| /* $OpenBSD: compat.c,v 1.99 2016/05/24 02:31:57 dtucker Exp $ */ |
| /* |
| * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "includes.h" |
| |
| #include <sys/types.h> |
| |
| #include <stdlib.h> |
| #include <string.h> |
| #include <stdarg.h> |
| |
| #include "xmalloc.h" |
| #include "buffer.h" |
| #include "packet.h" |
| #include "compat.h" |
| #include "log.h" |
| #include "match.h" |
| |
| int compat13 = 0; |
| int compat20 = 0; |
| int datafellows = 0; |
| |
| void |
| enable_compat20(void) |
| { |
| if (compat20) |
| return; |
| debug("Enabling compatibility mode for protocol 2.0"); |
| compat20 = 1; |
| } |
| void |
| enable_compat13(void) |
| { |
| debug("Enabling compatibility mode for protocol 1.3"); |
| compat13 = 1; |
| } |
| /* datafellows bug compatibility */ |
| u_int |
| compat_datafellows(const char *version) |
| { |
| int i; |
| static struct { |
| char *pat; |
| int bugs; |
| } check[] = { |
| { "OpenSSH-2.0*," |
| "OpenSSH-2.1*," |
| "OpenSSH_2.1*," |
| "OpenSSH_2.2*", SSH_OLD_SESSIONID|SSH_BUG_BANNER| |
| SSH_OLD_DHGEX|SSH_BUG_NOREKEY| |
| SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR}, |
| { "OpenSSH_2.3.0*", SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES| |
| SSH_OLD_DHGEX|SSH_BUG_NOREKEY| |
| SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR}, |
| { "OpenSSH_2.3.*", SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX| |
| SSH_BUG_NOREKEY|SSH_BUG_EXTEOF| |
| SSH_OLD_FORWARD_ADDR}, |
| { "OpenSSH_2.5.0p1*," |
| "OpenSSH_2.5.1p1*", |
| SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX| |
| SSH_BUG_NOREKEY|SSH_BUG_EXTEOF| |
| SSH_OLD_FORWARD_ADDR}, |
| { "OpenSSH_2.5.0*," |
| "OpenSSH_2.5.1*," |
| "OpenSSH_2.5.2*", SSH_OLD_DHGEX|SSH_BUG_NOREKEY| |
| SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR}, |
| { "OpenSSH_2.5.3*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF| |
| SSH_OLD_FORWARD_ADDR}, |
| { "OpenSSH_2.*," |
| "OpenSSH_3.0*," |
| "OpenSSH_3.1*", SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR}, |
| { "OpenSSH_3.*", SSH_OLD_FORWARD_ADDR }, |
| { "Sun_SSH_1.0*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF}, |
| { "OpenSSH_4*", 0 }, |
| { "OpenSSH_5*", SSH_NEW_OPENSSH|SSH_BUG_DYNAMIC_RPORT}, |
| { "OpenSSH_6.6.1*", SSH_NEW_OPENSSH}, |
| { "OpenSSH_6.5*," |
| "OpenSSH_6.6*", SSH_NEW_OPENSSH|SSH_BUG_CURVE25519PAD}, |
| { "OpenSSH*", SSH_NEW_OPENSSH }, |
| { "*MindTerm*", 0 }, |
| { "2.1.0*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| |
| SSH_OLD_SESSIONID|SSH_BUG_DEBUG| |
| SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE| |
| SSH_BUG_FIRSTKEX }, |
| { "2.1 *", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| |
| SSH_OLD_SESSIONID|SSH_BUG_DEBUG| |
| SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE| |
| SSH_BUG_FIRSTKEX }, |
| { "2.0.13*," |
| "2.0.14*," |
| "2.0.15*," |
| "2.0.16*," |
| "2.0.17*," |
| "2.0.18*," |
| "2.0.19*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| |
| SSH_OLD_SESSIONID|SSH_BUG_DEBUG| |
| SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| |
| SSH_BUG_PKOK|SSH_BUG_RSASIGMD5| |
| SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE| |
| SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX }, |
| { "2.0.11*," |
| "2.0.12*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| |
| SSH_OLD_SESSIONID|SSH_BUG_DEBUG| |
| SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| |
| SSH_BUG_PKAUTH|SSH_BUG_PKOK| |
| SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE| |
| SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX }, |
| { "2.0.*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| |
| SSH_OLD_SESSIONID|SSH_BUG_DEBUG| |
| SSH_BUG_PKSERVICE|SSH_BUG_X11FWD| |
| SSH_BUG_PKAUTH|SSH_BUG_PKOK| |
| SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE| |
| SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN| |
| SSH_BUG_FIRSTKEX }, |
| { "2.2.0*," |
| "2.3.0*", SSH_BUG_HMAC|SSH_BUG_DEBUG| |
| SSH_BUG_RSASIGMD5|SSH_BUG_FIRSTKEX }, |
| { "2.3.*", SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5| |
| SSH_BUG_FIRSTKEX }, |
| { "2.4", SSH_OLD_SESSIONID }, /* Van Dyke */ |
| { "2.*", SSH_BUG_DEBUG|SSH_BUG_FIRSTKEX| |
| SSH_BUG_RFWD_ADDR }, |
| { "3.0.*", SSH_BUG_DEBUG }, |
| { "3.0 SecureCRT*", SSH_OLD_SESSIONID }, |
| { "1.7 SecureFX*", SSH_OLD_SESSIONID }, |
| { "1.2.18*," |
| "1.2.19*," |
| "1.2.20*," |
| "1.2.21*," |
| "1.2.22*", SSH_BUG_IGNOREMSG }, |
| { "1.3.2*", /* F-Secure */ |
| SSH_BUG_IGNOREMSG }, |
| { "Cisco-1.*", SSH_BUG_DHGEX_LARGE| |
| SSH_BUG_HOSTKEYS }, |
| { "*SSH Compatible Server*", /* Netscreen */ |
| SSH_BUG_PASSWORDPAD }, |
| { "*OSU_0*," |
| "OSU_1.0*," |
| "OSU_1.1*," |
| "OSU_1.2*," |
| "OSU_1.3*," |
| "OSU_1.4*," |
| "OSU_1.5alpha1*," |
| "OSU_1.5alpha2*," |
| "OSU_1.5alpha3*", SSH_BUG_PASSWORDPAD }, |
| { "*SSH_Version_Mapper*", |
| SSH_BUG_SCANNER }, |
| { "PuTTY_Local:*," /* dev versions < Sep 2014 */ |
| "PuTTY-Release-0.5*," /* 0.50-0.57, DH-GEX in >=0.52 */ |
| "PuTTY_Release_0.5*," /* 0.58-0.59 */ |
| "PuTTY_Release_0.60*," |
| "PuTTY_Release_0.61*," |
| "PuTTY_Release_0.62*," |
| "PuTTY_Release_0.63*," |
| "PuTTY_Release_0.64*", |
| SSH_OLD_DHGEX }, |
| { "FuTTY*", SSH_OLD_DHGEX }, /* Putty Fork */ |
| { "Probe-*", |
| SSH_BUG_PROBE }, |
| { "TeraTerm SSH*," |
| "TTSSH/1.5.*," |
| "TTSSH/2.1*," |
| "TTSSH/2.2*," |
| "TTSSH/2.3*," |
| "TTSSH/2.4*," |
| "TTSSH/2.5*," |
| "TTSSH/2.6*," |
| "TTSSH/2.70*," |
| "TTSSH/2.71*," |
| "TTSSH/2.72*", SSH_BUG_HOSTKEYS }, |
| { "WinSCP_release_4*," |
| "WinSCP_release_5.0*," |
| "WinSCP_release_5.1*," |
| "WinSCP_release_5.5*," |
| "WinSCP_release_5.6*," |
| "WinSCP_release_5.7," |
| "WinSCP_release_5.7.1," |
| "WinSCP_release_5.7.2," |
| "WinSCP_release_5.7.3," |
| "WinSCP_release_5.7.4", |
| SSH_OLD_DHGEX }, |
| { NULL, 0 } |
| }; |
| |
| /* process table, return first match */ |
| for (i = 0; check[i].pat; i++) { |
| if (match_pattern_list(version, check[i].pat, 0) == 1) { |
| debug("match: %s pat %s compat 0x%08x", |
| version, check[i].pat, check[i].bugs); |
