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 <sys/types.h> 27 28 #include <stdlib.h> 29 #include <string.h> 30 #include <stdarg.h> 31 32 #include "xmalloc.h" 33 #include "buffer.h" 34 #include "packet.h" 35 #include "compat.h" 36 #include "log.h" 37 #include "match.h" 38 39 int compat13 = 0; 40 int compat20 = 0; 41 int datafellows = 0; 42 43 void 44 enable_compat20(void) 45 { 46 debug("Enabling compatibility mode for protocol 2.0"); 47 compat20 = 1; 48 } 49 void 50 enable_compat13(void) 51 { 52 debug("Enabling compatibility mode for protocol 1.3"); 53 compat13 = 1; 54 } 55 /* datafellows bug compatibility */ 56 void 57 compat_datafellows(const char *version) 58 { 59 int i; 60 static struct { 61 char *pat; 62 int bugs; 63 } check[] = { 64 { "OpenSSH-2.0*," 65 "OpenSSH-2.1*," 66 "OpenSSH_2.1*," 67 "OpenSSH_2.2*", SSH_OLD_SESSIONID|SSH_BUG_BANNER| 68 SSH_OLD_DHGEX|SSH_BUG_NOREKEY| 69 SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR}, 70 { "OpenSSH_2.3.0*", SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES| 71 SSH_OLD_DHGEX|SSH_BUG_NOREKEY| 72 SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR}, 73 { "OpenSSH_2.3.*", SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX| 74 SSH_BUG_NOREKEY|SSH_BUG_EXTEOF| 75 SSH_OLD_FORWARD_ADDR}, 76 { "OpenSSH_2.5.0p1*," 77 "OpenSSH_2.5.1p1*", 78 SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX| 79 SSH_BUG_NOREKEY|SSH_BUG_EXTEOF| 80 SSH_OLD_FORWARD_ADDR}, 81 { "OpenSSH_2.5.0*," 82 "OpenSSH_2.5.1*," 83 "OpenSSH_2.5.2*", SSH_OLD_DHGEX|SSH_BUG_NOREKEY| 84 SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR}, 85 { "OpenSSH_2.5.3*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF| 86 SSH_OLD_FORWARD_ADDR}, 87 { "OpenSSH_2.*," 88 "OpenSSH_3.0*," 89 "OpenSSH_3.1*", SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR}, 90 { "OpenSSH_3.*", SSH_OLD_FORWARD_ADDR }, 91 { "Sun_SSH_1.0*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF}, 92 { "OpenSSH_4*", 0 }, 93 { "OpenSSH*", SSH_NEW_OPENSSH }, 94 { "*MindTerm*", 0 }, 95 { "2.1.0*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 96 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 97 SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE| 98 SSH_BUG_FIRSTKEX }, 99 { "2.1 *", 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 { "2.0.13*," 104 "2.0.14*," 105 "2.0.15*," 106 "2.0.16*," 107 "2.0.17*," 108 "2.0.18*," 109 "2.0.19*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 110 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 111 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 112 SSH_BUG_PKOK|SSH_BUG_RSASIGMD5| 113 SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE| 114 SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX }, 115 { "2.0.11*," 116 "2.0.12*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 117 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 118 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 119 SSH_BUG_PKAUTH|SSH_BUG_PKOK| 120 SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE| 121 SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX }, 122 { "2.0.*", 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_DERIVEKEY|SSH_BUG_DUMMYCHAN| 128 SSH_BUG_FIRSTKEX }, 129 { "2.2.0*," 130 "2.3.0*", SSH_BUG_HMAC|SSH_BUG_DEBUG| 131 SSH_BUG_RSASIGMD5|SSH_BUG_FIRSTKEX }, 132 { "2.3.*", SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5| 133 SSH_BUG_FIRSTKEX }, 134 { "2.4", SSH_OLD_SESSIONID }, /* Van Dyke */ 135 { "2.*", SSH_BUG_DEBUG|SSH_BUG_FIRSTKEX| 136 SSH_BUG_RFWD_ADDR }, 137 { "3.0.*", SSH_BUG_DEBUG }, 138 { "3.0 SecureCRT*", SSH_OLD_SESSIONID }, 139 { "1.7 SecureFX*", SSH_OLD_SESSIONID }, 140 { "1.2.18*," 141 "1.2.19*," 142 "1.2.20*," 143 "1.2.21*," 144 "1.2.22*", SSH_BUG_IGNOREMSG }, 145 { "1.3.2*", /* F-Secure */ 146 SSH_BUG_IGNOREMSG }, 147 { "*SSH Compatible Server*", /* Netscreen */ 148 SSH_BUG_PASSWORDPAD }, 149 { "*OSU_0*," 150 "OSU_1.0*," 151 "OSU_1.1*," 152 "OSU_1.2*," 153 "OSU_1.3*," 154 "OSU_1.4*," 155 "OSU_1.5alpha1*," 156 "OSU_1.5alpha2*," 157 "OSU_1.5alpha3*", SSH_BUG_PASSWORDPAD }, 158 { "*SSH_Version_Mapper*", 159 SSH_BUG_SCANNER }, 160 { "Probe-*", 161 SSH_BUG_PROBE }, 162 { NULL, 0 } 163 }; 164 165 /* process table, return first match */ 166 for (i = 0; check[i].pat; i++) { 167 if (match_pattern_list(version, check[i].pat, 168 strlen(check[i].pat), 0) == 1) { 169 debug("match: %s pat %s", version, check[i].pat); 170 datafellows = check[i].bugs; 171 return; 172 } 173 } 174 debug("no match: %s", version); 175 } 176 177 #define SEP "," 178 int 179 proto_spec(const char *spec) 180 { 181 char *s, *p, *q; 182 int ret = SSH_PROTO_UNKNOWN; 183 184 if (spec == NULL) 185 return ret; 186 q = s = xstrdup(spec); 187 for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) { 188 switch (atoi(p)) { 189 case 1: 190 if (ret == SSH_PROTO_UNKNOWN) 191 ret |= SSH_PROTO_1_PREFERRED; 192 ret |= SSH_PROTO_1; 193 break; 194 case 2: 195 ret |= SSH_PROTO_2; 196 break; 197 default: 198 logit("ignoring bad proto spec: '%s'.", p); 199 break; 200 } 201 } 202 xfree(s); 203 return ret; 204 } 205 206 char * 207 compat_cipher_proposal(char *cipher_prop) 208 { 209 Buffer b; 210 char *orig_prop, *fix_ciphers; 211 char *cp, *tmp; 212 213 if (!(datafellows & SSH_BUG_BIGENDIANAES)) 214 return(cipher_prop); 215 216 buffer_init(&b); 217 tmp = orig_prop = xstrdup(cipher_prop); 218 while ((cp = strsep(&tmp, ",")) != NULL) { 219 if (strncmp(cp, "aes", 3) != 0) { 220 if (buffer_len(&b) > 0) 221 buffer_append(&b, ",", 1); 222 buffer_append(&b, cp, strlen(cp)); 223 } 224 } 225 buffer_append(&b, "\0", 1); 226 fix_ciphers = xstrdup(buffer_ptr(&b)); 227 buffer_free(&b); 228 xfree(orig_prop); 229 debug2("Original cipher proposal: %s", cipher_prop); 230 debug2("Compat cipher proposal: %s", fix_ciphers); 231 if (!*fix_ciphers) 232 fatal("No available ciphers found."); 233 234 return(fix_ciphers); 235 } 236