crypto/openssh/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 RCSID("$OpenBSD: compat.c,v 1.65 2002/09/27 10:42:09 mickey Exp $");
  27 RCSID("$FreeBSD: src/crypto/openssh/compat.c,v 1.1.1.1.2.7 2003/02/03 17:31:06 des Exp $");
  28
  29 #include "buffer.h"
  30 #include "packet.h"
  31 #include "xmalloc.h"
  32 #include "compat.h"
  33 #include "log.h"
  34 #include "match.h"
  35
  36 int compat13 = 0;
  37 int compat20 = 0;
  38 int datafellows = 0;
  39
  40 void
  41 enable_compat20(void)
  42 {
  43         debug("Enabling compatibility mode for protocol 2.0");
  44         compat20 = 1;
  45 }
  46 void
  47 enable_compat13(void)
  48 {
  49         debug("Enabling compatibility mode for protocol 1.3");
  50         compat13 = 1;
  51 }
  52 /* datafellows bug compatibility */
  53 void
  54 compat_datafellows(const char *version)
  55 {
  56         int i;
  57         static struct {
  58                 char    *pat;
  59                 int     bugs;
  60         } check[] = {
  61                 { "OpenSSH-2.0*,"
  62                   "OpenSSH-2.1*,"
  63                   "OpenSSH_2.1*,"
  64                   "OpenSSH_2.2*",       SSH_OLD_SESSIONID|SSH_BUG_BANNER|
  65                                         SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
  66                                         SSH_BUG_EXTEOF},
  67                 { "OpenSSH_2.3.0*",     SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES|
  68                                         SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
  69                                         SSH_BUG_EXTEOF},
  70                 { "OpenSSH_2.3.*",      SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
  71                                         SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
  72                 { "OpenSSH_2.5.0p1*,"
  73                   "OpenSSH_2.5.1p1*",
  74                                         SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
  75                                         SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
  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},
  80                 { "OpenSSH_2.5.3*",     SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
  81                 { "OpenSSH_2.*,"
  82                   "OpenSSH_3.0*,"
  83                   "OpenSSH_3.1*",       SSH_BUG_EXTEOF},
  84                 { "Sun_SSH_1.0*",       SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
  85                 { "OpenSSH*",           0 },
  86                 { "*MindTerm*",         0 },
  87                 { "2.1.0*",             SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
  88                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
  89                                         SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE },
  90                 { "2.1 *",              SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
  91                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
  92                                         SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE },
  93                 { "2.0.13*,"
  94                   "2.0.14*,"
  95                   "2.0.15*,"
  96                   "2.0.16*,"
  97                   "2.0.17*,"
  98                   "2.0.18*,"
  99                   "2.0.19*",            SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
 100                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
 101                                         SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
 102                                         SSH_BUG_PKOK|SSH_BUG_RSASIGMD5|
 103                                         SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE|
 104                                         SSH_BUG_DUMMYCHAN },
 105                 { "2.0.11*,"
 106                   "2.0.12*",            SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
 107                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
 108                                         SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
 109                                         SSH_BUG_PKAUTH|SSH_BUG_PKOK|
 110                                         SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
 111                                         SSH_BUG_DUMMYCHAN },
 112                 { "2.0.*",              SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
 113                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
 114                                         SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
