1 /* $NetBSD: compat.c,v 1.18 2018/04/06 18:59:00 christos Exp $ */ 2 /* $OpenBSD: compat.c,v 1.106 2018/02/16 04:43:11 dtucker Exp $ */ 3 /* 4 * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include "includes.h" 28 __RCSID("$NetBSD: compat.c,v 1.18 2018/04/06 18:59:00 christos Exp $"); 29 #include <sys/types.h> 30 31 #include <stdlib.h> 32 #include <string.h> 33 #include <stdarg.h> 34 35 #include "xmalloc.h" 36 #include "buffer.h" 37 #include "packet.h" 38 #include "compat.h" 39 #include "log.h" 40 #include "match.h" 41 #include "kex.h" 42 43 int datafellows = 0; 44 45 /* datafellows bug compatibility */ 46 u_int 47 compat_datafellows(const char *version) 48 { 49 int i; 50 static struct { 51 const char *pat; 52 int bugs; 53 } check[] = { 54 { "OpenSSH_2.*," 55 "OpenSSH_3.0*," 56 "OpenSSH_3.1*", SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR}, 57 { "OpenSSH_3.*", SSH_OLD_FORWARD_ADDR }, 58 { "Sun_SSH_1.0*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF}, 59 { "OpenSSH_2*," 60 "OpenSSH_3*," 61 "OpenSSH_4*", 0 }, 62 { "OpenSSH_5*", SSH_NEW_OPENSSH|SSH_BUG_DYNAMIC_RPORT}, 63 { "OpenSSH_6.6.1*", SSH_NEW_OPENSSH}, 64 { "OpenSSH_6.5*," 65 "OpenSSH_6.6*", SSH_NEW_OPENSSH|SSH_BUG_CURVE25519PAD}, 66 { "OpenSSH*", SSH_NEW_OPENSSH }, 67 { "*MindTerm*", 0 }, 68 { "3.0.*", SSH_BUG_DEBUG }, 69 { "3.0 SecureCRT*", SSH_OLD_SESSIONID }, 70 { "1.7 SecureFX*", SSH_OLD_SESSIONID }, 71 { "1.2.18*," 72 "1.2.19*," 73 "1.2.20*," 74 "1.2.21*," 75 "1.2.22*", SSH_BUG_IGNOREMSG }, 76 { "1.3.2*", /* F-Secure */ 77 SSH_BUG_IGNOREMSG }, 78 { "Cisco-1.*", SSH_BUG_DHGEX_LARGE| 79 SSH_BUG_HOSTKEYS }, 80 { "*SSH Compatible Server*", /* Netscreen */ 81 SSH_BUG_PASSWORDPAD }, 82 { "*OSU_0*," 83 "OSU_1.0*," 84 "OSU_1.1*," 85 "OSU_1.2*," 86 "OSU_1.3*," 87 "OSU_1.4*," 88 "OSU_1.5alpha1*," 89 "OSU_1.5alpha2*," 90 "OSU_1.5alpha3*", SSH_BUG_PASSWORDPAD }, 91 { "*SSH_Version_Mapper*", 92 SSH_BUG_SCANNER }, 93 { "PuTTY_Local:*," /* dev versions < Sep 2014 */ 94 "PuTTY-Release-0.5*," /* 0.50-0.57, DH-GEX in >=0.52 */ 95 "PuTTY_Release_0.5*," /* 0.58-0.59 */ 96 "PuTTY_Release_0.60*," 97 "PuTTY_Release_0.61*," 98 "PuTTY_Release_0.62*," 99 "PuTTY_Release_0.63*," 100 "PuTTY_Release_0.64*", 101 SSH_OLD_DHGEX }, 102 { "FuTTY*", SSH_OLD_DHGEX }, /* Putty Fork */ 103 { "Probe-*", 104 SSH_BUG_PROBE }, 105 { "TeraTerm SSH*," 106 "TTSSH/1.5.*," 107 "TTSSH/2.1*," 108 "TTSSH/2.2*," 109 "TTSSH/2.3*," 110 "TTSSH/2.4*," 111 "TTSSH/2.5*," 112 "TTSSH/2.6*," 113 "TTSSH/2.70*," 114 "TTSSH/2.71*," 115 "TTSSH/2.72*", SSH_BUG_HOSTKEYS }, 116 { "WinSCP_release_4*," 117 "WinSCP_release_5.0*," 118 "WinSCP_release_5.1," 119 "WinSCP_release_5.1.*," 120 "WinSCP_release_5.5," 121 "WinSCP_release_5.5.*," 122 "WinSCP_release_5.6," 123 "WinSCP_release_5.6.