compat.c

   1 /*
   2  * Copyright (c) 1999, 2000, 2001, 2002 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
  27 #include "buffer.h"
  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         debug("Enabling compatibility mode for protocol 2.0");
  42         compat20 = 1;
  43 }
  44 void
  45 enable_compat13(void)
  46 {
  47         debug("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                                         SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
  65                 { "OpenSSH_2.3.0*",     SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES|
  66                                         SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
  67                                         SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
  68                 { "OpenSSH_2.3.*",      SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
  69                                         SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
  70                                         SSH_OLD_FORWARD_ADDR},
  71                 { "OpenSSH_2.5.0p1*,"
  72                   "OpenSSH_2.5.1p1*",
  73                                         SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
  74                                         SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
  75                                         SSH_OLD_FORWARD_ADDR},
  76                 { "OpenSSH_2.5.0*,"
  77                   "OpenSSH_2.5.1*,"
  78                   "OpenSSH_2.5.2*",     SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
  79                                         SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
  80                 { "OpenSSH_2.5.3*",     SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
  81                                         SSH_OLD_FORWARD_ADDR},
  82                 { "OpenSSH_2.*,"
  83                   "OpenSSH_3.0*,"
  84                   "OpenSSH_3.1*",       SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
  85                 { "OpenSSH_3.*",        SSH_OLD_FORWARD_ADDR },
  86                 { "Sun_SSH_1.0*",       SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
  87                 { "OpenSSH*",           0 },
  88                 { "*MindTerm*",         0 },
  89                 { "2.1.0*",             SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
  90                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
  91                                         SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
  92                                         SSH_BUG_FIRSTKEX },
  93                 { "2.1 *",              SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
  94                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
  95                                         SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
  96                                         SSH_BUG_FIRSTKEX },
  97                 { "2.0.13*,"
  98                   "2.0.14*,"
  99                   "2.0.15*,"
 100                   "2.0.16*,"
 101                   "2.0.17*,"
 102                   "2.0.18*,"
 103                   "2.0.19*",            SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
 104                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
 105                                         SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
 106                                         SSH_BUG_PKOK|SSH_BUG_RSASIGMD5|
 107                                         SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE|
 108                                         SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
 109                 { "2.0.11*,"
 110                   "2.0.12*",            SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
 111                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
 112                                         SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
 113                                         SSH_BUG_PKAUTH|SSH_BUG_PKOK|
 114                                         SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
 115                                         SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
 116                 { "2.0.*",              SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
 117                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
 118                                         SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
 119                                         SSH_BUG_PKAUTH|SSH_BUG_PKOK|
 120                                         SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
 121                                         SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN|
 122                                         SSH_BUG_FIRSTKEX },
 123                 { "2.2.0*,"
 124                   "2.3.0*",             SSH_BUG_HMAC|SSH_BUG_DEBUG|
 125                                         SSH_BUG_RSASIGMD5|SSH_BUG_FIRSTKEX },
 126                 { "2.3.*",              SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5|
 127                                         SSH_BUG_FIRSTKEX },
 128                 { "2.4",                SSH_OLD_SESSIONID },    /* Van Dyke */
 129                 { "2.*",                SSH_BUG_DEBUG|SSH_BUG_FIRSTKEX },
 130                 { "3.0.*",              SSH_BUG_DEBUG },
 131                 { "3.0 SecureCRT*",     SSH_OLD_SESSIONID },
 132                 { "1.7 SecureFX*",      SSH_OLD_SESSIONID },
 133                 { "1.2.18*,"
 134                   "1.2.19*,"
 135                   "1.2.20*,"
 136                   "1.2.21*,"
 137                   "1.2.22*",            SSH_BUG_IGNOREMSG },
 138                 { "1.3.2*",             /* F-Secure */
 139                                         SSH_BUG_IGNOREMSG },
 140                 { "*SSH Compatible Server*",                    /* Netscreen */
 141                                         SSH_BUG_PASSWORDPAD },
 142                 { "*OSU_0*,"
 143                   "OSU_1.0*,"
 144                   "OSU_1.1*,"
 145                   "OSU_1.2*,"
 146                   "OSU_1.3*,"
 147                   "OSU_1.4*,"
 148                   "OSU_1.5alpha1*,"
 149                   "OSU_1.5alpha2*,"
 150                   "OSU_1.5alpha3*",     SSH_BUG_PASSWORDPAD },
 151                 { "*SSH_Version_Mapper*",
 152                                         SSH_BUG_SCANNER },
 153                 { "Probe-*",
 154                                         SSH_BUG_PROBE },
 155                 { NULL,                 0 }
 156         };
 157
 158         /* process table, return first match */
 159         for (i = 0; check[i].pat; i++) {
 160                 if (match_pattern_list(version, check[i].pat,
 161                     strlen(check[i].pat), 0) == 1) {
 162                         debug("match: %s pat %s", version, check[i].pat);
 163                         datafellows = check[i].bugs;
 164                         return;
 165                 }
 166         }
 167         debug("no match: %s", version);
 168 }
 169
 170 #define SEP     ","
 171 int
 172 proto_spec(const char *spec)
 173 {
 174         char *s, *p, *q;
 175         int ret = SSH_PROTO_UNKNOWN;
 176
 177         if (spec == NULL)
 178                 return ret;
 179         q = s = xstrdup(spec);
 180         for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) {
 181                 switch (atoi(p)) {
 182                 case 1:
 183                         if (ret == SSH_PROTO_UNKNOWN)
 184                                 ret |= SSH_PROTO_1_PREFERRED;
 185                         ret |= SSH_PROTO_1;
 186                         break;
 187                 case 2:
 188                         ret |= SSH_PROTO_2;
 189                         break;
 190                 default:
 191                         logit("ignoring bad proto spec: '%s'.", p);
 192                         break;
 193                 }
 194         }
 195         xfree(s);
 196         return ret;
 197 }
 198
 199 char *
 200 compat_cipher_proposal(char *cipher_prop)
 201 {
 202         Buffer b;
 203         char *orig_prop, *fix_ciphers;
 204         char *cp, *tmp;
 205
 206         if (!(datafellows & SSH_BUG_BIGENDIANAES))
 207                 return(cipher_prop);
 208
 209         buffer_init(&b);
 210         tmp = orig_prop = xstrdup(cipher_prop);
 211         while ((cp = strsep(&tmp, ",")) != NULL) {
 212                 if (strncmp(cp, "aes", 3) != 0) {
 213                         if (buffer_len(&b) > 0)
 214                                 buffer_append(&b, ",", 1);
 215                         buffer_append(&b, cp, strlen(cp));
 216                 }
 217         }
 218         buffer_append(&b, "\0", 1);
 219         fix_ciphers = xstrdup(buffer_ptr(&b));
 220         buffer_free(&b);
 221         xfree(orig_prop);
 222         debug2("Original cipher proposal: %s", cipher_prop);
 223         debug2("Compat cipher proposal: %s", fix_ciphers);
 224         if (!*fix_ciphers)
 225                 fatal("No available ciphers found.");
 226
 227         return(fix_ciphers);
 228 }