Example #1
0
static int
send_userauth_info_request(struct ssh *ssh)
{
	struct authctxt *authctxt = ssh->authctxt;
	struct kbdintctxt *kbdintctxt = authctxt->kbdintctxt;
	char *name, *instr, **prompts;
	u_int r, i, *echo_on;

	if (kbdintctxt->device->query(kbdintctxt->ctxt,
	    &name, &instr, &kbdintctxt->nreq, &prompts, &echo_on))
		return 0;

	if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST)) != 0 ||
	    (r = sshpkt_put_cstring(ssh, name)) != 0 ||
	    (r = sshpkt_put_cstring(ssh, instr)) != 0 ||
	    (r = sshpkt_put_cstring(ssh, "")) != 0 ||	/* language not used */
	    (r = sshpkt_put_u32(ssh, kbdintctxt->nreq)) != 0)
		fatal("%s: %s", __func__, ssh_err(r));
	for (i = 0; i < kbdintctxt->nreq; i++) {
		if ((r = sshpkt_put_cstring(ssh, prompts[i])) != 0 ||
		    (r = sshpkt_put_u8(ssh, echo_on[i])) != 0)
			fatal("%s: %s", __func__, ssh_err(r));
	}
	if ((r = sshpkt_send(ssh)) != 0)
		fatal("%s: %s", __func__, ssh_err(r));
	ssh_packet_write_wait(ssh);

	for (i = 0; i < kbdintctxt->nreq; i++)
		free(prompts[i]);
	free(prompts);
	free(echo_on);
	free(name);
	free(instr);
	return 1;
}
Example #2
0
/*
 * Wait until all buffered output has been sent to the client.
 * This is used when the program terminates.
 */
static void
drain_output(struct ssh *ssh)
{
	int r;

	/* Send any buffered stdout data to the client. */
	if (sshbuf_len(stdout_buffer) > 0) {
		if ((r = sshpkt_start(ssh, SSH_SMSG_STDOUT_DATA)) != 0 ||
		    (r = sshpkt_put_string(ssh, sshbuf_ptr(stdout_buffer),
		    sshbuf_len(stdout_buffer))) != 0 ||
		    (r = sshpkt_send(ssh)) != 0)
			fatal("%s: %s", __func__, ssh_err(r));
		/* Update the count of sent bytes. */
		stdout_bytes += sshbuf_len(stdout_buffer);
	}
	/* Send any buffered stderr data to the client. */
	if (sshbuf_len(stderr_buffer) > 0) {
		if ((r = sshpkt_start(ssh, SSH_SMSG_STDERR_DATA)) != 0 ||
		    (r = sshpkt_put_string(ssh, sshbuf_ptr(stderr_buffer),
		    sshbuf_len(stderr_buffer))) != 0 ||
		    (r = sshpkt_send(ssh)) != 0)
		/* Update the count of sent bytes. */
		stderr_bytes += sshbuf_len(stderr_buffer);
	}
	/* Wait until all buffered data has been written to the client. */
	ssh_packet_write_wait(ssh);
}
Example #3
0
void
packet_write_wait(void)
{
	int r;

	if ((r = ssh_packet_write_wait(active_state)) < 0)
		sshpkt_fatal(active_state, __func__, r);
}
Example #4
0
int
dispatch_protocol_error(int type, u_int32_t seq, struct ssh *ssh)
{
	int r;

	logit("dispatch_protocol_error: type %d seq %u", type, seq);
	if ((r = sshpkt_start(ssh, SSH2_MSG_UNIMPLEMENTED)) != 0 ||
	    (r = sshpkt_put_u32(ssh, seq)) != 0 ||
	    (r = sshpkt_send(ssh)) != 0 ||
	    (r = ssh_packet_write_wait(ssh)) != 0)
		sshpkt_fatal(ssh, r, "%s", __func__);
	return 0;
}
Example #5
0
/*
 * Computes the proper response to a RSA challenge, and sends the response to
 * the server.
 */
static void
respond_to_rsa_challenge(struct ssh *ssh, BIGNUM * challenge, RSA * prv)
{
    u_char buf[32], response[16];
    MD5_CTX md;
    int r, len;

