1 /* $OpenBSD: compat.c,v 1.77 2006/12/12 03:58:42 djm 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*", 0 }, 93 { "*MindTerm*", 0 }, 94 { "2.1.0*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 95 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 96 SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE| 97 SSH_BUG_FIRSTKEX }, 98 { "2.1 *", 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 { "2.0.13*," 103 "2.0.14*," 104 "2.0.15*," 105 "2.0.16*," 106 "2.0.17*," 107 "2.0.18*," 108 "2.0.19*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 109 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 110 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 111 SSH_BUG_PKOK|SSH_BUG_RSASIGMD5| 112 SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE| 113 SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX }, 114 { "2.0.11*," 115 "2.0.12*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 116 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 117 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 118 SSH_BUG_PKAUTH|SSH_BUG_PKOK| 119 SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE| 120 SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX }, 121 { "2.0.*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 122 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 123 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 124 SSH_BUG_PKAUTH|SSH_BUG_PKOK| 125 SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE| 126 SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN| 127 SSH_BUG_FIRSTKEX }, 128 { "2.2.0*," 129 "2.3.0*", SSH_BUG_HMAC|SSH_BUG_DEBUG| 130 SSH_BUG_RSASIGMD5|SSH_BUG_FIRSTKEX }, 131 { "2.3.*", SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5| 132 SSH_BUG_FIRSTKEX }, 133 { "2.4", SSH_OLD_SESSIONID }, /* Van Dyke */ 134 { "2.*", SSH_BUG_DEBUG|SSH_BUG_FIRSTKEX| 135 SSH_BUG_RFWD_ADDR }, 136 { "3.0.*", SSH_BUG_DEBUG }, 137 { "3.0 SecureCRT*", SSH_OLD_SESSIONID }, 138 { "1.7 SecureFX*", SSH_OLD_SESSIONID }, 139 { "1.2.18*," 140 "1.2.19*," 141 "1.2.20*," 142 "1.2.21*," 143 "1.2.22*", SSH_BUG_IGNOREMSG }, 144 { "1.3.2*", /* F-Secure */ 145 SSH_BUG_IGNOREMSG }, 146 { "*SSH Compatible Server*", /* Netscreen */ 147 SSH_BUG_PASSWORDPAD }, 148 { "*OSU_0*," 149 "OSU_1.0*," 150 "OSU_1.1*," 151 "OSU_1.2*," 152 "OSU_1.3*," 153 "OSU_1.4*," 154 "OSU_1.5alpha1*," 155 "OSU_1.5alpha2*," 156 "OSU_1.5alpha3*", SSH_BUG_PASSWORDPAD }, 157 { "*SSH_Version_Mapper*", 158 SSH_BUG_SCANNER }, 159 { "Probe-*", 160 SSH_BUG_PROBE }, 161 { NULL, 0 } 162 }; 163 164 /* process table, return first match */ 165 for (i = 0; check[i].pat; i++) { 166 if (match_pattern_list(version, check[i].pat, 167 strlen(check[i].pat), 0) == 1) { 168 debug("match: %s pat %s", version, check[i].pat); 169 datafellows = check[i].bugs; 170 return; 171 } 172 } 173 debug("no match: %s", version); 174 } 175 176 #define SEP "," 177 int 178 proto_spec(const char *spec) 179 { 180 char *s, *p, *q; 181 int ret = SSH_PROTO_UNKNOWN; 182 183 if (spec == NULL) 184 return ret; 185 q = s = xstrdup(spec); 186 for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) { 187 switch (atoi(p)) { 188 case 1: 189 if (ret == SSH_PROTO_UNKNOWN) 190 ret |= SSH_PROTO_1_PREFERRED; 191 ret |= SSH_PROTO_1; 192 break; 193 case 2: 194 ret |= SSH_PROTO_2; 195 break; 196 default: 197 logit("ignoring bad proto spec: '%s'.", p); 198 break; 199 } 200 } 201 xfree(s); 202 return ret; 203 } 204 205 char * 206 compat_cipher_proposal(char *cipher_prop) 207 { 208 Buffer b; 209 char *orig_prop, *fix_ciphers; 210 char *cp, *tmp; 211 212 if (!(datafellows & SSH_BUG_BIGENDIANAES)) 213 return(cipher_prop); 214 215 buffer_init(&b); 216 tmp = orig_prop = xstrdup(cipher_prop); 217 while ((cp = strsep(&tmp, ",")) != NULL) { 218 if (strncmp(cp, "aes", 3) != 0) { 219 if (buffer_len(&b) > 0) 220 buffer_append(&b, ",", 1); 221 buffer_append(&b, cp, strlen(cp)); 222 } 223 } 224 buffer_append(&b, "\0", 1); 225 fix_ciphers = xstrdup(buffer_ptr(&b)); 226 buffer_free(&b); 227 xfree(orig_prop); 228 debug2("Original cipher proposal: %s", cipher_prop); 229 debug2("Compat cipher proposal: %s", fix_ciphers); 230 if (!*fix_ciphers) 231 fatal("No available ciphers found."); 232 233 return(fix_ciphers); 234 } 235