106                                         SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
 107                                         SSH_BUG_PKAUTH|SSH_BUG_PKOK|
 108                                         SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
 109                                         SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN },
 110                 { "2.2.0*,"
 111                   "2.3.0*",             SSH_BUG_HMAC|SSH_BUG_DEBUG|
 112                                         SSH_BUG_RSASIGMD5 },
 113                 { "2.3.*",              SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5 },
 114                 { "2.4",                SSH_OLD_SESSIONID },    /* Van Dyke */
 115                 { "2.*",                SSH_BUG_DEBUG },
 116                 { "3.0.*",              SSH_BUG_DEBUG },
 117                 { "3.0 SecureCRT*",     SSH_OLD_SESSIONID },
 118                 { "1.7 SecureFX*",      SSH_OLD_SESSIONID },
 119                 { "1.2.18*,"
 120                   "1.2.19*,"
 121                   "1.2.20*,"
 122                   "1.2.21*,"
 123                   "1.2.22*",            SSH_BUG_IGNOREMSG },
 124                 { "1.3.2*",             SSH_BUG_IGNOREMSG },    /* f-secure */
 125                 { "*SSH Compatible Server*",                    /* Netscreen */
 126                                         SSH_BUG_PASSWORDPAD },
 127                 { "*OSU_0*,"
 128                   "OSU_1.0*,"
 129                   "OSU_1.1*,"
 130                   "OSU_1.2*,"
 131                   "OSU_1.3*,"
 132                   "OSU_1.4*,"
 133                   "OSU_1.5alpha1*,"
 134                   "OSU_1.5alpha2*,"
 135                   "OSU_1.5alpha3*",     SSH_BUG_PASSWORDPAD },
 136                 { "*SSH_Version_Mapper*",
 137                                         SSH_BUG_SCANNER },
 138                 { NULL,                 0 }
 139         };
 140
 141         /* process table, return first match */
 142         for (i = 0; check[i].pat; i++) {
 143                 if (match_pattern_list(version, check[i].pat,
 144                     strlen(check[i].pat), 0) == 1) {
 145                         debug("match: %s pat %s", version, check[i].pat);
 146                         datafellows = check[i].bugs;
 147                         return;
 148                 }
 149         }
 150         debug("no match: %s", version);
 151 }
 152
 153 #define SEP     ","
 154 int
 155 proto_spec(const char *spec)
 156 {
 157         char *s, *p, *q;
 158         int ret = SSH_PROTO_UNKNOWN;
 159
 160         if (spec == NULL)
 161                 return ret;
 162         q = s = xstrdup(spec);
 163         for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) {
 164                 switch (atoi(p)) {
 165                 case 1:
 166                         if (ret == SSH_PROTO_UNKNOWN)
 167                                 ret |= SSH_PROTO_1_PREFERRED;
 168                         ret |= SSH_PROTO_1;
 169                         break;
 170                 case 2:
 171                         ret |= SSH_PROTO_2;
 172                         break;
 173                 default:
 174                         log("ignoring bad proto spec: '%s'.", p);
 175                         break;
 176                 }
 177         }
 178         xfree(s);
 179         return ret;
 180 }
 181
 182 char *
 183 compat_cipher_proposal(char *cipher_prop)
 184 {
 185         char *orig_prop, *fix_ciphers;
 186         char *cp, *tmp;
 187         size_t len;
 188
 189         if (!(datafellows & SSH_BUG_BIGENDIANAES))
 190                 return(cipher_prop);
 191
 192         len = strlen(cipher_prop) + 1;
 193         fix_ciphers = xmalloc(len);
 194         *fix_ciphers = '\0';
 195         tmp = orig_prop = xstrdup(cipher_prop);
 196         while ((cp = strsep(&tmp, ",")) != NULL) {
 197                 if (strncmp(cp, "aes", 3) && strncmp(cp, "rijndael", 8)) {
 198                         if (*fix_ciphers)
 199                                 strlcat(fix_ciphers, ",", len);
 200                         strlcat(fix_ciphers, cp, len);
 201                 }
 202         }
 203         xfree(orig_prop);
 204         debug2("Original cipher proposal: %s", cipher_prop);
 205         debug2("Compat cipher proposal: %s", fix_ciphers);
 206         if (!*fix_ciphers)
 207                 fatal("No available ciphers found.");
 208
 209         return(fix_ciphers);
 210 }