    /* Decrypt the challenge using the private key. */
    /* XXX think about Bleichenbacher, too */
    if ((r = rsa_private_decrypt(challenge, challenge, prv)) != 0) {
        ssh_packet_disconnect(ssh,  "%s: rsa_private_decrypt: %s",
                              __func__, ssh_err(r));
    }

    /* Compute the response. */
    /* The response is MD5 of decrypted challenge plus session id. */
    len = BN_num_bytes(challenge);
    if (len <= 0 || (u_int)len > sizeof(buf))
        ssh_packet_disconnect(ssh,
                              "respond_to_rsa_challenge: bad challenge length %d", len);

    memset(buf, 0, sizeof(buf));
    BN_bn2bin(challenge, buf + sizeof(buf) - len);
    MD5_Init(&md);
    MD5_Update(&md, buf, 32);
    MD5_Update(&md, session_id, 16);
    MD5_Final(response, &md);

    debug("Sending response to host key RSA challenge.");

    /* Send the response back to the server. */
    if ((r = sshpkt_start(ssh, SSH_CMSG_AUTH_RSA_RESPONSE)) != 0 ||
            (r = sshpkt_put(ssh, &response, sizeof(response))) != 0 ||
            (r = sshpkt_send(ssh)) != 0)
        fatal("%s: %s", __func__, ssh_err(r));
    ssh_packet_write_wait(ssh);

    memset(buf, 0, sizeof(buf));
    memset(response, 0, sizeof(response));
    memset(&md, 0, sizeof(md));
}
Example #6
0
/*ARGSUSED*/
static int
input_service_request(int type, u_int32_t seq, struct ssh *ssh)
{
    struct authctxt *authctxt = ssh->authctxt;
    char *service = NULL;
    int r, acceptit = 0;

    if ((r = sshpkt_get_cstring(ssh, &service, NULL)) != 0 ||
            (r = sshpkt_get_end(ssh)) != 0)
        goto out;

    if (authctxt == NULL)
        fatal("input_service_request: no authctxt");

    if (strcmp(service, "ssh-userauth") == 0) {
        if (!authctxt->success) {
            acceptit = 1;
            /* now we can handle user-auth requests */
            ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_REQUEST,
                             &input_userauth_request);
        }
    }
    /* XXX all other service requests are denied */

    if (acceptit) {
        if ((r = sshpkt_start(ssh, SSH2_MSG_SERVICE_ACCEPT)) != 0 ||
                (r = sshpkt_put_cstring(ssh, service)) != 0 ||
                (r = sshpkt_send(ssh)) != 0)
            goto out;
        ssh_packet_write_wait(ssh);
    } else {
        debug("bad service request %s", service);
        ssh_packet_disconnect(ssh, "bad service request %s", service);
    }
    r = 0;
out:
    free(service);
    return r;
}
Example #7
0
int
auth_rsa_challenge_dialog(struct sshkey *key)
{
	struct ssh *ssh = active_state;
	BIGNUM *challenge, *encrypted_challenge;
	u_char response[16];
	int r, success;

	if ((encrypted_challenge = BN_new()) == NULL)
		fatal("auth_rsa_challenge_dialog: BN_new() failed");

	challenge = PRIVSEP(auth_rsa_generate_challenge(key));

	/* Encrypt the challenge with the public key. */
	if ((r = rsa_public_encrypt(encrypted_challenge, challenge,
	    key->rsa)) != 0)
		fatal("%s: rsa_public_encrypt: %s", __func__, ssh_err(r));

	/* Send the encrypted challenge to the client. */
	if ((r = sshpkt_start(ssh, SSH_SMSG_AUTH_RSA_CHALLENGE)) != 0 ||
	    (r = sshpkt_put_bignum1(ssh, encrypted_challenge)) != 0 ||
	    (r = sshpkt_send(ssh)) != 0)
		fatal("%s: %s", __func__, ssh_err(r));
	BN_clear_free(encrypted_challenge);
	ssh_packet_write_wait(ssh);

