-
-/*
- * Returns the name of the forwarded authentication socket. Returns NULL if
- * there is no forwarded authentication socket. The returned value points to
- * a static buffer.
- */
-
-char *
-auth_get_socket_name()
-{
- return auth_sock_name;
-}
-
-/* removes the agent forwarding socket */
-
-void
-auth_sock_cleanup_proc(void *_pw)
-{
- struct passwd *pw = _pw;
-
- if (auth_sock_name) {
- temporarily_use_uid(pw);
- unlink(auth_sock_name);
- rmdir(auth_sock_dir);
- auth_sock_name = NULL;
- restore_uid();
- }
-}
-
-/*
- * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
- * This starts forwarding authentication requests.
- */
-
-int
-auth_input_request_forwarding(struct passwd * pw)
-{
- Channel *nc;
- int sock;
- struct sockaddr_un sunaddr;
-
- if (auth_get_socket_name() != NULL) {
- error("authentication forwarding requested twice.");
- return 0;
- }
-
- /* Temporarily drop privileged uid for mkdir/bind. */
- temporarily_use_uid(pw);
-
- /* Allocate a buffer for the socket name, and format the name. */
- auth_sock_name = xmalloc(MAXPATHLEN);
- auth_sock_dir = xmalloc(MAXPATHLEN);
- strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
-
- /* Create private directory for socket */
- if (mkdtemp(auth_sock_dir) == NULL) {
- packet_send_debug("Agent forwarding disabled: "
- "mkdtemp() failed: %.100s", strerror(errno));
- restore_uid();
- xfree(auth_sock_name);
- xfree(auth_sock_dir);
- auth_sock_name = NULL;
- auth_sock_dir = NULL;
- return 0;
- }
- snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%d",
- auth_sock_dir, (int) getpid());
-
- /* delete agent socket on fatal() */
- fatal_add_cleanup(auth_sock_cleanup_proc, pw);
-
- /* Create the socket. */
- sock = socket(AF_UNIX, SOCK_STREAM, 0);
- if (sock < 0)
- packet_disconnect("socket: %.100s", strerror(errno));
-
- /* Bind it to the name. */
- memset(&sunaddr, 0, sizeof(sunaddr));
- sunaddr.sun_family = AF_UNIX;
- strncpy(sunaddr.sun_path, auth_sock_name,
- sizeof(sunaddr.sun_path));
-
- if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
- packet_disconnect("bind: %.100s", strerror(errno));
-
- /* Restore the privileged uid. */
- restore_uid();
-
- /* Start listening on the socket. */
- if (listen(sock, 5) < 0)
- packet_disconnect("listen: %.100s", strerror(errno));
-
- /* Allocate a channel for the authentication agent socket. */
- nc = channel_new("auth socket",
- SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
- CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
- 0, xstrdup("auth socket"), 1);
- if (nc == NULL) {
- error("auth_input_request_forwarding: channel_new failed");
- auth_sock_cleanup_proc(pw);
- close(sock);
- return 0;
- }
- strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
- return 1;
-}
-
-/* This is called to process an SSH_SMSG_AGENT_OPEN message. */
-
-void
-auth_input_open_request(int type, int plen, void *ctxt)
-{
- Channel *c = NULL;
- int remote_id, sock;
- char *name;
-
- packet_integrity_check(plen, 4, type);
-
- /* Read the remote channel number from the message. */
- remote_id = packet_get_int();
-
- /*
- * Get a connection to the local authentication agent (this may again
- * get forwarded).
- */
- sock = ssh_get_authentication_socket();
-
- /*
- * If we could not connect the agent, send an error message back to
- * the server. This should never happen unless the agent dies,
- * because authentication forwarding is only enabled if we have an
- * agent.
- */
- if (sock >= 0) {
- name = xstrdup("authentication agent connection");
- c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
- -1, 0, 0, 0, name, 1);
- if (c == NULL) {
- error("auth_input_open_request: channel_new failed");
- xfree(name);
- close(sock);
- } else {
- c->remote_id = remote_id;
- }
- }
- if (c == NULL) {
- packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
- packet_put_int(remote_id);
- } else {
- /* Send a confirmation to the remote host. */
- debug("Forwarding authentication connection.");
- packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
- packet_put_int(remote_id);
- packet_put_int(c->self);
- }
- packet_send();
-}