1 /* $OpenBSD: compat.c,v 1.79 2011/09/23 07:45:05 markus 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 debug("Enabling compatibility mode for protocol 2.0"); 50 compat20 = 1; 51 } 52 void 53 enable_compat13(void) 54 { 55 debug("Enabling compatibility mode for protocol 1.3"); 56 compat13 = 1; 57 } 58 /* datafellows bug compatibility */ 59 void 60 compat_datafellows(const char *version) 61 { 62 int i; 63 static struct { 64 char *pat; 65 int bugs; 66 } check[] = { 67 { "OpenSSH-2.0*," 68 "OpenSSH-2.1*," 69 "OpenSSH_2.1*," 70 "OpenSSH_2.2*", SSH_OLD_SESSIONID|SSH_BUG_BANNER| 71 SSH_OLD_DHGEX|SSH_BUG_NOREKEY| 72 SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR}, 73 { "OpenSSH_2.3.0*", SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES| 74 SSH_OLD_DHGEX|SSH_BUG_NOREKEY| 75 SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR}, 76 { "OpenSSH_2.3.*", SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX| 77 SSH_BUG_NOREKEY|SSH_BUG_EXTEOF| 78 SSH_OLD_FORWARD_ADDR}, 79 { "OpenSSH_2.5.0p1*," 80 "OpenSSH_2.5.1p1*", 81 SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX| 82 SSH_BUG_NOREKEY|SSH_BUG_EXTEOF| 83 SSH_OLD_FORWARD_ADDR}, 84 { "OpenSSH_2.5.0*," 85 "OpenSSH_2.5.1*," 86 "OpenSSH_2.5.2*", SSH_OLD_DHGEX|SSH_BUG_NOREKEY| 87 SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR}, 88 { "OpenSSH_2.5.3*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF| 89 SSH_OLD_FORWARD_ADDR}, 90 { "OpenSSH_2.*," 91 "OpenSSH_3.0*," 92 "OpenSSH_3.1*", SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR}, 93 { "OpenSSH_3.*", SSH_OLD_FORWARD_ADDR }, 94 { "Sun_SSH_1.0*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF}, 95 { "OpenSSH_4*", 0 }, 96 { "OpenSSH_5*", SSH_NEW_OPENSSH|SSH_BUG_DYNAMIC_RPORT}, 97 { "OpenSSH*", SSH_NEW_OPENSSH }, 98 { "*MindTerm*", 0 }, 99 { "2.1.0*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 100 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 101 SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE| 102 SSH_BUG_FIRSTKEX }, 103 { "2.1 *", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 104 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 105 SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE| 106 SSH_BUG_FIRSTKEX }, 107 { "2.0.13*," 108 "2.0.14*," 109 "2.0.15*," 110 "2.0.16*," 111 "2.0.17*," 112 "2.0.18*," 113 "2.0.19*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 114 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 115 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 116 SSH_BUG_PKOK|SSH_BUG_RSASIGMD5| 117 SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE| 118 SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX }, 119 { "2.0.11*," 120 "2.0.12*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 121 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 122 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 123 SSH_BUG_PKAUTH|SSH_BUG_PKOK| 124 SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE| 125 SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX }, 126 { "2.0.