*," 124 "WinSCP_release_5.7," 125 "WinSCP_release_5.7.1," 126 "WinSCP_release_5.7.2," 127 "WinSCP_release_5.7.3," 128 "WinSCP_release_5.7.4", 129 SSH_OLD_DHGEX }, 130 { "ConfD-*", 131 SSH_BUG_UTF8TTYMODE }, 132 { NULL, 0 } 133 }; 134 135 /* process table, return first match */ 136 for (i = 0; check[i].pat; i++) { 137 if (match_pattern_list(version, check[i].pat, 0) == 1) { 138 debug("match: %s pat %s compat 0x%08x", 139 version, check[i].pat, check[i].bugs); 140 datafellows = check[i].bugs; /* XXX for now */ 141 /* Check to see if the remote side is OpenSSH and not HPN */ 142 if(strstr(version,"OpenSSH") != NULL) 143 { 144 if (strstr(version,"hpn") == NULL) 145 { 146 datafellows |= SSH_BUG_LARGEWINDOW; 147 debug("Remote is NON-HPN aware"); 148 } 149 } 150 return check[i].bugs; 151 } 152 } 153 debug("no match: %s", version); 154 return 0; 155 } 156 157 #define SEP "," 158 int 159 proto_spec(const char *spec) 160 { 161 char *s, *p, *q; 162 int ret = SSH_PROTO_UNKNOWN; 163 164 if (spec == NULL) 165 return ret; 166 q = s = strdup(spec); 167 if (s == NULL) 168 return ret; 169 for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) { 170 switch (atoi(p)) { 171 case 2: 172 ret |= SSH_PROTO_2; 173 break; 174 default: 175 logit("ignoring bad proto spec: '%s'.", p); 176 break; 177 } 178 } 179 free(s); 180 return ret; 181 } 182 183 const char * 184 compat_cipher_proposal(const char *cipher_prop) 185 { 186 if (!(datafellows & SSH_BUG_BIGENDIANAES)) 187 return cipher_prop; 188 debug2("%s: original cipher proposal: %s", __func__, cipher_prop); 189 if ((cipher_prop = match_filter_list(cipher_prop, "aes*")) == NULL) 190 fatal("match_filter_list failed"); 191 debug2("%s: compat cipher proposal: %s", __func__, cipher_prop); 192 if (*cipher_prop == '\0') 193 fatal("No supported ciphers found"); 194 return cipher_prop; 195 } 196 197 char * 198 compat_pkalg_proposal(char *pkalg_prop) 199 { 200 if (!(datafellows & SSH_BUG_RSASIGMD5)) 201 return pkalg_prop; 202 debug2("%s: original public key proposal: %s", __func__, pkalg_prop); 203 if ((pkalg_prop = match_filter_list(pkalg_prop, "ssh-rsa")) == NULL) 204 fatal("match_filter_list failed"); 205 debug2("%s: compat public key proposal: %s", __func__, pkalg_prop); 206 if (*pkalg_prop == '\0') 207 fatal("No supported PK algorithms found"); 208 return pkalg_prop; 209 } 210 211 const char * 212 compat_kex_proposal(const char *p) 213 { 214 if ((datafellows & (SSH_BUG_CURVE25519PAD|SSH_OLD_DHGEX)) == 0) 215 return p; 216 debug2("%s: original KEX proposal: %s", __func__, p); 217 if ((datafellows & SSH_BUG_CURVE25519PAD) != 0) 218 if ((p = match_filter_list(p, 219 "curve25519-sha256@libssh.org")) == NULL) 220 fatal("match_filter_list failed"); 221 if ((datafellows & SSH_OLD_DHGEX) != 0) { 222 if ((p = match_filter_list(p, 223 "diffie-hellman-group-exchange-sha256," 224 "diffie-hellman-group-exchange-sha1")) == NULL) 225 fatal("match_filter_list failed"); 226 } 227 debug2("%s: compat KEX proposal: %s", __func__, p); 228 if (*p == '\0') 229 fatal("No supported key exchange algorithms found"); 230 return p; 231 } 232 233