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