	/* Wait for a response. */
	ssh_packet_read_expect(ssh, SSH_CMSG_AUTH_RSA_RESPONSE);
	if ((r = sshpkt_get(ssh, &response, sizeof(response))) != 0 ||
	    (r = sshpkt_get_end(ssh)) != 0)
		fatal("%s: %s", __func__, ssh_err(r));

	success = PRIVSEP(auth_rsa_verify_response(key, challenge, response));
	BN_clear_free(challenge);
	return (success);
}
Example #8
0
void
userauth_finish(struct ssh *ssh, int authenticated, const char *method,
                const char *submethod)
{
    struct authctxt *authctxt = ssh->authctxt;
    char *methods;
    int r, partial = 0;

    if (!authctxt->valid && authenticated)
        fatal("INTERNAL ERROR: authenticated invalid user %s",
              authctxt->user);
    if (authenticated && authctxt->postponed)
        fatal("INTERNAL ERROR: authenticated and postponed");

    /* Special handling for root */
    if (authenticated && authctxt->pw->pw_uid == 0 &&
            !auth_root_allowed(method))
        authenticated = 0;

    if (authenticated && options.num_auth_methods != 0) {
        if (!auth2_update_methods_lists(authctxt, method, submethod)) {
            authenticated = 0;
            partial = 1;
        }
    }

    /* Log before sending the reply */
    auth_log(authctxt, authenticated, partial, method, submethod);

    if (authctxt->postponed)
        return;

    if (authenticated == 1) {
        /* turn off userauth */
        ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_REQUEST,
                         &dispatch_protocol_ignore);
        if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_SUCCESS)) != 0 ||
                (r = sshpkt_send(ssh)) != 0)
            fatal("%s: %s", __func__, ssh_err(r));
        ssh_packet_write_wait(ssh);
        /* now we can break out */
        authctxt->success = 1;
    } else {
        /* Allow initial try of "none" auth without failure penalty */
        if (!partial && !authctxt->server_caused_failure &&
                (authctxt->attempt > 1 || strcmp(method, "none") != 0))
            authctxt->failures++;
        if (authctxt->failures >= options.max_authtries)
            auth_maxtries_exceeded(ssh, authctxt);
        methods = authmethods_get(authctxt);
        debug3("%s: failure partial=%d next methods=\"%s\"", __func__,
               partial, methods);
        if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_FAILURE)) != 0 ||
                (r = sshpkt_put_cstring(ssh, methods)) != 0 ||
                (r = sshpkt_put_u8(ssh, partial)) != 0 ||
                (r = sshpkt_send(ssh)) != 0)
            fatal("%s: %s", __func__, ssh_err(r));
        ssh_packet_write_wait(ssh);
        free(methods);
    }
}
Example #9
0
/*
 * Checks if the user has an authentication agent, and if so, tries to
 * authenticate using the agent.
 */
static int
try_agent_authentication(struct ssh *ssh)
{
    int r, type, agent_fd, ret = 0;
    u_char response[16];
    size_t i;
    BIGNUM *challenge;
    struct ssh_identitylist *idlist = NULL;

    /* Get connection to the agent. */
    if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
        if (r != SSH_ERR_AGENT_NOT_PRESENT)
            debug("%s: ssh_get_authentication_socket: %s",
                  __func__, ssh_err(r));
        return 0;
    }

    if ((challenge = BN_new()) == NULL)
        fatal("try_agent_authentication: BN_new failed");

    /* Loop through identities served by the agent. */
    if ((r = ssh_fetch_identitylist(agent_fd, 1, &idlist)) != 0) {
        if (r != SSH_ERR_AGENT_NO_IDENTITIES)
            debug("%s: ssh_fetch_identitylist: %s",
                  __func__, ssh_err(r));
        goto out;
    }
    for (i = 0; i < idlist->nkeys; i++) {
        /* Try this identity. */
        debug("Trying RSA authentication via agent with '%.100s'",
              idlist->comments[i]);

