crypto/openssh/compat.c

   1 /* $OpenBSD: compat.c,v 1.79 2011/09/23 07:45:05 markus Exp $ */
   2 /* $FreeBSD$ */
   3 /*
   4  * Copyright (c) 1999, 2000, 2001, 2002 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
  27 #include "includes.h"
  28
  29 #include <sys/types.h>
  30
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <stdarg.h>
  34
  35 #include "xmalloc.h"
  36 #include "buffer.h"
  37 #include "packet.h"
  38 #include "compat.h"
  39 #include "log.h"
  40 #include "match.h"
  41
  42 int compat13 = 0;
  43 int compat20 = 0;
  44 int datafellows = 0;
  45
  46 void
  47 enable_compat20(void)
  48 {
  49         debug("Enabling compatibility mode for protocol 2.0");
  50         compat20 = 1;
  51 }
  52 void
  53 enable_compat13(void)
  54 {
  55         debug("Enabling compatibility mode for protocol 1.3");
  56         compat13 = 1;
  57 }
  58 /* datafellows bug compatibility */
  59 void
  60 compat_datafellows(const char *version)
  61 {
  62         int i;
  63         static struct {
  64                 char    *pat;
  65                 int     bugs;
  66         } check[] = {
  67                 { "OpenSSH-2.0*,"
  68                   "OpenSSH-2.1*,"
  69                   "OpenSSH_2.1*,"
  70                   "OpenSSH_2.2*",       SSH_OLD_SESSIONID|SSH_BUG_BANNER|
  71                                         SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
  72                                         SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
  73                 { "OpenSSH_2.3.0*",     SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES|
  74                                         SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
  75                                         SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
  76                 { "OpenSSH_2.3.*",      SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
  77                                         SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
  78                                         SSH_OLD_FORWARD_ADDR},
  79                 { "OpenSSH_2.5.0p1*,"
  80                   "OpenSSH_2.5.1p1*",
  81                                         SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
  82                                         SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
  83                                         SSH_OLD_FORWARD_ADDR},
  84                 { "OpenSSH_2.5.0*,"
  85                   "OpenSSH_2.5.1*,"
  86                   "OpenSSH_2.5.2*",     SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
  87                                         SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
  88                 { "OpenSSH_2.5.3*",     SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
  89                                         SSH_OLD_FORWARD_ADDR},
  90                 { "OpenSSH_2.*,"
  91                   "OpenSSH_3.0*,"
  92                   "OpenSSH_3.1*",       SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
  93                 { "OpenSSH_3.*",        SSH_OLD_FORWARD_ADDR },
  94                 { "Sun_SSH_1.0*",       SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
  95                 { "OpenSSH_4*",         0 },
  96                 { "OpenSSH_5*",         SSH_NEW_OPENSSH|SSH_BUG_DYNAMIC_RPORT},
  97                 { "OpenSSH*",           SSH_NEW_OPENSSH },
  98                 { "*MindTerm*",         0 },
  99                 { "2.1.0*",             SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
 100                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
 101                                         SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
 102                                         SSH_BUG_FIRSTKEX },
 103                 { "2.1 *",              SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
 104                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
 105                                         SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
 106                                         SSH_BUG_FIRSTKEX },
 107                 { "2.0.13*,"
 108                   "2.0.14*,"
 109                   "2.0.15*,"
 110                   "2.0.16*,"
 111                   "2.0.17*,"
 112                   "2.0.18*,"
 113                   "2.0.19*",            SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
 114                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
 115                                         SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
 116                                         SSH_BUG_PKOK|SSH_BUG_RSASIGMD5|
 117                                         SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE|
 118                                         SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
 119                 { "2.0.11*,"
 120                   "2.0.12*",            SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
 121                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
 122                                         SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
 123                                         SSH_BUG_PKAUTH|SSH_BUG_PKOK|
 124                                         SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
 125                                         SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
 126                 { "2.0.*",              SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
