Greg Hartman | 9768ca4 | 2017-06-22 20:49:52 -0700 | [diff] [blame] | 1 | /* $OpenBSD: compat.c,v 1.100 2017/02/03 23:01:19 djm Exp $ */ |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in the |
| 12 | * documentation and/or other materials provided with the distribution. |
| 13 | * |
| 14 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 15 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 16 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 17 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 18 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 19 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 20 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 21 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 22 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 23 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 24 | */ |
| 25 | |
| 26 | #include "includes.h" |
| 27 | |
| 28 | #include <sys/types.h> |
| 29 | |
| 30 | #include <stdlib.h> |
| 31 | #include <string.h> |
| 32 | #include <stdarg.h> |
| 33 | |
| 34 | #include "xmalloc.h" |
| 35 | #include "buffer.h" |
| 36 | #include "packet.h" |
| 37 | #include "compat.h" |
| 38 | #include "log.h" |
| 39 | #include "match.h" |
Greg Hartman | 9768ca4 | 2017-06-22 20:49:52 -0700 | [diff] [blame] | 40 | #include "kex.h" |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 41 | |
| 42 | int compat13 = 0; |
| 43 | int compat20 = 0; |
| 44 | int datafellows = 0; |
| 45 | |
| 46 | void |
| 47 | enable_compat20(void) |
| 48 | { |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 49 | if (compat20) |
| 50 | return; |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 51 | debug("Enabling compatibility mode for protocol 2.0"); |
| 52 | compat20 = 1; |
| 53 | } |
| 54 | void |
| 55 | enable_compat13(void) |
| 56 | { |
| 57 | debug("Enabling compatibility mode for protocol 1.3"); |
| 58 | compat13 = 1; |
| 59 | } |
| 60 | /* datafellows bug compatibility */ |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 61 | u_int |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 62 | compat_datafellows(const char *version) |
| 63 | { |
| 64 | int i; |
| 65 | static struct { |
| 66 | char *pat; |
| 67 | int bugs; |
| 68 | } check[] = { |
| 69 | { "OpenSSH-2.0*," |
| 70 | "OpenSSH-2.1*," |
| 71 | "OpenSSH_2.1*," |
| 72 | "OpenSSH_2.2*", SSH_OLD_SESSIONID|SSH_BUG_BANNER| |
| 73 | SSH_OLD_DHGEX|SSH_BUG_NOREKEY| |
| 74 | SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR}, |
| 75 | { "OpenSSH_2.3.0*", SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES| |
| 76 | SSH_OLD_DHGEX|SSH_BUG_NOREKEY| |
| 77 | SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR}, |
| 78 | { "OpenSSH_2.3.*", SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX| |
| 79 | SSH_BUG_NOREKEY|SSH_BUG_EXTEOF| |
| 80 | SSH_OLD_FORWARD_ADDR}, |
| 81 | { "OpenSSH_2.5.0p1*," |
| 82 | "OpenSSH_2.5.1p1*", |
| 83 | SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX| |
| 84 | SSH_BUG_NOREKEY|SSH_BUG_EXTEOF| |
| 85 | SSH_OLD_FORWARD_ADDR}, |
| 86 | { "OpenSSH_2.5.0*," |
| 87 | "OpenSSH_2.5.1*," |
| 88 | "OpenSSH_2.5.2*", SSH_OLD_DHGEX|SSH_BUG_NOREKEY| |
| 89 | SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR}, |
| 90 | { "OpenSSH_2.5.3*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF| |
| 91 | SSH_OLD_FORWARD_ADDR}, |
| 92 | { "OpenSSH_2.*," |
