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 $"); 27 RCSID("$FreeBSD$"); 28 29 #include "buffer.h" 30 #include "packet.h" 31 #include "xmalloc.h" 32 #include "compat.h" 33 #include "log.h" 34 #include "match.h" 35 36 int compat13 = 0; 37 int compat20 = 0; 38 int datafellows = 0; 39 40 void 41 enable_compat20(void) 42 { 43 verbose("Enabling compatibility mode for protocol 2.0"); 44 compat20 = 1; 45 } 46 void 47 enable_compat13(void) 48 { 49 verbose("Enabling compatibility mode for protocol 1.3"); 50 compat13 = 1; 51 } 52 /* datafellows bug compatibility */ 53 void 54 compat_datafellows(const char *version) 55 { 56 int i; 57 static struct { 58 char *pat; 59 int bugs; 60 } check[] = { 61 { "OpenSSH-2.0*," 62 "OpenSSH-2.1*," 63 "OpenSSH_2.1*," 64 "OpenSSH_2.2*", SSH_OLD_SESSIONID|SSH_BUG_BANNER| 65 SSH_OLD_DHGEX|SSH_BUG_NOREKEY| 66 SSH_BUG_EXTEOF}, 67 { "OpenSSH_2.3.0*", SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES| 68 SSH_OLD_DHGEX|SSH_BUG_NOREKEY| 69 SSH_BUG_EXTEOF}, 70 { "OpenSSH_2.3.*", SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX| 71 SSH_BUG_NOREKEY|SSH_BUG_EXTEOF}, 72 { "OpenSSH_2.5.0p1*," 73 "OpenSSH_2.5.1p1*", 74 SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX| 75 SSH_BUG_NOREKEY|SSH_BUG_EXTEOF}, 76 { "OpenSSH_2.5.0*," 77 "OpenSSH_2.5.1*," 78 "OpenSSH_2.5.2*", SSH_OLD_DHGEX|SSH_BUG_NOREKEY| 79 SSH_BUG_EXTEOF}, 80 { "OpenSSH_2.5.3*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF}, 81 { "OpenSSH_2.*," 82 "OpenSSH_3.0*," 83 "OpenSSH_3.1*", SSH_BUG_EXTEOF}, 84 { "Sun_SSH_1.0*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF}, 85 { "OpenSSH*", 0 }, 86 { "*MindTerm*", 0 }, 87 { "2.1.0*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 88 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 89 SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE }, 90 { "2.1 *", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 91 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 92 SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE }, 93 { "2.0.13*," 94 "2.0.14*," 95 "2.0.15*," 96 "2.0.16*," 97 "2.0.17*," 98 "2.0.18*," 99 "2.0.19*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 100 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 101 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 102 SSH_BUG_PKOK|SSH_BUG_RSASIGMD5| 103 SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE| 104 SSH_BUG_DUMMYCHAN }, 105 { "2.0.11*," 106 "2.0.12*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 107 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 108 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 109 SSH_BUG_PKAUTH|SSH_BUG_PKOK| 110 SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE| 111 SSH_BUG_DUMMYCHAN }, 112 { "2.0.*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 113 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 114 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 115 SSH_BUG_PKAUTH|SSH_BUG_PKOK| 116 SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE| 117 SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN }, 118 { "2.2.0*," 119 "2.3.0*", SSH_BUG_HMAC|SSH_BUG_DEBUG| 120 SSH_BUG_RSASIGMD5 }, 121 { "2.3.*", SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5 }, 122 { "2.4", SSH_OLD_SESSIONID }, /* Van Dyke */ 123 { "2.*", SSH_BUG_DEBUG }, 124 { "3.0.*", SSH_BUG_DEBUG }, 125 { "3.0 SecureCRT*", SSH_OLD_SESSIONID }, 126 { "1.7 SecureFX*", SSH_OLD_SESSIONID }, 127 { "1.2.18*," 128 "1.2.19*," 129 "1.2.20*," 130 "1.2.21*," 131 "1.2.22*", SSH_BUG_IGNOREMSG|SSH_BUG_K5USER }, 132 { "1.3.2*", /* F-Secure */ 133 SSH_BUG_IGNOREMSG|SSH_BUG_K5USER }, 134 { "1.2.1*," 135 "1.2.2*," 136 "1.2.3*", SSH_BUG_K5USER }, 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 { NULL, 0 } 151 }; 152 153 /* process table, return first match */ 154 for (i = 0; check[i].pat; i++) { 155 if (match_pattern_list(version, check[i].pat, 156 strlen(check[i].pat), 0) == 1) { 157 debug("match: %s pat %s", version, check[i].pat); 158 datafellows = check[i].bugs; 159 return; 160 } 161 } 162 debug("no match: %s", version); 163 } 164 165 #define SEP "," 166 int 167 proto_spec(const char *spec) 168 { 169 char *s, *p, *q; 170 int ret = SSH_PROTO_UNKNOWN; 171 172 if (spec == NULL) 173 return ret; 174 q = s = xstrdup(spec); 175 for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) { 176 switch (atoi(p)) { 177 case 1: 178 if (ret == SSH_PROTO_UNKNOWN) 179 ret |= SSH_PROTO_1_PREFERRED; 180 ret |= SSH_PROTO_1; 181 break; 182 case 2: 183 ret |= SSH_PROTO_2; 184 break; 185 default: 186 log("ignoring bad proto spec: '%s'.", p); 187 break; 188 } 189 } 190 xfree(s); 191 return ret; 192 } 193 194 char * 195 compat_cipher_proposal(char *cipher_prop) 196 { 197 Buffer b; 198 char *orig_prop, *fix_ciphers; 199 char *cp, *tmp; 200 201 if (!(datafellows & SSH_BUG_BIGENDIANAES)) 202 return(cipher_prop); 203 204 buffer_init(&b); 205 tmp = orig_prop = xstrdup(cipher_prop); 206 while ((cp = strsep(&tmp, ",")) != NULL) { 207 if (strncmp(cp, "aes", 3) != 0) { 208 if (buffer_len(&b) > 0) 209 buffer_append(&b, ",", 1); 210 buffer_append(&b, cp, strlen(cp)); 211 } 212 } 213 buffer_append(&b, "\0", 1); 214 fix_ciphers = xstrdup(buffer_ptr(&b)); 215 buffer_free(&b); 216 xfree(orig_prop); 217 debug2("Original cipher proposal: %s", cipher_prop); 218 debug2("Compat cipher proposal: %s", fix_ciphers); 219 if (!*fix_ciphers) 220 fatal("No available ciphers found."); 221 222 return(fix_ciphers); 223 } 224