        /*
         * Tell the server that we are willing to authenticate
         * using this key.
         */
        if ((r = sshpkt_start(ssh, SSH_CMSG_AUTH_RSA)) != 0 ||
                (r = sshpkt_put_bignum1(ssh, idlist->keys[i]->rsa->n)) != 0 ||
                (r = sshpkt_send(ssh)) != 0)
            fatal("%s: %s", __func__, ssh_err(r));
        ssh_packet_write_wait(ssh);

        /* Wait for server's response. */
        type = ssh_packet_read(ssh);

        /* The server sends failure if it doesn't like our key or
           does not support RSA authentication. */
        if (type == SSH_SMSG_FAILURE) {
            debug("Server refused our key.");
            continue;
        }
        /* Otherwise it should have sent a challenge. */
        if (type != SSH_SMSG_AUTH_RSA_CHALLENGE)
            ssh_packet_disconnect(ssh, "Protocol error during RSA "
                                  "authentication: %d", type);

        if ((r = sshpkt_get_bignum1(ssh, challenge)) != 0 ||
                (r = sshpkt_get_end(ssh)) != 0)
            fatal("%s: %s", __func__, ssh_err(r));

        debug("Received RSA challenge from server.");

        /* Ask the agent to decrypt the challenge. */
        if ((r = ssh_decrypt_challenge(agent_fd, idlist->keys[i],
                                       challenge, session_id, response)) != 0) {
            /*
             * The agent failed to authenticate this identifier
             * although it advertised it supports this.  Just
             * return a wrong value.
             */
            logit("Authentication agent failed to decrypt "
                  "challenge: %s", ssh_err(r));
            memset(response, 0, sizeof(response));
        }
        debug("Sending response to RSA challenge.");

        /* Send the decrypted challenge back to the server. */
        if ((r = sshpkt_start(ssh, SSH_CMSG_AUTH_RSA_RESPONSE)) != 0 ||
                (r = sshpkt_put(ssh, &response, sizeof(response))) != 0 ||
                (r = sshpkt_send(ssh)) != 0)
            fatal("%s: %s", __func__, ssh_err(r));
        ssh_packet_write_wait(ssh);

        /* Wait for response from the server. */
        type = ssh_packet_read(ssh);

        /*
         * The server returns success if it accepted the
         * authentication.
         */
        if (type == SSH_SMSG_SUCCESS) {
            debug("RSA authentication accepted by server.");
            ret = 1;
            break;
        } else if (type != SSH_SMSG_FAILURE)
            ssh_packet_disconnect(ssh, "Protocol error waiting RSA auth "
                                  "response: %d", type);
    }
    if (ret != 1)
        debug("RSA authentication using agent refused.");
out:
    ssh_free_identitylist(idlist);
    ssh_close_authentication_socket(agent_fd);
    BN_clear_free(challenge);
    return ret;
}
Example #10
0
/*
 * Performs the interactive session.  This handles data transmission between
 * the client and the program.  Note that the notion of stdin, stdout, and
 * stderr in this function is sort of reversed: this function writes to
 * stdin (of the child program), and reads from stdout and stderr (of the
 * child program).
 */
void
server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
{
	struct ssh *ssh = active_state; /* XXX */
	fd_set *readset = NULL, *writeset = NULL;
	int max_fd = 0;
	u_int nalloc = 0;
	int wait_status;	/* Status returned by wait(). */
	pid_t wait_pid;		/* pid returned by wait(). */
	int waiting_termination = 0;	/* Have displayed waiting close message. */
	u_int64_t max_time_milliseconds;
	u_int previous_stdout_buffer_bytes;
	u_int stdout_buffer_bytes;
	int r, type;

	debug("Entering interactive session.");

	/* Initialize the SIGCHLD kludge. */
	child_terminated = 0;
	signal(SIGCHLD, sigchld_handler);

	if (!use_privsep) {
		signal(SIGTERM, sigterm_handler);
		signal(SIGINT, sigterm_handler);
		signal(SIGQUIT, sigterm_handler);
	}

	/* Initialize our global variables. */
	fdin = fdin_arg;
	fdout = fdout_arg;
	fderr = fderr_arg;