| 93 | "OpenSSH_3.0*," |
| 94 | "OpenSSH_3.1*", SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR}, |
| 95 | { "OpenSSH_3.*", SSH_OLD_FORWARD_ADDR }, |
| 96 | { "Sun_SSH_1.0*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF}, |
| 97 | { "OpenSSH_4*", 0 }, |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 98 | { "OpenSSH_5*", SSH_NEW_OPENSSH|SSH_BUG_DYNAMIC_RPORT}, |
| 99 | { "OpenSSH_6.6.1*", SSH_NEW_OPENSSH}, |
| 100 | { "OpenSSH_6.5*," |
| 101 | "OpenSSH_6.6*", SSH_NEW_OPENSSH|SSH_BUG_CURVE25519PAD}, |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 102 | { "OpenSSH*", SSH_NEW_OPENSSH }, |
| 103 | { "*MindTerm*", 0 }, |
| 104 | { "2.1.0*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| |
| 105 | SSH_OLD_SESSIONID|SSH_BUG_DEBUG| |
| 106 | SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE| |
| 107 | SSH_BUG_FIRSTKEX }, |
| 108 | { "2.1 *", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| |
| 109 | SSH_OLD_SESSIONID|SSH_BUG_DEBUG| |
| 110 | SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE| |
| 111 | SSH_BUG_FIRSTKEX }, |
| 112 | { "2.0.13*," |
| 113 | "2.0.14*," |
| 114 | "2.0.15*," |
| 115 | "2.0.16*," |
| 116 | "2.0.17*," |
| 117 | "2.0.18*," |
| 118 | "2.0.19*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| |
| 119 | SSH_OLD_SESSIONID|SSH_BUG_DEBUG| |
| 120 | SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| |
| 121 | SSH_BUG_PKOK|SSH_BUG_RSASIGMD5| |
| 122 | SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE| |
| 123 | SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX }, |
| 124 | { "2.0.11*," |
| 125 | "2.0.12*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| |
| 126 | SSH_OLD_SESSIONID|SSH_BUG_DEBUG| |
| 127 | SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| |
| 128 | SSH_BUG_PKAUTH|SSH_BUG_PKOK| |
| 129 | SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE| |
| 130 | SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX }, |
| 131 | { "2.0.*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| |
| 132 | SSH_OLD_SESSIONID|SSH_BUG_DEBUG| |
| 133 | SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| |
| 134 | SSH_BUG_PKAUTH|SSH_BUG_PKOK| |
| 135 | SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE| |
| 136 | SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN| |
| 137 | SSH_BUG_FIRSTKEX }, |
| 138 | { "2.2.0*," |
| 139 | "2.3.0*", SSH_BUG_HMAC|SSH_BUG_DEBUG| |
| 140 | SSH_BUG_RSASIGMD5|SSH_BUG_FIRSTKEX }, |
| 141 | { "2.3.*", SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5| |
| 142 | SSH_BUG_FIRSTKEX }, |
| 143 | { "2.4", SSH_OLD_SESSIONID }, /* Van Dyke */ |
| 144 | { "2.*", SSH_BUG_DEBUG|SSH_BUG_FIRSTKEX| |
| 145 | SSH_BUG_RFWD_ADDR }, |
| 146 | { "3.0.*", SSH_BUG_DEBUG }, |
| 147 | { "3.0 SecureCRT*", SSH_OLD_SESSIONID }, |
| 148 | { "1.7 SecureFX*", SSH_OLD_SESSIONID }, |
| 149 | { "1.2.18*," |
| 150 | "1.2.19*," |
| 151 | "1.2.20*," |
| 152 | "1.2.21*," |
| 153 | "1.2.22*", SSH_BUG_IGNOREMSG }, |
| 154 | { "1.3.2*", /* F-Secure */ |
| 155 | SSH_BUG_IGNOREMSG }, |
Greg Hartman | ccacbc9 | 2016-02-03 09:59:44 -0800 | [diff] [blame] | 156 | { "Cisco-1.*", SSH_BUG_DHGEX_LARGE| |
| 157 | SSH_BUG_HOSTKEYS }, |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 158 | { "*SSH Compatible Server*", /* Netscreen */ |
| 159 | SSH_BUG_PASSWORDPAD }, |
| 160 | { "*OSU_0*," |
| 161 | "OSU_1.0*," |
| 162 | "OSU_1.1*," |
