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 1.63 2002/04/10 08:21:47 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 verbose("Enabling compatibility mode for protocol 2.0"); 43 compat20 = 1; 44 } 45 void 46 enable_compat13(void) 47 { 48 verbose("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 { "2.1 *", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 90 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 91 SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE }, 92 { "2.0.13*," 93 "2.0.14*," 94 "2.0.15*," 95 "2.0.16*," 96 "2.0.17*," 97 "2.0.18*," 98 "2.0.19*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 99 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 100 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 101 SSH_BUG_PKOK|SSH_BUG_RSASIGMD5| 102 SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE| 103 SSH_BUG_DUMMYCHAN }, 104 { "2.0.11*," 105 "2.0.12*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 106 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 107 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 108 SSH_BUG_PKAUTH|SSH_BUG_PKOK| 109 SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE| 110 SSH_BUG_DUMMYCHAN }, 111 { "2.0.*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 112 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 113 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 114 SSH_BUG_PKAUTH|SSH_BUG_PKOK| 115 SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE| 116 SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN }, 117 { "2.2.0*," 118 "2.3.0*", SSH_BUG_HMAC|SSH_BUG_DEBUG| 119 SSH_BUG_RSASIGMD5 }, 120 { "2.3.*", SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5 }, 121 { "2.4", SSH_OLD_SESSIONID }, /* Van Dyke */ 122 { "2.*", SSH_BUG_DEBUG }, 123 { "3.0.*", SSH_BUG_DEBUG }, 124 { "3.0 SecureCRT*", SSH_OLD_SESSIONID }, 125 { "1.7 SecureFX*", SSH_OLD_SESSIONID }, 126 { "1.2.18*," 127 "1.2.19*," 128 "1.2.20*," 129 "1.2.21*," 130 "1.2.22*", SSH_BUG_IGNOREMSG|SSH_BUG_K5USER }, 131 { "1.3.2*", /* F-Secure */ 132 SSH_BUG_IGNOREMSG|SSH_BUG_K5USER }, 133 { "1.2.1*," 134 "1.2.2*," 135 "1.2.3*", SSH_BUG_K5USER }, 136 { "*SSH Compatible Server*", /* Netscreen */ 137 SSH_BUG_PASSWORDPAD }, 138 { "*OSU_0*," 139 "OSU_1.0*," 140 "OSU_1.1*," 141 "OSU_1.2*," 142 "OSU_1.3*," 143 "OSU_1.4*," 144 "OSU_1.5alpha1*," 145 "OSU_1.5alpha2*," 146 "OSU_1.5alpha3*", SSH_BUG_PASSWORDPAD }, 147 { "*SSH_Version_Mapper*", 148 SSH_BUG_SCANNER }, 149 { NULL, 0 } 150 }; 151 152 /* process table, return first match */ 153 for (i = 0; check[i].pat; i++) { 154 if (match_pattern_list(version, check[i].pat, 155 strlen(check[i].pat), 0) == 1) { 156 debug("match: %s pat %s", version, check[i].pat); 157 datafellows = check[i].bugs; 158 return; 159 } 160 } 161 debug("no match: %s", version); 162 } 163 164 #define SEP "," 165 int 166 proto_spec(const char *spec) 167 { 168 char *s, *p, *q; 169 int ret = SSH_PROTO_UNKNOWN; 170 171 if (spec == NULL) 172 return ret; 173 q = s = xstrdup(spec); 174 for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) { 175 switch (atoi(p)) { 176 case 1: 177 if (ret == SSH_PROTO_UNKNOWN) 178 ret |= SSH_PROTO_1_PREFERRED; 179 ret |= SSH_PROTO_1; 180 break; 181 case 2: 182 ret |= SSH_PROTO_2; 183 break; 184 default: 185 log("ignoring bad proto spec: '%s'.", p); 186 break; 187 } 188 } 189 xfree(s); 190 return ret; 191 } 192 193 char * 194 compat_cipher_proposal(char *cipher_prop) 195 { 196 Buffer b; 197 char *orig_prop, *fix_ciphers; 198 char *cp, *tmp; 199 200 if (!(datafellows & SSH_BUG_BIGENDIANAES)) 201 return(cipher_prop); 202 203 buffer_init(&b); 204 tmp = orig_prop = xstrdup(cipher_prop); 205 while ((cp = strsep(&tmp, ",")) != NULL) { 206 if (strncmp(cp, "aes", 3) != 0) { 207 if (buffer_len(&b) > 0) 208 buffer_append(&b, ",", 1); 209 buffer_append(&b, cp, strlen(cp)); 210 } 211 } 212 buffer_append(&b, "\0", 1); 213 fix_ciphers = xstrdup(buffer_ptr(&b)); 214 buffer_free(&b); 215 xfree(orig_prop); 216 debug2("Original cipher proposal: %s", cipher_prop); 217 debug2("Compat cipher proposal: %s", fix_ciphers); 218 if (!*fix_ciphers) 219 fatal("No available ciphers found."); 220 221 return(fix_ciphers); 222 } 223