1 /* 2 * Copyright (c) 1999, 2000, 2001 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 1.53 2001/09/20 13:50:40 markus Exp $"); 27 28 #include <regex.h> 29 30 #include "packet.h" 31 #include "xmalloc.h" 32 #include "compat.h" 33 #include "log.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, ret; 56 char ebuf[1024]; 57 regex_t reg; 58 static struct { 59 char *pat; 60 int bugs; 61 } check[] = { 62 { "^OpenSSH[-_]2\\.[012]", 63 SSH_OLD_SESSIONID|SSH_BUG_BANNER| 64 SSH_OLD_DHGEX|SSH_BUG_NOREKEY }, 65 { "^OpenSSH_2\\.3\\.0", SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES| 66 SSH_OLD_DHGEX|SSH_BUG_NOREKEY}, 67 { "^OpenSSH_2\\.3\\.", SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX| 68 SSH_BUG_NOREKEY}, 69 { "^OpenSSH_2\\.5\\.[01]p1", 70 SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX| 71 SSH_BUG_NOREKEY }, 72 { "^OpenSSH_2\\.5\\.[012]", 73 SSH_OLD_DHGEX|SSH_BUG_NOREKEY }, 74 { "^OpenSSH_2\\.5\\.3", 75 SSH_BUG_NOREKEY }, 76 { "^OpenSSH", 0 }, 77 { "MindTerm", 0 }, 78 { "^2\\.1\\.0", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 79 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 80 SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE }, 81 { "^2\\.1 ", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 82 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 83 SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE }, 84 { "^2\\.0\\.1[3-9]", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 85 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 86 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 87 SSH_BUG_PKOK|SSH_BUG_RSASIGMD5| 88 SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE| 89 SSH_BUG_DUMMYCHAN }, 90 { "^2\\.0\\.1[1-2]", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 91 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 92 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 93 SSH_BUG_PKAUTH|SSH_BUG_PKOK| 94 SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE| 95 SSH_BUG_DUMMYCHAN }, 96 { "^2\\.0\\.", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| 97 SSH_OLD_SESSIONID|SSH_BUG_DEBUG| 98 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| 99 SSH_BUG_PKAUTH|SSH_BUG_PKOK| 100 SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE| 101 SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN }, 102 { "^2\\.[23]\\.0", SSH_BUG_HMAC|SSH_BUG_DEBUG| 103 SSH_BUG_RSASIGMD5 }, 104 { "^2\\.3\\.", SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5 }, 105 { "^2\\.[2-9]\\.", SSH_BUG_DEBUG }, 106 { "^3\\.0\\.", SSH_BUG_DEBUG }, 107 { "^2\\.4$", SSH_OLD_SESSIONID }, /* Van Dyke */ 108 { "^3\\.0 SecureCRT", SSH_OLD_SESSIONID }, 109 { "^1\\.7 SecureFX", SSH_OLD_SESSIONID }, 110 { "^1\\.2\\.1[89]", SSH_BUG_IGNOREMSG }, 111 { "^1\\.2\\.2[012]", SSH_BUG_IGNOREMSG }, 112 { "^1\\.3\\.2", SSH_BUG_IGNOREMSG }, /* f-secure */ 113 { "^SSH Compatible Server", /* Netscreen */ 114 SSH_BUG_PASSWORDPAD }, 115 { "^OSU_0", SSH_BUG_PASSWORDPAD }, 116 { "^OSU_1\\.[0-4]", SSH_BUG_PASSWORDPAD }, 117 { "^OSU_1\\.5alpha[1-3]", 118 SSH_BUG_PASSWORDPAD }, 119 { "^SSH_Version_Mapper", 120 SSH_BUG_SCANNER }, 121 { NULL, 0 } 122 }; 123 /* process table, return first match */ 124 for (i = 0; check[i].pat; i++) { 125 ret = regcomp(®, check[i].pat, REG_EXTENDED|REG_NOSUB); 126 if (ret != 0) { 127 regerror(ret, ®, ebuf, sizeof(ebuf)); 128 ebuf[sizeof(ebuf)-1] = '\0'; 129 error("regerror: %s", ebuf); 130 continue; 131 } 132 ret = regexec(®, version, 0, NULL, 0); 133 regfree(®); 134 if (ret == 0) { 135 debug("match: %s pat %s", version, check[i].pat); 136 datafellows = check[i].bugs; 137 return; 138 } 139 } 140 debug("no match: %s", version); 141 } 142 143 #define SEP "," 144 int 145 proto_spec(const char *spec) 146 { 147 char *s, *p, *q; 148 int ret = SSH_PROTO_UNKNOWN; 149 150 if (spec == NULL) 151 return ret; 152 q = s = xstrdup(spec); 153 for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) { 154 switch(atoi(p)) { 155 case 1: 156 if (ret == SSH_PROTO_UNKNOWN) 157 ret |= SSH_PROTO_1_PREFERRED; 158 ret |= SSH_PROTO_1; 159 break; 160 case 2: 161 ret |= SSH_PROTO_2; 162 break; 163 default: 164 log("ignoring bad proto spec: '%s'.", p); 165 break; 166 } 167 } 168 xfree(s); 169 return ret; 170 } 171 172 char * 173 compat_cipher_proposal(char *cipher_prop) 174 { 175 char *orig_prop, *fix_ciphers; 176 char *cp, *tmp; 177 size_t len; 178 179 if (!(datafellows & SSH_BUG_BIGENDIANAES)) 180 return(cipher_prop); 181 182 len = strlen(cipher_prop) + 1; 183 fix_ciphers = xmalloc(len); 184 *fix_ciphers = '\0'; 185 tmp = orig_prop = xstrdup(cipher_prop); 186 while((cp = strsep(&tmp, ",")) != NULL) { 187 if (strncmp(cp, "aes", 3) && strncmp(cp, "rijndael", 8)) { 188 if (*fix_ciphers) 189 strlcat(fix_ciphers, ",", len); 190 strlcat(fix_ciphers, cp, len); 191 } 192 } 193 xfree(orig_prop); 194 debug2("Original cipher proposal: %s", cipher_prop); 195 debug2("Compat cipher proposal: %s", fix_ciphers); 196 if (!*fix_ciphers) 197 fatal("No available ciphers found."); 198 199 return(fix_ciphers); 200 } 201