| datafellows = check[i].bugs; /* XXX for now */ |
| return check[i].bugs; |
| } |
| } |
| debug("no match: %s", version); |
| return 0; |
| } |
| |
| #define SEP "," |
| int |
| proto_spec(const char *spec) |
| { |
| char *s, *p, *q; |
| int ret = SSH_PROTO_UNKNOWN; |
| |
| if (spec == NULL) |
| return ret; |
| q = s = strdup(spec); |
| if (s == NULL) |
| return ret; |
| for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) { |
| switch (atoi(p)) { |
| case 1: |
| #ifdef WITH_SSH1 |
| if (ret == SSH_PROTO_UNKNOWN) |
| ret |= SSH_PROTO_1_PREFERRED; |
| ret |= SSH_PROTO_1; |
| #endif |
| break; |
| case 2: |
| ret |= SSH_PROTO_2; |
| break; |
| default: |
| logit("ignoring bad proto spec: '%s'.", p); |
| break; |
| } |
| } |
| free(s); |
| return ret; |
| } |
| |
| /* |
| * Filters a proposal string, excluding any algorithm matching the 'filter' |
| * pattern list. |
| */ |
| static char * |
| filter_proposal(char *proposal, const char *filter) |
| { |
| Buffer b; |
| char *orig_prop, *fix_prop; |
| char *cp, *tmp; |
| |
| buffer_init(&b); |
| tmp = orig_prop = xstrdup(proposal); |
| while ((cp = strsep(&tmp, ",")) != NULL) { |
| if (match_pattern_list(cp, filter, 0) != 1) { |
| if (buffer_len(&b) > 0) |
| buffer_append(&b, ",", 1); |
| buffer_append(&b, cp, strlen(cp)); |
| } else |
| debug2("Compat: skipping algorithm \"%s\"", cp); |
| } |
| buffer_append(&b, "\0", 1); |
| fix_prop = xstrdup((char *)buffer_ptr(&b)); |
| buffer_free(&b); |
| free(orig_prop); |
| |
| return fix_prop; |
| } |
| |
| char * |
| compat_cipher_proposal(char *cipher_prop) |
| { |
| if (!(datafellows & SSH_BUG_BIGENDIANAES)) |
| return cipher_prop; |
| debug2("%s: original cipher proposal: %s", __func__, cipher_prop); |
| cipher_prop = filter_proposal(cipher_prop, "aes*"); |
| debug2("%s: compat cipher proposal: %s", __func__, cipher_prop); |
| if (*cipher_prop == '\0') |
| fatal("No supported ciphers found"); |
| return cipher_prop; |
| } |
| |
| char * |
| compat_pkalg_proposal(char *pkalg_prop) |
| { |
| if (!(datafellows & SSH_BUG_RSASIGMD5)) |
| return pkalg_prop; |
| debug2("%s: original public key proposal: %s", __func__, pkalg_prop); |
| pkalg_prop = filter_proposal(pkalg_prop, "ssh-rsa"); |
| debug2("%s: compat public key proposal: %s", __func__, pkalg_prop); |
| if (*pkalg_prop == '\0') |
| fatal("No supported PK algorithms found"); |
| return pkalg_prop; |
| } |
| |
| char * |
| compat_kex_proposal(char *p) |
| { |
| if ((datafellows & (SSH_BUG_CURVE25519PAD|SSH_OLD_DHGEX)) == 0) |
| return p; |
| debug2("%s: original KEX proposal: %s", __func__, p); |
| if ((datafellows & SSH_BUG_CURVE25519PAD) != 0) |
| p = filter_proposal(p, "curve25519-sha256@libssh.org"); |
| if ((datafellows & SSH_OLD_DHGEX) != 0) { |
| p = filter_proposal(p, "diffie-hellman-group-exchange-sha256"); |
| p = filter_proposal(p, "diffie-hellman-group-exchange-sha1"); |
| } |
| debug2("%s: compat KEX proposal: %s", __func__, p); |
| if (*p == '\0') |
| fatal("No supported key exchange algorithms found"); |
| return p; |
| } |
| |
