/*      $OpenBSD: vendor.c,v 1.6 2017/11/08 13:33:49 patrick Exp $      */
/*
 * Copyright (c) 2006 Hans-Joerg Hoexer <hshoexer@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <stdlib.h>
#include <string.h>

#include "exchange.h"
#include "hash.h"
#include "log.h"
#include "message.h"
#include "vendor.h"

static struct vendor_cap openbsd_vendor_cap[] = {
        { "OpenBSD-6.3", NULL, 0 },
};

#define NUMVIDS (sizeof openbsd_vendor_cap / sizeof openbsd_vendor_cap[0])

static int
setup_vendor_hashes(void)
{
        struct hash     *hash;
        int              i, n = NUMVIDS;

        hash = hash_get(HASH_MD5);
        if (!hash) {
                log_print("setup_vendor_hashes: could not find MD5 hash");
                return -1;
        }

        for (i = 0; i < n; i++) {
                openbsd_vendor_cap[i].hashsize = hash->hashsize;
                openbsd_vendor_cap[i].hash = calloc(hash->hashsize,
                    sizeof(u_int8_t));
                if (openbsd_vendor_cap[i].hash == NULL) {
                        log_error("setup_vendor_hashes: calloc failed");
                        goto errout;
                }

                hash->Init(hash->ctx);
                hash->Update(hash->ctx,
                    (unsigned char *)openbsd_vendor_cap[i].text,
                    strlen(openbsd_vendor_cap[i].text));
                hash->Final(openbsd_vendor_cap[i].hash, hash->ctx);

                LOG_DBG((LOG_EXCHANGE, 50, "setup_vendor_hashes: "
                    "MD5(\"%s\") (%lu bytes)", openbsd_vendor_cap[i].text,
                    (unsigned long)hash->hashsize));
                LOG_DBG_BUF((LOG_EXCHANGE, 50, "setup_vendor_hashes",
                    openbsd_vendor_cap[i].hash, hash->hashsize));
        }
        return 0;

errout:
        for (i = 0; i < n; i++)
                free(openbsd_vendor_cap[i].hash);
        return -1;
}

void
vendor_init(void)
{
        setup_vendor_hashes();
}

int
add_vendor_openbsd(struct message *msg)
{
        u_int8_t        *buf;
        size_t           buflen;
        int              i, n = NUMVIDS;

        for (i = 0; i < n; i++) {
                buflen = openbsd_vendor_cap[i].hashsize + ISAKMP_GEN_SZ;
                if ((buf = calloc(buflen, sizeof(char))) == NULL) {
                        log_error("add_vendor_payload: calloc(%lu) failed",
                            (unsigned long)buflen);
                        return -1;
                }

                SET_ISAKMP_GEN_LENGTH(buf, buflen);
                memcpy(buf + ISAKMP_VENDOR_ID_OFF, openbsd_vendor_cap[i].hash,
                    openbsd_vendor_cap[i].hashsize);
                if (message_add_payload(msg, ISAKMP_PAYLOAD_VENDOR, buf,
                    buflen, 1)) {
                        free(buf);
                        return -1;
                }
        }

        return 0;
}

void
check_vendor_openbsd(struct message *msg, struct payload *p)
{
        u_int8_t        *pbuf = p->p;
        ssize_t          vlen;
        int              i, n = NUMVIDS;

        if (msg->exchange->flags & EXCHANGE_FLAG_OPENBSD) {
                p->flags |= PL_MARK;
                return;
        }

        vlen = GET_ISAKMP_GEN_LENGTH(pbuf) - ISAKMP_GEN_SZ;

        for (i = 0; i < n; i++) {
                if (vlen != openbsd_vendor_cap[i].hashsize) {
                        LOG_DBG((LOG_EXCHANGE, 90,
                            "check_vendor_openbsd: bad size %lu != %lu",
                            (unsigned long)vlen,
                            (unsigned long)openbsd_vendor_cap[i].hashsize));
                        continue;
                }
                if (memcmp(openbsd_vendor_cap[i].hash, pbuf + ISAKMP_GEN_SZ,
                    vlen) == 0) {
                        msg->exchange->flags |= EXCHANGE_FLAG_OPENBSD;
                        LOG_DBG((LOG_EXCHANGE, 10, "check_vendor_openbsd: "
                            "OpenBSD (%s)", openbsd_vendor_cap[i].text));
                }
                p->flags |= PL_MARK;
        }
}