#define SSH_SMSG_STDERR_DATA 18
#define SSH_SMSG_SUCCESS 14
#define SSH_SMSG_FAILURE 15
#define SSH_SMSG_EXITSTATUS 20
#define SSH_MSG_IGNORE 32
#define SSH_CMSG_EXIT_CONFIRMATION 33
#define SSH_MSG_DEBUG 36
#define SSH_CMSG_AUTH_TIS 39
#define SSH_SMSG_AUTH_TIS_CHALLENGE 40
#define SSH_CMSG_AUTH_TIS_RESPONSE 41

#define SSH_AUTH_TIS              5

/* Coroutine mechanics for the sillier bits of the code */
#define crBegin1	static int crLine = 0;
#define crBegin2	switch(crLine) { case 0:;
#define crBegin		crBegin1; crBegin2;
#define crFinish(z)	} crLine = 0; return (z)
#define crFinishV	} crLine = 0; return

static void ssh_protocol(unsigned char *in, int inlen, int ispkt) {
    int i, j, len;
    unsigned char session_id[16];
    unsigned char *rsabuf, *keystr1, *keystr2;
    unsigned char cookie[8];
    struct RSAKey servkey, hostkey;
    struct MD5Context md5c;
    static unsigned long supported_ciphers_mask, supported_auths_mask;
    int cipher_type;

    extern struct ssh_cipher ssh_3des;
    extern struct ssh_cipher ssh_des;
    extern struct ssh_cipher ssh_blowfish;

    crBegin;

    MD5Init(&md5c);

    i = makekey(pktin.body+8, &servkey, &keystr1);

    j = makekey(pktin.body+8+i, &hostkey, &keystr2);

    supported_ciphers_mask = ((pktin.body[12+i+j] << 24) |
                              (pktin.body[13+i+j] << 16) |
                              (pktin.body[14+i+j] << 8) |
                              (pktin.body[15+i+j]));

    supported_auths_mask = ((pktin.body[16+i+j] << 24) |
                            (pktin.body[17+i+j] << 16) |
                            (pktin.body[18+i+j] << 8) |
                            (pktin.body[19+i+j]));

    MD5Update(&md5c, keystr2, hostkey.bytes);
    MD5Update(&md5c, keystr1, servkey.bytes);
    MD5Update(&md5c, pktin.body, 8);

    MD5Final(session_id, &md5c);

    do { crReturnV; } while (!ispkt);

    while (pktin.type == SSH_SMSG_FAILURE) {
	static char password[100];
	static int pos;
	static char c;
        static int pwpkt_type;

        /*
         * Show password prompt, having first obtained it via a TIS
         * exchange if we're doing TIS authentication.
         */
        pwpkt_type = SSH_CMSG_AUTH_PASSWORD;
        if (pktin.type == SSH_SMSG_FAILURE &&
            cfg.try_tis_auth &&
            (supported_auths_mask & (1<<SSH_AUTH_TIS))) {
            pwpkt_type = SSH_CMSG_AUTH_TIS_RESPONSE;
            s_wrpkt_start(SSH_CMSG_AUTH_TIS, 0);
            s_wrpkt();
            do { crReturnV; } while (!ispkt);
            if (pktin.type != SSH_SMSG_AUTH_TIS_CHALLENGE) {
                c_write("TIS authentication refused.\r\n", 29);
            } else {
                int challengelen = ((pktin.body[0] << 24) |
                                    (pktin.body[1] << 16) |
                                    (pktin.body[2] << 8) |
                                    (pktin.body[3]));
                c_write(pktin.body+4, challengelen);
            }
        }
        if (pwpkt_type == SSH_CMSG_AUTH_PASSWORD)
            c_write("password: ", 10);

	pos = 0;
	while (pos >= 0) {
	    do { crReturnV; } while (ispkt);
	    while (inlen--) switch (c = *in++) {
	      case 10: case 13:
		password[pos] = 0;
		pos = -1;

	      default:
		if (c >= ' ' && c <= '~' && pos < 40)
		    password[pos++] = c;
		break;
	    }
	}
	c_write("\r\n", 2);
	s_wrpkt_start(pwpkt_type, 4+strlen(password));
	pktout.body[0] = pktout.body[1] = pktout.body[2] = 0;
	pktout.body[3] = strlen(password);
	memcpy(pktout.body+4, password, strlen(password));
	s_wrpkt();
	memset(password, 0, strlen(password));
	do { crReturnV; } while (!ispkt);
	if (pktin.type == 15) {

        pktout.body[i++] = (cols >> 16) & 0xFF;
        pktout.body[i++] = (cols >> 8) & 0xFF;
        pktout.body[i++] = cols & 0xFF;
        memset(pktout.body+i, 0, 9);       /* 0 pixwidth, 0 pixheight, 0.b endofopt */
        s_wrpkt();
        ssh_state = SSH_STATE_INTERMED;
        do { crReturnV; } while (!ispkt);
        if (pktin.type != SSH_SMSG_SUCCESS && pktin.type != SSH_SMSG_FAILURE) {
            fatalbox("Protocol confusion");
        } else if (pktin.type == SSH_SMSG_FAILURE) {
            c_write("Server refused to allocate pty\r\n", 32);
        }
    }

    s_wrpkt_start(SSH_CMSG_EXEC_SHELL, 0);
    s_wrpkt();

                pktin.type == SSH_SMSG_STDERR_DATA) {
		long len = 0;
		for (i = 0; i < 4; i++)
		    len = (len << 8) + pktin.body[i];
		c_write(pktin.body+4, len);
	    } else if (pktin.type == SSH_MSG_DISCONNECT) {
                ssh_state = SSH_STATE_CLOSED;
	    } else if (pktin.type == SSH_SMSG_SUCCESS) {
		/* may be from EXEC_SHELL on some servers */
	    } else if (pktin.type == SSH_SMSG_FAILURE) {
		/* may be from EXEC_SHELL on some servers
		 * if no pty is available or in other odd cases. Ignore */
	    } else if (pktin.type == SSH_SMSG_EXITSTATUS) {
		s_wrpkt_start(SSH_CMSG_EXIT_CONFIRMATION, 0);
		s_wrpkt();
	    } else {
		fatalbox("Strange packet received: type %d", pktin.type);