1 /* 2 * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 23 */ 24 25 #include "includes.h" 26 RCSID("$OpenBSD: compat.c,v 1.70 2003/11/02 11:01:03 markus Exp $"); 27 28 #include "buffer.h" 29 #include "packet.h" 30 #include "xmalloc.h" 31 #include "compat.h" 32 #include "log.h" 33 #include "match.h" 34 35 int compat13 = 0; 36 int compat20 = 0; 37 int datafellows = 0; 38 39 void 40 enable_compat20(void) 41 { 42 debug("Enabling compatibility mode for protocol 2.0"); 43 compat20 = 1; 44 } 45 void 46 enable_compat13(void) 47 { 48 debug("Enabling compatibility mode for protocol 1.3"); 49 compat13 = 1; 50 } 51 /* datafellows bug compatibility */ 52 void 53 compat_datafellows(const char *version) 54 { 55 int i; 56 static struct { 57 char *pat; 58 int bugs; 59 } check[] = { 60 { "OpenSSH-2.0*," 61 "OpenSSH-2.1*," 62 "OpenSSH_2.1*," 63 "OpenSSH_2.2*", SSH_OLD_SESSIONID|SSH_BUG_BANNER| 64 SSH_OLD_DHGEX|SSH_BUG_NOREKEY| 65 SSH_BUG_EXTEOF}, 66 { "OpenSSH_2.3.0*", SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES| 67 SSH_OLD_DHGEX|SSH_BUG_NOREKEY| 68 SSH_BUG_EXTEOF}, 69 { "OpenSSH_2.3.*", SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX| 70 SSH_BUG_NOREKEY|SSH_BUG_EXTEOF}, 71 { "OpenSSH_2.5.0p1*," 72 "OpenSSH_2.5.1p1*", 73 SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX| 74 SSH_BUG_NOREKEY|SSH_BUG_EXTEOF}, 75 { "OpenSSH_2.5.0*," 76 "OpenSSH_2.5.1*," 77 "OpenSSH_2.5.2*", SSH_OLD_DHGEX|SSH_BUG_NOREKEY| 78 SSH_BUG_EXTEOF}, 79 { "OpenSSH_2.5.3*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF}, 80 { "OpenSSH_2.*," 81 "OpenSSH_3.0*," 82 "OpenSSH_3.1*", SSH_BUG_EXTEOF}, 83 { "Sun_SSH_1.0*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF}, 84 { "OpenSSH*", 0 }, 85 { "*MindTerm*", 0 }, 86 { "2.1.0*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 87 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 88 SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE| 89 SSH_BUG_FIRSTKEX }, 90 { "2.1 *", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 91 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 92 SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE| 93 SSH_BUG_FIRSTKEX }, 94 { "2.0.13*," 95 "2.0.14*," 96 "2.0.15*," 97 "2.0.16*," 98 "2.0.17*," 99 "2.0.18*," 100 "2.0.19*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 101 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 102 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 103 SSH_BUG_PKOK|SSH_BUG_RSASIGMD5| 104 SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE| 105 SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX }, 106 { "2.0.11*," 107 "2.0.12*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 108 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 109 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 110 SSH_BUG_PKAUTH|SSH_BUG_PKOK| 111 SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE| 112 SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX }, 113 { "2.0.*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 114 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 115 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 116 SSH_BUG_PKAUTH|SSH_BUG_PKOK| 117 SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE| 118 SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN| 119 SSH_BUG_FIRSTKEX }, 120 { "2.2.0*," 121 "2.3.0*", SSH_BUG_HMAC|SSH_BUG_DEBUG| 122 SSH_BUG_RSASIGMD5|SSH_BUG_FIRSTKEX }, 123 { "2.3.*", SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5| 124 SSH_BUG_FIRSTKEX }, 125 { "2.4", SSH_OLD_SESSIONID }, /* Van Dyke */ 126 { "2.*", SSH_BUG_DEBUG|SSH_BUG_FIRSTKEX }, 127 { "3.0.*", SSH_BUG_DEBUG }, 128 { "3.0 SecureCRT*", SSH_OLD_SESSIONID }, 129 { "1.7 SecureFX*", SSH_OLD_SESSIONID }, 130 { "1.2.18*," 131 "1.2.19*," 132 "1.2.20*," 133 "1.2.21*," 134 "1.2.22*", SSH_BUG_IGNOREMSG }, 135 { "1.3.2*", /* F-Secure */ 136 SSH_BUG_IGNOREMSG }, 137 { "*SSH Compatible Server*", /* Netscreen */ 138 SSH_BUG_PASSWORDPAD }, 139 { "*OSU_0*," 140 "OSU_1.0*," 141 "OSU_1.1*," 142 "OSU_1.2*," 143 "OSU_1.3*," 144 "OSU_1.4*," 145 "OSU_1.5alpha1*," 146 "OSU_1.5alpha2*," 147 "OSU_1.5alpha3*", SSH_BUG_PASSWORDPAD }, 148 { "*SSH_Version_Mapper*", 149 SSH_BUG_SCANNER }, 150 { "Probe-*", 151 SSH_BUG_PROBE }, 152 { NULL, 0 } 153 }; 154 155 /* process table, return first match */ 156 for (i = 0; check[i].pat; i++) { 157 if (match_pattern_list(version, check[i].pat, 158 strlen(check[i].pat), 0) == 1) { 159 debug("match: %s pat %s", version, check[i].pat); 160 datafellows = check[i].bugs; 161 return; 162 } 163 } 164 debug("no match: %s", version); 165 } 166 167 #define SEP "," 168 int 169 proto_spec(const char *spec) 170 { 171 char *s, *p, *q; 172 int ret = SSH_PROTO_UNKNOWN; 173 174 if (spec == NULL) 175 return ret; 176 q = s = xstrdup(spec); 177 for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) { 178 switch (atoi(p)) { 179 case 1: 180 if (ret == SSH_PROTO_UNKNOWN) 181 ret |= SSH_PROTO_1_PREFERRED; 182 ret |= SSH_PROTO_1; 183 break; 184 case 2: 185 ret |= SSH_PROTO_2; 186 break; 187 default: 188 logit("ignoring bad proto spec: '%s'.", p); 189 break; 190 } 191 } 192 xfree(s); 193 return ret; 194 } 195 196 char * 197 compat_cipher_proposal(char *cipher_prop) 198 { 199 Buffer b; 200 char *orig_prop, *fix_ciphers; 201 char *cp, *tmp; 202 203 if (!(datafellows & SSH_BUG_BIGENDIANAES)) 204 return(cipher_prop); 205 206 buffer_init(&b); 207 tmp = orig_prop = xstrdup(cipher_prop); 208 while ((cp = strsep(&tmp, ",")) != NULL) { 209 if (strncmp(cp, "aes", 3) != 0) { 210 if (buffer_len(&b) > 0) 211 buffer_append(&b, ",", 1); 212 buffer_append(&b, cp, strlen(cp)); 213 } 214 } 215 buffer_append(&b, "\0", 1); 216 fix_ciphers = xstrdup(buffer_ptr(&b)); 217 buffer_free(&b); 218 xfree(orig_prop); 219 debug2("Original cipher proposal: %s", cipher_prop); 220 debug2("Compat cipher proposal: %s", fix_ciphers); 221 if (!*fix_ciphers) 222 fatal("No available ciphers found."); 223 224 return(fix_ciphers); 225 } 226