	/* nonblocking IO */
	set_nonblock(fdin);
	set_nonblock(fdout);
	/* we don't have stderr for interactive terminal sessions, see below */
	if (fderr != -1)
		set_nonblock(fderr);

	if (!(ssh->compat & SSH_BUG_IGNOREMSG) && isatty(fdin))
		fdin_is_tty = 1;

	connection_in = ssh_packet_get_connection_in(ssh);
	connection_out = ssh_packet_get_connection_out(ssh);

	notify_setup();

	previous_stdout_buffer_bytes = 0;

	/* Set approximate I/O buffer size. */
	if (ssh_packet_is_interactive(ssh))
		buffer_high = 4096;
	else
		buffer_high = 64 * 1024;

#if 0
	/* Initialize max_fd to the maximum of the known file descriptors. */
	max_fd = MAX(connection_in, connection_out);
	max_fd = MAX(max_fd, fdin);
	max_fd = MAX(max_fd, fdout);
	if (fderr != -1)
		max_fd = MAX(max_fd, fderr);
#endif

	/* Initialize Initialize buffers. */
	if ((stdin_buffer = sshbuf_new()) == NULL)
		fatal("%s: sshbuf_new failed", __func__);
	if ((stdout_buffer = sshbuf_new()) == NULL)
		fatal("%s: sshbuf_new failed", __func__);
	if ((stderr_buffer = sshbuf_new()) == NULL)
		fatal("%s: sshbuf_new failed", __func__);

	/*
	 * If we have no separate fderr (which is the case when we have a pty
	 * - there we cannot make difference between data sent to stdout and
	 * stderr), indicate that we have seen an EOF from stderr.  This way
	 * we don't need to check the descriptor everywhere.
	 */
	if (fderr == -1)
		fderr_eof = 1;

	server_init_dispatch(ssh);

	/* Main loop of the server for the interactive session mode. */
	for (;;) {

		/* Process buffered packets from the client. */
		process_buffered_input_packets(ssh);

		/*
		 * If we have received eof, and there is no more pending
		 * input data, cause a real eof by closing fdin.
		 */
		if (stdin_eof && fdin != -1 && sshbuf_len(stdin_buffer) == 0) {
			if (fdin != fdout)
				close(fdin);
			else
				shutdown(fdin, SHUT_WR); /* We will no longer send. */
			fdin = -1;
		}
		/* Make packets from buffered stderr data to send to the client. */
		make_packets_from_stderr_data(ssh);

		/*
		 * Make packets from buffered stdout data to send to the
		 * client. If there is very little to send, this arranges to
		 * not send them now, but to wait a short while to see if we
		 * are getting more data. This is necessary, as some systems
		 * wake up readers from a pty after each separate character.
		 */
		max_time_milliseconds = 0;
		stdout_buffer_bytes = sshbuf_len(stdout_buffer);
		if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 &&
		    stdout_buffer_bytes != previous_stdout_buffer_bytes) {
			/* try again after a while */
			max_time_milliseconds = 10;
		} else {
			/* Send it now. */
			make_packets_from_stdout_data(ssh);
		}
		previous_stdout_buffer_bytes = sshbuf_len(stdout_buffer);

		/* Send channel data to the client. */
		if (ssh_packet_not_very_much_data_to_write(ssh))
			channel_output_poll();

		/*
		 * Bail out of the loop if the program has closed its output
		 * descriptors, and we have no more data to send to the
		 * client, and there is no pending buffered data.
		 */
		if (fdout_eof && fderr_eof && !ssh_packet_have_data_to_write(ssh) &&
		    sshbuf_len(stdout_buffer) == 0 && sshbuf_len(stderr_buffer) == 0) {
			if (!channel_still_open())
				break;
			if (!waiting_termination) {
				const char *s = "Waiting for forwarded connections to terminate...\r\n";
				char *cp = channel_open_message();

				waiting_termination = 1;
				/* Display list of open channels. */
				if ((r = sshbuf_put(stderr_buffer,
				    s, strlen(s))) != 0 ||
				    (r = sshbuf_put(stderr_buffer,
				    s, strlen(s))) != 0)
					fatal("%s: buffer error: %s",
					    __func__, ssh_err(r));
				free(cp);
			}
		}
		max_fd = MAX(connection_in, connection_out);
		max_fd = MAX(max_fd, fdin);
		max_fd = MAX(max_fd, fdout);
		max_fd = MAX(max_fd, fderr);
		max_fd = MAX(max_fd, notify_pipe[0]);

