1 /* $OpenBSD: compat.c,v 1.78 2008/09/11 14:22:37 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*", SSH_NEW_OPENSSH }, 96 { "*MindTerm*", 0 }, 97 { "2.1.0*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 98 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 99 SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE| 100 SSH_BUG_FIRSTKEX }, 101 { "2.1 *", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 102 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 103 SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE| 104 SSH_BUG_FIRSTKEX }, 105 { "2.0.13*," 106 "2.0.14*," 107 "2.0.15*," 108 "2.0.16*," 109 "2.0.17*," 110 "2.0.18*," 111 "2.0.19*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 112 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 113 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 114 SSH_BUG_PKOK|SSH_BUG_RSASIGMD5| 115 SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE| 116 SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX }, 117 { "2.0.11*," 118 "2.0.12*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 119 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 120 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 121 SSH_BUG_PKAUTH|SSH_BUG_PKOK| 122 SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE| 123 SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX }, 124 { "2.0.*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 125 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 126 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 127 SSH_BUG_PKAUTH|SSH_BUG_PKOK| 128 SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE| 129 SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN| 130 SSH_BUG_FIRSTKEX }, 131 { "2.2.0*," 132 "2.3.0*", SSH_BUG_HMAC|SSH_BUG_DEBUG| 133 SSH_BUG_RSASIGMD5|SSH_BUG_FIRSTKEX }, 134 { "2.3.*", SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5| 135 SSH_BUG_FIRSTKEX }, 136 { "2.4", SSH_OLD_SESSIONID }, /* Van Dyke */ 137 { "2.*", SSH_BUG_DEBUG|SSH_BUG_FIRSTKEX| 138 SSH_BUG_RFWD_ADDR }, 139 { "3.0.*", SSH_BUG_DEBUG }, 140 { "3.0 SecureCRT*", SSH_OLD_SESSIONID }, 141 { "1.7 SecureFX*", SSH_OLD_SESSIONID }, 142 { "1.2.18*," 143 "1.2.19*," 144 "1.2.20*," 145 "1.2.21*," 146 "1.2.22*", SSH_BUG_IGNOREMSG }, 147 { "1.3.2*", /* F-Secure */ 148 SSH_BUG_IGNOREMSG }, 149 { "*SSH Compatible Server*", /* Netscreen */ 150 SSH_BUG_PASSWORDPAD }, 151 { "*OSU_0*," 152 "OSU_1.0*," 153 "OSU_1.1*," 154 "OSU_1.2*," 155 "OSU_1.3*," 156 "OSU_1.4*," 157 "OSU_1.5alpha1*," 158 "OSU_1.5alpha2*," 159 "OSU_1.5alpha3*", SSH_BUG_PASSWORDPAD }, 160 { "*SSH_Version_Mapper*", 161 SSH_BUG_SCANNER }, 162 { "Probe-*", 163 SSH_BUG_PROBE }, 164 { NULL, 0 } 165 }; 166 167 /* process table, return first match */ 168 for (i = 0; check[i].pat; i++) { 169 if (match_pattern_list(version, check[i].pat, 170 strlen(check[i].pat), 0) == 1) { 171 debug("match: %s pat %s", version, check[i].pat); 172 datafellows = check[i].bugs; 173 /* Check to see if the remote side is OpenSSH and not HPN */ 174 if(strstr(version,"OpenSSH") != NULL) 175 { 176 if (strstr(version,"hpn") == NULL) 177 { 178 datafellows |= SSH_BUG_LARGEWINDOW; 179 debug("Remote is NON-HPN aware"); 180 } 181 } 182 return; 183 } 184 } 185 debug("no match: %s", version); 186 } 187 188 #define SEP "," 189 int 190 proto_spec(const char *spec) 191 { 192 char *s, *p, *q; 193 int ret = SSH_PROTO_UNKNOWN; 194 195 if (spec == NULL) 196 return ret; 197 q = s = xstrdup(spec); 198 for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) { 199 switch (atoi(p)) { 200 case 1: 201 if (ret == SSH_PROTO_UNKNOWN) 202 ret |= SSH_PROTO_1_PREFERRED; 203 ret |= SSH_PROTO_1; 204 break; 205 case 2: 206 ret |= SSH_PROTO_2; 207 break; 208 default: 209 logit("ignoring bad proto spec: '%s'.", p); 210 break; 211 } 212 } 213 xfree(s); 214 return ret; 215 } 216 217 char * 218 compat_cipher_proposal(char *cipher_prop) 219 { 220 Buffer b; 221 char *orig_prop, *fix_ciphers; 222 char *cp, *tmp; 223 224 if (!(datafellows & SSH_BUG_BIGENDIANAES)) 225 return(cipher_prop); 226 227 buffer_init(&b); 228 tmp = orig_prop = xstrdup(cipher_prop); 229 while ((cp = strsep(&tmp, ",")) != NULL) { 230 if (strncmp(cp, "aes", 3) != 0) { 231 if (buffer_len(&b) > 0) 232 buffer_append(&b, ",", 1); 233 buffer_append(&b, cp, strlen(cp)); 234 } 235 } 236 buffer_append(&b, "\0", 1); 237 fix_ciphers = xstrdup(buffer_ptr(&b)); 238 buffer_free(&b); 239 xfree(orig_prop); 240 debug2("Original cipher proposal: %s", cipher_prop); 241 debug2("Compat cipher proposal: %s", fix_ciphers); 242 if (!*fix_ciphers) 243 fatal("No available ciphers found."); 244 245 return(fix_ciphers); 246 } 247