source: trunk/third/openssh/compat.c @ 18763

/*
 * 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"
RCSID("$OpenBSD: compat.c,v 1.65 2002/09/27 10:42:09 mickey Exp $");

#include "buffer.h"
#include "packet.h"
#include "xmalloc.h"
#include "compat.h"
#include "log.h"
#include "match.h"

int compat13 = 0;
int compat20 = 0;
int datafellows = 0;

void
enable_compat20(void)
{
        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 */
void
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},
                { "OpenSSH_2.3.0*",     SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES|
                                        SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
                                        SSH_BUG_EXTEOF},
                { "OpenSSH_2.3.*",      SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
                                        SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
                { "OpenSSH_2.5.0p1*,"
                  "OpenSSH_2.5.1p1*",
                                        SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
                                        SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
                                        SSH_OLD_GSSAPI},
                { "OpenSSH_2.5.0*,"
                  "OpenSSH_2.5.1*,"
                  "OpenSSH_2.5.2*",     SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
                                        SSH_BUG_EXTEOF},
                { "OpenSSH_2.5.3*",     SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
                { "OpenSSH_2.9p*",      SSH_BUG_EXTEOF|SSH_OLD_GSSAPI},
                { "OpenSSH_2.*,"
                  "OpenSSH_3.0*,"
                  "OpenSSH_3.1*",       SSH_BUG_EXTEOF},
                { "Sun_SSH_1.0*",       SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
                { "OpenSSH*",           0 },
                { "*MindTerm*",         0 },
                { "2.1.0*",             SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
                                        SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
                                        SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE },
                { "2.1 *",              SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
                                        SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
                                        SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE },
                { "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 },
                { "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 },
                { "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 },
                { "2.2.0*,"
                  "2.3.0*",             SSH_BUG_HMAC|SSH_BUG_DEBUG|
                                        SSH_BUG_RSASIGMD5 },
                { "2.3.*",              SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5 },
                { "2.4",                SSH_OLD_SESSIONID },    /* Van Dyke */
                { "2.*",                SSH_BUG_DEBUG },
                { "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|SSH_BUG_K5USER },
                { "1.3.2*",             /* F-Secure */
                                        SSH_BUG_IGNOREMSG|SSH_BUG_K5USER },
                { "1.2.1*,"
                  "1.2.2*,"
                  "1.2.3*",             SSH_BUG_K5USER },
                { "*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 },
                { "Probe-*",
                                        SSH_BUG_PROBE },
                { NULL,                 0 }
        };

        /* process table, return first match */
        for (i = 0; check[i].pat; i++) {
                if (match_pattern_list(version, check[i].pat,
                    strlen(check[i].pat), 0) == 1) {
                        debug("match: %s pat %s", version, check[i].pat);
                        datafellows = check[i].bugs;
                        return;
                }
        }
        debug("no match: %s", version);
}

#define SEP     ","
int
proto_spec(const char *spec)
{
        char *s, *p, *q;
        int ret = SSH_PROTO_UNKNOWN;

        if (spec == NULL)
                return ret;
        q = s = xstrdup(spec);
        for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) {
                switch (atoi(p)) {
                case 1:
                        if (ret == SSH_PROTO_UNKNOWN)
                                ret |= SSH_PROTO_1_PREFERRED;
                        ret |= SSH_PROTO_1;
                        break;
                case 2:
                        ret |= SSH_PROTO_2;
                        break;
                default:
                        log("ignoring bad proto spec: '%s'.", p);
                        break;
                }
        }
        xfree(s);
        return ret;
}

char *
compat_cipher_proposal(char *cipher_prop)
{
        Buffer b;
        char *orig_prop, *fix_ciphers;
        char *cp, *tmp;

        if (!(datafellows & SSH_BUG_BIGENDIANAES))
                return(cipher_prop);

        buffer_init(&b);
        tmp = orig_prop = xstrdup(cipher_prop);
        while ((cp = strsep(&tmp, ",")) != NULL) {
                if (strncmp(cp, "aes", 3) != 0) {
                        if (buffer_len(&b) > 0)
                                buffer_append(&b, ",", 1);
                        buffer_append(&b, cp, strlen(cp));
                }
        }
        buffer_append(&b, "\0", 1);
        fix_ciphers = xstrdup(buffer_ptr(&b));
        buffer_free(&b);
        xfree(orig_prop);
        debug2("Original cipher proposal: %s", cipher_prop);
        debug2("Compat cipher proposal: %s", fix_ciphers);
        if (!*fix_ciphers)
                fatal("No available ciphers found.");

        return(fix_ciphers);
}