		/* Sleep in select() until we can do something. */
		wait_until_can_do_something(ssh, &readset, &writeset, &max_fd,
		    &nalloc, max_time_milliseconds);

		if (received_sigterm) {
			logit("Exiting on signal %d", (int)received_sigterm);
			/* Clean up sessions, utmp, etc. */
			cleanup_exit(255);
		}

		/* Process any channel events. */
		channel_after_select(readset, writeset);

		/* Process input from the client and from program stdout/stderr. */
		process_input(ssh, readset);

		/* Process output to the client and to program stdin. */
		process_output(ssh, writeset);
	}
	free(readset);
	free(writeset);

	/* Cleanup and termination code. */

	/* Wait until all output has been sent to the client. */
	drain_output(ssh);

	debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.",
	    stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);

	/* Free and clear the buffers. */
	sshbuf_free(stdin_buffer);
	sshbuf_free(stdout_buffer);
	sshbuf_free(stderr_buffer);

	/* Close the file descriptors. */
	if (fdout != -1)
		close(fdout);
	fdout = -1;
	fdout_eof = 1;
	if (fderr != -1)
		close(fderr);
	fderr = -1;
	fderr_eof = 1;
	if (fdin != -1)
		close(fdin);
	fdin = -1;

	channel_free_all();

	/* We no longer want our SIGCHLD handler to be called. */
	signal(SIGCHLD, SIG_DFL);

	while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0)
		if (errno != EINTR)
			ssh_packet_disconnect(ssh, "wait: %.100s", strerror(errno));
	if (wait_pid != pid)
		error("Strange, wait returned pid %ld, expected %ld",
		    (long)wait_pid, (long)pid);

	/* Check if it exited normally. */
	if (WIFEXITED(wait_status)) {
		/* Yes, normal exit.  Get exit status and send it to the client. */
		debug("Command exited with status %d.", WEXITSTATUS(wait_status));
		if ((r = sshpkt_start(ssh, SSH_SMSG_EXITSTATUS)) != 0 ||
		    (r = sshpkt_put_u32(ssh, WEXITSTATUS(wait_status))) != 0 ||
		    (r = sshpkt_send(ssh)) != 0)
			fatal("%s: %s", __func__, ssh_err(r));
		ssh_packet_write_wait(ssh);

		/*
		 * Wait for exit confirmation.  Note that there might be
		 * other packets coming before it; however, the program has
		 * already died so we just ignore them.  The client is
		 * supposed to respond with the confirmation when it receives
		 * the exit status.
		 */
		do {
			type = ssh_packet_read(ssh);
		}
		while (type != SSH_CMSG_EXIT_CONFIRMATION);

		debug("Received exit confirmation.");
		return;
	}
	/* Check if the program terminated due to a signal. */
	if (WIFSIGNALED(wait_status))
		ssh_packet_disconnect(ssh, "Command terminated on signal %d.",
		    WTERMSIG(wait_status));

	/* Some weird exit cause.  Just exit. */
	ssh_packet_disconnect(ssh, "wait returned status %04x.", wait_status);
	/* NOTREACHED */
}
Example #11
0
static int
server_input_global_request(int type, u_int32_t seq, struct ssh *ssh)
{
	char *rtype = NULL;
	u_char want_reply;
	int r, success = 0, allocated_listen_port = 0;
	struct sshbuf *resp = NULL;

	if ((r = sshpkt_get_cstring(ssh, &rtype, NULL)) != 0 ||
	    (r = sshpkt_get_u8(ssh, &want_reply)) != 0)
		goto out;
	debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply);

