const struct ssh_compress *cscomp_tobe;
	const struct ssh_compress *sccomp_tobe;
	char *hostkeydata, *sigdata, *keystr, *fingerprint;
	int hostkeylen, siglen;
	void *hkey;		       /* actual host key */
	unsigned char exchange_hash[20];
	int n_preferred_kex;
	const struct ssh_kexes *preferred_kex[KEX_MAX];
	int n_preferred_ciphers;
	const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
	const struct ssh_compress *preferred_comp;
	int got_session_id, activated_authconn;
	struct Packet *pktout;
        int dlgret;
	int guessok;

	s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
	for (i = 0; i < 16; i++)
	    ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
	/* List key exchange algorithms. */
	ssh2_pkt_addstring_start(s->pktout);
	commalist_started = 0;
	for (i = 0; i < s->n_preferred_kex; i++) {
	    const struct ssh_kexes *k = s->preferred_kex[i];
	    if (!k) continue;	       /* warning flag */
	    for (j = 0; j < k->nkexes; j++) {
		if (commalist_started)
		    ssh2_pkt_addstring_str(s->pktout, ",");
		ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
		commalist_started = 1;
	    }
	}
	/* List server host key algorithms. */
	ssh2_pkt_addstring_start(s->pktout);
	for (i = 0; i < lenof(hostkey_algs); i++) {
	    ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
	    if (i < lenof(hostkey_algs) - 1)
		ssh2_pkt_addstring_str(s->pktout, ",");

	s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;

	pktin->savedpos += 16;	        /* skip garbage cookie */
	ssh_pkt_getstring(pktin, &str, &len);    /* key exchange algorithms */

	preferred = NULL;
	for (i = 0; i < s->n_preferred_kex; i++) {
	    const struct ssh_kexes *k = s->preferred_kex[i];
	    if (!k) {
		s->warn_kex = TRUE;
	    } else {
		for (j = 0; j < k->nkexes; j++) {
		    if (!preferred) preferred = k->list[j]->name;
		    if (in_commasep_string(k->list[j]->name, str, len)) {
			ssh->kex = k->list[j];
			break;
		    }
		}
	    }
	    if (ssh->kex)
		break;
	}
	if (!ssh->kex) {
	    bombout(("Couldn't agree a key exchange algorithm (available: %s)",
		     str ? str : "(null)"));

    s->K = dh_find_K(ssh->kex_ctx, s->f);

    /* We assume everything from now on will be quick, and it might
     * involve user interaction. */
    set_busy_status(ssh->frontend, BUSY_NOT);

    hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
    if (!ssh->kex->pdata) {
	hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
	hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
	hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
    }
    hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
    hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
    hash_mpint(ssh->kex->hash, ssh->exhash, s->K);

		  ssh->sccomp->text_name);

    /*
     * Free key exchange data.
     */
    freebn(s->f);
    freebn(s->K);
    if (!ssh->kex->pdata) {
	freebn(s->g);
	freebn(s->p);
    }

    /*
     * Key exchange is over. Loop straight back round if we have a
     * deferred rekey reason.