 127                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
 128                                         SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
 129                                         SSH_BUG_PKAUTH|SSH_BUG_PKOK|
 130                                         SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
 131                                         SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN|
 132                                         SSH_BUG_FIRSTKEX },
 133                 { "2.2.0*,"
 134                   "2.3.0*",             SSH_BUG_HMAC|SSH_BUG_DEBUG|
 135                                         SSH_BUG_RSASIGMD5|SSH_BUG_FIRSTKEX },
 136                 { "2.3.*",              SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5|
 137                                         SSH_BUG_FIRSTKEX },
 138                 { "2.4",                SSH_OLD_SESSIONID },    /* Van Dyke */
 139                 { "2.*",                SSH_BUG_DEBUG|SSH_BUG_FIRSTKEX|
 140                                         SSH_BUG_RFWD_ADDR },
 141                 { "3.0.*",              SSH_BUG_DEBUG },
 142                 { "3.0 SecureCRT*",     SSH_OLD_SESSIONID },
 143                 { "1.7 SecureFX*",      SSH_OLD_SESSIONID },
 144                 { "1.2.18*,"
 145                   "1.2.19*,"
 146                   "1.2.20*,"
 147                   "1.2.21*,"
 148                   "1.2.22*",            SSH_BUG_IGNOREMSG },
 149                 { "1.3.2*",             /* F-Secure */
 150                                         SSH_BUG_IGNOREMSG },
 151                 { "*SSH Compatible Server*",                    /* Netscreen */
 152                                         SSH_BUG_PASSWORDPAD },
 153                 { "*OSU_0*,"
 154                   "OSU_1.0*,"
 155                   "OSU_1.1*,"
 156                   "OSU_1.2*,"
 157                   "OSU_1.3*,"
 158                   "OSU_1.4*,"
 159                   "OSU_1.5alpha1*,"
 160                   "OSU_1.5alpha2*,"
 161                   "OSU_1.5alpha3*",     SSH_BUG_PASSWORDPAD },
 162                 { "*SSH_Version_Mapper*",
 163                                         SSH_BUG_SCANNER },
 164                 { "Probe-*",
 165                                         SSH_BUG_PROBE },
 166                 { NULL,                 0 }
 167         };
 168
 169         /* process table, return first match */
 170         for (i = 0; check[i].pat; i++) {
 171                 if (match_pattern_list(version, check[i].pat,
 172                     strlen(check[i].pat), 0) == 1) {
 173                         debug("match: %s pat %s", version, check[i].pat);
 174                         datafellows = check[i].bugs;
 175                         /*
 176                          * Check to see if the remote side is OpenSSH and not
 177                          * HPN.  It is utterly strange to check it from the
 178                          * version string and expose the option that way.
 179                          */
 180                         if (strstr(version,"OpenSSH") != NULL &&
 181                             strstr(version,"hpn") == NULL) {
 182                                 datafellows |= SSH_BUG_LARGEWINDOW;
 183                                 debug("Remote is not HPN-aware");
 184                         }
 185                         return;
 186                 }
 187         }
 188         debug("no match: %s", version);
 189 }
 190
 191 #define SEP     ","
 192 int
 193 proto_spec(const char *spec)
 194 {
 195         char *s, *p, *q;
 196         int ret = SSH_PROTO_UNKNOWN;
 197
 198         if (spec == NULL)
 199                 return ret;
 200         q = s = xstrdup(spec);
 201         for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) {
 202                 switch (atoi(p)) {
 203                 case 1:
 204                         if (ret == SSH_PROTO_UNKNOWN)
 205                                 ret |= SSH_PROTO_1_PREFERRED;
 206                         ret |= SSH_PROTO_1;
 207                         break;
 208                 case 2:
 209                         ret |= SSH_PROTO_2;
 210                         break;
 211                 default:
 212                         logit("ignoring bad proto spec: '%s'.", p);
 213                         break;
 214                 }
 215         }
 216         xfree(s);
 217         return ret;
 218 }
 219
 220 char *
 221 compat_cipher_proposal(char *cipher_prop)
 222 {
 223         Buffer b;
 224         char *orig_prop, *fix_ciphers;
 225         char *cp, *tmp;
 226
 227         if (!(datafellows & SSH_BUG_BIGENDIANAES))
 228                 return(cipher_prop);
 229
 230         buffer_init(&b);
 231         tmp = orig_prop = xstrdup(cipher_prop);
 232         while ((cp = strsep(&tmp, ",")) != NULL) {
 233                 if (strncmp(cp, "aes", 3) != 0) {
 234                         if (buffer_len(&b) > 0)
 235                                 buffer_append(&b, ",", 1);
 236                         buffer_append(&b, cp, strlen(cp));
 237                 }
 238         }
 239         buffer_append(&b, "\0", 1);
 240         fix_ciphers = xstrdup(buffer_ptr(&b));
 241         buffer_free(&b);
 242         xfree(orig_prop);
 243         debug2("Original cipher proposal: %s", cipher_prop);
 244         debug2("Compat cipher proposal: %s", fix_ciphers);
 245         if (!*fix_ciphers)
 246                 fatal("No available ciphers found.");
 247
 248         return(fix_ciphers);
 249 }