| 163 | "OSU_1.2*," |
| 164 | "OSU_1.3*," |
| 165 | "OSU_1.4*," |
| 166 | "OSU_1.5alpha1*," |
| 167 | "OSU_1.5alpha2*," |
| 168 | "OSU_1.5alpha3*", SSH_BUG_PASSWORDPAD }, |
| 169 | { "*SSH_Version_Mapper*", |
| 170 | SSH_BUG_SCANNER }, |
Greg Hartman | ccacbc9 | 2016-02-03 09:59:44 -0800 | [diff] [blame] | 171 | { "PuTTY_Local:*," /* dev versions < Sep 2014 */ |
| 172 | "PuTTY-Release-0.5*," /* 0.50-0.57, DH-GEX in >=0.52 */ |
| 173 | "PuTTY_Release_0.5*," /* 0.58-0.59 */ |
| 174 | "PuTTY_Release_0.60*," |
| 175 | "PuTTY_Release_0.61*," |
| 176 | "PuTTY_Release_0.62*," |
| 177 | "PuTTY_Release_0.63*," |
| 178 | "PuTTY_Release_0.64*", |
| 179 | SSH_OLD_DHGEX }, |
| 180 | { "FuTTY*", SSH_OLD_DHGEX }, /* Putty Fork */ |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 181 | { "Probe-*", |
| 182 | SSH_BUG_PROBE }, |
Greg Hartman | ccacbc9 | 2016-02-03 09:59:44 -0800 | [diff] [blame] | 183 | { "TeraTerm SSH*," |
| 184 | "TTSSH/1.5.*," |
| 185 | "TTSSH/2.1*," |
| 186 | "TTSSH/2.2*," |
| 187 | "TTSSH/2.3*," |
| 188 | "TTSSH/2.4*," |
| 189 | "TTSSH/2.5*," |
| 190 | "TTSSH/2.6*," |
| 191 | "TTSSH/2.70*," |
| 192 | "TTSSH/2.71*," |
| 193 | "TTSSH/2.72*", SSH_BUG_HOSTKEYS }, |
| 194 | { "WinSCP_release_4*," |
| 195 | "WinSCP_release_5.0*," |
| 196 | "WinSCP_release_5.1*," |
| 197 | "WinSCP_release_5.5*," |
| 198 | "WinSCP_release_5.6*," |
| 199 | "WinSCP_release_5.7," |
| 200 | "WinSCP_release_5.7.1," |
| 201 | "WinSCP_release_5.7.2," |
| 202 | "WinSCP_release_5.7.3," |
| 203 | "WinSCP_release_5.7.4", |
| 204 | SSH_OLD_DHGEX }, |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 205 | { NULL, 0 } |
| 206 | }; |
| 207 | |
| 208 | /* process table, return first match */ |
| 209 | for (i = 0; check[i].pat; i++) { |
Greg Hartman | ccacbc9 | 2016-02-03 09:59:44 -0800 | [diff] [blame] | 210 | if (match_pattern_list(version, check[i].pat, 0) == 1) { |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 211 | debug("match: %s pat %s compat 0x%08x", |
| 212 | version, check[i].pat, check[i].bugs); |
| 213 | datafellows = check[i].bugs; /* XXX for now */ |
| 214 | return check[i].bugs; |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 215 | } |
| 216 | } |
| 217 | debug("no match: %s", version); |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 218 | return 0; |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 219 | } |
| 220 | |
| 221 | #define SEP "," |
| 222 | int |
| 223 | proto_spec(const char *spec) |
| 224 | { |
| 225 | char *s, *p, *q; |
| 226 | int ret = SSH_PROTO_UNKNOWN; |
| 227 | |
| 228 | if (spec == NULL) |
| 229 | return ret; |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 230 | q = s = strdup(spec); |
| 231 | if (s == NULL) |
| 232 | return ret; |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 233 | for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) { |
| 234 | switch (atoi(p)) { |
| 235 | case 1: |
Greg Hartman | ccacbc9 | 2016-02-03 09:59:44 -0800 | [diff] [blame] | 236 | #ifdef WITH_SSH1 |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 237 | if (ret == SSH_PROTO_UNKNOWN) |
| 238 | ret |= SSH_PROTO_1_PREFERRED; |
| 239 | ret |= SSH_PROTO_1; |
Greg Hartman | ccacbc9 | 2016-02-03 09:59:44 -0800 | [diff] [blame] | 240 | #endif |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 241 | break; |
| 242 | case 2: |
| 243 | ret |= SSH_PROTO_2; |
| 244 | break; |