	/* -R style forwarding */
	if (strcmp(rtype, "tcpip-forward") == 0) {
		struct authctxt *authctxt = ssh->authctxt;
		struct Forward fwd;

		if (authctxt->pw == NULL || !authctxt->valid)
			fatal("server_input_global_request: no/invalid user");
		memset(&fwd, 0, sizeof(fwd));
		if ((r = sshpkt_get_cstring(ssh, &fwd.listen_host, NULL)) != 0 ||
		    (r = sshpkt_get_u32(ssh, &fwd.listen_port)) != 0)
			goto out;
		debug("server_input_global_request: tcpip-forward listen %s port %d",
		    fwd.listen_host, fwd.listen_port);

		/* check permissions */
		if ((options.allow_tcp_forwarding & FORWARD_REMOTE) == 0 ||
		    no_port_forwarding_flag ||
		    (!want_reply && fwd.listen_port == 0) ||
		    (fwd.listen_port != 0 && fwd.listen_port < IPPORT_RESERVED &&
		    authctxt->pw->pw_uid != 0)) {
			success = 0;
			ssh_packet_send_debug(ssh,
			    "Server has disabled port forwarding.");
		} else {
			/* Start listening on the port */
			success = channel_setup_remote_fwd_listener(ssh, &fwd,
			    &allocated_listen_port, &options.fwd_opts);
		}
		free(fwd.listen_host);
		if ((resp = sshbuf_new()) == NULL)
			fatal("%s: sshbuf_new", __func__);
		if (allocated_listen_port != 0 &&
		    (r = sshbuf_put_u32(resp, allocated_listen_port)) != 0)
			fatal("%s: sshbuf_put_u32: %s", __func__, ssh_err(r));
	} else if (strcmp(rtype, "cancel-tcpip-forward") == 0) {
		struct Forward fwd;

		memset(&fwd, 0, sizeof(fwd));
		if ((r = sshpkt_get_cstring(ssh, &fwd.listen_host, NULL)) != 0 ||
		    (r = sshpkt_get_u32(ssh, &fwd.listen_port)) != 0)
			goto out;
		debug("%s: cancel-tcpip-forward addr %s port %d", __func__,
		    fwd.listen_host, fwd.listen_port);

		success = channel_cancel_rport_listener(&fwd);
		free(fwd.listen_host);
	} else if (strcmp(rtype, "*****@*****.**") == 0) {
		struct Forward fwd;

		memset(&fwd, 0, sizeof(fwd));
		if ((r = sshpkt_get_cstring(ssh, &fwd.listen_path, NULL)) != 0)
			goto out;
		debug("server_input_global_request: streamlocal-forward listen path %s",
		    fwd.listen_path);

		/* check permissions */
		if ((options.allow_streamlocal_forwarding & FORWARD_REMOTE) == 0
		    || no_port_forwarding_flag) {
			success = 0;
			ssh_packet_send_debug(ssh, "Server has disabled port forwarding.");
		} else {
			/* Start listening on the socket */
			success = channel_setup_remote_fwd_listener(ssh,
			    &fwd, NULL, &options.fwd_opts);
		}
		free(fwd.listen_path);
	} else if (strcmp(rtype, "*****@*****.**") == 0) {
		struct Forward fwd;

		memset(&fwd, 0, sizeof(fwd));
		if ((r = sshpkt_get_cstring(ssh, &fwd.listen_path, NULL)) != 0)
			goto out;
		debug("%s: cancel-streamlocal-forward path %s", __func__,
		    fwd.listen_path);

		success = channel_cancel_rport_listener(&fwd);
		free(fwd.listen_path);
	} else if (strcmp(rtype, "*****@*****.**") == 0) {
		no_more_sessions = 1;
		success = 1;
	} else if (strcmp(rtype, "*****@*****.**") == 0) {
		success = server_input_hostkeys_prove(&resp);
	}
	if (want_reply) {
		if ((r = sshpkt_start(ssh, success ?
		    SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE)) != 0 ||
		    (success && resp != NULL &&
		    (r = sshpkt_put(ssh, sshbuf_ptr(resp), sshbuf_len(resp)))
		    != 0) ||
		    (r = sshpkt_send(ssh)) != 0) 
			goto out;
		ssh_packet_write_wait(ssh);
	}
	r = 0;
 out:
	free(rtype);
	sshbuf_free(resp);
	return r;
}