crypto/openssh/compat.c

   1 /* $OpenBSD: compat.c,v 1.104 2017/07/25 09:22:25 dtucker Exp $ */
   2 /*
   3  * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "includes.h"
  27
  28 #include <sys/types.h>
  29
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <stdarg.h>
  33
  34 #include "xmalloc.h"
  35 #include "buffer.h"
  36 #include "packet.h"
  37 #include "compat.h"
  38 #include "log.h"
  39 #include "match.h"
  40 #include "kex.h"
  41
  42 int datafellows = 0;
  43
  44 /* datafellows bug compatibility */
  45 u_int
  46 compat_datafellows(const char *version)
  47 {
  48         int i;
  49         static struct {
  50                 char    *pat;
  51                 int     bugs;
  52         } check[] = {
  53                 { "OpenSSH-2.0*,"
  54                   "OpenSSH-2.1*,"
  55                   "OpenSSH_2.1*,"
  56                   "OpenSSH_2.2*",       SSH_OLD_SESSIONID|SSH_BUG_BANNER|
  57                                         SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
  58                                         SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
  59                 { "OpenSSH_2.3.0*",     SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES|
  60                                         SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
  61                                         SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
  62                 { "OpenSSH_2.3.*",      SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
  63                                         SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
  64                                         SSH_OLD_FORWARD_ADDR},
  65                 { "OpenSSH_2.5.0p1*,"
  66                   "OpenSSH_2.5.1p1*",
  67                                         SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
  68                                         SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
  69                                         SSH_OLD_FORWARD_ADDR},
  70                 { "OpenSSH_2.5.0*,"
  71                   "OpenSSH_2.5.1*,"
  72                   "OpenSSH_2.5.2*",     SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
  73                                         SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
  74                 { "OpenSSH_2.5.3*",     SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
  75                                         SSH_OLD_FORWARD_ADDR},
  76                 { "OpenSSH_2.*,"
  77                   "OpenSSH_3.0*,"
  78                   "OpenSSH_3.1*",       SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
  79                 { "OpenSSH_3.*",        SSH_OLD_FORWARD_ADDR },
  80                 { "Sun_SSH_1.0*",       SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
  81                 { "OpenSSH_4*",         0 },
  82                 { "OpenSSH_5*",         SSH_NEW_OPENSSH|SSH_BUG_DYNAMIC_RPORT},
  83                 { "OpenSSH_6.6.1*",     SSH_NEW_OPENSSH},
  84                 { "OpenSSH_6.5*,"
  85                   "OpenSSH_6.6*",       SSH_NEW_OPENSSH|SSH_BUG_CURVE25519PAD},
  86                 { "OpenSSH*",           SSH_NEW_OPENSSH },
  87                 { "*MindTerm*",         0 },
  88                 { "2.1.0*",             SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
  89                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
  90                                         SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
  91                                         SSH_BUG_FIRSTKEX },
  92                 { "2.1 *",              SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
  93                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
  94                                         SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
  95                                         SSH_BUG_FIRSTKEX },
  96                 { "2.0.13*,"
  97                   "2.0.14*,"
  98                   "2.0.15*,"
  99                   "2.0.16*,"
 100                   "2.0.17*,"
 101                   "2.0.18*,"
 102                   "2.0.19*",            SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
 103                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
 104                                         SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
 105                                         SSH_BUG_PKOK|SSH_BUG_RSASIGMD5|
 106                                         SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE|
 107                                         SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
 108                 { "2.0.11*,"
 109                   "2.0.12*",            SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
 110                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
 111                                         SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
 112                                         SSH_BUG_PKAUTH|SSH_BUG_PKOK|
 113                                         SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
 114                                         SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
 115                 { "2.0.*",              SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
 116                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
 117                                         SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
 118                                         SSH_BUG_PKAUTH|SSH_BUG_PKOK|
 119                                         SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
 120                                         SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN|
 121                                         SSH_BUG_FIRSTKEX },
 122                 { "2.2.0*,"
 123                   "2.3.0*",             SSH_BUG_HMAC|SSH_BUG_DEBUG|
 124                                         SSH_BUG_RSASIGMD5|SSH_BUG_FIRSTKEX },
 125                 { "2.3.*",              SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5|
 126                                         SSH_BUG_FIRSTKEX },
 127                 { "2.4",                SSH_OLD_SESSIONID },    /* Van Dyke */