 115                                         SSH_BUG_PKAUTH|SSH_BUG_PKOK|
 116                                         SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
 117                                         SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN },
 118                 { "2.2.0*,"
 119                   "2.3.0*",             SSH_BUG_HMAC|SSH_BUG_DEBUG|
 120                                         SSH_BUG_RSASIGMD5 },
 121                 { "2.3.*",              SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5 },
 122                 { "2.4",                SSH_OLD_SESSIONID },    /* Van Dyke */
 123                 { "2.*",                SSH_BUG_DEBUG },
 124                 { "3.0.*",              SSH_BUG_DEBUG },
 125                 { "3.0 SecureCRT*",     SSH_OLD_SESSIONID },
 126                 { "1.7 SecureFX*",      SSH_OLD_SESSIONID },
 127                 { "1.2.18*,"
 128                   "1.2.19*,"
 129                   "1.2.20*,"
 130                   "1.2.21*,"
 131                   "1.2.22*",            SSH_BUG_IGNOREMSG|SSH_BUG_K5USER },
 132                 { "1.3.2*",             /* F-Secure */
 133                                         SSH_BUG_IGNOREMSG|SSH_BUG_K5USER },
 134                 { "1.2.1*,"
 135                   "1.2.2*,"
 136                   "1.2.3*",             SSH_BUG_K5USER },
 137                 { "*SSH Compatible Server*",                    /* Netscreen */
 138                                         SSH_BUG_PASSWORDPAD },
 139                 { "*OSU_0*,"
 140                   "OSU_1.0*,"
 141                   "OSU_1.1*,"
 142                   "OSU_1.2*,"
 143                   "OSU_1.3*,"
 144                   "OSU_1.4*,"
 145                   "OSU_1.5alpha1*,"
 146                   "OSU_1.5alpha2*,"
 147                   "OSU_1.5alpha3*",     SSH_BUG_PASSWORDPAD },
 148                 { "*SSH_Version_Mapper*",
 149                                         SSH_BUG_SCANNER },
 150                 { "Probe-*",
 151                                         SSH_BUG_PROBE },
 152                 { NULL,                 0 }
 153         };
 154
 155         /* process table, return first match */
 156         for (i = 0; check[i].pat; i++) {
 157                 if (match_pattern_list(version, check[i].pat,
 158                     strlen(check[i].pat), 0) == 1) {
 159                         debug("match: %s pat %s", version, check[i].pat);
 160                         datafellows = check[i].bugs;
 161                         return;
 162                 }
 163         }
 164         debug("no match: %s", version);
 165 }
 166
 167 #define SEP     ","
 168 int
 169 proto_spec(const char *spec)
 170 {
 171         char *s, *p, *q;
 172         int ret = SSH_PROTO_UNKNOWN;
 173
 174         if (spec == NULL)
 175                 return ret;
 176         q = s = xstrdup(spec);
 177         for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) {
 178                 switch (atoi(p)) {
 179                 case 1:
 180                         if (ret == SSH_PROTO_UNKNOWN)
 181                                 ret |= SSH_PROTO_1_PREFERRED;
 182                         ret |= SSH_PROTO_1;
 183                         break;
 184                 case 2:
 185                         ret |= SSH_PROTO_2;
 186                         break;
 187                 default:
 188                         log("ignoring bad proto spec: '%s'.", p);
 189                         break;
 190                 }
 191         }
 192         xfree(s);
 193         return ret;
 194 }
 195
 196 char *
 197 compat_cipher_proposal(char *cipher_prop)
 198 {
 199         Buffer b;
 200         char *orig_prop, *fix_ciphers;
 201         char *cp, *tmp;
 202
 203         if (!(datafellows & SSH_BUG_BIGENDIANAES))
 204                 return(cipher_prop);
 205
 206         buffer_init(&b);
 207         tmp = orig_prop = xstrdup(cipher_prop);
 208         while ((cp = strsep(&tmp, ",")) != NULL) {
 209                 if (strncmp(cp, "aes", 3) != 0) {
 210                         if (buffer_len(&b) > 0)
 211                                 buffer_append(&b, ",", 1);
 212                         buffer_append(&b, cp, strlen(cp));
 213                 }
 214         }
 215         buffer_append(&b, "\0", 1);
 216         fix_ciphers = xstrdup(buffer_ptr(&b));
 217         buffer_free(&b);
 218         xfree(orig_prop);
 219         debug2("Original cipher proposal: %s", cipher_prop);
 220         debug2("Compat cipher proposal: %s", fix_ciphers);
 221         if (!*fix_ciphers)
 222                 fatal("No available ciphers found.");
 223
 224         return(fix_ciphers);
 225 }