*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 127 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 128 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 129 SSH_BUG_PKAUTH|SSH_BUG_PKOK| 130 SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE| 131 SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN| 132 SSH_BUG_FIRSTKEX }, 133 { "2.2.0*," 134 "2.3.0*", SSH_BUG_HMAC|SSH_BUG_DEBUG| 135 SSH_BUG_RSASIGMD5|SSH_BUG_FIRSTKEX }, 136 { "2.3.*", SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5| 137 SSH_BUG_FIRSTKEX }, 138 { "2.4", SSH_OLD_SESSIONID }, /* Van Dyke */ 139 { "2.*", SSH_BUG_DEBUG|SSH_BUG_FIRSTKEX| 140 SSH_BUG_RFWD_ADDR }, 141 { "3.0.*", SSH_BUG_DEBUG }, 142 { "3.0 SecureCRT*", SSH_OLD_SESSIONID }, 143 { "1.7 SecureFX*", SSH_OLD_SESSIONID }, 144 { "1.2.18*," 145 "1.2.19*," 146 "1.2.20*," 147 "1.2.21*," 148 "1.2.22*", SSH_BUG_IGNOREMSG }, 149 { "1.3.2*", /* F-Secure */ 150 SSH_BUG_IGNOREMSG }, 151 { "*SSH Compatible Server*", /* Netscreen */ 152 SSH_BUG_PASSWORDPAD }, 153 { "*OSU_0*," 154 "OSU_1.0*," 155 "OSU_1.1*," 156 "OSU_1.2*," 157 "OSU_1.3*," 158 "OSU_1.4*," 159 "OSU_1.5alpha1*," 160 "OSU_1.5alpha2*," 161 "OSU_1.5alpha3*", SSH_BUG_PASSWORDPAD }, 162 { "*SSH_Version_Mapper*", 163 SSH_BUG_SCANNER }, 164 { "Probe-*", 165 SSH_BUG_PROBE }, 166 { NULL, 0 } 167 }; 168 169 /* process table, return first match */ 170 for (i = 0; check[i].pat; i++) { 171 if (match_pattern_list(version, check[i].pat, 172 strlen(check[i].pat), 0) == 1) { 173 debug("match: %s pat %s", version, check[i].pat); 174 datafellows = check[i].bugs; 175 /* 176 * Check to see if the remote side is OpenSSH and not 177 * HPN. It is utterly strange to check it from the 178 * version string and expose the option that way. 179 */ 180 if (strstr(version,"OpenSSH") != NULL && 181 strstr(version,"hpn") == NULL) { 182 datafellows |= SSH_BUG_LARGEWINDOW; 183 debug("Remote is not HPN-aware"); 184 } 185 return; 186 } 187 } 188 debug("no match: %s", version); 189 } 190 191 #define SEP "," 192 int 193 proto_spec(const char *spec) 194 { 195 char *s, *p, *q; 196 int ret = SSH_PROTO_UNKNOWN; 197 198 if (spec == NULL) 199 return ret; 200 q = s = xstrdup(spec); 201 for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) { 202 switch (atoi(p)) { 203 case 1: 204 if (ret == SSH_PROTO_UNKNOWN) 205 ret |= SSH_PROTO_1_PREFERRED; 206 ret |= SSH_PROTO_1; 207 break; 208 case 2: 209 ret |= SSH_PROTO_2; 210 break; 211 default: 212 logit("ignoring bad proto spec: '%s'.", p); 213 break; 214 } 215 } 216 xfree(s); 217 return ret; 218 } 219 220 char * 221 compat_cipher_proposal(char *cipher_prop) 222 { 223 Buffer b; 224 char *orig_prop, *fix_ciphers; 225 char *cp, *tmp; 226 227 if (!(datafellows & SSH_BUG_BIGENDIANAES)) 228 return(cipher_prop); 229 230 buffer_init(&b); 231 tmp = orig_prop = xstrdup(cipher_prop); 232 while ((cp = strsep(&tmp, ",")) != NULL) { 233 if (strncmp(cp, "aes", 3) != 0) { 234 if (buffer_len(&b) > 0) 235 buffer_append(&b, ",", 1); 236 buffer_append(&b, cp, strlen(cp)); 237 } 238 } 239 buffer_append(&b, "\0", 1); 240 fix_ciphers = xstrdup(buffer_ptr(&b)); 241 buffer_free(&b); 242 xfree(orig_prop); 243 debug2("Original cipher proposal: %s", cipher_prop); 244 debug2("Compat cipher proposal: %s", fix_ciphers); 245 if (!*fix_ciphers) 246 fatal("No available ciphers found."); 247 248 return(fix_ciphers); 249 } 250