1 /* $OpenBSD: compat.c,v 1.80 2012/08/17 01:30:00 djm 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 if (compat20) 50 return; 51 debug("Enabling compatibility mode for protocol 2.0"); 52 compat20 = 1; 53 } 54 void 55 enable_compat13(void) 56 { 57 debug("Enabling compatibility mode for protocol 1.3"); 58 compat13 = 1; 59 } 60 /* datafellows bug compatibility */ 61 void 62 compat_datafellows(const char *version) 63 { 64 int i; 65 static struct { 66 char *pat; 67 int bugs; 68 } check[] = { 69 { "OpenSSH-2.0*," 70 "OpenSSH-2.1*," 71 "OpenSSH_2.1*," 72 "OpenSSH_2.2*", SSH_OLD_SESSIONID|SSH_BUG_BANNER| 73 SSH_OLD_DHGEX|SSH_BUG_NOREKEY| 74 SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR}, 75 { "OpenSSH_2.3.0*", SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES| 76 SSH_OLD_DHGEX|SSH_BUG_NOREKEY| 77 SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR}, 78 { "OpenSSH_2.3.*", SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX| 79 SSH_BUG_NOREKEY|SSH_BUG_EXTEOF| 80 SSH_OLD_FORWARD_ADDR}, 81 { "OpenSSH_2.5.0p1*," 82 "OpenSSH_2.5.1p1*", 83 SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX| 84 SSH_BUG_NOREKEY|SSH_BUG_EXTEOF| 85 SSH_OLD_FORWARD_ADDR}, 86 { "OpenSSH_2.5.0*," 87 "OpenSSH_2.5.1*," 88 "OpenSSH_2.5.2*", SSH_OLD_DHGEX|SSH_BUG_NOREKEY| 89 SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR}, 90 { "OpenSSH_2.5.3*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF| 91 SSH_OLD_FORWARD_ADDR}, 92 { "OpenSSH_2.*," 93 "OpenSSH_3.0*," 94 "OpenSSH_3.1*", SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR}, 95 { "OpenSSH_3.*", SSH_OLD_FORWARD_ADDR }, 96 { "Sun_SSH_1.0*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF}, 97 { "OpenSSH_4*", 0 }, 98 { "OpenSSH_5*", SSH_NEW_OPENSSH|SSH_BUG_DYNAMIC_RPORT}, 99 { "OpenSSH*", SSH_NEW_OPENSSH }, 100 { "*MindTerm*", 0 }, 101 { "2.1.0*", 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 { "2.1 *", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 106 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 107 SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE| 108 SSH_BUG_FIRSTKEX }, 109 { "2.0.13*," 110 "2.0.14*," 111 "2.0.15*," 112 "2.0.16*," 113 "2.0.17*," 114 "2.0.18*," 115 "2.0.19*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 116 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 117 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 118 SSH_BUG_PKOK|SSH_BUG_RSASIGMD5| 119 SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE| 120 SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX }, 121 { "2.0.11*," 122 "2.0.12*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 123 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 124 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 125 SSH_BUG_PKAUTH|SSH_BUG_PKOK| 126 SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE| 127 SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX }, 128 { "2.0.