| 245 | default: |
| 246 | logit("ignoring bad proto spec: '%s'.", p); |
| 247 | break; |
| 248 | } |
| 249 | } |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 250 | free(s); |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 251 | return ret; |
| 252 | } |
| 253 | |
| 254 | char * |
| 255 | compat_cipher_proposal(char *cipher_prop) |
| 256 | { |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 257 | if (!(datafellows & SSH_BUG_BIGENDIANAES)) |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 258 | return cipher_prop; |
| 259 | debug2("%s: original cipher proposal: %s", __func__, cipher_prop); |
Greg Hartman | 9768ca4 | 2017-06-22 20:49:52 -0700 | [diff] [blame] | 260 | if ((cipher_prop = match_filter_list(cipher_prop, "aes*")) == NULL) |
| 261 | fatal("match_filter_list failed"); |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 262 | debug2("%s: compat cipher proposal: %s", __func__, cipher_prop); |
| 263 | if (*cipher_prop == '\0') |
| 264 | fatal("No supported ciphers found"); |
| 265 | return cipher_prop; |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 266 | } |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 267 | |
| 268 | char * |
| 269 | compat_pkalg_proposal(char *pkalg_prop) |
| 270 | { |
| 271 | if (!(datafellows & SSH_BUG_RSASIGMD5)) |
| 272 | return pkalg_prop; |
| 273 | debug2("%s: original public key proposal: %s", __func__, pkalg_prop); |
Greg Hartman | 9768ca4 | 2017-06-22 20:49:52 -0700 | [diff] [blame] | 274 | if ((pkalg_prop = match_filter_list(pkalg_prop, "ssh-rsa")) == NULL) |
| 275 | fatal("match_filter_list failed"); |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 276 | debug2("%s: compat public key proposal: %s", __func__, pkalg_prop); |
| 277 | if (*pkalg_prop == '\0') |
| 278 | fatal("No supported PK algorithms found"); |
| 279 | return pkalg_prop; |
| 280 | } |
| 281 | |
| 282 | char * |
Greg Hartman | ccacbc9 | 2016-02-03 09:59:44 -0800 | [diff] [blame] | 283 | compat_kex_proposal(char *p) |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 284 | { |
Greg Hartman | ccacbc9 | 2016-02-03 09:59:44 -0800 | [diff] [blame] | 285 | if ((datafellows & (SSH_BUG_CURVE25519PAD|SSH_OLD_DHGEX)) == 0) |
| 286 | return p; |
| 287 | debug2("%s: original KEX proposal: %s", __func__, p); |
| 288 | if ((datafellows & SSH_BUG_CURVE25519PAD) != 0) |
Greg Hartman | 9768ca4 | 2017-06-22 20:49:52 -0700 | [diff] [blame] | 289 | if ((p = match_filter_list(p, |
| 290 | "curve25519-sha256@libssh.org")) == NULL) |
| 291 | fatal("match_filter_list failed"); |
Greg Hartman | ccacbc9 | 2016-02-03 09:59:44 -0800 | [diff] [blame] | 292 | if ((datafellows & SSH_OLD_DHGEX) != 0) { |
Greg Hartman | 9768ca4 | 2017-06-22 20:49:52 -0700 | [diff] [blame] | 293 | if ((p = match_filter_list(p, |
| 294 | "diffie-hellman-group-exchange-sha256," |
| 295 | "diffie-hellman-group-exchange-sha1")) == NULL) |
| 296 | fatal("match_filter_list failed"); |
Greg Hartman | ccacbc9 | 2016-02-03 09:59:44 -0800 | [diff] [blame] | 297 | } |
| 298 | debug2("%s: compat KEX proposal: %s", __func__, p); |
| 299 | if (*p == '\0') |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 300 | fatal("No supported key exchange algorithms found"); |
Greg Hartman | ccacbc9 | 2016-02-03 09:59:44 -0800 | [diff] [blame] | 301 | return p; |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 302 | } |
| 303 | |