 128                 { "2.*",                SSH_BUG_DEBUG|SSH_BUG_FIRSTKEX|
 129                                         SSH_BUG_RFWD_ADDR },
 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                 { "Cisco-1.*",          SSH_BUG_DHGEX_LARGE|
 141                                         SSH_BUG_HOSTKEYS },
 142                 { "*SSH Compatible Server*",                    /* Netscreen */
 143                                         SSH_BUG_PASSWORDPAD },
 144                 { "*OSU_0*,"
 145                   "OSU_1.0*,"
 146                   "OSU_1.1*,"
 147                   "OSU_1.2*,"
 148                   "OSU_1.3*,"
 149                   "OSU_1.4*,"
 150                   "OSU_1.5alpha1*,"
 151                   "OSU_1.5alpha2*,"
 152                   "OSU_1.5alpha3*",     SSH_BUG_PASSWORDPAD },
 153                 { "*SSH_Version_Mapper*",
 154                                         SSH_BUG_SCANNER },
 155                 { "PuTTY_Local:*,"      /* dev versions < Sep 2014 */
 156                   "PuTTY-Release-0.5*," /* 0.50-0.57, DH-GEX in >=0.52 */
 157                   "PuTTY_Release_0.5*," /* 0.58-0.59 */
 158                   "PuTTY_Release_0.60*,"
 159                   "PuTTY_Release_0.61*,"
 160                   "PuTTY_Release_0.62*,"
 161                   "PuTTY_Release_0.63*,"
 162                   "PuTTY_Release_0.64*",
 163                                         SSH_OLD_DHGEX },
 164                 { "FuTTY*",             SSH_OLD_DHGEX }, /* Putty Fork */
 165                 { "Probe-*",
 166                                         SSH_BUG_PROBE },
 167                 { "TeraTerm SSH*,"
 168                   "TTSSH/1.5.*,"
 169                   "TTSSH/2.1*,"
 170                   "TTSSH/2.2*,"
 171                   "TTSSH/2.3*,"
 172                   "TTSSH/2.4*,"
 173                   "TTSSH/2.5*,"
 174                   "TTSSH/2.6*,"
 175                   "TTSSH/2.70*,"
 176                   "TTSSH/2.71*,"
 177                   "TTSSH/2.72*",        SSH_BUG_HOSTKEYS },
 178                 { "WinSCP_release_4*,"
 179                   "WinSCP_release_5.0*,"
 180                   "WinSCP_release_5.1,"
 181                   "WinSCP_release_5.1.*,"
 182                   "WinSCP_release_5.5,"
 183                   "WinSCP_release_5.5.*,"
 184                   "WinSCP_release_5.6,"
 185                   "WinSCP_release_5.6.*,"
 186                   "WinSCP_release_5.7,"
 187                   "WinSCP_release_5.7.1,"
 188                   "WinSCP_release_5.7.2,"
 189                   "WinSCP_release_5.7.3,"
 190                   "WinSCP_release_5.7.4",
 191                                         SSH_OLD_DHGEX },
 192                 { NULL,                 0 }
 193         };
 194
 195         /* process table, return first match */
 196         for (i = 0; check[i].pat; i++) {
 197                 if (match_pattern_list(version, check[i].pat, 0) == 1) {
 198                         debug("match: %s pat %s compat 0x%08x",
 199                             version, check[i].pat, check[i].bugs);
 200                         datafellows = check[i].bugs;    /* XXX for now */
 201                         return check[i].bugs;
 202                 }
 203         }
 204         debug("no match: %s", version);
 205         return 0;
 206 }
 207
 208 #define SEP     ","
 209 int
 210 proto_spec(const char *spec)
 211 {
 212         char *s, *p, *q;
 213         int ret = SSH_PROTO_UNKNOWN;
 214
 215         if (spec == NULL)
 216                 return ret;
 217         q = s = strdup(spec);
 218         if (s == NULL)
 219                 return ret;
 220         for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) {
 221                 switch (atoi(p)) {
 222                 case 2:
 223                         ret |= SSH_PROTO_2;
 224                         break;
 225                 default:
 226                         logit("ignoring bad proto spec: '%s'.", p);
 227                         break;
 228                 }
 229         }
 230         free(s);
 231         return ret;
 232 }
 233
 234 char *
 235 compat_cipher_proposal(char *cipher_prop)
 236 {
 237         if (!(datafellows & SSH_BUG_BIGENDIANAES))
 238                 return cipher_prop;
 239         debug2("%s: original cipher proposal: %s", __func__, cipher_prop);
 240         if ((cipher_prop = match_filter_list(cipher_prop, "aes*")) == NULL)
 241                 fatal("match_filter_list failed");
 242         debug2("%s: compat cipher proposal: %s", __func__, cipher_prop);
 243         if (*cipher_prop == '\0')
 244                 fatal("No supported ciphers found");
 245         return cipher_prop;
 246 }
 247
 248 char *
 249 compat_pkalg_proposal(char *pkalg_prop)
 250 {
 251         if (!(datafellows & SSH_BUG_RSASIGMD5))
 252                 return pkalg_prop;
 253         debug2("%s: original public key proposal: %s", __func__, pkalg_prop);
 254         if ((pkalg_prop = match_filter_list(pkalg_prop, "ssh-rsa")) == NULL)
 255                 fatal("match_filter_list failed");
 256         debug2("%s: compat public key proposal: %s", __func__, pkalg_prop);
 257         if (*pkalg_prop == '\0')
 258                 fatal("No supported PK algorithms found");
 259         return pkalg_prop;
 260 }
 261
 262 char *
 263 compat_kex_proposal(char *p)
 264 {
 265         if ((datafellows & (SSH_BUG_CURVE25519PAD|SSH_OLD_DHGEX)) == 0)
 266                 return p;
 267         debug2("%s: original KEX proposal: %s", __func__, p);
 268         if ((datafellows & SSH_BUG_CURVE25519PAD) != 0)
 269                 if ((p = match_filter_list(p,
 270                     "curve25519-sha256@libssh.org")) == NULL)
 271                         fatal("match_filter_list failed");
 272         if ((datafellows & SSH_OLD_DHGEX) != 0) {
 273                 if ((p = match_filter_list(p,
 274                     "diffie-hellman-group-exchange-sha256,"
 275                     "diffie-hellman-group-exchange-sha1")) == NULL)
 276                         fatal("match_filter_list failed");
 277         }
 278         debug2("%s: compat KEX proposal: %s", __func__, p);
 279         if (*p == '\0')
 280                 fatal("No supported key exchange algorithms found");
 281         return p;
 282 }
 283