*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 129 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 130 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 131 SSH_BUG_PKAUTH|SSH_BUG_PKOK| 132 SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE| 133 SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN| 134 SSH_BUG_FIRSTKEX }, 135 { "2.2.0*," 136 "2.3.0*", SSH_BUG_HMAC|SSH_BUG_DEBUG| 137 SSH_BUG_RSASIGMD5|SSH_BUG_FIRSTKEX }, 138 { "2.3.*", SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5| 139 SSH_BUG_FIRSTKEX }, 140 { "2.4", SSH_OLD_SESSIONID }, /* Van Dyke */ 141 { "2.*", SSH_BUG_DEBUG|SSH_BUG_FIRSTKEX| 142 SSH_BUG_RFWD_ADDR }, 143 { "3.0.*", SSH_BUG_DEBUG }, 144 { "3.0 SecureCRT*", SSH_OLD_SESSIONID }, 145 { "1.7 SecureFX*", SSH_OLD_SESSIONID }, 146 { "1.2.18*," 147 "1.2.19*," 148 "1.2.20*," 149 "1.2.21*," 150 "1.2.22*", SSH_BUG_IGNOREMSG }, 151 { "1.3.2*", /* F-Secure */ 152 SSH_BUG_IGNOREMSG }, 153 { "*SSH Compatible Server*", /* Netscreen */ 154 SSH_BUG_PASSWORDPAD }, 155 { "*OSU_0*," 156 "OSU_1.0*," 157 "OSU_1.1*," 158 "OSU_1.2*," 159 "OSU_1.3*," 160 "OSU_1.4*," 161 "OSU_1.5alpha1*," 162 "OSU_1.5alpha2*," 163 "OSU_1.5alpha3*", SSH_BUG_PASSWORDPAD }, 164 { "*SSH_Version_Mapper*", 165 SSH_BUG_SCANNER }, 166 { "Probe-*", 167 SSH_BUG_PROBE }, 168 { NULL, 0 } 169 }; 170 171 /* process table, return first match */ 172 for (i = 0; check[i].pat; i++) { 173 if (match_pattern_list(version, check[i].pat, 174 strlen(check[i].pat), 0) == 1) { 175 debug("match: %s pat %s", version, check[i].pat); 176 datafellows = check[i].bugs; 177 /* 178 * Check to see if the remote side is OpenSSH and not 179 * HPN. It is utterly strange to check it from the 180 * version string and expose the option that way. 181 */ 182 if (strstr(version,"OpenSSH") != NULL && 183 strstr(version,"hpn") == NULL) { 184 datafellows |= SSH_BUG_LARGEWINDOW; 185 debug("Remote is not HPN-aware"); 186 } 187 return; 188 } 189 } 190 debug("no match: %s", version); 191 } 192 193 #define SEP "," 194 int 195 proto_spec(const char *spec) 196 { 197 char *s, *p, *q; 198 int ret = SSH_PROTO_UNKNOWN; 199 200 if (spec == NULL) 201 return ret; 202 q = s = xstrdup(spec); 203 for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) { 204 switch (atoi(p)) { 205 case 1: 206 if (ret == SSH_PROTO_UNKNOWN) 207 ret |= SSH_PROTO_1_PREFERRED; 208 ret |= SSH_PROTO_1; 209 break; 210 case 2: 211 ret |= SSH_PROTO_2; 212 break; 213 default: 214 logit("ignoring bad proto spec: '%s'.", p); 215 break; 216 } 217 } 218 xfree(s); 219 return ret; 220 } 221 222 char * 223 compat_cipher_proposal(char *cipher_prop) 224 { 225 Buffer b; 226 char *orig_prop, *fix_ciphers; 227 char *cp, *tmp; 228 229 if (!(datafellows & SSH_BUG_BIGENDIANAES)) 230 return(cipher_prop); 231 232 buffer_init(&b); 233 tmp = orig_prop = xstrdup(cipher_prop); 234 while ((cp = strsep(&tmp, ",")) != NULL) { 235 if (strncmp(cp, "aes", 3) != 0) { 236 if (buffer_len(&b) > 0) 237 buffer_append(&b, ",", 1); 238 buffer_append(&b, cp, strlen(cp)); 239 } 240 } 241 buffer_append(&b, "\0", 1); 242 fix_ciphers = xstrdup(buffer_ptr(&b)); 243 buffer_free(&b); 244 xfree(orig_prop); 245 debug2("Original cipher proposal: %s", cipher_prop); 246 debug2("Compat cipher proposal: %s", fix_ciphers); 247 if (!*fix_ciphers) 248 fatal("No available ciphers found."); 249 250 return(fix_ciphers); 251 } 252